WO1999009331A1

WO1999009331A1 - Hydraulic, rotary transmission system

Info

Publication number: WO1999009331A1
Application number: PCT/KR1998/000251
Authority: WO
Inventors: Seong Joo Kim; Seong Joong Kim
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-08-13
Filing date: 1998-08-12
Publication date: 1999-02-25
Anticipated expiration: 2000-02-13
Also published as: KR19990016171A; KR100259397B1

Abstract

A hydraulic, rotary transmissions system is disclosed. The system transmits rotational force from an input (2) to an output shaft (3) while controlling or changing the rotating speed of the output shaft using hyraulic force of actuating fluid filling an oil chamber 'C' formed between two rotors (20, 30) integrated with the input and output shafts (2, 3). The system is also designed in that the hydraulic force of the fluid is hydrostatically tranmsitted to the output shaft by a chamber closing means, such as vanes (35), without any flow loss of the fluid. The system thus remarkably improves power transmission efficiency and effectively conserves energy in comparison with conventional torque converters or hydraulic couplings.

Description

HYDRAULIC, ROTARY TRANSMISSION SYSTEM

Technical Field

The present invention relates, in general, to power transmission systems used for transmitting power or rotational force from an input to an output shaft and, more particularly, to a hydraulic, rotary transmission system capable of transmitting the rotational force from the input shaft to the output shaft while controlling or changing the rotating speed of the output shaft using the hydraulic force of actuating fluid selectively pressurized by the rotational force of the input shaft.

Background Art

As well known to those skilled in the art, varieties of machines, such as automobiles, construction equipments, lathes and milling machines, are provided with transmission systems for transmitting power from an input or driving shaft to an output or driven shaft. In such a case, the rotating speed of the output shaft is controlled or changed by such a transmission system while the speed of the input shaft remains constant.

Such transmission systems are typically classified into several types. For example, clutch systems, torque converter systems and hydraulic coupling systems are used as such transmission systems. In typical clutch transmission systems, a clutch disk is mounted on each of the input and output shafts, so that the clutch disks of the two shafts are selectively brought into contact with each other, thus controllably transmitting the power from the input to the output shaft. Meanwhile, each of the typical torque converter transmission systems or the hydraulic coupling transmission systems comprises a pump impeller, a turbine rurmer and a stator, which are provided on the input and output shafts and are filled with actuating fluid for transmitting the power from the input to the output shaft.

Another example of known transmission systems is a hydrostatic system, a chain or belt transmission system or a gear transmission system. In typical hydrostatic transmission systems, the power is transmitted from an input to an output shaft due to a hydraulic reciprocating motion of a piston. In typical chain, belt or gear transmission systems preferably used with lathes or milling machines, the rotational force of a motor is transmitted to the spindle of a machine using a chain, a belt or a gear to rotate the spindle.

However, such clutch transmission systems, typically used as manual transmission systems for automobiles, are problematic in that the power transmission capacity of the systems is determined by both the contact area between the clutch disks of the input and output shafts and the force biasing the two disks to each other. It is thus somewhat difficult to smoothly and easily operate the clutches. In addition, the power transmission efficiency of the systems is undesirably reduced with the clutch disks being frictionally abraded.

Torque converter transmission systems, typically used as automatic transmission systems for automobiles, use a turbo-type impeller of which both the pump impeller and the power receiving turbine runner are opened during the operation. In addition, the actuating fluid in the system is dynamically actuated. Therefore, such torque converter systems increase power consumption, complicate the system -3-

construction and are somewhat expensive.

Disclosure of the Invention

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a hydraulic, rotary transmission system which is capable of transmitting rotational force from an input shaft to an output shaft while controlling or changing the rotating speed of the output shaft using actuating fluid filling an oil chamber formed between two rotors respectively integrated with the input and output shafts.

Another object of the present invention is tύ provide a hydraulic, rotary transmission system which improves power transmission efficiency, thus conserving energy. In order to accomplish the above object, the preferred embodiment of this invention provides a hydraulic, rotary transmission system for transmitting rotational force from an input shaft to an output shaft while controlling rotational speed of the output shaft, comprising: an outside rotor integrated with either one of the input and output shafts; an inside rotor integrated with a remaining one of the two shafts and fitted into the outside rotor, with an annular chamber being formed between the two rotors and being filled with actuating fluid; first means set on either one of the two rotors to project into the chamber and used for selectively moving the actuating fluid while pressurizing the fluid in the chamber; and second means set on a remaining one of the two rotors to be alternated with the first means and used for controlling an opening area of the chamber, thus selectively stopping a movement of the fluid in the chamber to transmit rotational force between the two rotors, with either one rotor, having relatively higher rotational force, acting as a hydraulic pump and a remaining rotor, having relatively lower rotational force, acting as a hydraulic motor.

Brief Description of the Drawings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. 1 is a partially broken perspective view of a hydraulic, rotary transmission system in accordance with the primary embodiment of the present invention;

Fig. 2 is a cross-sectioned view of the system of Fig. 1;

Fig. 3 is a longitudinal sectioned view of the above system taken along the line I-I of Fig. 2;

Fig. 4 is a cross-sectioned view of a hydraulic, rotary transmission system in accordance with the second embodiment of the present invention;

Fig. 5 is a longitudinal sectioned view of the system taken along the line II-II of Fig. 4;

Fig. 6 is a cross-sectioned view of a hydraulic, rotary transmission system in accordance with the third embodiment of the present invention;

Fig. 7 is a cross-sectioned view of a hydraulic, rotary transmission system in accordance with the fourth embodiment of the present invention;

Fig. 8 is a cross-sectioned view of a hydraulic, rotary transmission system in accordance with the fifth embodiment of the present invention; Fig. 9 is a longitudinal sectioned view of the system taken along the line III-III of Fig. 8;

Fig. 10 is a longitudinal sectioned view of a hydraulic, rotary transmission system in accordance with the sixth embodiment of the present invention; and

Fig. 11 is a block diagram showing the operation of the control unit for the system of Fig. 1.

Best Mode for Carrying Out the Invention

Figs. 1 to 3 show a hydraulic, rotary transmission system in accordance with the primary embodiment of this invention. Of the drawings, Fig. 1 is a partially broken perspective view showing the whole construction of the above system, Fig. 2 is a cross-sectioned view of the system of Fig. 1, and Fig. 3 is a longitudinal sectioned view of the above system taken along the line I-I of Fig. 2.

As shown in the drawings, the system of this invention comprises an input shaft 2, an output shaft 3 and two rotors, that is, outside and inside rotors 20 and 30. The input shaft 2 is directly connected to a power source 1, such as a motor or an engine, thus being used as a driving shaft for outputting the power of the source 1. The output shaft 3 receives the power from the input shaft 2 and transmits the power to a drive part of a machine. The two rotors 20 and 30 are installed at the junction between the two shafts 2 and 3 with actuating fluid filling the annular chamber formed between the two rotors. The two rotors 20 and 30 thus transmit the power from the input shaft 2 to the output shaft 3 while ,. controlling or changing the speed of the output shaft 3 using the actuating fluid. The outside rotor 20, positioned around the inside rotor 30 with an annular oil chamber or main chamber "C" being formed between the two rotors 20 and 30, is integrated with the input shaft 2, thus being rotatable along with the shaft 2. Meanwhile, the inside rotor 30 is integrated with the output shaft 3 and transmits the power from input shaft 2 to the output shaft 3.

A plurality of planetary rotors 25 and spring-biased vanes 35 are provided in the annular oil chamber "C" formed between the two rotors 20 and 30. The planetary rotors 25 are held by the outside rotor 20 and are brought into movable contact with the exterior surface of the inside rotor 30, while the vanes 35 are held by the inside rotor 30 and are brought into contact with the interior surface of the outside rotor 20. The actuating fluid, filling the chamber "C", is incompressible fluid.

Therefore, the rotational force, transmitted from the input shaft 2 to the outside rotor 20, is also transmitted to the incompressible actuating fluid through the planetary rotors 25 of the outside rotor 20, thus causing the fluid to flow in the chamber "C" . The vanes 35 of the inside rotor 30 are thus rotated, so that the inside rotor 30 is rotated. In a brief description, the system is designed for transmitting the power of the power source 1 to the output shaft 3 in a way such that the rotational force of the outside rotor 20 integrated with the input shaft 2 is hydraulically transmitted to both the inside rotor 30 and the output shaft 3.

As best seen in Fig. 2 , four spring-biased vanes 35 are radially set on the exterior surface of the inside rotor 30 to be elastically movable in a radial direction. It is thus possible to control the height of the vanes 35, the vanes 35 projecting from the external surface of the inside rotor 30 and coming into contact with the interior surface of the outside rotor 20 to partition the chamber "C" into four parts. In addition, a bypass passage 20L is formed on the outside rotor 20 with both ends of the bypass passage 20L opening into the main chamber "C" at opposite sides of each planetary rotor 25. A check valve 21 is provided in each of the bypass passages 20L for controlling the amount of bypass fluid.

When the outside rotor 20 is rotated during the operation of the above system, the actuating fluid flows in the rotating direction of the rotor 20 by the planetary rotors 25. In such a case, both flow rate and velocity of the above fluid, acting on the vanes 35, are changeable in accordance with the opening area of both the chamber "C" and the bypass passages 20L, the chamber "C" and the passages 20L being controlled by the vanes 35 and the check valves 21, respectively. It is thus possible to control or change the speed of the rotational force transmitted from the outside rotor 20 to the inside rotor 30.

The hydraulic force, acting on the vanes 35, is in inverse proportion to the opening area of both the chamber "C" and the passages 20L. Meanwhile, the rotating speed of both the inside rotor 30 and the output shaft 3 is in proportion to the hydraulic force acting on the vanes 35. That is, when the opening areas of both the chamber "C" and the passages 20L are enlarged, the hydraulic force, acting on the vanes 35, is reduced and this reduces the rotating speed of the output shaft 30. On the contrary, when the opening areas of both the chamber "C" and the passages 20L are reduced, the hydraulic force, acting on the vanes 35, is increased and this increases the rotating speed of the output shaft 30. In a detailed description for the construction of the above system, the outside rotor 20 is integrated with the input shaft 2 and has an opening for receiving the inside rotor 30, thus having an annular configuration. A groove 20a is formed along the interior surface of the outside rotor 20. The above groove 20a forms the annular chamber "C" in cooperation with the external surface of the inside rotor 30. The planetary rotors 25 are regularly set on the groove 20a. The above rotors 25 are designed for being revolvable around the external surface of the inside rotor 30 and being rotatable around its central axis while moving the actuating fluid in the rotating direction of the input shaft 2. A planetary gear 25G is fixed to an end of each planetary rotor 25 and engages with a rotor gear 30G which is fixed to an end Of the inside rotor 30. The planetary rotors 25 are thus revolvable around the inside rotor 30 at the same speed while always coming into close contact with the inside rotor 30. In order to prevent the planetary rotors 25 from interfering with the vanes 35 when the rotors 25 pass over the vanes 35, a groove 25a is axially formed on the outer surface of each planetary rotor 25 to receive the top edges of the vanes 35. As described above, a check valve 21 is provided in each of the bypass passages 20L of the outside rotor 20. When a first actuator 23 starts under the control of a control unit 60, a valve sleeve 22 for the check valve 21 axially moves along the input shaft 2. Therefore, a valve rod 22a, connected to the valve sleeve 22, moves the check valve 21, thus controlling the opening area of the bypass passage 20L.

A circular opening 20b is formed on a side wall of the outside rotor 20 at a position around the output shaft

3. Both an oil seal 45 and a bearing 46 are installed in the opening 20b. The above seal 45 tightly closes the opening 20b. An annular hole is formed around the circular opening 20b, while a vane sleeve 40, provided with a vane contact 40a, is led into the above annular hole at the contact 40a. The above vane sleeve 40 is for selectively moving the vanes 35 of the inside rotor 30.

As described above, a plurality of spring-biased vanes 35 are set on the external surface of the inside rotor 30 to control the opening area of the main chamber "C". The above vanes 35 are radially set in the vane holes formed on the inside rotor 30 and are individually and radially biased upwardly by a spring 36, thus being radially movable in opposite directions. The vane contact 40a of the sleeve 40 is led to a side wall of the inside rotor 30 and selectively comes into contact with the side surfaces of the vanes 35 at inclined cams "D", thus moving the vanes 35 downwardly in the radial direction to gradually open the main chamber "C".

In order to allow the vane contact 40a of the sleeve 40 to be led to the side wall of the inside rotor 30 prior to coming into contact with the side surfaces of the vanes 35, an annular slot 35b is formed on the side wall of the inside rotor 30.

As shown in Figs. 2 and 3, a spring 36 is set in each vane hole of the inside rotor 30 at a position under each vane 35, thus normally biasing the vane 35 upwardly in the radial direction. That is, the above spring 36 biases an associated vane 35 in a direction opposite to the acting direction of the vane sleeve 40, thus allowing the vane 35 to be brought into elastic and close contact with the interior surface of the outside rotor 20.

Of course, it is preferable to set the elasticity of each spring 36 to a level at which the vanes 35 automatically move downwardly in the vane holes to open the chamber "C" when the inner pressure of the main chamber "C" becomes higher than a preset limit pressure due to an exceeding overload acting on the output shaft 3 with the chamber "C" being completely closed by the vanes 35.

Since the vane contact 40a of the sleeve 40 axially passes through the side wall of the outside rotor 20, the vane sleeve 40 is rotatable at the same speed as the rotating speed of the outside rotor 20. In order to prevent the rotational force of the vane sleeve 40 from being directly transmitted to the output shaft 3, the vane sleeve 40 is designed for being idle-rotatable around the output shaft 3. The system of this invention is designed in that the rotational force of the input shaft 2 is normally and hydraulically transmitted to both the inside rotor 30 and the output shaft 3 through the outside rotor 20. In such a case, the actuating fluid in the chamber "C" practically transmits the rotational force from the outside rotor 20 to both the inside rotor 30 and the output shaft 3. However, in order to allow the rotational force of the outside rotor 20 to be selectively and directly transmitted to the output shaft 3 when both rotors 20 and 30 are synchronously rotated, both the output shaft 3 and the vane sleeve 40 are provided with spline gears 3a and 40b, respectively.

That is, the two gears 3a and 40b, splined at their opposite surfaces, are set on the output shaft 3 and the vane sleeve 40, respectively, at positions where the vane sleeve 40 does not restrict the vanes 35. The two gears 3a and- Ob. selectively engage with each other to bring the vane sleeve 40 into engagement with the output shaft 3. The above vane sleeve 40 is designed for moving along the output shaft 3 by a second actuator 41 to move the vanes 35. The above actuator 41 is operated under the control of the control unit 60. The first and second actuators 23 and 41 are designed in that their actuating rods hydraulically move in an axial direction under the control of the control unit 60, thus operating the valve sleeve 22 and the vane sleeve 40, respectively. In such a case, the actuating rods of the two actuators 23 and 41 are actuated by both hydraulic force of a hydraulic mechanism and spring force of an internal spring. Of course, it should be understood that conventional solenoid actuators, which are operated in response to electric signals, may be used as the above actuators 23 and 41 in place of the above-mentioned hydraulic actuators.

The operation of the above control unit 60 is shown in the block diagram of Fig. 11. As shown in the drawing, the control unit 60 receives both a clutch signal from a clutch pedal 61 and a speed signal from a shift lever 62. The clutch pedal 61 is selectively operated by a driver to controllably transmit the rotating force from the input shaft 2 to the output shaft 3. When the clutch pedal 61 is operated, the pedal 61 outputs such a clutch signal to the control unit 60. Meanwhile, the shift lever 62 is selectively operated by the driver to convert the position of the shafts 2 and 3 from a half-clutching position into a full-clutching position. When the shift lever 62 is operated, the lever 62 outputs such a speed signal to the control unit 60. Upon receiving signals from the pedal and lever 61 and 62, the control unit 60 controls the operation of the two actuators 23 and 41 to control both the opening area of the check valves 21 and the projecting height of the vanes 35 in the chamber "C".

The above control unit 60 also checks the operational condition of the system when receiving a signal from one or both the pedal and lever 61 and 62 with both rotating speed and torque of each shaft 2, 3 being received by the

-control unit 60. Thereafter, the control unit 60 controls the actuators 23 and 41 and a speed gear 50.

The operational effect of the system according to the primary embodiment will be described hereinbelow. The above system is designed for selectively transmitting the rotational force from the input shaft 2 to the output shaft 3. That is, the system may stop the power transmission from the input shaft 2 to the output shaft 3. In addition, the system may transmit the rotational force from the input shaft 2 to the output haft 3 while converting the position of the two shafts 2 and 3 from a half-clutching position into a full- clutching position.

When it is necessary to stop the power transmission from the input shaft 2 to the output shaft 3, the vanes 35 fully move downwardly in the vane holes of the inside rotor 30 to completely open the main chamber "C" . Of course, when the check valves 21 completely open the bypass passages 20 , respectively, the power transmission from the input shaft 2 to the output shaft 3 is stopped.

When the control unit 60 starts the second actuator

41, the actuator 41 pushes the vane sleeve 40 to the inside rotor 30. In such a case, the vane sleeve 40 slides along the output shaft 3, so that the vane contact 40a of the sleeve 40 is received into the annular slot 35b of the inside rotor 30. The vane contact 40a thus comes into contact with the vanes 35 at the inclined cams "D", thus retracting the vanes 35 into the vane holes of the rotor 30. Therefore, the chamber "C" is fully opened.

In such a case, the rotational force of both the power source 1 and the input shaft 2 is transmitted to the outside rotor 20. The planetary rotors 25 revolve around the outer surface of the inside rotor 30 while moving the actuating fluid in the rotating direction of the outside rotor 20. However, since the vanes 35 are fully retracted into the vane holes of the inside rotor 30, the vanes 35 fail to receive the rotational force or the moving force of the fluid. The rotational force of the outside rotor 20 is thus not transmitted to either the inside rotor 30 or the output shaft 3.

In order to open the bypass passages 20L around the planetary rotors 25, the first actuator 23 is operated in response to a signal from the control unit 60, thus pulling the valve sleeve 22. In such a case, the valve sleeve 22 moves along the input shaft 2 in a direction toward the end of the shaft 2, so that the check valves 21, coupled to the valve sleeve 22 through the valve rods 22a, moves in the same direction. The bypass passages 20L are thus fully opened.

When both the outside rotor 20 and the planetary rotors 25 are rotated, the actuating fluid is discharged from the front into the rear chamber of the chamber "C" through the bypass passages 20L. Therefore, the chamber "C" is free from any hydraulic pressure even when the vanes 35 close the chamber "C". Thus, the vanes 35 are not rotated, so that it is impossible to transmit the rotational force of the outside rotor 20 to the inside rotor 30.

In order to transmit the rotational force from the inpu.t shaft 2- to the output shaft 3, both the main chamber "C" and the bypass passages 20L are fully closed to allow the hydraulic force of the actuating fluid to act on the vanes 35. When it is necessary to control the rotational force transmitted from the outside rotor 20 to the inside rotor 30, the opening area of the chamber "C" is changed by the vanes 35.

That is, when the first actuator 23 for the check valves 21 is operated in response to a signal from the control unit 60, both the check valves 21 and the valve sleeve 22 move forward along the input shaft 2 to close the bypass passages 20L. In such a case, the actuating fluid in the chamber "C" flows around the inside rotor 30 along with the planetary rotors 25 due to the rotational force of the outside rotor 20.

Thereafter, the control unit 60 starts the second actuator 41 for the vanes 35, thus pulling the vane sleeve 40 in a direction toward the outside of the output shaft 3. The above vanes 35 thus gradually project into the chamber "C" by the restoring force of the springs 36. The pressurized actuating fluid, biased by the planetary rotors 25, acts on the vanes 35 in the chamber "C", so that the inside rotor 30 starts to rotate.

In a brief description, the rotational force of the power source 1 is primarily transmitted to the planetary rotors 25 through both the input shaft 2 and the outside rotor 20. Due to the rotational force of the planetary rotors 25, the actuating fluid in the chamber "C" is pressurized and moves in the chamber "C" to act on the vanes 35. Therefore, the inside rotor 30, with the vanes 35, is rotated along with the output shaft 3. The rotational force of the power source 1 is transmitted to the output shaft 3, thus rotating the output shaft 3.

When the vanes 35 fully close the chamber "C", the rotational force of the outside rotor 20 is directly transmitted to the inside rotor 30 by the actuating fluid acting on the vanes 35 since the fluid is incompressible fluid. Therefore, the rotational force of the output shaft 3 becomes equal to that of the input shaft 2. When the actuator 41 fully pulls the vane sleeve 40 under the control of the control unit 60, the spline gear 40a of the vane sleeve 40 is brought into engagement with the spline gear 3a of the output shaft 3. The rotational force of the outside rotor 20 is thus directly transmitted to the output shaft 3 through the vane sleeve 40. In such a case, the actuating fluid in the chamber "C" becomes free, so that it is possible to reduce the generation of heat from the actuating fluid pressurized between the planetary rotors 25 and the vanes 35. The rotational speed of the output shaft 3 may be controlled by controlling the projecting height of the vanes 35 in the chamber "C". Alternatively, such rotational speed of the output shaft 3 may be controlled by controlling the opening area of the bypass passages 20L with the vanes 35 completely closing the chamber "C".

As shown in Fig. 1, when a speed gear 50, such as a manual or automatic transmission system for automobiles, is installed on the output shaft 3, the system of this invention can transmit the rotational force from the input shaft 2 to the output shaft 3 while controlling or changing the rotational speed of the output shaft 3. In such a case, the system of this invention somewhat freely changes the rotational speed in the same manner as a conventional nonstop variable speed gear. in the primary embodiment, the outside rotor 20 is integrated with the input shaft 2, while the inside rotor 30 is integrated 'with the output shaft 3. However, it should be understood the system of this invention may be designed in that the outside and inside rotors 20 and 30 are integrated with the output and input shafts 3 and 2, respectively.

In addition, both the check valves 21 and the vanes 35 are mechanically operated by the actuators 23 and 41 and the sleeves 22 and 40 in the primary embodiment. However, the system of this invention may be designed in that both the check valves 21 and the vanes 35 are operated by hydraulic pressure or electric signals. In the operation of the system of this invention, either one rotor, having relatively higher rotational force, acts as a conventional hydraulic pump, while a remaining rotor, having relatively lower rotational force, acts as a conventional hydraulic motor. Figs. 4 to 10 show hydraulic, rotary transmission systems in accordance with the other embodiments of this invention, respectively.

The system according to the second embodiment is shown in Figs. 4 and 5. In the second embodiment, a plurality of planetary rotors 135 are set on the inside rotor 130, while a plurality of vanes 125 are set on the outside rotor 120.

That is, the vanes 125, radially set on the interior surface of the outside rotor 120 integrated with the input shaft 102, are individually biased by a spring 126. The above vanes 125 are thus elastically movable in a radial direction to control the opening area of the chamber "C".

The planetary rotors 135 are set on the exterior surface of the inside rotor 130 and are brought into close and movable contact with the interior surface of the outside rotor 120. The above planetary rotors 135 are designed for being revolvable and rot^'atabie while moving the actuating fluid in the rotating direction of the input shaft 120.

Therefore, in the system according to the second embodiment, the rotational force of the input shaft 102 is primarily transmitted to the actuating fluid through the outside rotor 120 integrated with the input shaft 102. In such a case, the hydraulic force of the actuating fluid is changed in accordance with the opening area of the chamber "C^rt controlled by the spring-biased vanes 125. The pressurized fluid thus pushes the planetary rotors 135 and rotates the inside rotor 130, so that the rotational force of the input shaft 102 is transmitted to the output shaft 103.

Of course, when the vanes 125 open the chamber "C" , the rotational force of the outside rotor 120 is not transmitted to the actuating fluid. In such a case, the rotational force of the input shaft 102 is transmitted to neither the inside rotor 130 nor the output shaft 103. The general construction of the system according to the second embodiment except for the aboye-mentioned parts remains the same as that described for the system according to the primary embodiment and further explanation is thus not deemed necessary.

Fig. 6 is a cross-sectioned view of a hydraulic, rotary transmission system in accordance with the third embodiment of this invention. In the third embodiment, the system is free from any gears or planetary rotors, but is provided with vanes 225 and 235 at the outside and inside rotors 220 and 230.

That is, when the rotational force is transmitted to either the outside rotor 220 or the inside rotor 230, the rotational force is transmitted to vanes 225 or 235 through the pressurized fluid in accordance with the opening area of the chamber "C" controlled by the other vanes 235 or 225 .

In the system of the third embodiment, the vanes 235 of the inside rotor 230 are movable vanes capable of being radially movable to control the chamber "C" . Meanwhile, the vanes 225 of the outside rotor 220 are fixed vanes coming into close contact with the exterior surface of the inside rotor 230.

The movable vanes 235 are individually biased by a spring 236, so that the movable vanes 235 elastically retract into the vane holes when the vanes 235 come into contact with the fixed vanes 225. Of course, the movable vanes 235 elastically return to the projecting position when the vanes 235 are free from the fixed vanes 225. The top edge of each of the two types of vanes 225 and 235 is inclined, so that the fixed vanes 225 smoothly pass over the movable vanes 235 without interfering with the movable vanes 235.

Therefore, when the rotational force is transmitted to the actuating fluid through the inside rotor 220 with the fixed vanes 225 of the outside rotor 220 being brought into close contact with the exterior surface of the inside rotor 230 to close the chamber "C", the hydraulic force of the actuating fluid is changed in accordance with the opening area of the chamber "C" controlled by the movable vane 235. Therefore, the outside rotor 220 is rotated along with the fixed vanes 225 by the hydraulic force of the actuating fluid.

In the third embodiment, both the check valves and bypass passages are formed in the system in the same manner as that described for the primary and second embodiments. In addition, the movable vanes 235 may be designed for being mechanically movable in a radial direction by a vane sleeve or being hydraulically movable in the radial direction.

Particularly, when the rotating force of the output shaft is higher than that of the input shaft due to, for example, rotational inertia force, the system of the third embodiment is operated as a one way clutch, so that the system does not exert any effect on the input shaft.

Fig. 7 is a cross-sectioned view of a hydraulic, rotary transmission system in accordance with the fourth embodiment of this invention. In the fourth embodiment, the general shape of the system remains the same as that of the third embodiment, but all vanes 325 and 335, provided on both rotors 320 and 330, are designed for being movable different from the system of the third embodiment. Of course, each of the vanes 325 and 335 is biased by a spring 326 and 336 at its lower end.

Figs. 8 and 9 show a hydraulic, rotary transmission system in accordance with the fifth embodiment of this invention. In the fifth embodiment, the outside rotor 420 is free from any planetary rotors or vanes, but the interior surface of the outside rotor 420 is shaped into an elliptical configuration capable of circumscribing the circular exterior surface of the inside rotor 430 at two variable points.

The inside rotor 430 has a circular configuration capable of being inscribed with the elliptical interior surface of the outside rotor 420, thus forming two variable crescent oil chambers "C" between the two rotors 420 and 430. Two movable vanes 435, individually biased by a spring 436, are set on the inside rotor 430 at diametrically opposite positions to control the two chambers "C", respectively.

The above movable vanes 435 of the inside rotor 430 have to be designed in that they are movable in a radial direction. The vanes 435 are externally controlled in the same manner as that described for the primary embodiment. Two bypass passages 420L are formed on the interior surface of the outside rotor 420 at positions around the inscribed points of the inside rotor 430. A check valve 421 is set in each of the bypass passages 420L.

Therefore, the system of the fifth embodiment selectively transmits the rotational force of the outside rotor 420 to the inside rotor 430 through the actuating fluid while changing the speed of the inside rotor 430 in accordance with the opening area of both the chambers "C" and the bypass passages 420L.

In the system of the fifth embodiment, the movable vanes 435 are designed in that they are radially movable in accordance with the hydraulic pressure applied from the oil passages 403a and 430a of both the output shaft 403 and the inside rotor 430. A solenoid valve 441 is installed on the oil line 440 for the first oil passage 403a, thus controlling the hydraulic pressure in response to an external signal.

Of course, the above vanes 435 may be designed for being mechanically controlled by, for example, an actuator or a vane sleeve in the same manner as that described for the primary embodiment. Fig. 10 is a longitudinal sectioned view of a hydraulic, rotary transmission system in accordance with the sixth embodiment of this invention. In the sixth embodiment, two rotors 520 and 530, used for controllably transmitting rotational force from an input shaft 502 to an output shaft 503, are oppositely and coaxially positioned on the input and output shafts 502 and 503, respectively, different from the primary to fifth embodiments where an outside rotor is fitted over an inside rotor.

That is, the two rotors 520 and 530 are commonly cased by a casing 510 which is supported on the two shafts 502 and 503 by bearings 515. An annular oil chamber "C" is externally formed at the junction between the two rotors 520 and 530. First and second vanes 525 and 535 are respectively set on the two rotors 520 and 530 to controllably transmit the rotational force from the first rotor 520 to the second rotor 530 while controlling the opening area of the chamber "C". The above vanes 525 and 535 are respectively biased by springs 526 and 536, thus being movable in a radial direction.

In the sixth embodiment, the casing 510 may be fixed to either rotor 520 or 530.

Industrial Applicability

As described above, the present invention provides a hydraulic, rotary transmission system capable of transmitting rotational force from an input shaft to an output shaft while controlling or changing the rotating speed of the output shaft using the hydraulic force of actuating fluid filling an oil chamber formed between two rotors integrated with the input and output shafts. The system thus easily transmits the rotational force of the input to the output shaft while changing the rotational speed of the output shaft. Another advantage of the system resides in that the system has a simple construction.

The system of this invention is also designed in that the hydraulic force of the actuating fluid filling the oil ' chamber is hydrostaticfe'lly transmitted to the output shaft by a first means or a chamber closing means, such as vanes, without any flow loss of the fluid. Therefore, the system remarkably improves power transmission efficiency, thus effectively conserving energy in comparison with conventional torque converters or hydraulic couplings. Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

Claims :

1. A hydraulic, rotary transmission system for transmitting rotational force from an input shaft to an output shaft while controlling rotational speed of said output shaft, comprising: an outside rotor integrated with either one of the input and output shafts; an inside rotor integrated with a remaining one of the two shafts and fitted into said outside rotor, with an annular chamber being formed between the two rotors and being filled with actuating fluid; first means set on either one of the two rotors to project into said chamber and used for selectively moving the actuating fluid while pressurizing the fluid in said chamber; and second means set on a remaining one of the two rotors to be alternated with the first means and used for controlling an opening area of said chamber, thus selectively stopping a movement of the fluid in the chamber to transmit rotational force between the two rotors, with either one rotor, having relatively higher rotational force, acting as a hydraulic pump and a remaining rotor, having relatively lower rotational force, acting as a hydraulic motor.

2. The system according to claim 1, further comprising: third means for selectively controlling the projecting height of at least one of said first and second means in the chamber, thus allowing a selected means to become a variable means, said third means being controlled by a control unit, said control unit also controlling a power transmission between the two rotors.

3. The system according to claim 2, wherein said variable means comprises a vane, said vane being radially set on either one of the two rotors and being movable by said third means in a radial direction, thus selectively closing the chamber; and a remaining one of the first and second means comprises a planetary rotor, said planetary rotor being set on a remaining one of the two rotors and being brought into close and rotatable contact with opposite rotor to close the chamber, said planetary rotor also having an axial groove on its outer surface to receive a top edge of said vane, thus smoothly passing over the vane without interfering with the vane.

4. The system according to claim 2, wherein said first and second means comprise first and second vanes respectively and radially set on said two rotors, at least one of said first and second vanes being movable in a radial direction, both the first and second vanes being also inclined at their top edges, thus smoothly passing over each other without having any interference.

5. The system according to claim 2 , wherein said outside rotor has an elliptical opening, while said inside rotor has a circular configuration capable of being inscribed with an elliptical interior surface of said opening at two variable points, with said chamber being divided into two crescent chambers; and said variable means is radially set on the exterior surface of the inside rotor to be movable in a radial direction.

6. The system according to claim 2, wherein said variable means is spring-biased to project into said chamber; and said third means comprises: an actuator selectively operated under the control of said control unit; and a sleeve positioned to be selectively and linearly movable by said actuator in an axial direction prior to being brought into contact with said variable means at inclined cams, thus selectively changing the projecting height of said variable means in the chamber.

7. The system according to claim 2, wherein said third means comprises a hydraulic actuator, said actuator selectively moving said variable means in a radial direction using a hydraulic pressure applied to the variable means through an oil passage formed on at least one of the two rotors.

8. The system according to claim 1, further comprising: a bypass passage formed at a position around at least one of said first and second means and opening into the chamber at opposite sides of a selected means; and fourth means provided in said bypass passage for controlling a bypass flow rate of the actuating fluid passing through the bypass passage, said fourth means being controlled by a control unit, said control unit also controlling a power transmission between the two rotors.

9. The system according to claim 8, wherein said fourth means comprises : a valve provided in said bypass passage for controlling the opening area of the bypass passage; and a valve actuator selectively actuating said valve under the control of said control unit.

10. The system according to claim 1, further comprising: axially movable fifth means for selectively and directly coupling one rotor, integrated with said input shaft, to said output shaft.

11. A hydraulic, rotary transmission system for transmitting rotational force from an input shaft to an output shaft while controlling rotational speed of said output shaft, comprising: two rotors oppositely and coaxially integrated with said two shafts, respectively, with an annular chamber being formed at a junction between said two rotors and being filled with actuating fluid; first means set on either one of the two rotors to project into said chamber and used for selectively moving the actuating fluid while pressurizing the fluid in said chamber; second means set on a remaining one of the two rotors to be alternated with the first means and used for controlling an opening area of said chamber, thus selectively stopping a movement of the fluid in the chamber to transmit rotational force between the two rotors; and third means for selectively controlling the projecting height of at least one of said first and second means in the chamber, thus allowing a selected means to become a variable means, said third means being controlled by a control unit, said control unit also controlling a power transmission between the two rotors.