KR102802983B1 - Integratde drive axle assembly - Google Patents

Abstract

The present invention relates to an integrated drive axle assembly that prevents mixing of grease for a constant velocity joint and grease for a wheel bearing. In the present invention, an integrated drive axle assembly is introduced, which comprises: a wheel housing having a wheel bearing assembled on an outer surface thereof and a constant velocity joint coupled therein; an outer boot that is assembled between a drive shaft to which the constant velocity joint is coupled and the wheel bearing, and is assembled in a fixed state while allowing relative rotation with respect to the drive shaft; and an inner boot that seals an opening of the wheel housing within the outer boot to seal the interior of the wheel housing.

Description

Integrated drive axle assembly {Integratde drive axle assembly}

The present invention relates to an integrated drive axle assembly which prevents mixing of grease for a constant velocity joint and grease for a wheel bearing.

An integrated drive axle (IDA) is a structure that integrates the outer race of the drive shaft and the hub of the wheel bearing.

That is, by integrating the functions of the wheel bearing and drive shaft, the product is lightweight and the product cost is reduced. In addition, the joint center distance is reduced to increase the angle of the drive shaft, and the wheel bearing PCD is increased to increase the lateral rigidity of the vehicle.

However, an increase in wheel bearing size increases the drag torque of the wheel bearing, which ultimately has a negative effect on vehicle fuel efficiency.

Accordingly, the drag torque of the wheel bearing can be reduced by changing the structure of the bearing inner seal responsible for the sealing property of the wheel bearing.

For example, by assembling a boot on the outer ring side of the wheel bearing, foreign substances can be prevented from entering the wheel bearing by the boot, thereby eliminating the bearing inner seal, thereby reducing the drag torque of the wheel bearing.

However, in the case of the above structure, since a gap is formed between the wheel housing and the boot, when the wheel housing rotates, the grease for the constant velocity joint flows out of the wheel housing due to centrifugal force, and the grease for the wheel bearing also flows out of the wheel bearing, so there is a problem that the grease for the constant velocity joint and the grease for the wheel bearing may mix.

Furthermore, there is a risk that grease for constant velocity joints and wheel bearings may leak into the small diameter part of the boot.

The matters described as background technology above are only intended to enhance understanding of the background of the present invention, and should not be taken as an acknowledgment that they correspond to prior art already known to those skilled in the art.

JP 5868643 B2 JP 2007-315423 A

The present invention has been made to solve the problems described above, and provides an integrated drive axle assembly that prevents grease for a constant velocity joint and grease for a wheel bearing from mixing.

The present invention provides an integrated drive axle assembly which prevents grease within the wheel housing and wheel bearing from leaking out of the boot.

The composition of the present invention for achieving the above purpose may be characterized by including: a wheel housing having a wheel bearing assembled on an outer surface thereof and a constant velocity joint coupled therein; an outer boot assembled between a drive shaft to which the constant velocity joint is coupled and the wheel bearing, and assembled in a fixed state while allowing relative rotation with respect to the drive shaft; and an inner boot that seals the inside of the wheel housing by blocking an opening of the wheel housing within the outer boot.

The above outer boot has a large diameter portion assembled to the outer ring of the wheel bearing, and the small diameter portion and the drive shaft can be supported by a bearing seal unit.

The above inner boot has a large diameter portion that is assembled into the opening of the wheel housing, and a small diameter portion that can be supported on the outer surface of the drive shaft.

An orbital forming portion having a shape that is rolled outward toward the wheel bearing is formed at the end of the opening side of the above wheel housing; the large-diameter portion of the inner boot can be assembled in a shape that wraps around the edge of the orbital forming portion.

The small diameter portion of the above inner boot is formed in a cylindrical shape into which a drive shaft can be inserted.

The small diameter portion of the inner boot can be attached to the drive shaft by forming its end toward the wheel housing.

The inner boot can be fixed to the wheel housing by assembling a ring-shaped inner plate that covers the large diameter of the inner boot.

The above inner plate can be assembled in a shape that covers the perimeter of the opening side end of the wheel housing.

The above inner plate can be assembled in a shape that covers the perimeter of the opening side end of the wheel housing and the inner ring of the wheel bearing connected thereto.

An encoder can be integrally formed on the above inner plate.

Through the above-described problem-solving means, the present invention prevents the grease for the constant velocity joint inside the wheel housing from leaking out of the wheel housing, thereby preventing the grease for the constant velocity joint and the grease for the bearing inside the wheel bearing from mixing, thereby preventing the occurrence of a quality problem of the grease. In addition, it also has the effect of preventing the grease from leaking out of the boot.

Moreover, since there is no need to apply a bearing seal to prevent mixing of grease for constant velocity joints and grease for bearings, there is also an advantage of improving the vehicle's fuel efficiency by reducing drag torque generated by the sealing action.

FIG. 1 is a cross-sectional view illustrating an integrated drive axle assembly according to the present invention.
Figure 2 is an enlarged drawing showing the assembled shape of the inner boot and inner plate according to the present invention.
FIG. 3 is a drawing illustrating another assembly embodiment of an inner plate according to the present invention.

Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing symbols, identical or similar components will be given the same reference numerals and redundant descriptions thereof will be omitted.

The suffixes "module" and "part" used for components in the following description are given or used interchangeably only for the convenience of writing the specification, and do not have distinct meanings or roles in themselves.

In describing the embodiments disclosed in this specification, if it is determined that a detailed description of a related known technology may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The terms are used only to distinguish one component from another.

When it is said that a component is "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components in between. On the other hand, when it is said that a component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this specification, it should be understood that the terms “comprises” or “has” and the like are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

A preferred embodiment of the present invention is described in detail with reference to the attached drawings as follows.

FIG. 1 is a cross-sectional view illustrating an integrated drive axle assembly according to the present invention, and FIG. 2 is an enlarged view illustrating the assembled shape of an inner boot (400) and an inner plate (500) according to the present invention.

Referring to FIGS. 1 and 2, the present invention comprises: a wheel housing (100) having a wheel bearing (200) assembled on an outer surface thereof and a constant velocity joint coupled therein; an outer boot (300) assembled between a drive shaft (600) to which the constant velocity joint is coupled and the wheel bearing (200), and fixedly assembled so as to allow relative rotation with respect to the drive shaft (600); and an inner boot (400) that seals the interior of the wheel housing (100) by blocking an opening (100a) of the wheel housing (100) within the outer boot (300).

Specifically, the present invention is an integrated drive axle (IDA) structure, in which a wheel housing (100) is formed in a shape in which a conventional hub and an outer race are integrated, and a wheel bearing (200) is coupled to the middle portion of the outer surface of the wheel housing (100).

The wheel bearing (200) is configured such that the inner ring (220) is inserted into the outer surface of the wheel housing (100), the outer ring (210) is fixed to a knuckle or carrier, and a ball (230) (or roller) is assembled between the outer ring (210) and the inner ring (220) of the wheel bearing (200).

Then, a groove is formed on the inner surface of the wheel housing (100), and a cage with power transmission balls is fitted together with an inner race on the outer end (wheel side end) of the drive shaft (600) to form a constant velocity joint (CVJ).

At this time, as the power transmission ball is inserted into the groove, the drive shaft (600) is connected through the constant velocity joint inside the wheel housing (100), so that the driving force of the powertrain is transmitted to the constant velocity joint through the drive shaft (600), and the constant velocity joint rotates as it floats and bends according to the movement of the vehicle, thereby rotating the wheel housing (100).

In addition, the outer boot (300) has a structure in which the large diameter part (300a) is assembled to the outer ring (210) of the wheel bearing (200), and the small diameter part (300b) and the drive shaft (600) are supported by a bearing seal unit (700).

For example, the large diameter portion (300a) of the outer boot (300) may be directly connected to the outer ring (210) of the wheel bearing (200). However, an outer ring made of a rigid material may be separately fixed within the large diameter portion (300a) of the outer boot (300) and connected in a state where the outer ring is press-fitted into the outer ring (210) of the wheel bearing (200).

In this way, by connecting the large diameter portion (300a) of the outer boot (300) to the outer ring (210) of the wheel bearing (200), the outer boot (300) acts to block the space between the outer ring (210) and the inner ring (220), thereby preventing foreign substances from entering the wheel bearing (200).

Accordingly, by removing the existing bearing inner seal applied to the wheel bearing (200), the drag torque generated by the sealing action is reduced, thereby improving the vehicle's power/fuel efficiency.

For reference, a dust string (800) is press-fitted and assembled on the outer side (wheel side) of the wheel bearing (200) to prevent foreign substances flowing in from the wheel side from flowing into the wheel bearing (200).

In addition, a bearing seal unit (700) is press-fitted and assembled between the small diameter portion (300b) of the outer boot (300) and the drive shaft (600) in a shape that is inserted into the outer surface of the drive shaft (600), thereby allowing relative rotation of the drive shaft (600) with respect to the outer boot (300) through the bearing seal unit (700), and thus the outer boot (300) is mounted in a fixed state without rotating.

Briefly describing the above bearing seal unit (700), a shaft bearing (710) is assembled between the small diameter portion (300b) of the outer boot (300) and the drive shaft (600) in a shape that surrounds the drive shaft (600), and a shaft seal (720) is assembled between the shaft bearing (710) and the end of the small diameter portion (300b) of the outer boot (300) in a shape that surrounds the drive shaft (600).

In addition, on the outer side of the small diameter portion (300b) of the outer boot (300) facing the power train, a dust cover (900) is press-fitted and assembled onto the outer surface of the drive shaft (600) to prevent foreign substances from entering the outer boot (300) through the small diameter portion (300b) of the outer boot (300).

In addition, the present invention has an opening (100a) formed at the powertrain side end of the wheel housing (100), and a constant velocity joint is inserted and connected into the wheel housing (100) through the opening (100a).

In particular, as the inner boot (400) is assembled within the outer boot (300), the inner boot (400) is assembled in a shape that blocks the opening (100a) of the wheel housing (100) within the outer boot (300).

Accordingly, when the constant velocity joint rotates, the constant velocity joint grease inside the wheel housing (100) is prevented from flowing out of the wheel housing (100) due to centrifugal force, thereby preventing the constant velocity joint grease inside the wheel housing (100) and the bearing grease inside the wheel bearing (200) from mixing, thereby preventing the occurrence of grease quality problems.

Furthermore, since there is no need to apply a bearing seal to prevent mixing of grease for constant velocity joints and grease for bearings, the drag torque generated by the sealing action is reduced, thereby improving the vehicle's power/fuel efficiency.

Continuing, referring to FIG. 2, the inner boot (400) according to the present invention is configured such that the large-diameter portion (400a) is assembled into the opening (100a) of the wheel housing (100), and the small-diameter portion (400b) is supported on the outer surface of the drive shaft (600).

That is, the inner boot (400) is assembled between the opening (100a) of the wheel housing (100) and the drive shaft (600), thereby blocking the opening (100a) of the wheel housing (100) within the outer boot (300).

Specifically, an orbital forming portion (110) having a shape that is rolled outward toward the wheel bearing (200) is formed at the end of the opening (100a) of the wheel housing (100); and a large-diameter portion (400a) of the inner boot (400) can be assembled in a shape that surrounds the edge of the orbital forming portion (110).

For example, by performing orbital forming processing along the edge of the opening (100a) of the wheel housing (100), the edge of the opening (100a) of the wheel housing (100) is rolled outward.

Accordingly, an orbital forming portion (110) is formed on the edge of the opening (100a) of the wheel housing (100), so that the orbital forming portion (110) applies a preload to the inner ring (220) of the wheel bearing (200), thereby firmly fixing the inner ring (220) to the wheel housing (100).

In particular, since the large-diameter portion (400a) of the inner boot (400) is assembled in a shape that covers the orbital forming portion (110) while being in close contact with it, the contact area between the large-diameter portion (400a) of the inner boot (400) and the orbital forming portion (110) is increased, thereby preventing grease for the constant velocity joint from leaking toward the large-diameter portion (400a) of the inner boot (400).

In addition, in the present invention, the small diameter portion (400b) of the inner boot (400) is formed in a cylindrical shape so that a drive shaft (600) can be inserted.

That is, the small diameter portion (400b) of the inner boot (400) is formed to be long along the longitudinal direction of the drive shaft (600) and inserted into the drive shaft (600), thereby increasing the contact area between the small diameter portion (400b) of the inner boot (400) and the drive shaft (600), thereby preventing grease for the constant velocity joint from leaking toward the small diameter portion (400b) of the inner boot (400).

In addition, in the present invention, the small diameter portion (400b) of the inner boot (400) can be configured to be in close contact with the drive shaft (600) while having its end formed toward the wheel housing (100).

That is, since the end of the small diameter portion (400b) of the inner boot (400) is formed in a tubular shape that is rolled inward, and the end of the small diameter portion (400b) is formed toward the wheel housing (100), and is configured to be in close contact with the outer surface of the drive shaft (600), it is possible to more reliably block grease for the constant velocity joint from flowing out toward the small diameter portion (400b) of the inner boot (400).

Continuing, in the present invention, a ring-shaped inner plate (500) is assembled in a shape that covers the large diameter portion (400a) of the inner boot (400) to secure the inner boot (400) to the wheel housing (100).

As an example of assembling the inner plate (500), as shown in FIG. 2, the inner plate (500) can be assembled in a shape that covers the perimeter of the end portion on the opening (100a) side of the wheel housing (100).

That is, the inner plate (500) is formed in a ring shape and assembled in a shape that covers the large-diameter portion (400a) of the inner boot (400) that overlaps the orbital forming portion (110) together with the orbital forming portion (110), thereby stably fixing the inner boot (400) to the wheel housing (100).

FIG. 3 is a drawing illustrating another assembly embodiment of an inner plate (500) according to the present invention.

Referring to the drawing, the inner plate (500) can be assembled in a shape that covers the perimeter of the end of the opening (100a) of the wheel housing (100) and the inner ring (220) of the wheel bearing (200) connected thereto.

That is, the inner plate (500) is formed in a ring shape and is formed in a shape that covers the large-diameter portion (400a) of the inner boot (400) that overlaps the orbital forming portion (110) together with the orbital forming portion (110), and is formed to extend toward the inner ring (220) that borders the orbital forming portion (110) to cover the inner ring (220), thereby more stably fixing the inner boot (400) to the wheel housing (100).

Meanwhile, in the present invention, a magnetic encoder (510) is formed integrally with the inner plate (500).

That is, when the inner plate (500) and the encoder (510) are applied as independent parts as in Fig. 2, a process of pressing the encoder (510) into the inner ring (220) is additionally required in addition to the process of fixing the inner plate (500).

However, when the encoder (510) is formed integrally with the inner plate (500) as shown in Fig. 3, the encoder (510) is fixed to the inner ring through the assembly process of the inner plate (500), so that the inner plate (500) and the encoder (510) can be assembled in one process, simplifying the assembly process.

For reference, a wheel sensor (310) is installed integrally in the large diameter portion (300a) of the outer boot (300), and the wheel sensor (310) is installed in a position adjacent to the encoder (510) to sense the wheel speed.

As described above, the present invention prevents the grease for the constant velocity joint inside the wheel housing from leaking out of the wheel housing, thereby preventing the grease for the constant velocity joint and the grease for the bearing inside the wheel bearing (200) from mixing, thereby preventing the occurrence of a quality problem of the grease, and also preventing the grease from leaking out of the boot.

Furthermore, since there is no need to apply a bearing seal to prevent mixing of grease for constant velocity joints and grease for bearings, the drag torque generated by the sealing action is reduced, thereby improving the vehicle's power/fuel efficiency.

Meanwhile, although the present invention has been described in detail only with respect to the above-mentioned specific examples, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and it is natural that such modifications and variations fall within the scope of the appended claims.

100 : Wheel Housing
100a : opening
110: Orbital Forming Section
200 : Wheel bearing
210 : Outer ring
220 : Inner ring
230 : Ball
300 : Outer Boots
300a : Daegyeongbu
300b: Small diameter
310 : Wheel sensor
400 : Inner boot
400a : Daegyeongbu
400b : Small diameter
500 : Inner plate
510 : Encoder
600 : Drive shaft
700 : Bearing seal unit
710 : Shaft bearing
720 : Shaft seal
800 : The String
900 : Dust cover
CVJ : Constant velocity joint

Claims (10)

A wheel housing with a wheel bearing assembled on the outer surface and a constant velocity joint combined on the inside;
An outer boot assembled between a drive shaft and a wheel bearing to which a constant velocity joint is combined, and which is assembled in a fixed state while allowing relative rotation with respect to the drive shaft;
Including an inner boot that seals the opening of the wheel housing within the outer boot and seals the interior of the wheel housing;
The above outer boots are,
The large diameter part is assembled to the outer ring of the wheel bearing;
The space between the small diameter part and the drive shaft is supported by a bearing seal unit, so that the space between the outer ring and inner ring of the wheel bearing is blocked;
The above inner boot is,
The large diameter part is assembled into the opening of the wheel housing;
An integrated drive axle assembly characterized in that the small diameter portion is supported on the outer surface of the drive shaft so that the inside of the wheel housing is sealed, thereby blocking the constant velocity joint grease inside the wheel housing from leaking out of the wheel housing during the rotation of the constant velocity joint, thereby preventing the constant velocity joint grease inside the wheel housing and the bearing grease inside the wheel bearing from mixing. delete delete In claim 1,
An orbital forming portion having a shape that is rolled outward toward the wheel bearing is formed at the end of the opening side of the wheel housing;
An integrated drive axle assembly characterized in that the inner boot's large diameter portion is assembled in a shape that surrounds the edge of the orbital forming portion. In claim 1,
An integrated drive axle assembly characterized in that the inner boot's small diameter portion is formed in a cylindrical shape into which a drive shaft is inserted. In claim 5,
An integrated drive axle assembly characterized in that the small diameter portion of the inner boot is formed so that its end faces the wheel housing and is in close contact with the drive shaft. In claim 1,
An integrated drive axle assembly characterized by assembling a ring-shaped inner plate that covers the large diameter of the inner boot and fixing the inner boot to the wheel housing. In claim 7,
An integrated drive axle assembly characterized in that the inner plate is assembled in a shape that covers the periphery of the opening side end of the wheel housing. In claim 7,
An integrated drive axle assembly characterized in that the inner plate is assembled in a shape that covers the perimeter of the opening side end of the wheel housing and the inner ring of the wheel bearing connected thereto. In claim 7,
An integrated drive axle assembly characterized in that an encoder is formed integrally with the inner plate.

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