Multi-steel-ball ball cage type constant velocity universal joint for rear axle

Abstract

The utility model discloses a multi-steel-ball ball cage type constant velocity universal joint for a rear shaft. The multi-steel-ball ball cage type constant velocity universal joint comprises a bell housing, a starlike sleeve, a retainer and n steel balls, the center of the inner spherical surface of the bell housing, the center of the outer spherical surface of the starlike sleeve and the centers of the outer spherical surface and the inner spherical surface of the retainer coincide; the distance between the center I of the track of the steel ball rolling along the inner raceway arc A of the bell housing and the center of the inner / outer spherical surface of the retainer is E1, the distance between the center II of the track of the steel ball rolling along the outer raceway arc B of the starlike sleeve and the center of the inner / outer spherical surface of the retainer is E2, and E1 is equal to E2 + 0.08-0.12; l1 is equal to (0.65 to 0.75) * L5, L1lt; and D < 2 > / 2, L < 2 > = (0.7-0.8) * L < 6 >, L < 3 > = (0.65-0.75) * L < 7 >, and L < 4 > = 0.75-0.85) * L < 8 >. The vehicle-mounted device is relatively small in size, relatively light in weight, relatively low in cost and capable of meeting the requirement for development of vehicles in the light-weight and low-cost direction.

Description

Technical Field

[0001] This utility model belongs to the field of automotive parts and relates to a multi-steel ball cage constant velocity universal joint for rear axles. Background Technology

[0002] The rear drive axle of passenger cars typically employs two structures. The first type uses sliding constant velocity joints (CV joints) at both ends, with a shaft connecting them in the middle. These sliding CV joints are often VL (Vendor-Low), DOJ (Dollar-Joint Joint), or TJ (Tall-Joint Joint), meaning the structure is: VL + shaft + VL, DOJ + shaft + DOJ, or TJ + shaft + TJ. The second type is similar to the front drive axle, with fixed CV joints at the wheel ends and sliding CV joints such as VL, DOJ, or TJ at the differential end. For the first type, the CV joints are relatively large, heavy, and expensive, failing to meet the demands of vehicle development towards lightweight and low-cost designs. For the second application, the wheel end universal joint uses a fixed ball cage type constant velocity universal joint. Since the cage and CV inner ring assembly need to be installed by aligning the cage window with the raceway of the bell shell, and the cage needs to rotate freely inside the bell shell cavity, the inner cavity of the bell shell needs to be large enough to meet the assembly conditions. This results in the constant velocity universal joint being relatively large, heavy, and costly, which cannot meet the development direction of vehicles towards lightweight and low cost.

[0003] For the front drive axle, to meet the large turning angle (small turning radius) requirements of the vehicle, the maximum universal joint angle of the constant velocity joint at the wheel end needs to reach 47°, or even 52°. To prevent the steel balls from detaching from the raceways of the bell-shaped housing and star-shaped sleeve, the inner raceway of the bell-shaped housing needs to be relatively long, resulting in a large volume, heavy weight, and high cost for the constant velocity joint at the wheel end. For the rear axle, the maximum universal joint angle of the constant velocity joint at the wheel end generally does not exceed 25°, and at most does not exceed 30°. Therefore, the inner raceway length of the bell-shaped housing does not need to be too long. If the inner depth can be reduced, the volume, weight, and cost of the constant velocity joint used at the rear axle wheel end can be reduced, meeting the development trend of vehicles towards lightweight and low-cost designs. Figure 2 As shown, the existing installation method for constant velocity universal joints involves first assembling the cage and the star sleeve together, then aligning the cage and star sleeve assembly with the raceway of the bell-shaped housing according to the cage window, and finally inserting the steel balls. In this installation method, the cage needs to rotate freely within the inner cavity of the bell-shaped housing, which requires the inner cavity of the bell-shaped housing to be sufficiently deep to meet the assembly conditions, and it is impossible to shorten the length of the raceway within the bell-shaped housing of the constant velocity universal joint.

[0004] Existing fixed ball-cage type constant velocity universal joints, such as Figure 1As shown, 01 is the bell-shaped shell, 02 is the cage, 03 is the star-shaped sleeve, 04 is the steel ball, 05 is the grease, L5 is the distance from the bottom surface of the inner cavity of the existing bell-shaped shell to the center of its inner spherical surface, L6 is the distance from the large end face of the existing bell-shaped shell to the center of its inner spherical surface, L7 is the total width of the existing star-shaped sleeve, and L8 is the total width of the existing cage. Figure 3 This is a front sectional view of the constant velocity universal joint at its maximum angle. The maximum universal joint angle is controlled by the contact between the shaft 06 of the drive shaft and the end face of the bell-shaped housing 01 of the universal joint, so as to keep the steel ball 04 still in the raceway of the bell-shaped housing 01 and the star-shaped sleeve 03. The maximum universal joint angle α can reach 47°, or even 52°. Utility Model Content

[0005] The purpose of this invention is to solve the aforementioned problems in the prior art and provide a rear axle multi-ball cage constant velocity universal joint that is relatively small in size, relatively light in weight, and relatively low in cost, so as to meet the development direction of vehicles towards lightweight and low cost.

[0006] To achieve the above objectives, the technical solution of this utility model is: a multi-ball cage type constant velocity universal joint for rear axles, comprising a bell-shaped shell, a star-shaped sleeve located in the inner cavity of the bell-shaped shell, a cage with n windows evenly distributed alternately, and n steel balls; n=6,7,8,9,10; the inner surface of the bell-shaped shell has n identical inner raceways, and the outer surface of the star-shaped sleeve has n identical outer raceways at positions corresponding to the inner raceways; the n steel balls are mounted by the cage between the outer raceways of the star-shaped sleeve and the inner raceways of the bell-shaped shell; the outer raceways of the star-shaped sleeve and the inner raceways of the bell-shaped shell are connected to the steel balls. The transition fit between them is as follows: the spherical surface containing the inner cavity of the bell-shaped shell is the inner spherical surface, and the spherical surface containing the outer surface of the star-shaped sleeve is the outer spherical surface; the center of the inner spherical surface and the center of the outer spherical surface coincide with the center of the outer spherical surface and the center of the inner spherical surface of the cage, and the outer spherical surface of the cage and the inner spherical surface of the bell-shaped shell are in clearance fit, as are the inner spherical surface of the cage and the outer spherical surface of the star-shaped sleeve; the inner raceway of the bell-shaped shell consists of a single arc A and a straight line C, and the outer raceway of the star-shaped sleeve consists of a single arc B and a straight line D; the distance between the center I of the trajectory of the steel ball rolling along the inner raceway arc A of the bell-shaped shell and the center of the inner / outer spherical surface of the cage is E1. The distance between the center of the trajectory II of the steel ball rolling along the outer raceway B of the star-shaped sleeve and the center of the inner / outer spherical surface of the cage is E2. The trajectory center I and trajectory center II are located on both sides of the center of the inner / outer spherical surface of the cage, respectively. E1 = E2 + 0.08~0.12; L1 is the distance from the bottom surface of the inner cavity of the bell-shaped shell to the center of the inner spherical surface, L2 is the distance from the large end face of the bell-shaped shell to the center of the inner spherical surface, L3 is the total width of the star-shaped sleeve, L4 is the total width of the cage, and D2 is the diameter of the inner spherical surface of the bell-shaped shell; L1 = (0.65~0.75) × L5, and L1 <D2 / 2,L2=(0.7~0.8)×L6,L3=(0.65~0.75)×L7,L4=0.75~0.85)×L8。

[0007] More preferably, the distance L2 from the large end face of the bell-shaped shell to the center of the inner spherical surface is 1.5~2.0mm; the large end face of the bell-shaped shell and the inner spherical surface are connected by a cylindrical surface, the diameter of which is 0.1~0.2mm smaller than the diameter D5 of the outer spherical surface of the cage. Therefore, after the cage, star-shaped sleeve, and steel ball assembly are fitted into the inner cavity of the bell-shaped shell with a small interference fit, the center of the inner / outer spherical surface of the cage coincides with the center of the inner spherical surface of the bell-shaped shell, and this prevents the cage, star-shaped sleeve, and steel ball assembly from dislodging from the bell-shaped shell during operation of the constant velocity universal joint.

[0008] More preferably, after the star-shaped sleeve and the cage are assembled together, the steel ball is placed inside the cage window, and then the assembly of the star-shaped sleeve, the cage and the steel ball is press-fitted into the inner cavity of the bell-shaped shell.

[0009] The advantages of this invention compared to existing technologies are as follows: The inner raceway of the bell-shaped shell is a UF structure composed of a single-segment circular arc A and a straight line C, while the outer raceway of the star-shaped sleeve is a UF structure composed of a single-segment circular arc B and a straight line D. This shortens the distance from the bottom surface of the bell-shaped shell's inner cavity to the center of the inner spherical surface, and also shortens the distance from the large end face of the bell-shaped shell to the center of the inner spherical surface. This results in a shorter inner cavity depth for the bell-shaped shell, a narrower total width for the star-shaped sleeve and the cage, a smaller overall universal joint volume, and a lighter overall weight. This saves materials, reduces manufacturing costs, and meets the development trend of vehicles towards lightweight and low-cost designs. Furthermore, because the distance L1 from the bottom surface of the bell-shaped shell's inner cavity to the center of the inner spherical surface is less than the radius D2 / 2 of the inner spherical surface, when the constant velocity universal joint angle reaches its maximum angle (approximately 33°), the bottom of the bell-shaped shell contacts the star-shaped sleeve. At this time, the shaft does not contact the end face of the bell-shaped shell. Therefore, the shaft diameter can be increased, significantly improving the static torsional strength and fatigue strength of the shaft. Third, it changed the installation method of the universal joint, allowing the star-shaped sleeve, cage, and steel ball to be assembled together and then pressed into the inner cavity of the bell-shaped housing, reducing the installation time of the universal joint and increasing work efficiency. Attached Figure Description

[0010] Figure 1 Front sectional view of the existing standard front drive shaft and rear axle using the outer end UF type constant velocity universal joint;

[0011] Figure 2 A schematic diagram of the assembly process for using external UF type constant velocity universal joints for existing standard front drive shafts and rear axles;

[0012] Figure 3 A front sectional view of the existing standard front drive shaft and rear axle with the outer end UF type constant velocity universal joint in the maximum angle state;

[0013] Figure 4 This is a front sectional view of the present invention;

[0014] Figure 5 This is a front sectional view of the bell-shaped shell in this utility model;

[0015] Figure 6 for Figure 5 Enlarged view of Part I;

[0016] Figure 7 This is a right view of the bell-shaped shell in this utility model;

[0017] Figure 8 This is a front sectional view of the cage in this utility model;

[0018] Figure 9 This is a right view of the cage in this utility model;

[0019] Figure 10This is a front sectional view of the star-shaped sleeve in this utility model;

[0020] Figure 11 This is a right view of the star-shaped sleeve in this utility model;

[0021] Figure 12 This is a front sectional view of the present invention when it is in its maximum angle state;

[0022] Figure 13 This is a schematic diagram of the assembly process of this utility model. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments.

[0024] like Figures 4 to 13As shown in the figure, this embodiment includes a bell housing 1, a star sleeve 3 located in the inner cavity of the bell housing 1, a cage 2 evenly distributed with n windows, and n steel balls 4. n = 6, 7, 8, 9, 10. The inner surface of the inner cavity of the bell housing 1 is provided with n identical inner raceways, and the outer surface of the star sleeve 3 is provided with n identical outer raceways at positions corresponding to the inner raceways. The n steel balls 4 are installed between the outer raceway of the star sleeve 3 and the inner raceway of the bell housing 1 by an annular cage 3. There is an interference fit between the outer raceway of the star sleeve 3, the inner raceway of the bell housing 1 and the steel balls 4. The spherical surface where the inner cavity of the bell housing 1 is located is an inner spherical surface 7, and the spherical surface where the outer surface of the star sleeve 3 is located is an outer spherical surface. The center of the inner spherical surface, the center of the outer spherical surface coincide with the center of the outer spherical surface of the cage 2 and the center of the inner spherical surface, and there is a clearance fit between the outer spherical surface of the cage 2 and the inner spherical surface of the bell housing 1, and a clearance fit between the inner spherical surface of the cage 2 and the outer spherical surface of the star sleeve 3. The inner raceway of the bell housing 1 is composed of a single-segment arc A and a straight line C, and the outer raceway of the star sleeve 3 is composed of a single-segment arc B and a straight line D. The distance from the center of the trajectory I where the steel ball 4 rolls along the arc A of the inner raceway of the bell housing 1 to the center of the inner / outer spherical surface of the cage 2 is E1, and the distance from the center of the trajectory II where the steel ball 4 rolls along the arc B of the outer raceway of the star sleeve 3 to the center of the inner / outer spherical surface of the cage 2 is E2. The center of the trajectory I and the center of the trajectory II are respectively located on both sides of the center of the inner / outer spherical surface of the cage 2, and E1 = E2 + 0.08 - 0.12. L1 is the distance from the bottom surface of the inner cavity of the bell housing 1 to the center of the inner spherical surface, L2 is the distance from the large end surface of the bell housing 1 to the center of the inner spherical surface, L3 is the total width of the star sleeve 3, L4 is the total width of the cage 2, and D2 is the diameter of the inner spherical surface of the bell housing 1. L1 = (0.65 - 0.75)×L5, L1 < D2 / 2, L2 = (0.7 - 0.8)×L6, L3 = (0.65 - 0.75)×L7, L4 = 0.75 - 0.85)×L8. Preferably, the distance L2 from the large end surface of the bell housing 1 to the center of the inner spherical surface is 1.5 - 2.0 mm; the large end surface of the bell housing 1 and the inner spherical surface are connected by a cylindrical surface 6, and the diameter of the cylindrical surface 6 is 0.1 - 0.2 mm smaller than the diameter D5 of the outer spherical surface of the cage 2. Therefore, after the cage 2, the star sleeve 3 and the steel ball 4 assembly are press-fitted into the inner cavity of the bell housing 1 with a small interference, the center of the inner / outer spherical surface of the cage 2 coincides with the center of the inner spherical surface of the bell housing 1, and it prevents the cage 2, the star sleeve 3 and the steel ball 2 assembly from disengaging from the bell housing 1 during the operation of this constant velocity universal joint. Preferably, after the star sleeve 3 and the cage 2 are assembled together, the steel balls 4 are placed in the windows of the cage, and then the assembly of the star sleeve 3, the cage 2 and the steel balls 4 is press-fitted into the inner cavity of the bell housing 1. 5 is grease, and the injection amount of the grease 5 is about 70% of that of the existing ball cage constant velocity universal joint (UF).L5 is the distance between the bottom surface of the existing bell-shaped shell and the plane where the center of the steel ball is located; L6 is the distance between the end face of the existing bell-shaped shell and the plane where the center of the steel ball is located; L7 is the thickness of the existing star-shaped sleeve; L8 is the thickness of the existing cage; D1 is the maximum outer diameter of the bell-shaped shell; D2 is the diameter of the inner spherical surface of the bell-shaped shell; D3 is the diameter of the circle where the center of each steel ball is located; d is the diameter of the steel ball; D4 is the diameter of the inner spherical surface of the cage; and D5 is the diameter of the outer spherical surface of the cage.

[0025] The above-described embodiments are merely preferred and exemplary, and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A rear axle multi-ball cage type constant velocity universal joint, comprising a bell-shaped housing, a star-shaped sleeve located in the inner cavity of the bell-shaped housing, a cage with n windows evenly and alternately distributed, and n steel balls; characterized in that: n=6,7,8,9,10; n identical inner raceways are formed on the inner surface of the bell-shaped shell, and n identical outer raceways are formed on the outer surface of the star-shaped sleeve at positions corresponding to the inner raceways; n steel balls are mounted between the outer raceways of the star-shaped sleeve and the inner raceways of the bell-shaped shell by a cage; the outer raceways of the star-shaped sleeve and the inner raceways of the bell-shaped shell are transitionally fitted with the steel balls; the spherical surface containing the inner cavity of the bell-shaped shell is the inner spherical surface, and the spherical surface containing the outer surface of the star-shaped sleeve is the outer spherical surface; the centers of the inner and outer spherical surfaces coincide with the centers of the outer and inner spherical surfaces of the cage, and the outer spherical surface of the cage and the inner spherical surface of the bell-shaped shell are in clearance fit, as are the inner spherical surface of the cage and the outer spherical surface of the star-shaped sleeve; the inner raceway of the bell-shaped shell consists of a single arc A and a straight line C, and the outer raceway of the star-shaped sleeve consists of a single arc B and a straight line D; the distance E1 between the center I of the trajectory of the steel ball rolling along the inner raceway arc A of the bell-shaped shell and the center of the inner / outer spherical surface of the cage is... The distance between the center of the trajectory II of the steel ball rolling along the outer raceway B of the star-shaped sleeve and the center of the inner / outer spherical surface of the cage is E2. The trajectory center I and trajectory center II are located on both sides of the center of the inner / outer spherical surface of the cage, respectively. E1 = E2 + 0.08~0.12; L1 is the distance from the bottom surface of the inner cavity of the bell-shaped shell to the center of the inner spherical surface, L2 is the distance from the large end face of the bell-shaped shell to the center of the inner spherical surface, L3 is the total width of the star-shaped sleeve, L4 is the total width of the cage, and D2 is the diameter of the inner spherical surface of the bell-shaped shell; L1 = (0.65~0.75) × L5, L1 <D2 / 2,L2=(0.7~0.8)×L6,L3=(0.65~0.75)×L7,L4=0.75~0.85)×L8。 2. The multi-ball cage constant velocity universal joint for rear axle according to claim 1, characterized in that: The distance L2 from the large end face of the bell-shaped shell to the center of the inner spherical surface is 1.5~2.0mm; the large end face of the bell-shaped shell and the inner spherical surface are connected by a cylindrical surface, the diameter of which is 0.1~0.2mm smaller than the diameter D5 of the outer spherical surface of the cage.

3. The multi-ball cage type constant velocity universal joint for rear axle according to claim 1 or 2, characterized in that: After the star-shaped sleeve and the cage are assembled together, the steel ball is placed inside the cage window, and then the assembly of the star-shaped sleeve, the cage and the steel ball is press-fitted into the inner cavity of the bell-shaped shell.

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