JPH1182644A - Automatic transmission - Google Patents

Abstract

(57) [Summary] An object of the present invention is to make the body cover of an oil pump as small as possible to make the automatic transmission lighter and more compact as a whole. A second clutch that does not engage during first forward speed or reverse speed is provided.
Is disposed between the oil pump O / P and the counter drive gear 16. Since the second clutch C2 has a small capacity, its outer diameter is set to be small, so that the front opening β of the case 15 is formed more compact. Further, an oil pump O /
P has an outer diameter of the flange-shaped portion 22a of the body cover 22 formed to be small in accordance with the front opening β, and is formed crescentless. As described above, since the body cover 22 is formed more compactly without waste, the automatic transmission A is formed more lightweight and compact as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque converter which is mounted on, for example, a front-wheel-drive vehicle and to which the driving force of an engine is sequentially input from the front to the rear of the engine.
An oil pump, which is rotationally driven by the torque converter, is provided in a transmission mechanism that shifts the output of the torque converter to a plurality of speeds and outputs the plurality of friction engagement elements. One of the first
A friction engagement element, a counter drive gear that outputs the output of the transmission mechanism, a center support that rotatably supports the counter drive gear, and another friction engagement element other than the first friction engagement element of the transmission mechanism are arranged. The present invention belongs to the technical field of an automatic transmission having a torque converter, and more particularly to the technical field of an automatic transmission having a compact oil pump and good mountability on a vehicle.

[0002]

2. Description of the Related Art For example, in an automatic transmission such as an automobile, a planetary gear unit having a plurality of rotating elements and a plurality of frictional engagement elements including clutches and brakes for engaging or locking the plurality of rotating elements, respectively. Various automatic transmissions having an automatic transmission mechanism having the same have been developed. In this automatic transmission, automatic transmission control is performed by appropriately controlling engagement and disengagement of frictional engagement elements and controlling rotation of a plurality of rotation elements of a planetary gear unit.

As an example of such a conventional automatic transmission, an input is shifted by an automatic transmission mechanism including a planetary gear unit and a friction engagement element on a first shaft, and the output is output from a substantially central portion of the first shaft. An automatic transmission in which the gear is taken out via a gear and transmitted to a third shaft of a differential device via a second shaft f has been proposed in, for example, Japanese Patent Application Laid-Open No. 3-181644.

FIG. 7 is a skeleton diagram schematically showing the automatic transmission disclosed in this publication. In FIG. 7, when one of the ranges P, R, N, and D is selected and set by a manual shift valve (not shown), the automatic transmission A turns on / off each solenoid valve in a hydraulic control circuit (not shown). According to the combination of the signals, as shown in FIG.
Are engaged or disengaged in accordance with the range selected and set. Thereby, the rotation of the rotating elements such as the sun gear, the ring gear, the pinion gear, and the carrier of the planetary gear unit b is controlled, and the engine driving force input to the first shaft d as the input shaft via the torque converter T / C is changed. The output is output from a counter drive gear e disposed at the center of the automatic transmission A. In FIG. 8, ８ indicates engagement, and X indicates non-engagement.

The output from the counter drive gear e is transmitted to the counter driven gear g of the second shaft f, and further transmitted from the second shaft f to the left and right differential shafts i and j of the third shaft of the differential device h. .

[0006] In recent years, it has been increasingly strictly required that such automatic transmissions be formed as compact as possible as a whole to improve vehicle mountability. Especially F
In the F car, the engine room of the car is a relatively small space that is limited, and in this engine room, in addition to the automatic transmission, various other devices and components such as an engine and a differential device are arranged. Therefore, it is very important to make the automatic transmission a little compact.

Therefore, in the automatic transmission A disclosed in the above-mentioned publication, the following configuration is employed as one of the compact configurations. That is, FIG.
As shown in FIG. 1, the automatic transmission A includes a torque converter T / C, an oil pump O / P for the automatic transmission,
The clutch C2 and the brake B1, the counter drive gear e, the center support c, and the remaining components of the main transmission unit a are arranged respectively. By arranging the counter drive gear e substantially in the center of the main transmission portion a in this manner, the shaft length of the second shaft f provided with the counter driven gear g meshing with the counter drive gear e is further reduced. .

On the first shaft d side of the engine,
By arranging the clutch C2 and the brake B1 on the front side of the counter drive gear e, the torque converter (front) on the front side of the counter drive gear e, which is generated to engage the counter drive gear e with the counter driven gear g of the second shaft f, T / C) space m
Is being used effectively.

By arranging the components of the automatic transmission A in this manner, the axial dimensions of the first shaft d and the second shaft f can be shortened, and the automatic transmission A is correspondingly compact. become.

[0010]

In recent years, the demands for lighter and more compact automatic transmissions have become more and more strict. However, in order to meet these strict demands, the automatic transmissions have been made compact as described above. The automatic transmission A is also required to be as compact as possible.

Therefore, as one of further downsizing of the automatic transmission A, downsizing of the oil pump O / P is considered. The oil pump O / P is generally constituted by a gear pump. However, considering the oil pump O / P, the outermost diameter of the gear chamber of the oil pump O / P is determined by the conventional design method. Is determined from the discharge capacity of the oil pump O / P required for the automatic transmission A, and the size of the body cover n of the oil pump O / P is determined by setting the body cover n to the case of the automatic transmission A. It is determined from the space for attaching to o. That is, the size of the body cover n of the oil pump O / P is determined to be larger than necessary in relation to the size of the case o of the automatic transmission A to which the body cover n is attached. The reason for this determination is that the size of the body cover n of the oil pump O / P is originally determined in relation to the outermost diameter α of the gear chamber.
Automatic transmission A on the other side to which this body cover n is attached
Since the case o accommodates the clutch C2 and the brake B1, the counter drive gear e, the center support c, and other components of the main transmission portion a, the dimensions thereof are
This is because it must be larger than the dimension of the body cover n determined in relation to the dimension α.

Therefore, it is conceivable to make the size of the case o of the automatic transmission A smaller so as to make the size of the body cover n of the oil pump O / P set in accordance with the size of the case o smaller. .

However, in the conventional automatic transmission A,
Since the clutch C2 having a large outer diameter to be engaged at the time of starting is arranged between the oil pump O / P and the counter drive gear, the front opening β of the case o of the automatic transmission A is
Since the size must be increased, it cannot be simply reduced. For this reason, in the conventional automatic transmission A, the body cover n of the oil pump O / P is correspondingly larger than necessary, resulting in an increase in the weight of the entire automatic transmission. In particular, in the conventional automatic transmission A, since the body cover n of the oil pump O / P is a cast iron casting part, the increase in the size of the body cover n is larger than that of the aluminum case o of the automatic transmission A. The impact of the increase is greater.

Further, in general, a body cover n of an oil pump O / P in a conventional automatic transmission A often has a lubricating oil passage (not shown) through which lubricating oil flows. Is required, and this also increases the size of the body cover n.

Therefore, the automatic transmission A disclosed in the above-mentioned publication responds to the recent strict demands for compactness of the automatic transmission to some extent, but does not always sufficiently respond to it.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an automatic transmission in which the body cover of an oil pump can be made as small as possible to make the overall lighter and more compact. To provide.

[0017]

According to a first aspect of the present invention, there is provided a torque converter in which a driving force of an engine is sequentially input from the front to the rear of the engine. An oil pump, which is rotationally driven by a converter, is provided in a speed change mechanism that shifts the output of a torque converter to a plurality of speeds and outputs the output. One first friction engagement element, a counter drive gear for outputting the output of the transmission mechanism, a center support rotatably supporting the counter drive gear, and another friction engagement other than the first friction engagement element of the transmission mechanism In the automatic transmission in which the elements are arranged, the first frictional engagement element is a frictional engagement element that does not engage at any of the first forward speed and the reverse speed. It is a symptom.

The invention according to claim 2 is characterized in that the oil pump is constituted by a crescentless gear pump. Further, the invention of claim 3 is characterized in that an inlet of a lubricating oil passage for supplying lubricating oil to a portion of the automatic transmission that requires lubricating oil is provided at a rear end of the automatic transmission.

Further, in the invention according to claim 4, the automatic transmission has at least three clutches, and
The frictional engagement element is a first clutch that does not engage during first speed or reverse movement among the three clutches, and another clutch is disposed behind the counter drive gear, and is disposed behind this counter drive gear. The second of two of the clutches
Each servo piston of each hydraulic servo of the third clutch is formed in a double piston structure.

Further, according to a fifth aspect of the present invention, the second clutch has a second frictional engagement member which is engaged by its servo piston when the vehicle starts moving forward, and the third clutch has a third frictional engagement member.
The clutch has a third frictional engagement member that is engaged by the servo piston when the vehicle starts moving backward, and the second frictional engagement member is disposed on the inner peripheral side of the third frictional engagement member. And the engagement pressure of the third clutch is set higher than the engagement pressure of the first clutch.

[0021]

In the automatic transmission according to any one of the first to fifth aspects of the present invention, since the first frictional engagement element does not engage at the first speed or at the time of reverse traveling, the first frictional engagement element does not engage. Since the coupling element has a relatively small torque capacity, its outer diameter can be reduced. By arranging the small-diameter first frictional engagement element between the oil pump and the counter gear, the front opening of the case of the automatic transmission to which the oil pump is attached can be made compact. With the downsizing of the front opening of the case, a pump case such as a body cover of an oil pump attached to the front opening can also be made compact.

In addition, since the pump case of the oil pump is conventionally formed of a casting made of cast iron,
Although the weight is relatively large, since the weight of the oil pump can be effectively reduced because the pump case is formed compact in this way, it is possible to surely reduce the weight of the pump case such as a body cover. As a result, the weight of the automatic transmission A can be greatly reduced.

Further, in the invention of claim 2, further,
By forming the oil pump O / P in a crescentless manner, no space is required for the crescent. Thus, the diameter of the gear chamber of the oil pump can be reduced, and the weight of the oil pump can be reduced accordingly.
In that case, making the oil pump crescentless does not hinder any reduction in the diameter of the oil pump mounting portion of the case of the automatic transmission.

Further, according to the third aspect of the present invention, by supplying the lubricating oil from the rear end of the automatic transmission, the lubricating oil passage formed in the pump case of the oil pump can be reduced. As a result, a space for forming a lubricating oil passage can be made unnecessary, so that the size and weight of the pump case of the oil pump can be reduced. In this case, the supply of the lubricating oil from the rear end of the automatic transmission does not hinder the reduction of the diameter of the oil pump mounting portion of the case of the automatic transmission as described above.

Further, in the invention according to claim 4, by disposing a clutch other than the first clutch which is not engaged at the time of the first speed or at the time of reverse movement behind the counter drive gear, the rear portion of the automatic transmission can move forward. Becomes larger than the department. However, conventionally, the case of the automatic transmission has generally been made of an aluminum case, and the rear part of the automatic transmission is enlarged by making the case of the automatic transmission a lightweight aluminum. However, the weight does not increase so much, and the reduction in the weight of the automatic transmission as a whole is not hindered.

Further, by making each servo piston of the second and third clutches a double piston structure, the axial length of the automatic transmission can be shortened, and the automatic transmission can be made more compact and lightweight. Can be achieved.

Further, according to the fifth aspect of the present invention, the friction engagement member of the second clutch engaged at the time of forward start is arranged on the inner peripheral side of the friction engagement member of the third clutch engaged at the time of reverse movement. Therefore, the outer diameter of the sliding portion of the frictional engagement member of the second clutch is reduced to reduce the sliding resistance, and the outer diameter of the sliding portion of the frictional engagement member of the third clutch is increased. The sliding resistance increases. Therefore, the responsiveness of the engagement of the friction engagement member of the second clutch is better than the responsiveness of the engagement of the friction engagement member of the third clutch.
No dragging of the friction engagement member of the third clutch occurs when the friction engagement member of the clutch is engaged.

The responsiveness of the automatic transmission when the automatic transmission is selected to the forward start stage is improved by engaging the friction engagement member of the second clutch at the time of forward start, and also at the time of sudden start. The vehicle can start reliably.
Further, as a result, the slip of the second clutch is reduced, and the durability of the friction engagement member can be satisfactorily ensured even at the time of sudden start.

Further, the sliding resistance of the third clutch at the time of engagement of the friction engaging member is larger than the sliding resistance of the friction engaging member of the second clutch. Is set to be higher than the engagement pressure of the friction engagement member of the second clutch in the forward gear, so that the engagement responsiveness during reverse travel is well ensured.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of an automatic transmission according to the present invention, FIG. 2 is a skeleton diagram schematically showing the automatic transmission of this embodiment, and FIG. 3 is each element of the automatic transmission of this embodiment. It is a figure which shows the operation state in each range. In FIG. 3, ３ indicates engagement, and X indicates non-engagement. Further, the symbols C1, C2, C3 of the respective clutches and the symbols B1, B2 of the respective brakes used in the following description of the present invention are the respective clutches C1, C2 of the conventional automatic transmission described in the aforementioned publication. , C3 and the brakes B1, B2 do not correspond at all and are different from each other. The first, second, and third clutches of the present invention correspond to the second clutch C2,
It corresponds to the first clutch C1 and the third clutch C3.

As shown in FIGS. 1 and 2, the automatic transmission A of the present embodiment has an input shaft 2 of a first shaft, a counter shaft 3 of a second shaft and a counter shaft 3 of a second shaft arranged coaxially with an engine crankshaft 1. Third
It has three axle shafts 4a and 4b, a torque converter 6 having a lock-up clutch (L / C) 5 and an automatic transmission mechanism 7 on the input shaft 2, and a counter shaft 3 A counter mechanism 8 is provided on the upper side, and a differential device 9 is provided on the axle shafts 4a and 4b.
Are arranged.

The automatic transmission mechanism 7 has a planetary gear mechanism, and this planetary gear mechanism has a planetary gear unit 12 in which a single planetary gear 10 and a dual planetary gear 11 are combined. The pinion of the single planetary gear 10 meshing with the second sun gear S2 of the single planetary gear 10, the ring gear R1 of the dual planetary gear 11, and the dual planetary gear 1
The pinion of the dual planetary gear 11 that meshes with one short pinion P1 is integrally formed as a common long pinion P. Further, a carrier supporting the long pinion P and the short pinion P1 is integrally formed as a common carrier CR for both the planetary gears 10, 11. Further, the first sun gear S1 of the dual planetary gear 11 is formed integrally with a first hollow shaft 13 rotatably supported on the outer periphery of the input shaft 2, and the second sun gear S2 of the single planetary gear 10 has a first hollow gear. It is formed integrally with a second hollow shaft 14 supported on the outer periphery of the shaft 13.

The input shaft 2 and the first hollow shaft 13, that is, the first sun gear S1 of the dual planetary gear 11, are connected via a first (forward) clutch C1, and the input shaft 2 and the second hollow shaft 13 are connected. 14, ie, the second sun gear S2 of the single planetary gear 10 is connected via a third (reverse) clutch C3. Also,
The second sun gear S2 is moved by the first brake B1 to the case 1
4 and can be locked to the case 15 by a second brake B2 via a first one-way clutch F1 disposed in series with the second brake B2 when the motor rotates in one direction. It is supposed to be.

Further, the carrier CR is connected to the second clutch C2.
And is connected to the input shaft 2 via a third brake B3.
In addition, a second one-way clutch F2 disposed in parallel with the third brake B3 is locked to the case 15 during one-way rotation. The ring gear R1 of the dual planetary gear 11 is connected to a counter drive gear 16 rotatably supported by the case 15, and the counter drive gear 16 is an output member of the automatic transmission mechanism 7.

The counter mechanism 8 includes a counter driven gear 17 supported by the counter shaft 3 and meshing with the counter drive gear 16 and a reduction gear 18 supported by the counter shaft 3 and serving as an output member of the counter mechanism 8. It has.

Further, the differential device 9 includes a differential carrier 19 serving as a gear mount case and left and right side gears 20a and 20b. This differential carrier 1
A ring gear 21 is fixed to 9, and this ring gear 21 meshes with the reduction gear 18 of the counter mechanism 8 to constitute a final reduction mechanism. The left and right side gears 20
a, 20b are connected to the left and right axle shafts 4a, 4b, respectively.

The thus constructed automatic transmission A is provided with a hydraulic control circuit (not shown) in each of the ranges P, R, N, D, 2, and L set by a manual shift valve in a valve body (not shown). , The clutches corresponding to the respective ranges of the clutches C1 to C3, the respective brakes B1 to B3, and the respective one-way clutches F1 to F2 are engaged as shown in FIG. Each of the shift speeds 1ST to 4TH in the D range, each of the shift speeds 1ST to 3RD in the 2 range, and each of the shift speeds 1ST to 2ND in the L range are obtained.

The operation will be described below. I. Drive range (D range) In order to perform N → D shift, the manual shift valve is set to the position of the drive range (D range).

In the first speed state in the D range, the first clutch C1 is engaged, and the second one-way clutch F2 is engaged. In this state, the rotation of the input shaft 2 is controlled by the first sun gear S via the first clutch C1.
1 and further transmitted to the short pinion P1, and the rotation of the short pinion P1 is transmitted to the long pinion P. At this time, the long pinion P rotates in the forward direction while idling the second sun gear S2. The rotation of the long pinion P causes the common carrier CR to rotate in the reverse direction, but the second one-way clutch F2 locks the carrier CR to the case 15 against the reverse rotation, so that the carrier CR Is prevented from rotating. Therefore, the ring gear R1 is largely decelerated and rotated in the forward direction, and this rotation is
6 and transmitted to the counter driven gear 17 of the counter mechanism 8. Thereby, the first speed of the D range is achieved.

Further, in the counter mechanism 8, the rotation of the counter driven gear 17 is transmitted to the reduction gear 18 via the counter shaft 3, and further reduced and transmitted to the differential carrier 19 of the differential device 9 via the ring gear 21. Finally, the rotation of the differential carrier 19 is transmitted to the left and right axle shafts 4a, 4b via the left and right side gears 20a, 20b, respectively.

In the second speed state in the D range, the engaged state of the first clutch C1 is maintained. Also, the second
Is engaged, and the first one-way clutch F1 is engaged. In this state, the aforementioned 1
Similarly to the speed, the rotation of the input shaft 2 is transmitted to the long pinion P via the first clutch C1, the first sun gear S1, and the short pinion P1. This long pinion P
, The second sun gear S2 tries to rotate in the reverse direction. However, since the second brake B2 is engaged and the first one-way clutch F1 is engaged with the reverse rotation, The rotation of the second sun gear S2 is prevented. Therefore, the carrier CR rotates in the forward direction, the ring gear R1 rotates in the forward direction, and the rotation of the ring gear R1 is taken out from the counter drive gear 16, thereby achieving the second speed.

In the third speed state in the D range, the engaged state of the first clutch C1 and the second brake B2
Are held respectively. Further, the second clutch C2 is engaged. In this state, the rotation of the input shaft 2 is transmitted not only to the second sun gear S2 via the first clutch C1, but also to the carrier CR via the second clutch C2. Therefore, the first sun gear S1 and the carrier CR rotate integrally in the forward direction, so that both the short pinion P1 and the long pinion P
R, the first sun gear S1, and the input shaft 2 rotate integrally, but do not rotate. At this time, even if the second brake B2 is engaged, the first one-way clutch F
1 does not engage with the forward rotation, the long pinion P rotates around the input shaft 2 and does not rotate, so that the second sun gear S2 rotates integrally with the long pinion P in the forward direction and the ring gear R1 also rotates together with the long pinion P in the forward direction. That is, the ring gear R1 is directly connected to the input shaft 2 and rotates. By extracting the rotation of the ring gear R1 from the counter drive gear 16, the third speed is achieved.

In the fourth speed state in the D range, the engagement state of the second clutch C2 and the second brake B2
Are held respectively. In addition, the first clutch C1 is released, and the first brake B1 is engaged. In this state, the rotation of the input shaft 2 is transmitted to the carrier CR via the second clutch C2, but the first sun gear S1 is disconnected from the input shaft 2, so that the rotation of the input shaft 2 is reduced to the first sun gear S1. Is not transmitted to Therefore, the carrier CR rotates integrally with the input shaft 2 and the rotation of the carrier CR causes the long pinion P
And the short pinion P1 both rotate about the input shaft 2. At this time, the first brake B1 is engaged and the second sun gear S2 does not rotate.
Since 1 is cut off from the input shaft 2 and is free,
The long pinion P and the short pinion P1 both rotate, and the first sun gear S1 idles. Due to the rotation and rotation of the long pinion P about the input shaft 2, the ring gear R <b> 1 rotates at a higher speed than the input shaft 2 in the forward direction. By extracting the rotation of the ring gear R1 from the counter drive gear 16, the fourth speed of the high-speed rotation that overdrives the rotation of the input shaft 2 is achieved.

II. Reverse Range (R Range) In order to perform the N → R shift, the manual shift valve is set to the position of the reverse range (R range).

In the R range, the third clutch C3 is engaged and the third brake B3 is engaged. In this state, the carrier CR is set to the third brake B3.
Are fixed by the engagement of. Further, the rotation of the input shaft 2 is transmitted to the second sun gear S2 via the third clutch C3. Due to the rotation of the second sun gear S2, the long pinion P rotates in the reverse direction, and the carrier CR does not rotate, so that the ring gear R1 rotates at a reduced speed in the reverse direction.
The reverse rotation of the ring gear CR is the counter drive gear 1
It is taken out to 6.

III. Parking Range (P Range) and Neutral Range (N Range) The manual shift valve is set to the position of the parking range (P range) or the neutral range (N range), respectively.

In the P range or the N range, none of the clutches, any brakes, and any one-way clutches are engaged. In this state, the rotation of the input shaft 2 is not transmitted to the counter gear 16 and the rotation of the axle shaft 4
a and 4b do not rotate.

IV. Second Range (2 Ranges) The manual shift valve is set to the position of the second range (2 ranges).

The first speed state in the two ranges is exactly the same as the first speed state in the D range, and the first speed in the two ranges is achieved in the same manner as the first speed in the D range.
In the second speed state of the two ranges, the first brake B1 is further engaged in the case of the second speed of the D range. In this state, the second speed is different from the case of the second speed in the D range.
The sun gear S2 is prevented from rotating in either the forward or reverse direction. As a result, the second speed in the two ranges is achieved, and the engine brake is activated. The state of the third speed in the two ranges is the same as the case of the third speed in the D range, and the third speed in the two ranges is achieved similarly to the third speed in the D range.

V. Low range (L range) The manual shift valve is set to the low range (L range) position.

In the first speed state in the L range, the third brake B3 is further engaged in the case of the first speed in the D range. As a result, the engine brake having a relatively large braking force operates. In the 2nd speed state of the L range, the operation is exactly the same as that in the 2nd speed of the 2 range described above.
Second gear in the range has been achieved and engine braking has been activated. The braking force of this engine brake is smaller than the engine brake at the first speed in the L range.
Further, in the 3rd speed state of the L range, the speed is exactly the same as that of the 3rd speed of the 2 range described above, and the 3rd speed in the L range similar to the 3rd speed of the 2 range is achieved.

Incidentally, in the automatic transmission A of the present embodiment, the second clutch C2 is provided on the engine side, that is, the front side of the counter drive gear 16, and the first and third friction engagement elements as the remaining friction engagement elements are provided. Clutch C1, C
3, the first to third brakes B1, B2, B3 and the first
And second one-way clutches F1 and F2 are arranged behind the counter drive gear 16, respectively. As can be seen from FIG. 3, the second clutch C2 is connected to the third and fourth speeds of the D range, the third speed of the second range, and the third speed of the L range.
And engaged at other speeds. In that case, D is engaged by the second clutch C2.
In the third speed range, the first clutch C1 is also engaged together with the second clutch C2, and the torque from the input shaft 2 is shared between the first clutch C1 and the second clutch C2. Further, at the 4th speed in the D range in which the second clutch C2 is engaged, the stall torque from the torque converter 6 is not transmitted to the input shaft 2 because the torque converter 6 hardly amplifies the engine output torque.

Therefore, the second clutch C2 is not required to have a large capacity. That is, the second clutch C2
The axial and radial dimensions are set smaller than those of the clutches and brakes that are engaged in the first and second gears of the D range or the R range. By arranging the second clutch C2 having a small size in front of the counter drive gear 16, the automatic transmission A
The case 15 of the case 15 facing the second clutch C2 and the case 15 of the front opening (that is, the mounting end of the oil pump O / P) β are closer to the input shaft 2 side, and The part is formed more compact.

As shown in FIG. 4, the flange-like portion 22a of the body cover 22 of the oil pump O / P is attached to the case 15 of the front opening β by bolts 23, but the case 15 is formed compact. The body cover 2 of this oil pump O / P
The outer diameter of the second flange portion 22a is also reduced. In the body cover 22 of the oil pump O / P, as shown in FIGS. 1 and 5 (b), a drive gear 24 having external teeth 24a disposed coaxially with the input shaft 2.
And a driven gear 25 having internal teeth 25a eccentrically disposed on the drive gear 24. In this case, the drive gear 24 and the driven gear 25 are meshed on one side with the external teeth 24a and the internal teeth 25a, and on the opposite side, the addendum circle of the external teeth 24a and the internal teeth 25a
Are arranged so as to be almost in contact with the tip circle. That is, the gear pump of the present embodiment is disposed between the external teeth 24a and the internal teeth 25a on the side opposite to the meshing side and on the side opposite to each other, which is also used in the conventional automatic transmission shown in FIG. The crescent p is formed in the omitted crescentless.

As described above, since the oil pump O / P is formed in a crescentless manner, a space for the crescent p is not required, so that the gear chamber 42 of the oil pump O / P (see FIG. 5B) (Shown) can be reduced, and the oil pump O / can be reduced in weight accordingly. In this case, making the oil pump O / P crescentless does not hinder any reduction in the diameter of the mounting portion of the oil pump O / P of the case 15.

Further, the flange-like portion 2 of the body cover 22
2a and a portion of the case 15 facing the flange portion 22a, a suction hole 26 of the oil pump O / P, a discharge hole 27 of the oil pump O / P, and a flow of hydraulic oil when the lock-up clutch 5 is turned on. A hole 28, a flow hole 29 for hydraulic oil when the lock-up clutch 5 is off, and a flow hole 31 for hydraulic oil supplied to the hydraulic servo 30 when the second clutch C2 is engaged are formed.

Now, as in the case of the conventional automatic transmission shown in FIG. 9, the case where the first clutch C1 engaged when starting or the third clutch C3 having a large capacity engaged when moving backward is provided. In comparison with the case where the second clutch C2 having a small capacity that is not engaged at the time of starting and reversing according to the present invention is compared with the case where the second clutch C2 is provided, the capacity of the first or third clutch C1, C3 is determined in the former case. 4 and 5 (a),
(B), the portion of the case 15 of the automatic transmission A facing the first or third clutches C1 and C3 and the front opening β are separated from the input shaft 2 as indicated by two-dot chain lines, respectively. Fifteen of these parts are formed larger. Therefore, the inner and outer diameters of the flange portion 22a of the body cover 22 formed in accordance with the case 15 are formed to be large.

On the other hand, in the case of the present invention, the second clutch C2 having a small capacity which is not engaged at the time of start and reverse is arranged between the oil pump O / P and the counter drive gear 16. Therefore, since the outer diameter is reduced, the portion of the case 15 of the automatic transmission A facing the second clutch C2 and the front portion as shown by solid lines in FIGS. 4 and 5A and 5B, respectively. The opening β is closer to the input shaft 2, and these portions of the case 15 are formed smaller. Therefore, the flange-like portion 22 of the body cover 22 formed in accordance with the case 15
The inner and outer diameters of a are also formed more compactly.
In this case, the dimension α of the outermost diameter of the gear chamber 42 of the oil pump O / P is determined by the oil pump O / P required for the automatic transmission A.
Since it is determined from the discharge capacity of P and the like, the same is set in both the former case and the latter case. As described above, although the outermost diameter dimension α of the gear chamber 42 of the oil pump O / P is the same, in the former case, the inner and outer diameters of the flange portion 22a of the body cover 22 are large, and in the latter case, In the former case, the pump case 43 such as the body cover 22 is inevitably formed large because the inner and outer diameters of the flange-like portion 22a become smaller, whereas in the latter case, the pump case 43 such as the body cover 22 is used. 43 without waste
It can be made more compact.

Further, in the automatic transmission A of the present invention, the pump case 43 such as the body cover 22 of the oil pump O / P is formed of a cast iron casting, similarly to the conventional general automatic transmission. Since the pump case 43 such as the body cover 22 can be formed more compact as described above, the weight of the pump case 43 can be effectively reduced, and as a result, it greatly contributes to the weight reduction of the automatic transmission A as a whole. .

Further, in the automatic transmission A of the present embodiment, since the axial dimension of the second clutch C2 is smaller than the axial dimension of the frictional engagement element such as another clutch having a large capacity, the second clutch C2 has a small axial dimension. By arranging the second clutch C2 in front of the counter drive gear 16, a space δ is formed between the counter drive gear 16 and the second clutch C2 without moving the counter drive gear 16 backward. Become so. In this space δ, a parking gear 32 provided integrally with the counter drive gear 16 has a second gear.
And without being radially overlapped with the clutch C2. The counter drive gear 16 has a rear cylindrical shaft portion 16 a rotatably supported by a center support 40 of the case 15 via a bearing 41. In this manner, the parking gear 32 is disposed between the counter drive gear 16 and the second clutch C2, so that the parking gear 32 does not interfere with the second clutch C2 and the counter shaft 3 is connected to the input shaft 2 Can be approached. In addition, since the counter driven gear 17 does not need to be moved rearward, the length of the second shaft composed of the counter shaft 3 does not become longer, and is equal to or shorter than the second shaft of the conventional automatic transmission. Can be.

A first lubricating oil supply hole 33 is formed in the rear end 2 a of the input shaft 2, and the first lubricating oil supply hole 33 is formed in the center of the input shaft 2. A lubricating oil supply hole 35 communicated with the axial second lubricating oil introduction hole 34 and formed in the case 15 at the rear end of the automatic transmission A.
Is in communication with These first and second lubricating oil introduction holes 33 and 34 and the lubricating oil supply hole 35 constitute a part of a lubricating oil passage for introducing lubricating oil to each lubricating oil required portion of the automatic transmission A. The lubricating oil supply hole 35 at the rear end of the automatic transmission A forms an inlet of the lubricating oil passage. Then, the low-pressure lubricating oil supplied from the lubricating oil supply hole 35 of the case 15 is supplied to the first and second lubricating oil introduction holes 33 and 34.
Through the lubricating oil required portion.

As described above, by supplying the lubricating oil from the rear end of the automatic transmission A, the number of lubricating oil passages formed in the pump case 43 of the oil pump O / P can be reduced. As a result, it is not necessary to secure a space for forming a lubricating oil passage, so that the size and weight of the pump case 43 of the oil pump O / P can be reduced. In this case, supplying the lubricating oil from the rear end of the automatic transmission A does not cause any obstacle in reducing the diameter of the mounting portion of the oil pump O / P of the case 15.

Further, as shown in FIG. 1, in the automatic transmission A of this embodiment, the third clutch engaged with the first servo piston 36 of the hydraulic servo of the first clutch C1 engaged when the vehicle starts moving forward when moving backward. The third servo piston 37 of the hydraulic servo of the clutch C3 is formed in a double piston structure. More specifically, as shown in detail in FIG. 6, the drum member 44 of the hydraulic servo of the third clutch C3
Are a large-diameter cylindrical portion 44a and a small-diameter cylindrical portion 44b extending in the axial direction, and a large-diameter cylindrical portion 4 extending in the radial direction.
4a and a flat portion 44c connecting between both ends of the small-diameter side tubular portion 44b are formed into a bottomed tubular shape, and the inner peripheral end of the flat portion 44c is connected and fixed to the input shaft 2. ing.

A third servo piston 37 of the third clutch C3 is disposed in the drum member 44. The third servo piston 37 has a bottomed cylindrical shape having substantially the same shape as the drum member 44. A large-diameter cylindrical portion 37a and a small-diameter cylindrical portion 37b extending in the axial direction and both ends of the large-diameter cylindrical portion 37a and the small-diameter cylindrical portion 37b extending in the radial direction. And a flat plate-like portion 37c connecting the spaces. Then, the small-diameter side cylindrical portion 37b of the third servo piston 37 extends through the small-diameter side cylindrical portion 37b on the outer peripheral surface of the small-diameter side cylindrical portion 44b of the drum member 44.
The O-ring 45 is disposed so as to be oil-tight and slidable in the axial direction, and the large-diameter cylindrical portion 37a of the third servo piston 37 is connected to the inner periphery of the large-diameter cylindrical portion 44a of the drum member 44. On the surface, the seal member 46 is disposed so as to be oil-tight and slidable in the axial direction.

The first servo piston 36 of the first clutch C1 is disposed on the inner peripheral side of the large-diameter cylindrical portion 37a of the third servo piston 37 of the third clutch C3. The first servo piston 36 is formed in a bottomed cylindrical shape having substantially the same shape as the third servo piston 37 of the third clutch C3, and has a large-diameter cylindrical portion 36 extending in the axial direction.
a and a small-diameter cylindrical portion 36b, and a flat plate portion 36c extending in the radial direction and connecting between both ends of the large-diameter cylindrical portion 36a and the small-diameter cylindrical portion 36b. Then, the small diameter side cylindrical portion 3 of the first servo piston 36
6b penetrates the small diameter side cylindrical portion 36b.
Is disposed on the outer peripheral surface of the first servo piston 36 in an oil-tight and axially slidable manner by an O-ring 47, and the large-diameter cylindrical portion 36a of the first servo piston 36 is connected to the third clutch C3 of the third clutch C3.
On the inner peripheral surface of the large diameter side cylindrical portion 37a of the servo piston 37,
The seal member 48 is provided so as to be oil-tight and slidable in the axial direction.

As described above, the cylindrical third servo piston 37 of the third clutch C3 is disposed on the inner peripheral side of the single cylindrical drum member 44, and the cylindrical third servo piston 37 of the third clutch C3 is further provided. A double piston structure is provided in which the cylindrical first servo piston 36 of the first clutch C1 is disposed on the inner peripheral side of the third servo piston 37. In addition, a multi-plate frictional engagement member 38 of the third clutch C3 is disposed to face the tip of the large-diameter cylindrical portion 37a of the third servo piston 37, and the third servo piston 37 moves. Thus, the multi-plate friction engagement members 38 are frictionally engaged with each other. At this time, in the movement of the third servo piston 37, only the friction engagement member 38 of the third clutch C3 is engaged. Also, the first servo piston 3
6 and is located on the inner peripheral side of the frictional engagement member 38 of the third clutch C3 so as to face the distal end of the large-diameter side cylindrical portion 36a of the first clutch C1. A plurality of friction engagement members 39 of these multiple plates are frictionally engaged with each other by the movement of the first servo piston 36.

Further, in the automatic transmission A of this embodiment, a second clutch C2 having a small capacity is disposed in front of the counter drive gear 16, and the first and third clutches C1, C3 and C3 having a large remaining capacity are arranged. By arranging the first to third brakes B1 to B3 behind the counter drive gear 16, the rear portion of the automatic transmission A expands as compared with the front portion. Since the case 15 is made of an aluminum case, even if the rear portion of the automatic transmission A is enlarged, the weight does not increase so much, and the reduction in the weight of the automatic transmission A as a whole is prevented. Absent.

Further, the first and third clutches C1, C
By making the first and third servo pistons 36 and 37 of the third embodiment a double piston structure, the length of the automatic transmission A in the axial direction can be shortened, and the automatic transmission A can be made more compact and lighter. Can be achieved.

Further, since the frictional engagement member 39 of the first clutch C1 is disposed on the inner peripheral side of the frictional engagement member 38 of the third clutch C3, the sliding portion of the frictional engagement member 39 As the outer diameter decreases, the sliding resistance decreases, and the outer diameter of the sliding portion of the friction engagement member 38 increases, so that the sliding resistance increases. For this reason, the frictional engagement member 39 of the first clutch C1 engaged when the vehicle starts moving forward is lower than the engagement pressure with which the frictional engagement member 38 of the third clutch C3 is engaged when the vehicle moves backward. And smooth engagement, the responsiveness of the engagement of the frictional engagement member 39 is better than the responsiveness of the engagement of the frictional engagement member 38. No dragging of the joining member 38 occurs.

When the vehicle starts moving forward, the first clutch C
Since the first frictional engagement member 39 is engaged, the responsiveness of the automatic transmission A when the automatic transmission A is selected to the forward start position is improved, so that the vehicle can start reliably even at a sudden start. At the same time, the durability of the friction engagement member 39 can be ensured satisfactorily even at the time of sudden start.

Further, although the sliding resistance of the third clutch C3 when the frictional engagement member 38 is engaged is greater than the sliding resistance of the frictional engagement member 39, the engagement of the frictional engagement member 38 in the reverse gear is performed. Since the pressure is set to be higher than the engagement pressure of the friction engagement member 38 in the forward gear, the engagement responsiveness in reverse is not deteriorated.

In the above example, the oil pump O / P
Between the second drive C and the counter drive gear 16
2 is arranged, but the present invention is not limited to this, and another frictional engagement element may be arranged as long as it is a frictional engagement element that does not engage at the first speed or reverse. it can.

The present invention is not limited to the above-described gear train, but may be applied to any other gear train as long as a relatively small-capacity engaging element that does not engage during first speed or reverse movement can be arranged. Can also be applied.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an embodiment of an automatic transmission according to the present invention.

FIG. 2 is a skeleton diagram schematically showing the automatic transmission shown in FIG.

FIG. 3 is a diagram showing an operation state of each clutch, each brake, and each one-way clutch of the automatic transmission shown in FIG. 1 in each range.

FIG. 4 is a partially enlarged sectional view showing an oil pump / 0 of the automatic transmission shown in FIG. 1;

5A and 5B show a portion of the automatic transmission shown in FIG. 4 viewed from the axial direction, FIG. 5A is a diagram showing a front opening of a case of the automatic transmission, and FIG. 5B is a diagram showing a body cover. .

FIG. 6 is a partially enlarged cross-sectional view showing a rear portion of the automatic transmission shown in FIG. 1 in an enlarged manner.

FIG. 7 is a skeleton diagram schematically showing a conventional automatic transmission.

8 is a diagram showing an operation state of each element of the conventional automatic transmission shown in FIG. 7 in each range.

FIG. 9 is a sectional view partially showing the conventional automatic transmission shown in FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine crankshaft, 2 ... Input shaft, 2a ... Input shaft 2
3 ... Counter shaft, 4a, 4b ... Axle shaft,
5: Lock-up clutch (L / C), 6: Torque converter, 7: Automatic transmission mechanism, 8: Counter mechanism, 9: Differential device, 10: Single planetary gear, 11: Dual planetary gear, 12: Planetary gear unit, 15: Case , 16 ... Counter drive gear, 17 ... Counter driven gear, 22 ... Body cover of oil pump O / P, 22a ... Flange-shaped part of body cover 22, 24 ... Drive gear, 25 ... Driven gear, 26 ... Suction hole of oil pump O / P , 27 ... Discharge hole of oil pump O / P, 28 ... Lock-up clutch 5
, The hydraulic oil flow when the lock-up clutch 5 is off, 30 the hydraulic servo of the second clutch C2, 31 the hydraulic oil supplied to the hydraulic servo 30 Holes, 33: first lubricating oil introduction hole, 34: second lubricating oil introduction hole, 35: lubricating oil supply hole, 36: first servo piston, 37: third servo piston, 38: third
, A frictional engagement member of the clutch C3, 39... A frictional engagement member of the second clutch C2, 40.
Gear chamber, 43: pump case, C1: first (forward) clutch, C2: second clutch, C3: third (reverse) clutch, B1: first brake, B2 ...
Second brake, B3: third brake, F1: first one-way clutch, F2: second one-way clutch, O / P: oil pump

[Procedure amendment]

[Submission date] September 17, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

[0017]

According to a first aspect of the present invention, there is provided a torque converter and an oil pump to which a driving force of an engine is sequentially input from the front to the rear of the engine. A first frictional engagement element among a plurality of frictional engagement elements provided in a speed change mechanism for shifting and outputting the output of the torque converter to a plurality of speeds;
An automatic transmission in which a counter drive gear that outputs the output of the transmission mechanism, a center support that rotatably supports the counter drive gear, and a friction engagement element other than the first friction engagement element are provided. The first
It is characterized in that the frictional engagement element is a frictional engagement element that does not engage in either the first forward speed or the reverse speed.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akitoshi Kato 10 Takane, Fujii-cho, Anjo, Aichi Prefecture Inside Aisin AW Co., Ltd. (72) Tomohiro Kobayashi 10 Takane, Fujii-cho, Anjo, Aichi Aisin・ AW Co., Ltd. (72) Inventor Tokuyuki Takahashi 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Masafumi Kinoshita 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation

Claims (5)

[Claims] 1. From the front to the rear on the engine side,
In order, a torque converter to which the driving force of the engine is input, an oil pump that is rotationally driven by the torque converter, and a transmission mechanism that shifts and outputs the output of the torque converter to a plurality of speeds are provided. One of the plurality of friction engagement elements controlled to be engaged by the first, the first friction engagement element, a counter drive gear for outputting the output of the speed change mechanism, a center support rotatably supporting the counter drive gear, and a speed change An automatic transmission in which a friction engagement element other than the first friction engagement element of the mechanism is arranged, wherein the first friction engagement element is not engaged in either the first forward speed or the reverse speed. An automatic transmission characterized by being a combined element. 2. The automatic transmission according to claim 1, wherein said oil pump is constituted by a crescentless gear pump. 3. The automatic transmission according to claim 1, wherein an inlet of a lubricating oil passage for supplying lubricating oil to a necessary portion of the automatic transmission is provided at a rear end of the automatic transmission. Automatic transmission. 4. The automatic transmission has at least three clutches, and the first frictional engagement element is
One of the clutches is a first clutch that is not engaged at the first speed or at the time of reverse travel, and the other clutch is disposed behind the counter drive gear. 2. The automatic transmission according to claim 1, wherein each servo piston of each hydraulic servo of the third clutch is formed in a double piston structure. 5. The second clutch has a second frictional engagement member that is engaged by the servo piston when the vehicle starts moving forward, and the third clutch is engaged by the servo piston when the vehicle starts moving backward. A third frictional engagement member, and the second frictional engagement member is disposed on the inner peripheral side of the third frictional engagement member, and the engagement pressure of the third clutch is reduced. 5. The automatic transmission according to claim 4, wherein the pressure is set to be larger than the engagement pressure of the second clutch.