阅读说明：本技术 轮毂内置型等速设备 (Hub built-in type constant speed device ) 是由 柳成树 崔元准 金羲日 郑昌熙 曺永旭 李范宰 于 2020-11-27 设计创作，主要内容包括：本发明提供一种轮毂内置型等速设备,包括：轮毂壳体,其具有向内联接的等速接头；内座圈,其联接到所述轮毂壳体的外周表面；以及预压环,其联接到所述轮毂壳体的外周表面,并且位于所述内座圈的一侧,其中,所述轮毂壳体的端部形成为朝向所述预压环向上翻卷,以形成联接到所述预压环的成形部,所述成形部用于向所述预压环和所述内座圈施加压力。(The present invention provides a hub built-in type constant velocity device including: a hub shell having an inwardly coupled constant velocity joint; an inner race coupled to an outer peripheral surface of the hub shell; and a pre-pressing ring coupled to an outer circumferential surface of the hub shell and located at one side of the inner race, wherein an end portion of the hub shell is formed to be rolled up toward the pre-pressing ring to form a formed portion coupled to the pre-pressing ring, the formed portion being for applying a pressing force to the pre-pressing ring and the inner race.)

1. A hub built-in type constant velocity device comprising:

a hub shell having an internally coupled constant velocity joint;

an inner race coupled to an outer peripheral surface of the hub shell; and

a pre-compression ring coupled to an outer circumferential surface of the hub shell and located at one side of the inner race,

wherein an end of the hub shell is formed to be rolled up toward the pre-compression ring to form a contoured portion coupled to the pre-compression ring for applying pressure to the pre-compression ring and the inner race.

2. The hub built-in type constant velocity device according to claim 1, further comprising:

a shield coupled to an outer circumferential surface of the pre-compression ring,

wherein a coupling structure is formed on each of an outer circumferential surface of the pre-compression ring and an inner circumferential surface portion of the shield coupled with the pre-compression ring.

3. The hub built-in type constant velocity device according to claim 1, wherein a plurality of teeth are formed on an inner peripheral surface of the pre-compression ring to prevent the pre-compression ring from rotating on an outer peripheral surface of the hub shell.

4. The hub built-in type constant velocity device according to claim 2,

wherein the shield is accommodated on an outer circumferential surface of the pre-compression ring and an upper end portion of the forming portion.

5. The hub built-in type constant velocity device according to claim 4,

wherein a sealing portion is formed inside the shield in at least one direction of a direction of one surface of the forming portion and a direction of a surface where the pre-pressing ring and the forming portion contact each other.

6. The hub built-in type constant velocity device according to claim 5, wherein the sealing portion includes:

a first seal portion that extends in an axial direction of the pre-compression ring from a surface of the shield that adjoins a side surface of the forming portion inside the shield, and is formed to adjoin the side surface of the forming portion; and

a second sealing portion formed inward from an inside of the shield cap and extending in a surface direction in which the pre-compression ring and the forming portion contact each other.

7. The hub built-in type constant velocity device according to claim 1,

wherein a first seat portion on which the inner race is accommodated and a second seat portion on which the pre-compression ring is accommodated are provided on an outer peripheral surface of the hub shell,

a step is formed between the first seat and the second seat.

8. The hub built-in type constant velocity device according to claim 7,

wherein a step is formed in a portion of the pre-compression ring that contacts the inner race,

the step formed in the pre-pressing ring corresponds to the step formed between the first seat and the second seat.

9. The hub built-in type constant velocity device according to claim 1, wherein a washer is provided between the inner race and the pre-compression ring.

10. The hub built-in type constant velocity device according to claim 9, wherein the washer is fixed to the pre-compression ring.

11. A hub built-in type constant velocity device according to claim 1, wherein a low friction structure for reducing a friction force with the inner race is provided on a surface of the pre-compression ring abutting the inner race.

12. A hub built-in type constant velocity device according to claim 11, wherein the low friction structure includes a male protrusion formed on a surface of the pre-compression ring abutting the inner race to reduce a friction area in contact with the inner race.

13. A hub built-in type constant velocity device according to claim 11, wherein the low friction structure includes a female protrusion formed on a surface of the pre-compression ring abutting the inner race.

14. The hub built-in type constant velocity device according to claim 1, wherein the inner race and the pre-compression ring are formed of different materials.

15. The hub built-in type constant velocity device according to claim 1, wherein a value obtained by dividing an outermost diameter of the pre-compression ring by an outer diameter of the formed portion is 0.8 to 1.2.

16. The hub built-in type constant velocity device according to claim 1, wherein a value obtained by dividing a thickness of the pre-compression ring by a thickness of the formed portion is 1.2 to 1.6.

17. The hub built-in type constant velocity device according to claim 1, wherein a value obtained by dividing an inner diameter of the pre-compression ring by a total length of the pre-compression ring is 5 to 7.

18. The hub built-in type constant velocity device according to claim 1, wherein a value obtained by dividing an outer diameter of the formed portion by an inner diameter of the pre-compression ring is 1.1 to 1.4.

19. The hub built-in type constant velocity device according to claim 2, wherein a protrusion is formed on an outer peripheral surface of the pre-compression ring or on an inner surface of the boot along an outer peripheral surface of the pre-compression ring.

Technical Field

The present invention relates to a constant velocity device, and more particularly, to a hub built-in type constant velocity device in which torque transmission and bearing functions are combined by integrating a hub housing and an outer race of the constant velocity device.

Background

Generally, a hub and a bearing are mounted on a tire wheel (tire) connected to a drive shaft for receiving loads in up-down and front-rear directions of a vehicle and horizontal loads when the vehicle turns. Further, the constant velocity device is mounted on a drive shaft of the vehicle, and is used to transmit power transmitted from the transmission to wheels. The constant velocity device, the hub and the bearing are assembled together organically by the fastening member and used as one unit.

Meanwhile, the constant velocity device is a component that performs transmission of driving force from an engine (motor) to a wheel, and the constant velocity device and a wheel-side hub bearing are spline-coupled. However, at the time of power transmission, problems such as a seam, a backlash, nut loosening, and the like occur at the coupling portion between the constant velocity device and the hub bearing.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

Various aspects of the present invention are directed to provide a hub built-in type constant velocity apparatus configured to improve a quality problem between boundary portions and reduce weight by integrating a hub and an outer race of a constant velocity joint, and configured to improve a hinge angle by reducing a distance between a wheel center and a center of the constant velocity joint, thereby improving traveling performance.

According to various exemplary embodiments of the present invention, a hub built-in type constant velocity device includes: a hub shell having an inwardly coupled constant velocity joint; an inner race coupled to an outer peripheral surface of the hub shell; and a pre-pressing ring coupled to an outer circumferential surface of the hub shell and located at one side of the inner race, wherein an end portion of the hub shell is formed to be rolled up toward the pre-pressing ring to form a formed portion coupled to the pre-pressing ring, the formed portion being for applying a pressing force to the pre-pressing ring and the inner race.

The hub built-in type constant velocity device may further include: a shield coupled to an outer circumferential surface of the pre-compression ring, wherein a coupling structure may be formed on each of the outer circumferential surface of the pre-compression ring and an inner circumferential surface portion of the shield coupled with the pre-compression ring.

A plurality of teeth may be formed on an inner circumferential surface of the pre-compression ring to prevent the pre-compression ring from rotating on an outer circumferential surface of the hub shell.

The shield may be accommodated on an outer circumferential surface of the pre-pressing ring and an upper end portion of the forming portion, and a sealing portion may be formed inside the shield in at least one of a direction of one surface of the forming portion and a direction of a surface where the pre-pressing ring and the forming portion contact each other.

The sealing part may include: a first seal portion that extends in an axial direction of the pre-compression ring from a surface of the shield that adjoins a side surface of the forming portion inside the shield, and is formed to adjoin the side surface of the forming portion; and a second sealing portion formed inward from an inside of the shield cap and extending in a surface direction in which the pre-compression ring and the forming portion contact each other.

A first seat on which the inner race is accommodated and a second seat on which the pre-compression ring is accommodated may be provided on an outer circumferential surface of the hub shell, and a step may be formed between the first seat and the second seat.

A step may be formed in a portion of the pre-pressing ring that contacts the inner race, and the step formed in the pre-pressing ring may correspond to the step formed between the first seat and the second seat.

A low friction washer may be disposed between the inner race and the pre-compression ring.

The low friction washer may be secured to the pre-compression ring.

A low friction structure may be formed on a surface of the pre-compression ring abutting the inner race, the low friction structure for reducing friction with the inner race.

The inner race and the pre-compression ring may be formed of different materials.

A value obtained by dividing an outermost diameter of the pre-compression ring by an outer diameter of the forming portion may be 0.8 to 1.2.

A value obtained by dividing the thickness of the pre-compression ring by the thickness of the forming part may be 1.2 to 1.6.

A value obtained by dividing the inner diameter of the pre-compression ring by the total length of the pre-compression ring may be 5 to 7.

A value obtained by dividing the outer diameter of the formed part by the inner diameter of the pre-compression ring may be 1.1 to 1.4.

Other features and advantages of the methods and apparatus of the present invention will be more particularly apparent from or elucidated with reference to the drawings described herein, and subsequently, described in conjunction with the accompanying drawings, which serve to explain certain principles of the invention.

Drawings

Fig. 1 is a view exemplarily showing an overall configuration of a hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

Fig. 2 is a view exemplarily showing that an inner race and a pre-compression ring are pre-compressed by a forming part formed at a hub shell in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

Fig. 3 is a view exemplarily showing a coupling structure formed on an outer circumferential surface of a pre-compression ring in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

Fig. 4 is a view exemplarily showing a plurality of teeth formed on an inner circumferential surface of a pre-compression ring in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

Fig. 5 is a view exemplarily illustrating a sealing portion formed at a boot in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

Fig. 6 is a view exemplarily showing a state in which an inner race and a pre-compression ring are accommodated on first and second seats of a hub shell in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

Fig. 7 is a view exemplarily showing a step structure formed at a first seat and a second seat in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention, wherein Φ D1 is a diameter of the first seat; Φ D2 is the diameter of the second seat.

Fig. 8 is a view exemplarily showing a low friction washer fixed to a pre-compression ring by a clamping method in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

Fig. 9 is a view exemplarily showing a low-friction washer fixed to a pre-compression ring by an adhesive in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

Fig. 10 is a view exemplarily illustrating a step structure formed at a pre-pressing ring in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

Fig. 11 is a view exemplarily showing a low friction structure formed on a surface of a pre-pressure ring abutting on an inner race in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

Fig. 12 is a view exemplarily showing a low friction structure formed on a surface of a pre-pressure ring abutting on an inner race in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

Fig. 13 is a view exemplarily showing a numerical relationship between each component in the hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

It should be understood that the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. The specific design features of the invention disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes, will be determined in part by the particular application and environment of use contemplated.

In the drawings, like or equivalent elements of the invention are designated by reference numerals throughout the several views of the drawings.

Detailed Description

Reference will now be made in detail to various embodiments of the invention, examples of which are illustrated in the accompanying drawings and described below. While the invention will be described in conjunction with the exemplary embodiments, it will be understood that this description is not intended to limit the invention to those exemplary embodiments. On the other hand, the invention is intended to cover not only these exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

Hereinafter, a hub built-in type constant velocity device according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

Fig. 1 is a view exemplarily showing an overall configuration of a hub built-in type constant velocity device according to various exemplary embodiments of the present invention, fig. 2 is a view exemplarily showing that an inner race and a pre-pressure ring are pre-pressurized by a forming part formed at a hub shell in the hub built-in type constant velocity device according to various exemplary embodiments of the present invention, fig. 3 is a view exemplarily showing a coupling structure formed on an outer circumferential surface of the pre-pressure ring in the hub built-in type constant velocity device according to various exemplary embodiments of the present invention, fig. 4 is a view exemplarily showing a plurality of teeth formed on an inner circumferential surface of the pre-pressure ring in the hub built-in type constant velocity device according to various exemplary embodiments of the present invention, fig. 5 is a view exemplarily showing in the hub built-in type constant velocity device according to various exemplary embodiments of the present invention, fig. 6 is a view exemplarily showing a state in which an inner race and a pre-compression ring are received on first and second seats of a hub housing in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention, fig. 7 is a view exemplarily showing a stepped structure formed at the first and second seats in the hub built-in type constant velocity device according to various exemplary embodiments of the present invention, fig. 8 is a view exemplarily showing a low friction washer fixed to the pre-compression ring by a clamping method in the hub built-in type constant velocity device according to various exemplary embodiments of the present invention, fig. 9 is a view exemplarily showing a low friction washer fixed to the pre-compression ring by an adhesive in the hub built-in type constant velocity device according to various exemplary embodiments of the present invention, fig. 10 is a view exemplarily showing a step structure formed at a pre-pressure ring in a hub built-in type constant velocity device according to various exemplary embodiments of the present invention, fig. 11 is a view exemplarily showing a low friction structure formed on a surface of the pre-pressure ring abutting an inner race in the hub built-in type constant velocity device according to various exemplary embodiments of the present invention, fig. 12 is a view exemplarily showing a low friction structure formed on a surface of the pre-pressure ring abutting the inner race in the hub built-in type constant velocity device according to various exemplary embodiments of the present invention, and fig. 13 is a view exemplarily showing a numerical relationship between each component in the hub built-in type constant velocity device according to various exemplary embodiments of the present invention.

As shown in fig. 1, a hub built-in type constant velocity apparatus according to various exemplary embodiments of the present invention may include one or more hub housings 100, an inner race 200, an outer race 600, a pre-loading ring 300, a constant velocity joint 400, a boot 500, a wheel bearing 700, a sealing device 800, a hub cap 900, and a wheel guide 910.

The wheel hub and outer race integrated hub housing 100 of the constant velocity joint 400 is provided with the constant velocity joint 400 coupled to the inside thereof to transmit the driving torque transmitted from the engine to the wheel. Meanwhile, the hub shell 100 may also serve as an inner race of the wheel bearing 700 to support the load of the vehicle.

Therefore, by forming the hub shell 100 by integrating the wheel hub and the outer race of the constant velocity joint 400, the center portion of the constant velocity joint 400 can be moved to the outside of the vehicle, thereby increasing the length of the drive shaft, and as a result, the articulation angle of the drive shaft of the constant velocity joint 400 can be improved.

Further, by forming the hub shell 100 by integrating the wheel hub and the outer race of the constant velocity joint 400, it is possible to eliminate a connecting member between the wheel hub and the constant velocity joint of the related art to reduce weight and manufacturing cost, improve driving fuel efficiency by reducing weight, improve noise problems due to the connecting member, and improve quality problems due to loosening of a wheel hub nut fixing the constant velocity joint shell and the wheel hub.

As shown in fig. 2, the hub shell 100 may have a formed part 130, the formed part 130 being provided at one end and being rolled (rolled upward) toward the pre-pressing ring 300 to apply pressure to the pre-pressing ring 300 and the inner race 200 coupled to the outer circumferential surface of the hub shell 100. Here, the forming part 130 may be formed by an orbital forming method. The pre-pressure may be applied to the inner race 200 of the wheel bearing 700 by the forming section 130 provided in the hub shell 100. Here, the magnitude of the pre-pressure may be set such that: based on the magnitude of this pre-stress, some of the components that make up the wheel bearing assembly are compressed and elastically deformed by a predetermined force applied in the axial direction during assembly.

The inner race 200 may be press-fitted to the outer circumferential surface of the hub shell 100 and may rotate together with the hub shell 100. Furthermore, the inner race 200 is configured as an inner track of the wheel bearing 700.

The outer race 600 may be disposed spaced apart from the hub shell 100 and the inner race 200 and configured as an outer track of the wheel bearing 700. Further, the outer race 600 is coupled to a knuckle 920. Since the outer race 600 is coupled with the knuckle 920, the outer race 600 may be a non-rotating element that does not move in position.

As shown in fig. 1, the first rolling elements 710 and the second rolling elements 720 may be located between the hub shell 100 and the outer race 600 and between the outer race 600 and the inner race 200. According to an exemplary embodiment, the first rolling elements 710 and the second rolling elements 720 may be balls or rollers and may rotate on the outer circumferential surfaces of the outer race 600 and the hub shell 100 and on the track portions of the outer race 600 and the inner race 200.

The sealing device 800 is configured to prevent foreign matter from entering the wheel bearing 700 and to prevent internal grease from leaking.

The hub cap 900 is configured to prevent grease in the constant velocity joint 400 from leaking and to prevent foreign matter from flowing into the constant velocity joint 400.

The wheel guide 910 is configured as an assembly guide for a wheel and a disk, and is configured to maintain the center position of the rotating body.

The constant velocity joint 400 is configured to transmit the driving force transmitted through the engine and the transmission to the hub shell 100.

The boot 500 is configured to prevent grease from leaking into the constant velocity joint 400 and to prevent foreign matter from flowing into the constant velocity joint 400.

Hereinafter, the structure of the pre-pressing ring 300, the structure of the outer circumferential surface of the hub shell 100 on which the pre-pressing ring 300 is accommodated, and the structure of the shield 500 coupled to the pre-pressing ring 300, which are core features of the present invention, will be described in more detail.

As shown in fig. 2, the pre-pressing ring 300 may be coupled to the outer circumferential surface of the hub shell 100 and may be located at one side of the inner race 200. Here, the pre-compression ring 300 may be coupled to the outer circumferential surface of the hub shell 100 by assembly, press-fitting, or the like.

The shield 500 may be coupled to an outer circumferential surface of the pre-compression ring 300, and a coupling structure for coupling with the shield 500 may be formed on the outer circumferential surface of the pre-compression ring 300. Similarly, a coupling structure may also be formed on an inner circumferential surface portion of the shield 500 coupled with the pre-compression ring 300. According to various exemplary embodiments of the present invention, as shown in fig. 3, a protrusion 320 may be formed on an outer circumferential surface of the pre-pressing ring 300 along the outer circumferential surface, and a recess corresponding to the shape of the protrusion may be provided on an inner circumferential surface of the shield 500. According to another exemplary embodiment of the present invention, a recess may be formed on an outer circumferential surface of the pre-pressing ring 300, and a protrusion corresponding to a shape of the recess may be formed on an inner surface of the shield 500 corresponding to the recess formed on the outer circumferential surface of the pre-pressing ring 300. However, this is only various exemplary embodiments of the present invention, and the shape of the coupling structure formed on the outer circumferential surface of the pre-pressing ring 300 and the inner circumferential surface portion of the shield 500 coupled with the pre-pressing ring 300 is not limited thereto.

Referring to fig. 4, a plurality of teeth 330 may be formed on an inner circumferential surface of the pre-pressing ring 300 to prevent the pre-pressing ring 300 from rotating on an outer circumferential surface of the hub shell 100. According to various exemplary embodiments of the present invention, serrations may be provided on an inner circumferential surface of the pre-pressing ring 300, the serrations being configured to prevent the pre-pressing ring 300 from rotating on an outer circumferential surface of the hub shell 100.

If the pre-compression ring 300 coupled to the outer circumferential surface of the hub shell 100 is rotated, the boot 500 coupled to the upper end portion of the pre-compression ring 300 may be deformed, and as the boot 500 is deformed, the sealing performance of the boot 500 may be degraded, resulting in a problem that grease or the like contained in the constant velocity joint 400 may leak. To prevent such a problem, in various exemplary embodiments of the present invention, a plurality of teeth may be provided on an inner circumferential surface of the pre-pressing ring 300, so that the pre-pressing ring 300 may be stably fixed to an outer circumferential surface of the hub shell 100 and prevent rotation, and thus deformation of the shield 500 and leakage of grease generated therefrom may be improved.

Referring to fig. 5, the protection cover 500 is received on the outer circumferential surface of the pre-pressing ring 300 and the upper end of the forming part 130. The sealing parts 510 and 520 may be formed in at least one of a direction of one surface of the forming part 130 and a direction in which the pre-compression ring 300 and the forming part 130 contact each other.

The sealing part may include a first sealing part 510 and a second sealing part 520, the first sealing part 510 extending in an axial direction of the pre-pressing ring from a surface adjacent to one surface of the forming part 130 inside the shield 500 to abut on one surface of the forming part 130, the second sealing part 520 being formed in an inner diameter direction from the inside of the shield 500 and extending in a surface direction in which the pre-pressing ring 300 and the forming part 130 contact each other.

For example, when a load having a predetermined magnitude or more (including a torque, an axial load, and a lateral force) is applied to the hub shell 100, the sealing performance of the formation 130 may be degraded, and if the sealing performance of the formation 130 is degraded, grease contained in the boot 500 may penetrate between the formation 130 and the pre-compression ring 300, and as a result, the rotation of the pre-compression ring 300 may be promoted to cause the boot 500 to be deformed, and thus the grease contained in the boot 500 to leak.

In order to solve the above-described problems, in various exemplary embodiments of the present invention, a first sealing part 510 and a second sealing part 520 are provided inside the shield cap, the first sealing part 510 extends in an axial direction from a surface adjacent to one surface of the forming part 130 from inside the shield cap 500 to abut one surface of the forming part 130, and the second sealing part 520 extends in a direction of a surface where the pre-compression ring 300 and the forming part 130 contact each other.

As described above, in various exemplary embodiments of the present invention, since the first sealing portion 510 and the second sealing portion 520 are provided inside the shield 500, even if a load having a predetermined size or more is applied to the hub shell 100 to reduce the sealing performance of the formation portion 130, it is possible to prevent the grease in the shield 500 from leaking mainly through the first sealing portion 510, and even if the grease passes through the first sealing portion 510, it is possible to prevent the grease from penetrating to the pre-pressing ring 300 through the leakage of the second sealing portion 520.

Meanwhile, a first seat 110 and a second seat 120 may be provided on the outer circumferential surface of the hub shell 100, the inner race 200 being accommodated on the first seat 110, and the pre-compression ring 300 being accommodated on the second seat 120. Referring to fig. 6 and 7, a step 140 may be formed between the first seat 110 and the second seat 120. As shown in fig. 7, the diameter of the first seat 110 is preferably larger than the diameter of the second seat 120.

Here, the reason why the step 140 is formed between the first seat 110 and the second seat 120 by making the diameter of the first seat 110 larger than the diameter of the second seat 120 is to make the fitting force of the pre-compression ring 300 larger than the fitting force of the inner race 200 when the inner race 200 and the pre-compression ring 300 are press-fitted and mounted to the outer circumferential surface of the hub shell 100.

When the inner race 200 is press-fitted and mounted to the outer peripheral surface of the hub shell 100, the groove formed in the hub shell 100 may be excessively deformed if the fitting force is greater than a predetermined level. That is, if the press-fitting is performed by applying a fitting force of press-fitting the pre-compression ring 300 to the outer peripheral surface of the hub shell 100 to the inner race 200, the groove formed in the hub shell 100 may be excessively deformed.

In order to solve this problem, in various exemplary embodiments of the present invention, a step 140 is provided between the first seat 110 having the inner race 200 received thereon and the second seat 120 having the pre-pressure ring 300 received thereon, and thus, different fitting forces may be applied to the inner race 200 and the pre-pressure ring 300, respectively.

Meanwhile, referring to fig. 10, the pre-pressing ring 300 may have a step 310 in a portion contacting the inner race 200. Here, the step 310 formed on the pre-pressing ring 300 may correspond to the step 140 formed between the first seat 110 and the second seat 120.

Here, the reason why the step 310 is formed in the portion of the pre-pressure ring 300 that contacts the inner race 200 is to balance the reaction force based on the press-fitting of the inner race 200 to the hub shell 100 and the load force based on the forming force when the end of the hub shell is formed.

If the forming force when forming the end portion of the hub shell 100 is larger than the reaction force based on the inner race 200, there is a problem that the inner race 200 is deformed and cracks may be generated in the inner race 200. To improve this problem, in various exemplary embodiments of the present invention, by forming the step 310 in the portion of the pre-pressure ring 300 that is in contact with the inner race 200, the reaction force based on the inner race 200 and the forming force at the time of forming can be balanced in the axial direction thereof.

Meanwhile, in order to prevent the rotation of the pre-pressure ring 300 caused by the load rotation force of the inner race 200, it is necessary to reduce the friction force between the inner race 200 and the pre-pressure ring 300. In various exemplary embodiments of the present invention, in order to reduce the frictional force between the inner race 200 and the pre-pressure ring 300, a low-friction washer 930 may be located between the inner race 200 and the pre-pressure ring 300. Here, the low friction washer 930 may be fixed to the pre-pressing ring 300 according to various exemplary embodiments of the present invention, where the low friction washer 930 may be fixed to the pre-pressing ring 300 by a clamping method as shown in fig. 8, or the low friction washer 930 may be fixed to the pre-pressing ring 300 by a bonding method by means of an adhesive or the like as shown in fig. 9 according to another exemplary embodiment of the present invention.

Meanwhile, a low friction structure 340 for reducing friction with the inner race 200 may be provided on a surface of the pre-pressing ring 300 abutting the inner race 200. According to various exemplary embodiments of the present invention, as shown in fig. 11, a male (positive) protrusion 340 may be formed on a surface of the pre-pressure ring 300 adjacent to the inner race 200 to reduce a friction area in contact with the inner race 200, thereby reducing a friction force between the inner race 200 and the pre-pressure ring 300. Further, according to another exemplary embodiment of the present invention, as shown in fig. 12, a female (negative) protrusion 340 may be formed on a surface of the pre-pressing ring 300 adjacent to the inner race 200 to reduce a friction area in contact with the inner race 200, thereby reducing a friction force between the inner race 200 and the pre-pressing ring 300.

Meanwhile, in various exemplary embodiments of the present invention, the inner race 200 and the pre-pressure ring 300 may be formed of different materials. According to various exemplary embodiments of the present invention, the inner race 200 may be formed of SUJ2 steel and the pre-compression ring 300 may be formed of S45C steel. However, this is merely an example, and the materials of the inner race 200 and the pre-compression ring 300 are not limited thereto.

Referring to fig. 13, in the hub built-in type constant velocity device 400 according to various exemplary embodiments of the present invention, a value obtained by dividing the outermost diameter of the pre-compression ring 300 by the outer diameter of the forming part 130 may be 0.8 to 1.2 for assemblability of the boot 500 and sealing performance of the boot 500.

Here, if a value obtained by dividing the outermost diameter of the pre-compression ring 300 by the outer diameter of the form 130 is less than 0.8 or greater than 1.2, the difference between the top of the pre-compression ring 300 and the top of the form 130 may increase by a predetermined interval or more, and in this case, assemblability of the shield 500 to be mounted to the top of the pre-compression ring 300 and the top of the form 130 may decrease, and since the shield 500 is not securely mounted, sealing performance of the shield 500 may decrease.

Further, in the hub built-in type constant velocity device 400 according to various exemplary embodiments of the present invention, in order to prevent deformation of the inner race 200 and generation of cracks on the inner race 200, a value obtained by dividing the thickness of the pre-compression ring 300 by the thickness of the forming part 130 may be 1.2 to 1.6.

Further, in order to optimally maintain the pre-pressure applied to the inner race 200, a value obtained by dividing the inner diameter of the pre-pressure ring 300 by the total length of the pre-pressure ring 300 may be 5 to 7, and a value obtained by dividing the outer diameter of the forming portion 130 by the inner diameter of the pre-pressure ring 300 may be 1.1 to 1.4.

According to various exemplary embodiments of the present invention, by integrating the hub housing and the outer race of the constant velocity joint, the problem of noise generated between the boundary portions when moving forward and backward can be improved, the problem of hub nut engagement can be improved, and by reducing the number of parts, the weight can be reduced and the mileage can be improved.

Further, the joint angle is improved by reducing the distance between the wheel center portion and the constant velocity joint center portion, so that the traveling performance can be improved.

For convenience in explanation and accurate definition in the appended claims, the terms "above", "below", "inner", "outer", "upper", "lower", "upward", "downward", "front", "rear", "back", "inside", "outside", "inward", "outward", "inner", "outer", "forward" and "rearward" are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. It will be further understood that the term "connected," or derivatives thereof, refers to both direct and indirect connections.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. The foregoing description is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable others skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the following claims and their equivalents.