Axle device

Abstract

The present invention relates to an axle device comprising: a shaft rotated by receiving power; an inner race rotated together with the shaft; and a hub connected to a wheel while being detachably connected to the inner race, wherein the hub includes: a joint space for accommodating the inner race; a first hole for allowing communication between the joint space and the outside such that the shaft extends from the inner race to the outside of the joint space; and a catcher for reducing the inner diameter of the first hole to be smaller than the outer diameter of the inner race, and thus a constant-velocity joint lubricant for lubricating the inner race and the hub can be prevented from leaking to the outside of the joint space.

Description

Axle device

[0001] The present invention relates to an axle device, and more particularly, to an axle device capable of transmitting power from a powertrain to a wheel.

[0002] In general, an axle device is a device that supports the weight of a vehicle through wheels and transmits power to the wheels, and a vehicle includes an axle device in a driving wheel or a non-driving wheel so that the vehicle can be driven.

[0003] Fig. 1 is a cross-sectional view showing a conventional axle device.

[0004] Referring to the attached drawing 1, a conventional axle device includes a shaft (10) that rotates by receiving power from a powertrain, an inner race (20) that rotates together with the shaft (10), a hub (40) that is angularly connected to the inner race (20) and is connected to a wheel (not shown), a hub bearing (50) that rotatably supports the hub (40), and a boot (60) that covers a connection portion between the inner race (20) and the hub (40).

[0005] The above hub bearing (50) includes an inner ring (52) that supports the hub (40), an outer ring (56) that accommodates the inner ring (52), and a ball (54) interposed between the inner ring (52) and the outer ring (56).

[0006] The above hub (40) includes a step portion (42) that supports one side of the inner ring (52) and an orbital forming portion (44) that supports the other side of the inner ring (52) to apply a preload to the hub bearing (50). The orbital forming portion (44) is initially formed to extend in the axial direction of the hub (40), and when the hub bearing (50) is placed on the outer surface of the hub (40) and the step portion (42), it is bent radially outwardly of the hub (40) and presses the inner ring (52) of the wheel bearing toward the step portion (42).

[0007] The above boot (60) includes a first end (62) that is fastened to the outer ring (56) and a second end (66) into which the shaft (10) is inserted.

[0008] Here, the hub (40) includes a joint space (S1) that accommodates the inner race (20) and an opening (46) that connects the joint space (S1) and the inner space (S2) of the boot (60), the inner race (20) is inserted into the joint space (S1) through the opening (46), and the shaft (10) extends from the inner race (20) toward the boot (60) through the opening (46).

[0009] And, to prevent the inner race (20) from being separated from the joint space (S1) to the inner space (S2) of the boot (60) through the opening (46), a stopper ring (80) is placed on the side of the opening (46).

[0010] However, in such a conventional axle device, there was a problem that the constant velocity joint lubricant filled in the joint space (S1) to lubricate the inner race (20) and the hub (40) leaked into the internal space (S2) of the boot (60) as the joint space (S1) was communicated with the internal space (S2) of the boot (60) through the opening (46). Accordingly, there was a problem that the constant velocity joint lubricant in the joint space (S1) was insufficient. In addition, as the space between the inner ring (52) and the outer ring (56) of the hub bearing (50) was communicated with the internal space (S2) of the boot (60), there was a problem that the constant velocity joint lubricant leaked from the joint space (S1) into the internal space (S2) of the boot (60) flowed into the hub bearing (50) and mixed with the hub bearing lubricant for lubricating the hub bearing (50). Here, the physical properties of the above-mentioned constant velocity joint lubricant and the above-mentioned hub bearing lubricant are different from each other, so when mixed together, the desired lubricating performance is not achieved.

[0011] In addition, there was a problem of increased manufacturing cost as the stopper ring (80) had to be provided separately to prevent the inner race (20) from coming off through the opening (46).

[0012] In addition, as preload was applied to the hub bearing (50) through the orbital forming section (44), there was difficulty in managing the preload of the hub bearing (50).

[0013] Accordingly, the present invention aims to provide an axle device capable of preventing a constant velocity joint lubricant for lubricating an inner race and a hub from leaking out of a joint space in which the inner race is accommodated.

[0014] In addition, another object of the present invention is to provide an axle device capable of reducing manufacturing costs.

[0015] In addition, another object of the present invention is to provide an axle device that can easily manage the preload applied to the hub bearing.

[0016] The present invention provides an axle device comprising: a shaft that receives power and rotates; an inner race that rotates together with the shaft; and a hub that is angularly connected to the inner race and connected to a wheel; wherein the hub includes a joint space that accommodates the inner race, a first hole that communicates the joint space with the outside so that the shaft extends from the inner race to the outside of the joint space, and a catcher portion that reduces the inner diameter of the first hole to be smaller than the outer diameter of the inner race.

[0017] The above catcher portion may be formed in an annular shape protruding radially inward from an annular wall portion forming the joint space.

[0018] The above catcher portion can be formed integrally with the annular wall portion.

[0019] The above catcher portion may include a curved surface whose center of curvature is located in the joint space.

[0020] The above hub may include an inner hub connected to the inner race and an outer hub connected to the inner hub and connected to the wheel.

[0021] The inner hub includes an annular wall portion forming the joint space, and an opening on one side of the annular wall portion forms the first hole, and an opening on the other side of the annular wall portion forms a second hole into which the inner race can be inserted.

[0022] The inner diameter of the second hole may be formed to be greater than or equal to the outer diameter of the inner race.

[0023] The above outer hub may include a circular portion covering the second hole and an annular fastening portion protruding from the outer peripheral portion of the circular portion toward the inner hub and fastened to the outer peripheral surface of the second hole side of the annular wall portion.

[0024] A female screw may be formed on the inner surface of the above-mentioned fastening portion, and a male screw capable of being fastened with the female screw may be formed on the outer surface of the above-mentioned annular wall portion.

[0025] The outer hub may further include a tool groove into which a tool for rotating the outer hub is inserted.

[0026] The above tool groove can be formed in a hexagonal socket shape on the center side of the above disc portion.

[0027] The above outer hub may further include a stop bolt hole radially penetrating the fastening portion so that a stop bolt is inserted to prevent loosening of the fastening between the fastening portion and the annular wall portion.

[0028] The inner hub further includes an annular anti-slip guide portion that protrudes radially outward from the outer surface of the first hole side of the annular wall portion, and a hub bearing that rotatably supports the hub may be arranged between the fastening portion and the anti-slip guide portion.

[0029] The above hub bearing includes an inner ring that supports an outer circumference of the annular wall portion between the fastening portion and the anti-slip guide portion, an outer ring that receives the inner ring, and a ball interposed between the inner ring and the outer ring, and a preload can be applied by the inner ring being pressed by the fastening portion and the anti-slip guide portion.

[0030] If the axial distance between the second hole-side end face of the annular wall portion and the inner ring facing surface of the anti-slip guide portion is a first distance, the distance between the annular wall facing surface of the disc portion and the inner ring facing surface of the fastening portion is a second distance, and the axial distance of the inner ring is a third distance, a value obtained by subtracting the second distance from the first distance can be formed to be smaller than the third distance.

[0031] An axle device according to the present invention comprises: a shaft that receives power and rotates; an inner race that rotates together with the shaft; and a hub that is angularly connected to the inner race and connected to a wheel; wherein the hub includes a joint space that accommodates the inner race, a first hole that communicates the joint space with the outside so that the shaft extends from the inner race to the outside of the joint space, and a catcher portion that reduces the inner diameter of the first hole to be smaller than the outer diameter of the inner race, thereby suppressing a constant velocity joint lubricant for lubricating the inner race and the hub from leaking out to the outside of the joint space.

[0032] In addition, since the catcher portion prevents the inner race from coming off, there is no need to provide a separate coming off prevention part such as a stopper ring, so manufacturing costs can be reduced.

[0033] In addition, the hub includes an inner hub connected to the inner race and an outer hub connected to the inner hub and connected to the wheel, and the outer hub is formed to pressurize a hub bearing that rotatably supports the hub when the outer hub is connected to the inner hub, so that the preload applied to the hub bearing can be easily managed.

[0034] Fig. 1 is a cross-sectional view showing a conventional axle device;

[0035] Figure 2 is a cross-sectional view showing an axle device according to one embodiment of the present invention;

[0036] Figure 3 is a cross-sectional view showing part A before the connection between the inner hub and the outer hub in the axle device of Figure 2 is completed.

[0037] Fig. 4 is a perspective view showing the inner hub in the axle device of Fig. 2;

[0038] Fig. 5 is a perspective view showing the outer hub in the axle device of Fig. 2;

[0039] Figure 6 is a perspective view showing the back surface of Figure 5.

[0040] Hereinafter, the axle device according to the present invention will be described in detail with reference to the attached drawings.

[0041] FIG. 2 is a cross-sectional view illustrating an axle device according to one embodiment of the present invention, FIG. 3 is a cross-sectional view illustrating part A in the axle device of FIG. 2 before the connection between the inner hub and the outer hub is completed, FIG. 4 is a perspective view illustrating the inner hub in the axle device of FIG. 2, FIG. 5 is a perspective view illustrating the outer hub in the axle device of FIG. 2, and FIG. 6 is a perspective view illustrating the back of FIG. 5.

[0042] Referring to the attached drawings 2 to 6, an axle device according to one embodiment of the present invention may include a shaft (110) that receives power from a powertrain and rotates, an inner race (120) that rotates together with the shaft (110), a hub (140) that is articulatedly connected to the inner race (120) by a ball joint (130) and connected to a wheel (not shown), a hub bearing (150) that rotatably supports the hub (140), and a boot (160) that covers a connection portion between the inner race (120) and the hub (140).

[0043] The above hub (140) may include an inner hub (142) connected to the inner race (120) and an outer hub (144) connected to the inner hub (142) and connected to the wheel (not shown).

[0044] The inner hub (142) may include a joint space (S1) that accommodates the inner race (120) and an annular wall portion (142a) that forms the joint space (S1).

[0045] One opening of the annular wall portion (142a) can form a first hole (142b) that connects the joint space (S1) and the outside so that the shaft (110) extends from the inner race (120) to the outside of the joint space (S1) (more precisely, the inner space (S2) of the boot (160)).

[0046] In addition, the inner hub (142) may further include a catcher portion (142c) that reduces the inner diameter of the first hole (142b) to be smaller than the outer diameter of the inner race (120).

[0047] The catcher portion (142c) is formed in a ring shape that protrudes radially inward from the inner surface of the annular wall portion (142a) and may include a curved surface (142d) in which the distance to the rotational axis of the inner hub (142) decreases as it goes toward the first hole (142b) in the axial direction of the annular wall portion (142a), but the center of curvature is located in the joint space (S1).

[0048] Here, the rotation axis of the shaft (110) and the inner race (120) is referred to as the first rotation axis, the rotation axis of the hub (140) is referred to as the second rotation axis, and the angle between the first rotation axes when the first rotation axis is arranged coaxially with the second rotation axis (see FIG. 2) and when tilted with respect to the second rotation axis (not shown) is referred to as the angle of incline, the maximum angle of incline, which is the maximum value of the angle of incline, can be formed to be, for example, 20 degrees, and the catcher portion (142c) can be formed to reduce the inner diameter of the first hole (142b) to the smallest possible extent within a range where it does not come into contact with the shaft (110) at the maximum angle of incline.

[0049] However, since the inner diameter of the first hole (142b) is formed to be smaller than the outer diameter of the inner race (120), the inner race (120) cannot be inserted into the joint space (S1) through the first hole (142b). However, since the other side opening of the annular wall portion (142a) forms a second hole (142e) that is formed to be larger than or equal to the outer diameter of the inner race (120), the inner race (120) can be inserted into the joint space (S1) through the second hole (142e).

[0050] Meanwhile, to prevent the inner race (120) from being separated from the joint space (S1) through the second hole (142e), the outer hub (144) may include a disc portion (144a) covering the second hole (142e).

[0051] In addition, the outer hub (144) may further include an annular fastening portion (144b) that protrudes axially from the outer peripheral portion of the disc portion (144a) toward the inner hub (142) and is fastened to the outer peripheral surface of the second hole (142e) of the annular wall portion (142a).

[0052] Here, a female screw may be formed on the inner surface of the fastening portion (144b), and a male screw capable of screw fastening with the female screw may be formed on the outer surface of the annular wall portion (142a).

[0053] In addition, the outer hub (144) may further include a tool groove (144d) that is engraved from the wheel-facing surface (144ab) of the disc portion (144a) (the back surface of the annular wall portion facing surface (144aa)) and into which a tool (not shown) for rotating the outer hub (144) is inserted.

[0054] The tool groove (144d) may be formed, for example, in the shape of a hexagonal socket on the center side of the disc portion (144a).

[0055] In addition, the outer hub (144) may further include a stop bolt hole (144e) penetrating radially through the fastening portion (144b) so that a stop bolt (146) is inserted to prevent the fastening between the fastening portion (144b) and the annular wall portion (142a) from being loosened.

[0056] The above stop bolt (146) and the above stop bolt hole (144e) may be formed in four pieces each, for example, and may be arranged at equal intervals along the circumferential direction of the fastening portion (144b).

[0057] Meanwhile, the hub bearing (150) is arranged on the outer surface of the annular wall portion (142a), and the hub bearing (150) can receive preload when the inner hub (142) and the outer hub (144) are fastened to each other.

[0058] Specifically, the inner hub (142) further includes an annular anti-slip guide portion (142f) that protrudes radially outward from the outer surface of the first hole (142b) of the annular wall portion (142a), and the hub bearing (150) includes an inner ring (152) that supports the outer surface of the annular wall portion (142a) between the fastening portion (144b) and the anti-slip guide portion (142f), an outer ring (156) that accommodates the inner ring (152), and a ball (154) that is interposed between the inner ring (152) and the outer ring (156), so that when the outer hub (144) is fastened to the inner hub (142), the inner ring (152) is pressed by the fastening portion (144b) and the anti-slip guide portion (142f), thereby applying a preload to the hub bearing (150). Can be.

[0059] Here, even if the outer hub (144) is fastened as closely as possible to the inner hub (142) so that the gap (G1) between the second hole (142e) side end surface of the annular wall portion (142a) and the annular wall portion facing surface (144aa) of the disc portion (144a) becomes zero (0), the gap (G2) between the inner ring facing surface (144ba) of the fastening portion (144b) and the inner ring (152) is greater than zero (0), i.e., the case where no preload is applied to the hub bearing (150) is prevented from occurring, as shown in FIG. 3, the gap (G2) between the inner ring facing surface (144ba) of the fastening portion (144b) and the inner ring (152) is the gap between the second hole (142e) side end surface of the annular wall portion (142a) and the annular wall portion facing surface (144aa) of the disc portion (144a). It is necessary to form it smaller than the gap (G1) between the annular wall portion opposing surfaces (144aa). That is, if the axial distance between the second hole (142e) side end surface of the annular wall portion (142a) and the inner ring opposing surface (144ba) of the anti-slip guide portion (142f) is a first distance, the distance between the annular wall portion opposing surface (144aa) of the disc portion (144a) and the inner ring opposing surface (144ba) of the fastening portion (144b) is a second distance, and the axial distance of the inner ring (152) is a third distance, then the value obtained by subtracting the second distance from the first distance needs to be formed smaller than the third distance.

[0060] Meanwhile, the outer hub (144) may further include a wheel guide portion (144f) that guides the wheel (not shown) to a predetermined position and a flange portion (144c) that is connected to the wheel (not shown).

[0061] The above wheel guide portion (144f) is formed in a ring shape that protrudes from the disk portion (144a) to the opposite side of the fastening portion (144b), and the tool groove (144d) can be formed on the inner circumference of the wheel guide portion (144f).

[0062] The above flange portion (144c) is formed to protrude radially outward from the outer circumference of the above disc portion (144a), and may include a hub bolt hole (144ca) that penetrates the flange portion (144c) in the axial direction so that a hub bolt (not shown) for fastening the wheel (not shown) to the outer hub (144) is inserted.

[0063] The above hub bolts (not shown) and the above hub bolt holes (144ca) may be formed, for example, in five pieces each and arranged at equal intervals along the circumferential direction of the flange portion (144c).

[0064] The boot (160) may include a first end (162) that is fastened to the outer ring (156), a second end (166) into which the shaft (110) is inserted, and a wrinkled portion (164) that is arranged between the first end (162) and the second end (166).

[0065] Here, a shaft bearing (170) that rotatably supports the shaft (110) may be placed in the second end (166).

[0066] In the axle device according to this configuration, since the inner diameter of the first hole (142b) connecting the joint space (S1) and the inner space (S2) of the boot (160) is reduced by the catcher portion (142c), the constant velocity joint lubricant filled in the joint space (S1) to lubricate the inner race (120) and the hub (140) can be suppressed from flowing out into the inner space (S2) of the boot (160). Accordingly, the problem of the constant velocity joint lubricant running out in the joint space (S1) can be suppressed. In addition, the constant velocity joint lubricant is suppressed from flowing into the hub bearing (150) through the inner space (S2) of the boot (160), and the case where the hub bearing lubricant for lubricating the hub bearing (150) is mixed with the constant velocity joint lubricant having different physical properties and fails to exhibit lubricating performance can be suppressed.

[0067] And, since the catcher portion (142c) is formed in an annular shape protruding from the annular wall portion (142a) toward the center of the first hole (142b) and includes the curved surface (142d) whose center of curvature is located in the joint space (S1), the constant velocity joint lubricant flowing from the joint space (S1) toward the boot (160) is guided to the joint space (S1) by the catcher portion (142c) as shown by the arrow in FIG. 2, thereby further suppressing the outflow of the constant velocity joint lubricant from the joint space (S1).

[0068] And, as the inner diameter of the first hole (142b) is reduced to be smaller than the outer diameter of the inner race (120) by the catcher portion (142c), not only is the outflow of the constant velocity joint lubricant in the joint space (S1) further suppressed, but also the inner race (120) can be prevented from being separated toward the boot (160). Accordingly, there is no need to provide a conventional stopper ring, so the manufacturing cost can be reduced. Here, as the catcher portion (142c) is formed integrally with the hub (140) (more precisely, the annular wall portion (142a) of the inner hub (142), the structure can be simplified, manufacturing can be facilitated, and the cost can be reduced.

[0069] And, since the hub (140) includes the inner hub (142) and the outer hub (144), and the inner hub (142) includes the second hole (142e) having an inner diameter larger than the outer diameter of the inner race (120) as well as the first hole (142b) and the catcher portion (142c), and the outer hub (144) is formed to be fastened to the inner hub (142) and cover the second hole (142e), the inner race (120), which cannot be inserted into the joint space (S1) through the first hole (142b) by the catcher portion (142c), can be inserted into the joint space (S1) through the second hole (142e). Accordingly, it can be easy to assemble the inner race (120) and the shaft (110) to the hub (140). Additionally, the cost required for processing the above hub (140) can be reduced.

[0070] And, as the inner hub (142) and the outer hub (144) are formed to be screw-connected, not only is the assembly of the inner hub (142) and the outer hub (144) easy, but the preload applied to the hub bearing (150) can also be easily managed. That is, by rotating the outer hub (144) by a predetermined angle and screw-connecting the outer hub (144) and the inner hub (142), the preload applied to the hub bearing (150) can be easily managed to a desired level.

[0071] Here, since the hub bearing (150) is applied with a preload in a manner that it is compressed by the fastening portion (144b) and the anti-slip guide portion (142f) when the outer hub (144) and the inner hub (142) are screw-joined, rather than by a conventional complex orbital forming method, the preload applied to the hub bearing (150) can be easily and precisely managed.

[0072] And, since the outer hub (144) includes the tool groove (144d), the outer hub (144) can be easily rotated.

[0073] And, since the inner hub (142) and the outer hub (144) are fixed by the stop bolt (146) after being screw-connected, the screw connection between the inner hub (142) and the outer hub (144) can be prevented from being loosened due to rotation of the hub (140), etc. Here, the stop bolt (146) can more reliably prevent the screw connection between the inner hub (142) and the outer hub (144) from being loosened by damaging the threads of the male screw of the inner hub (142).

[0074] Meanwhile, since the hub (140) includes the function of the outer race of the constant velocity joint, the number of parts of the axle device can be reduced, the length of the axle device in the direction of the rotation axis can be reduced, the manufacturing process can be reduced, and the cost and weight of the axle device can be reduced. In addition, since the center of the angle of the constant velocity joint is located within the range of the hub bearing (150), the time difference between the point in time when power is transmitted to the constant velocity joint and the point in time when the hub (140) rotates can be reduced. Accordingly, power transmission loss can be reduced, and the responsiveness of the vehicle can be improved.

Claims

1. A shaft (110) that rotates by receiving power; An inner race (120) that rotates together with the above shaft (110); and It includes a hub (140) connected to the wheel while being articulated and connected to the inner race (120); The above hub (140) is an axle device including a joint space (S1) that accommodates the inner race (120), a first hole (142b) that connects the joint space (S1) with the outside so that the shaft (110) extends from the inner race (120) to the outside of the joint space (S1), and a catcher portion (142c) that reduces the inner diameter of the first hole (142b) to be smaller than the outer diameter of the inner race (120).

2. In paragraph 1, The above catcher portion (142c) is an axle device formed in a ring shape that protrudes radially inward from the ring wall portion (142a) forming the above joint space (S1).

3. In paragraph 2, The above catcher part (142c) is an axle device formed integrally with the above annular wall part (142a).

4. In paragraph 1, The above catcher portion (142c) is an axle device including a curved surface (142d) whose center of curvature is located in the joint space (S1).

5. In paragraph 1, The above hub (140) is an axle device including an inner hub (142) connected to the inner race (120) and an outer hub (144) connected to the inner hub (142) and connected to the wheel.

6. In paragraph 5, An axle device in which the inner hub (142) includes an annular wall portion (142a) forming the joint space (S1), one opening of the annular wall portion (142a) forms the first hole (142b), and the other opening of the annular wall portion (142a) forms a second hole (142e) into which the inner race (120) can be inserted.

7. In paragraph 6, An axle device in which the inner diameter of the second hole (142e) is formed to be greater than or equal to the outer diameter of the inner race (120).

8. In paragraph 6, The outer hub (144) is an axle device including a circular plate portion (144a) covering the second hole (142e) and an annular fastening portion (144b) protruding from the outer peripheral portion of the circular plate portion (144a) toward the inner hub (142) and fastened to the outer peripheral surface of the second hole (142e) side of the annular wall portion (142a).

9. In paragraph 8, An axle device in which a female screw is formed on the inner surface of the above-mentioned fastening portion (144b), and a male screw capable of being fastened with the female screw is formed on the outer surface of the above-mentioned annular wall portion (142a).

10. In paragraph 9, An axle device in which the outer hub (144) further includes a tool groove (144d) into which a tool for rotating the outer hub (144) is inserted.

11. In paragraph 10, The above tool groove (144d) is an axle device formed in the shape of a hexagonal socket on the center side of the above disc portion (144a).

12. In paragraph 8, An axle device in which the outer hub (144) further includes a stop bolt hole (144e) penetrating radially through the fastening portion (144b) so that a stop bolt (146) is inserted to prevent loosening of the fastening between the fastening portion (144b) and the annular wall portion (142a).

13. In paragraph 8, An axle device in which the inner hub (142) further includes an annular anti-slip guide portion (142f) that protrudes radially outward from the outer surface of the first hole (142b) of the annular wall portion (142a), and a hub bearing (150) that rotatably supports the hub (140) is arranged between the fastening portion (144b) and the anti-slip guide portion (142f).

14. In paragraph 13, The above hub bearing (150) includes an inner ring (152) that supports the outer surface of the annular wall portion (142a) between the fastening portion (144b) and the anti-slip guide portion (142f), an outer ring (156) that accommodates the inner ring (152), and a ball (154) that is interposed between the inner ring (152) and the outer ring (156), and an axle device in which a preload is applied by the inner ring (152) being pressed by the fastening portion (144b) and the anti-slip guide portion (142f).

15. In paragraph 14, An axle device in which an axial distance between a second hole (142e) side end face of the annular wall portion (142a) and an inner ring facing surface (144ba) of the anti-slip guide portion (142f) is a first distance, a distance between an annular wall facing surface (144aa) of the disc portion (144a) and an inner ring facing surface (144ba) of the fastening portion (144b) is a second distance, and an axial distance of the inner ring (152) is a third distance, a value obtained by subtracting the second distance from the first distance is formed to be smaller than the third distance.

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