Bearing device for wheel and vehicle

Abstract

Provided is a wheel bearing device capable of suppressing the occurrence of abnormal noise and suppressing an increase in weight. In a bearing device (1) for a wheel, the ratio of the axial length (C) of a recess (3h) of a through hole (3e) formed in a hub ring (3) to the pitch diameter (A) of the recess (3h) formed in the inner peripheral surface of the hub ring (3) is 0.7 < = (C / A) < = 1.07. The ratio of the axial distance (E) between the flange surface (3j) of the wheel attachment flange (3b) and the inner-side end surface (4b) of the inner ring (4) to the pitch (F) between the balls of the inner-side ball row (5) and the outer-side ball row (6) is 2.85 < = (E / F), and the ratio of the axial distance (E) to the pitch diameter (D) of the balls (8) is 0.8 < = (E / D) < = 0.94.

Description

Technical Field

[0001] The present invention relates to a wheel bearing device and a vehicle. Background Art

[0002] Conventionally, as disclosed in Patent Document 1, there is known a wheel bearing device, which includes: a wheel bearing that rotatably supports a wheel in a suspension device of a motor vehicle or the like; and a constant velocity universal joint that is coupled to the wheel bearing in a torque-transmittable manner. In such a wheel bearing device, the wheel bearing is coupled to the constant velocity universal joint by spline-fitting an outer coupling member of the constant velocity universal joint with an inner diameter portion of a hub ring constituting the wheel bearing.

[0003] The driving force from the driving source of the vehicle is input to the constant velocity universal joint. In recent years, there is a tendency that electric vehicles using motors as a driving source in addition to vehicles using engines as a driving source are increasing.

[0004] The driving torque from the motor of an electric vehicle is input to the constant velocity universal joint instantaneously compared to the driving torque from the engine, so relative sliding occurs rapidly between the inner ring of the wheel bearing and the abutting surface of the constant velocity universal joint relative to the inner ring, sometimes causing abnormal noise caused by stick-slip, commonly known as clicking or crackling.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 3650746 Summary of the invention

[0008] Problems to be solved by the invention

[0009] In order to suppress the generation of abnormal noise caused by the sliding between the wheel bearing and the constant velocity universal joint, grease is applied between the inner ring of the wheel bearing and the contact surface of the constant velocity universal joint relative to the inner ring, or lubricant is applied to the contact surface of the constant velocity universal joint relative to the inner ring, or a plate coated with a low-friction coating agent is clamped between the inner ring of the wheel bearing and the contact surface of the constant velocity universal joint relative to the inner ring. However, it is difficult to fully suppress the generation of abnormal noise caused by the driving torque of the instantaneous load from the motor.

[0010] In addition, in order to suppress the generation of abnormal noise caused by the sliding between the wheel bearing and the constant velocity universal joint, it is considered to increase the fitting diameter of the spline fitting of the wheel bearing and the constant velocity universal joint according to the magnitude of the driving torque loaded by the constant velocity universal joint. However, if only the fitting diameter of the wheel bearing and the constant velocity universal joint is increased, there is a problem that the weight of the wheel bearing and the constant velocity universal joint increases.

[0011] The present invention has been made in view of the above-mentioned circumstances, and provides a wheel bearing device and a vehicle capable of suppressing the generation of abnormal noise and suppressing an increase in weight.

[0012] Means for solving problems

[0013] That is, a wheel bearing device, which comprises: a wheel bearing, which includes: an outer member, which has a double-row outer raceway surface on its inner circumference; an inner member, which is composed of a hub ring and at least one inner ring of a small-diameter step portion pressed into the hub ring, and has a double-row inner raceway surface opposite to the double-row outer raceway surface, the hub ring has a wheel mounting flange at one axial end for mounting a wheel, and the hub ring has a small-diameter step portion extending axially on the outer circumference and a through hole penetrating axially on the inner diameter portion; and double-row rolling elements, which are accommodated between the two raceway surfaces of the outer member and the inner member in a manner that allows them to roll freely; and a constant velocity universal joint, which has a fitting portion that can be fitted into the through hole of the hub ring. , characterized in that a recess extending in the axial direction is formed on the inner peripheral surface of the through hole of the hub ring, and a convex portion extending in the axial direction and spline-engaged with the recess is formed on the outer peripheral surface of the fitting portion of the constant velocity universal joint, the ratio of the axial length C of the recess to the pitch circle diameter A of the recess is 0.7≤(C / A)≤1.07, the ratio of the axial distance E between the flange surface of the wheel mounting flange and the axial other end side surface of the inner ring to the spacing F between the rolling elements on one axial side and the rolling elements on the other axial side of the double-row rolling elements is 2.85≤(E / F), and the ratio of the axial distance E to the pitch circle diameter D of the double-row rolling elements is 0.8≤(E / D)≤0.94.

[0014] Effects of the Invention

[0015] According to the present invention, it is possible to suppress the generation of abnormal noise and to suppress the increase in weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a side sectional view showing a wheel bearing device.

[0017] Figure 2 It is a side sectional view showing the shaft hole of the hub wheel and the rod portion of the outer coupling member.

[0018] Figure 3 This is an axial cross-sectional view showing the concave portion in the shaft hole of the hub wheel and the convex portion of the stem portion.

[0019] Figure 4 It is a side sectional view of the wheel bearing device showing a state in which the shaft has rotated to the maximum angle.

[0020] Figure 5 It is a side cross-sectional view showing a wheel bearing device according to a second embodiment.

[0021] Figure 6 It is a side sectional view showing a wheel bearing device according to a third embodiment.

[0022] Figure 7 It is a side sectional view showing a wheel bearing device according to a fourth embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, a mode for carrying out the present invention will be described using the drawings.

[0024] [Wheel bearing device]

[0025] Figure 1 The wheel bearing device 1 shown is one embodiment of the wheel bearing device of the present invention, and includes a wheel bearing 10 and a constant velocity universal joint 20 .

[0026] In the following description, the axial direction refers to the direction along the rotation axis X of the wheel bearing 10. In addition, the outer side refers to one side in the axial direction and is the wheel side of the wheel bearing device 1 when installed on the vehicle body, and the inner side refers to the other side in the axial direction and is the vehicle body side of the wheel bearing device 1 when installed on the vehicle body.

[0027] (Wheel bearings)

[0028] The wheel bearing 10 rotatably supports a wheel in a suspension device of a vehicle such as an automobile. The wheel bearing 10 includes an outer ring 2 as an outer member, a hub ring 3 and an inner ring 4 as inner members, an inner ball row 5 and an outer ball row 6 as two rolling rows, an inner seal member 9A, and an outer seal member 9B.

[0029] An inner opening 2a into which the inner sealing member 9A can be fitted is formed at the inner end of the outer ring 2. An outer opening 2b into which the outer sealing member 9B can be fitted is formed at the outer end of the outer ring 2.

[0030] The inner sealing member 9A is fitted into the inner opening 2a, thereby sealing the inner opening end of the annular space 15 formed by the outer ring 2 and the inner member. The outer sealing member 9B is fitted into the outer opening 2b, thereby sealing the outer opening end of the annular space 15.

[0031] The inner peripheral surface of the outer ring 2 is formed with an inner outer raceway surface 2c and an outer outer raceway surface 2d. The outer peripheral surface 2o of the outer ring 2 is integrally formed with a vehicle body mounting flange 2e for mounting the outer ring 2 to a vehicle body side member (steering knuckle). The vehicle body mounting flange 2e is provided with a bolt hole 2f through which a fastening member for fastening the vehicle body side member to the outer ring 2 is inserted.

[0032] A small-diameter step portion 3a is formed at the inner end of the outer peripheral surface 3o of the hub ring 3. A wheel mounting flange 3b for mounting a wheel is integrally formed at the outer end of the hub ring 3. Bolt holes 3f are provided in the wheel mounting flange 3b for press-fitting hub bolts 3g.

[0033] The wheel mounting flange 3b has a flange surface 3j with which a brake disc mounted on the wheel mounting flange 3b comes into contact. The flange surface 3j is a surface on the outer side of the wheel mounting flange 3b.

[0034] The hub 3 has an inner raceway surface 3c formed outside so as to face the outer raceway surface 2d outside the outer ring 2. In addition, the hub 3 has a lip sliding surface 3d formed on the base side of the wheel mounting flange 3b with which the outer seal member 9B slides.

[0035] The inner diameter portion of the hub ring 3 is formed with an axial hole 3e formed along the axial direction and connected to the constant velocity universal joint 20. The axial hole 3e penetrates the hub ring 3 in the axial direction. The axial hole 3e is an example of a through hole. The inner ring 4 is pressed into the small diameter step portion 3a of the hub ring 3. The inner ring 4 has an inner side end face 4b at the inner side end portion. The inner side end face 4b is an example of the axial other end side face of the inner ring.

[0036] An inner raceway surface 4a is formed on the outer circumferential surface of the inner race 4. In other words, the inner raceway surface 4a is formed by the inner race 4 on the inner side of the hub wheel 3. The inner raceway surface 4a faces the outer raceway surface 2c on the inner side of the outer race 2.

[0037] The inner ball row 5 and the outer ball row 6 as rolling rows are formed by holding a plurality of balls 7 as rolling bodies by a retainer 8. The inner ball row 5 is freely rollably sandwiched between the inner raceway surface 4a of the inner ring 4 and the outer raceway surface 2c on the inner side of the outer ring 2. The outer ball row 6 is freely rollably sandwiched between the inner raceway surface 3c of the hub ring 3 and the outer raceway surface 2d on the outer side of the outer ring 2. The inner ring 4 applies preload to the inner ball row 5 and the outer ball row 6 as rolling rows.

[0038] In the wheel bearing 10, a double row angular contact ball bearing is formed by the outer ring 2, the hub ring 3, the inner ring 4, the inner ball row 5, and the outer ball row 6. It should be noted that the wheel bearing 10 may also be formed by a double row tapered roller bearing.

[0039] (Constant velocity universal coupling)

[0040] The constant velocity universal joint 20 comprises: an outer coupling member 21 having a rolling groove 25 formed on its inner circumferential surface; an inner coupling member 22 having a rolling groove 22a formed on its outer circumferential surface opposite to the rolling groove 25; balls 23 assembled between the rolling groove 25 and the rolling groove 22a; and a retaining frame 24 sandwiched between the inner circumferential surface of the outer coupling member 21 and the outer circumferential surface of the inner coupling member 22 and retaining the balls 23.

[0041] The outer coupling member 21 has a mouth portion 26 that accommodates the inner coupling member 22, the balls 23, and the retainer 24, and a rod portion 27 that integrally extends from the mouth portion 26 toward the outer side in the axial direction. The mouth portion 26 has a contact surface 26a that contacts the inner side end surface 4b of the inner ring 4 at the outer side end portion.

[0042] The shaft end of the shaft 31 to which the driving force from the driving source such as the engine and the motor is input is pressed into the inner coupling member 22. The inner coupling member 22 and the shaft 31 are connected by spline fitting so as to transmit torque. The mouth 26 of the outer coupling member 21 supports the shaft 31 rotatably relative to the rotation axis X via the inner coupling member 22, the balls 23 and the retainer 24.

[0043] [Matching structure between the hub and the stem]

[0044] like Figure 2 , Figure 3 As shown, a recess 3h extending in the axial direction is formed on the inner peripheral surface of the shaft hole 3e of the hub ring 3. A plurality of recesses 3h are formed in the circumferential direction. A convex portion 28 extending in the axial direction and spline-engaged with the recess 3h is formed on the outer peripheral surface of the rod portion 27 of the outer coupling member 21. A plurality of convex portions 28 are formed in the circumferential direction. The inner spline is formed by the plurality of recesses 3h formed in the circumferential direction, and the outer spline is formed by the plurality of convex portions 28 formed in the circumferential direction. The rod portion 27 of the outer coupling member 21 is an example of a fitting portion that can be fitted with the through hole of the hub ring.

[0045] The recessed portion 3h of the shaft hole 3e may be formed to have a smaller diameter than the convex portion 28 of the rod portion 27. In this case, the recessed portion 3h has an interference n with the convex portion 28, and the convex portion 28 is pressed into the recessed portion 3h.

[0046] The rod 27 has an external threaded portion 27a on the outer side of the convex portion 28, and the hub ring 3 and the outer coupling member 21 are fixed in a state where the rod 27 is fitted into the shaft hole 3e by screwing the nut 41 into the external threaded portion 27a. By screwing the nut 41 into the external threaded portion 27a, the inner ring 4 can be pressed axially by the abutment surface 26a of the outer coupling member 21, thereby applying preload to the inner side ball row 5 and the outer side ball row 6.

[0047] When the rod 27 is fitted into the shaft hole 3e, if the rod 27 is moved from the inside to the outside of the shaft hole 3e, the recess 3h is formed to have a diameter smaller than that of the protrusion 28 and has an interference n relative to the protrusion 28, so that the protrusion 28 is pressed into the recess 3h.

[0048] When the convex portion 28 is pressed into the concave portion 3h, the inner peripheral surface of the concave portion 3h is minutely cut by the convex portion 28, and the shape of the convex portion 28 is transferred to the inner peripheral surface of the concave portion 3h with minute plastic deformation and elastic deformation.

[0049] When the convex portion 28 is pressed into the concave portion 3h, a spline-fitted fitting contact area Y between the concave portion 3h and the convex portion 28 is formed (see Figure 1 ). At the fitting contact portion Y, the outer peripheral surface of the protrusion 28 and the inner peripheral surface of the recess 3h are in close contact as a whole.

[0050] In this way, the concave portion 3h is spline-fitted with the convex portion 28 in a state of having an interference n, and the spline-fitted concave portion 3h and the convex portion 28 are in close contact with each other in the axial direction. Since the convex portion 28 and the concave portion 3h are in close contact with each other at the fitting contact portion Y, the allowable torque at the fitting contact portion Y can be increased, and the axial length of the fitting contact portion Y can be shortened to achieve the weight reduction of the wheel bearing 10.

[0051] [Relationship between dimensions of various parts in a wheel bearing device]

[0052] In the wheel bearing device 1 , the pitch diameter of the spline formed by the recessed portion 3 h and the convex portion 28 that fit together is A. The pitch diameter A of the spline is both the pitch diameter A of the recessed portion 3 h and the pitch diameter A of the convex portion 28 .

[0053] The axial length of the protrusion 28 of the rod portion 27 is B, and the axial length of the recess 3h of the shaft hole 3e is C. The axial distance E between the flange surface 3j of the wheel mounting flange 3b and the inner side end surface 4b of the inner ring 4 is.

[0054] The pitch circle diameter of the balls 8 constituting the inner ball row 5 and the pitch circle diameter of the balls 8 constituting the outer ball row 6 are formed to be the same size, and the pitch circle diameter of the balls 8 constituting the inner ball row 5 and the outer ball row 6 is D. The pitch circle diameter D is the diameter of a circle centered on the rotation axis X and passing through the center P of the balls 8 in the inner ball rows 5 and 6. The pitch circle diameter D of the balls 8 is an example of the pitch circle diameter D of the rolling element.

[0055] The balls 8 constituting the inner ball row 5 and the balls 8 constituting the outer ball row 6 are arranged so that the spacing between the balls in the axial direction is F. The spacing F between the balls is the distance in the axial direction between the center P of the balls 8 in the inner ball row 5 and the center P of the balls 8 in the outer ball row 6. The spacing F between the balls is an example of the spacing F between the rolling elements.

[0056] In the wheel bearing device 1 , the ratio of the axial length C of the recessed portion 3 h to the pitch circle diameter A of the recessed portion 3 h is set to 0.7≦(C / A)≦1.07.

[0057] In a conventional wheel bearing device, the ratio of the axial length B of the protrusion 28 to the pitch circle diameter A of the recess 3h is about 1.1≤(B / A)≤1.9, and the ratio of the axial length C of the recess 3h to the pitch circle diameter A of the recess 3h is about 1.25≤(C / A)≤1.8.

[0058] In contrast, in a wheel bearing device 1 in which the ratio of the axial length C of the recess 3h to the pitch circle diameter A of the recess 3h is 0.7≤(C / A)≤1.07 as in the present embodiment, the diameters of the axial hole 3e having the recess 3h and the rod portion 27 having the protrusion 28 are formed larger, and the axial length C of the recess 3h and the axial length B of the protrusion 28 are formed smaller, compared with conventional wheel bearing devices.

[0059] The convex portion 28 of the rod portion 27 twists in the rotational direction when the constant velocity universal joint 20 is loaded with a driving torque, but the twisting amount of the convex portion 28 increases as the length of the rod portion 27 increases, and is therefore proportional to the axial length B of the convex portion 28. In addition, the twisting amount of the convex portion 28 increases as the diameter of the rod portion 27 increases, and thus is inversely proportional to the pitch circle diameter A of the convex portion 28.

[0060] Furthermore, when the constant velocity universal joint 20 is loaded with a driving torque, relative sliding in the rotational direction occurs between the inner side end surface 4b of the inner ring 4 of the wheel bearing 10 and the abutment surface 26a of the mouth 26 of the constant velocity universal joint 20. In this case, when the amount of torsion of the convex portion 28 of the rod portion 27 decreases, the relative sliding amount between the inner side end surface 4b of the inner ring 4 and the abutment surface 26a of the mouth 26 decreases.

[0061] Therefore, by forming the diameter of the rod portion 27 to be larger and the axial length C of the recess 3h to be smaller, and setting the ratio of the axial length C of the recess 3h to the pitch circle diameter A of the recess 3h to be in the range of 0.7≤(C / A)≤1.07, the relative sliding amount between the inner side end surface 4b and the abutment surface 26a of the mouth portion 26 can be reduced, thereby suppressing the generation of abnormal noise caused by stick-slip.

[0062] Here, the convex portion 28 of the rod portion 27 is usually given a torsion angle of about 10 to 30 minutes relative to the axial direction to prevent shaking when splined with the concave portion 3h of the hub 3. Therefore, in the conventional wheel bearing device, there is a portion with a gap between the splined convex portion 28 and the concave portion 3h. For example, when the surface on one side of the rotation direction at one axial end of the convex portion 28 contacts the concave portion 3h, there is a gap between the surface on one side of the rotation direction at the other axial end of the convex portion 28 and the concave portion 3h. In addition, when the surface on the other side of the rotation direction at the other axial end of the convex portion 28 contacts the concave portion 3h, there is a gap between the surface on the other side of the rotation direction at one axial end of the convex portion 28 and the concave portion 3h.

[0063] Furthermore, the torsional direction of the protrusion 28 is unified in the same type of wheel bearing device 1, so when the wheel bearing device 1 is used for left and right wheels in a vehicle, the torsional direction of the protrusion 28 and the direction of the driving torque loaded by the rod 27 are different in the left and right wheels.

[0064] Therefore, when the rod 27 is loaded with driving torque, the relative slip amount in the rotational direction between the inner side end face 4b of the inner ring 4 and the abutment face 26a of the mouth 26 is greatly different between the left and right wheels, and the possibility of abnormal noise caused by stick-slip in the wheel on the side with larger slip amount becomes higher.

[0065] However, in the wheel bearing device 1, the ratio of the axial length C of the recess 3h to the pitch circle diameter A of the recess 3h is set in the range of 0.7≤(C / A)≤1.07, and the relative sliding amount in the rotational direction between the inner side end face 4b and the abutment surface 26a of the mouth 26 is suppressed to a small amount. Therefore, even the wheel on the side with a large sliding amount can suppress the generation of abnormal noise caused by stick-slip.

[0066] In addition, if the diameter of the rod portion 27 is increased and the pitch circle diameter A of the convex portion 28 is formed to be larger, the stress applied to the tooth surface of the convex portion 28 and the concave portion 3h when the rod portion 27 is loaded with driving torque is reduced, so the axial length B of the convex portion 28 and the axial length C of the concave portion 3h can be formed to be smaller, thereby reducing the axial length of the wheel bearing 10.

[0067] Therefore, in the wheel bearing device 1, the pitch F between the balls is formed to be smaller in such a manner that the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the pitch F between the balls is 2.85≤(E / F), thereby reducing the axial length of the wheel bearing 10. In this way, by reducing the axial length of the wheel bearing 10, the wheel bearing 10 can be made lighter.

[0068] In addition, in the wheel bearing device 1, the axial distance E between the flange surface 3j and the inner side end surface 4b is formed to be small in such a manner that the ratio of the axial distance E to the pitch circle diameter D of the ball 8 becomes 0.8≤(E / D)≤0.94, thereby reducing the axial length of the wheel bearing 10. In this way, by reducing the axial length of the wheel bearing 10, the weight of the wheel bearing 10 can be reduced.

[0069] In this way, in the wheel bearing device 1, the ratio of the axial length C of the recess 3h to the pitch circle diameter A of the recess 3h is set to a range of 0.7≤(C / A)≤1.07, the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the spacing F between the balls is set to a range of 2.85≤(E / F), and the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the pitch circle diameter D of the ball 8 is set to a range of 0.8≤(E / D)≤0.94, which can suppress the generation of abnormal noise caused by stick-slip and suppress the increase in weight.

[0070] Furthermore, in the wheel bearing device 1, the spline-engaged recessed portion 3h and the convex portion 28 are spline-engaged with an interference fit n and are tightly fitted as a whole in the axial direction. Therefore, compared with the case where the spline is engaged in a state where they are not tightly fitted as a whole, the stress resistance of the rod portion 27 when the driving torque is loaded is improved.

[0071] Therefore, the axial length B of the convex portion 28 is formed to be small so that the ratio of the axial length B of the convex portion 28 to the pitch circle diameter A of the concave portion 3h becomes 0.32≤(B / A)≤0.6, thereby reducing the axial length of the wheel bearing 10. In this way, by reducing the axial length of the wheel bearing 10, the weight of the wheel bearing 10 can be reduced.

[0072] It should be noted that, in the wheel bearing device 1, even when the spline-engaged recess 3h and the protrusion 28 are not in close contact as a whole, the ratio of the axial length C of the recess 3h to the pitch circle diameter A of the recess 3h is set to a range of 0.7≤(C / A)≤1.07, the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the spacing F between the balls is set to a range of 2.85≤(E / F), and the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the pitch circle diameter D of the ball 8 is set to a range of 0.8≤(E / D)≤0.94, thereby suppressing the generation of abnormal noise caused by stick-slip and suppressing the increase in weight.

[0073] In the wheel bearing device 1, the shaft diameter of the shaft 31 in the constant velocity universal joint 20 is G. Figure 4 As shown, the shaft 31 can rotate relative to the mouth 26 within a range R in which the shaft 31 contacts the mouth 26, and when the shaft 31 is rotated relative to the mouth 26 by a maximum angle, the contact point 31a of the shaft 31 contacts the mouth 26. The shaft diameter G is the shaft diameter of the portion of the shaft 31 including the contact point 31a, and is the minimum shaft diameter of the shaft 31.

[0074] The size of the rod 27 of the constant velocity universal joint 20 and the shaft diameter G of the shaft 31 are preferably determined based on the size of the driving torque loaded from a driving source such as a motor, but in the constant velocity universal joint 20 splined with the wheel bearing 10, the pitch circle diameter A of the convex portion 28 in the rod 27 and the shaft diameter G of the shaft 31 are set so that the ratio of the pitch circle diameter A of the convex portion 28 to the shaft diameter G is 1.1≤(A / G)≤1.41.

[0075] This ensures that the shaft diameter G of the shaft 31 required in the wheel bearing device 1 is sufficient, and that the safety factor for the driving torque applied to the constant velocity universal joint 20 and the torsional rigidity of the shaft 31 are sufficient.

[0076] [Second Embodiment of Wheel Bearing Device]

[0077] The wheel bearing device 1 can also be configured as the wheel bearing device 1A of the second embodiment. Figure 5 As shown, the wheel bearing device 1A is different from the wheel bearing device 1 in that a wheel bearing 10A having a hub wheel 3A is provided instead of the wheel bearing 10 having the hub wheel 3 .

[0078] In the wheel bearing 10A, the inner ring 4 pressed into the small-diameter step portion 3a of the hub ring 3A is fixed by being riveted by the hub ring 3A, and the hub ring 3A has a riveting portion 3k for riveting the inner side end face 4b of the inner ring 4. The inner ring 4 is riveted by the riveting portion 3k, thereby applying preload to the inner side ball row 5 and the outer side ball row 6.

[0079] In the wheel bearing 10A, the caulking portion 3k of the hub 3A abuts against the abutting surface 26a of the mouth 26. The other structures of the wheel bearing 10A and the hub 3A are the same as those of the wheel bearing 10 and the hub 3, and thus the same reference numerals are used and the description thereof is omitted.

[0080] In a structure where the inner ring 4 is riveted by the rivet portion 3k as in the wheel bearing 10A, since preload is applied by riveting the inner ring 4, it is not necessary to apply preload by pressing the inner ring 4 by the axial force when the nut 41 is screwed onto the external threaded portion 27a of the rod portion 27.

[0081] Therefore, when the nut 41 is screwed onto the external threaded portion 27a, it is not necessary to generate a large axial force, and the contact pressure between the rivet portion 3k of the hub 3A and the contact surface 26a of the mouth portion 26 can be reduced. By reducing the contact pressure between the rivet portion 3k and the contact surface 26a, it is possible to suppress the occurrence of stick-slip between the rivet portion 3k and the contact surface 26a, and to suppress the occurrence of abnormal noise caused by stick-slip.

[0082] In the wheel bearing device 1A, the ratio of the axial length C of the recess 3h to the pitch circle diameter A of the recess 3h can be set to a range of 0.7≤(C / A)≤1.07, the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the spacing F between the balls can be set to a range of 2.85≤(E / F), and the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the pitch circle diameter D of the ball 8 can be set to a range of 0.8≤(E / D)≤0.94. Thus, the generation of abnormal noise due to stick-slip can be further suppressed, and the increase in weight can be suppressed.

[0083] In the wheel bearing device 1A, the ratio of the axial length B of the protrusion 28 to the pitch circle diameter A of the recess 3h can be set to 0.32≤(B / A)≤0.6. This can suppress the occurrence of abnormal noise due to stick-slip and achieve weight reduction of the wheel bearing 10.

[0084] Furthermore, in the wheel bearing device 1A, the ratio of the pitch diameter A of the convex portion 28 to the shaft diameter G can also be set to 1.1≤(A / G)≤1.41. Thus, in the wheel bearing device 1A, the generation of abnormal noise due to stick-slip can be further suppressed, and the safety factor of the driving torque loaded by the constant velocity universal joint 20 and the torsional rigidity of the shaft 31 can be ensured.

[0085] [Third Embodiment of Wheel Bearing Device]

[0086] The wheel bearing device 1A can also be configured like the wheel bearing device 1B of the third embodiment. Figure 6As shown, the wheel bearing device 1B is different from the wheel bearing device 1A in that a wheel bearing device 10B having a hub wheel 3B is provided instead of the wheel bearing device 10A having the hub wheel 3A.

[0087] The difference between the hub 3B and the hub 3A is that the hub 3B has a wheel mounting flange 3m with screw holes 3n instead of the wheel mounting flange 3b with bolt holes 3f. The screw holes 3n are holes for screwing the wheel rim bolts used to fix the wheel rim and brake disc assembled to the wheel mounting flange 3m. The axial thickness of the wheel mounting flange 3m is H.

[0088] In the wheel bearing 10B, the hub ring 3B has a wheel mounting flange 3m having screw holes 3n for the wheel ring bolts to be screwed into, instead of the wheel mounting flange 3b having bolt holes 3f for the hub bolts 3g to be pressed into, thereby making it possible to increase the diameter of the outer ring 2. Thus, when the axial length of the wheel bearing 10B is reduced, the outer diameter of the outer ring 2 can be formed larger, thereby ensuring the life of the wheel bearing 10B.

[0089] The other structures of the wheel bearing 10B and the hub wheel 3B are the same as those of the wheel bearing 10A and the hub wheel 3A, and thus the same reference numerals are used and the description thereof is omitted.

[0090] In the wheel bearing device 1B, the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the axial thickness H of the wheel mounting flange 3m is set to 4.5≤(E / H)≤5.6. By setting in this way, even when the axial distance E in the wheel bearing device 1B is set to be small, the thickness H of the wheel mounting flange 3m can be ensured.

[0091] In the wheel bearing device 1B, the ratio of the axial length C of the recess 3h to the pitch circle diameter A of the recess 3h can be set to a range of 0.7≤(C / A)≤1.07, the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the spacing F between the balls can be set to a range of 2.85≤(E / F), and the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the pitch circle diameter D of the ball 8 can be set to a range of 0.8≤(E / D)≤0.94. Thus, the generation of abnormal noise caused by stick-slip can be further suppressed, and the increase in weight can be suppressed.

[0092] In the wheel bearing device 1B, the ratio of the axial length B of the protrusion 28 to the pitch circle diameter A of the recess 3h can be set to 0.32≤(B / A)≤0.6. This can suppress the occurrence of abnormal noise due to stick-slip and achieve weight reduction of the wheel bearing 10.

[0093] Furthermore, in the wheel bearing device 1B, the ratio of the pitch diameter A of the convex portion 28 to the shaft diameter G can also be set to 1.1≤(A / G)≤1.41. Thus, in the wheel bearing device 1B, the generation of abnormal noise due to stick-slip can be further suppressed, and the safety factor of the driving torque loaded by the constant velocity universal joint 20 and the torsional rigidity of the shaft 31 can be ensured.

[0094] [Fourth Embodiment of Wheel Bearing Device]

[0095] The wheel bearing device 1B can also be configured like the wheel bearing device 1C of the fourth embodiment. Figure 7 As shown, the wheel bearing device 1C is different from the wheel bearing device 1B in that a constant velocity universal joint 20A having a rod portion 27A is provided instead of the constant velocity universal joint 20 having the rod portion 27 .

[0096] The rod 27A has an internal threaded portion 27b formed from the outer side toward the inner side, and the bolt 42 is screwed into the internal threaded portion 27b, so that the hub 3B and the constant velocity universal joint 20A are fastened together in a state where the rod 27A is fitted into the shaft hole 3e. Thus, the wheel bearing 10B and the constant velocity universal joint 20A are fixed.

[0097] The outer side end of the shaft hole 3e in the hub ring 3B is formed with a surface perpendicular to the rotation axis X, which is the axis of the shaft hole 3e, i.e., a stop surface 3p. In the present embodiment, the bolt 42 is stopped on the stop surface 3p of the hub ring 3B via the washer 43, but as long as the axial force required when the bolt 42 is screwed to the internal threaded portion 27b can be obtained, the bolt 42 may be directly stopped on the stop surface 3p without the washer 43.

[0098] In this embodiment, the locking surface 3p is formed on a surface perpendicular to the axis of the axial hole 3e, so that the axial force required when the bolt 42 is screwed into the internal threaded portion 27b can be obtained, and the wheel bearing 10B and the constant velocity universal joint 20A can be stably maintained in a fixed state.

[0099] The other structures of the constant velocity universal joint 20A and the rod portion 27A are the same as those of the constant velocity universal joint 20 and the rod portion 27 , and thus the same reference numerals are used and the description thereof is omitted.

[0100] In the wheel bearing device 1C, the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the axial thickness H of the wheel mounting flange 3m can be set to 4.5≤(E / H)≤5.6. Thus, even when the axial distance E in the wheel bearing device 1C is set small, the thickness H of the wheel mounting flange 3m can be ensured.

[0101] In the wheel bearing device 1C, the ratio of the axial length C of the recess 3h to the pitch circle diameter A of the recess 3h can be set to a range of 0.7≤(C / A)≤1.07, the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the spacing F between the balls can be set to a range of 2.85≤(E / F), and the ratio of the axial distance E between the flange surface 3j and the inner side end surface 4b to the pitch circle diameter D of the ball 8 can be set to a range of 0.8≤(E / D)≤0.94. Thus, the generation of abnormal noise due to stick-slip can be further suppressed, and the increase in weight can be suppressed.

[0102] In the wheel bearing device 1C, the ratio of the axial length B of the protrusion 28 to the pitch circle diameter A of the recess 3h can be set to 0.32≤(B / A)≤0.6. This can suppress the occurrence of abnormal noise due to stick-slip and achieve weight reduction of the wheel bearing 10.

[0103] Furthermore, in the wheel bearing device 1C, the ratio of the pitch diameter A of the convex portion 28 to the shaft diameter G can also be set to 1.1≤(A / G)≤1.41. Thus, in the wheel bearing device 1C, the generation of abnormal noise due to stick-slip can be further suppressed, and the safety factor with respect to the driving torque loaded on the constant velocity universal joint 20A and the torsional rigidity of the shaft 31 can be ensured.

[0104] [Vehicle equipped with wheel bearing device]

[0105] The wheel bearing device 1, 1A, 1B, 1C can be used for a vehicle that uses an engine, a motor, etc. as a driving source. In particular, by using the wheel bearing device 1, 1A, 1B, 1C for a vehicle in which a driving torque is instantaneously input to the constant velocity universal joint 20, 20A, such as an electric vehicle that uses a motor as a driving source, it is possible to suppress an increase in the weight of the wheel bearing device 1, 1A, 1B, 1C and effectively suppress the generation of abnormal noise caused by stick-slip.

[0106] In addition, as in the wheel bearing devices 1, 1A, 1B, 1C, by forming the axial length of the wheel bearings 10, 10A, 10B to be smaller, for example in the case of an FF (front engine / front wheel drive) vehicle, the swing center of the wheel side in the constant velocity universal joint 20, 20A is moved toward the wheel side compared with the past, thereby achieving the suppression of the maximum angle of the constant velocity universal joint 20, 20A during steering and the suppression of the increase in the minimum rotation radius of the vehicle.

[0107] The embodiments of the present invention are described above, but the present invention is not limited to such embodiments and is merely illustrative. Of course, it can be further implemented in various ways within the scope of the main purpose of the present invention. The scope of the present invention is shown by the description of the scope of the claims, and also includes the equivalent meanings and all changes in the scope recorded in the scope of the claims.

[0108] Industrial Applicability

[0109] The present invention can be used in a wheel bearing device.

[0110] Description of reference numerals:

[0111] 1, 1A, 1B, 1C wheel bearing devices

[0112] 2 Outer ring

[0113] 2c (Inner side) Outer track surface

[0114] 2d (outer side) outer track surface

[0115] 3, 3A, 3B wheel hub

[0116] 3a Path Steps

[0117] 3b, 3m wheel mounting flange

[0118] 3c inner track surface

[0119] 3e shaft hole

[0120] 3h concave part

[0121] 3j flange surface

[0122] 3k riveting department

[0123] 3n screw hole

[0124] 4Inner circle

[0125] 4a Inner track surface

[0126] 4b Internal side surface

[0127] 5 internal side ball rows

[0128] 6 external side ball rows

[0129] 7 Ball

[0130] 8 Retainer

[0131] 10, 10A, 10B wheel bearings

[0132] 20, 20A constant velocity universal coupling

[0133] 27 Rod

[0134] 28 convex part

[0135] 31 axis

[0136] A pitch diameter

[0137] B The axial length of the convex part

[0138] C The axial length of the recess

[0139] D Pitch diameter of the ball

[0140] E Axial distance between flange surface and inner side end surface of inner ring

[0141] F The distance between balls

[0142] G-axis diameter

[0143] H Flange axial thickness

[0144] nInterference amount.

Claims

1. A wheel bearing device, comprising: A wheel bearing, comprising: An outer member having a double-row outer raceway surface on its inner circumference; an inner member consisting of a hub ring and at least one inner ring pressed into a small-diameter step portion of the hub ring, and having a double-row inner raceway surface opposite to the double-row outer raceway surface, the hub ring having a wheel mounting flange for mounting a wheel at one axial end, and the hub ring having an axially extending small-diameter step portion on its outer circumference and an axially penetrating through hole at its inner diameter portion; and double-row rolling elements accommodated between the two raceway surfaces of the outer member and the inner member in a rolling manner; and A constant velocity universal joint having a fitting portion that can fit into the through hole of the hub ring, It is characterized in that A recessed portion extending in the axial direction is formed on the inner peripheral surface of the through hole of the hub ring. A convex portion extending in the axial direction and spline-engaged with the concave portion is formed on the outer peripheral surface of the fitting portion of the constant velocity universal joint. The ratio of the axial length C of the recess to the pitch circle diameter A of the recess is 0.7≤(C / A)≤1.07, The ratio of the axial distance E between the flange surface of the wheel mounting flange and the axially other end side surface of the inner ring to the spacing F between the rolling elements on one axial side and the rolling elements on the other axial side of the double row of rolling elements is 2.85≤(E / F), A ratio of the axial distance E to the pitch diameter D of the double-row rolling element is 0.8≤(E / D)≤0.

94.

2. The wheel bearing device according to claim 1, characterized in that: The hub ring has a rivet portion for riveting the inner ring to the hub ring.

3. The wheel bearing device according to claim 1, characterized in that: The spline-engaged concave portion and the convex portion are in close contact with each other in the axial direction. A ratio of an axial length B of the convex portion to a pitch circle diameter A of the concave portion is 0.32≤(B / A)≤0.

6.

4. The wheel bearing device according to claim 1, characterized in that: The constant velocity universal joint includes a shaft coupled to the fitting portion in a torque-transmittable manner and to which a driving force is input. A ratio of a pitch circle diameter A of the convex portion to a shaft diameter G of the shaft is 1.1≤(A / G)≤1.

41.

5. The wheel bearing device according to claim 1, characterized in that: The wheel mounting flange has a plurality of screw holes for threading wheel rim bolts for fixing the wheel rim and the brake disc. A ratio of the axial distance E to an axial thickness H of the wheel mounting flange is 4.5≤(E / H)≤5.

6.

6. A vehicle, characterized in that: The vehicle has: The wheel bearing device according to any one of claims 1 to 5; and A motor, which generates driving force, The constant velocity universal joint includes a shaft that is coupled to the fitting portion in a torque-transmittable manner and to which the driving force from the motor is input.

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