Gap-variable differential structure

Abstract

The utility model discloses a variable-clearance differential structure which comprises a planetary gear shaft, a planetary bevel gear and a half shaft bevel gear which are installed in a shell, and a containing cavity is formed in the shell. A planetary gear shaft is arranged in the center of the containing cavity, the two ends of the planetary gear shaft are of conical structures, the two sides are milled to be flat, and planetary bevel gears are installed. The planetary bevel gear is meshed with the half shaft bevel gear; a special-shaped elastic planetary gear gasket is arranged on the outer side of the planetary gear shaft and comprises arc sections and drum-shaped arc sections, the arc sections on the two sides of the special-shaped elastic planetary gear gasket are attached to the spherical surfaces of the planetary bevel gears, and the middle of the special-shaped elastic planetary gear gasket is drum-shaped. An inner hole of the gasket is a flat groove hole and is matched with the planetary gear shaft to form a limiting rotation structure. According to the variable-gap differential structure, the stress point change under different working conditions can meet the requirements of high rotating speed, high torque and long service life of a differential.

Description

Technical Field

[0001] The utility model belongs to the technical field of gear differentials, and more specifically, relates to a variable clearance differential structure. Background Art

[0002] Transmissions and reduction gearboxes are crucial transmission components in automobiles. The differential, a crucial component, not only transmits torque but also differentiates the speeds of the two vehicles, enabling cornering. A variable-gap differential utilizes the free-spinning planetary gears and the connection between the axle gears. When cornering or driving on uneven surfaces, the differential ensures that the drive wheels on each side rotate at different speeds, adapting to varying driving conditions. This design allows the inside and outside wheels to adjust to varying road conditions, reducing tire wear and power consumption.

[0003] With the rapid development of new energy vehicles in recent years, traditional differential designs are becoming obsolete. These vehicles place high demands on differentials: high speed, high strength, and long life. These requirements place high demands on planetary gear shafts and semi-bevel gears. Traditional differential designs aim to improve safety and achieve long life, but this approach comes at the expense of space, weight, and cost. This contradicts the low-cost, lightweight design requirements of new energy vehicles and is gradually being phased out.

[0004] After searching, 202310171860.0 discloses a same-side output friction plate limited slip differential and its application. A transmission gear is provided between the housing and the support seat of the limited slip differential. The planetary bevel gear set is installed in the housing. Axle gear 1 and axle gear 2 are respectively provided on both sides of the star bevel gear set to mesh with the star bevel gear. Axle gear 1 drives transmission shaft 1 for output. Axle gear 2 is fitted on transmission shaft 1 and serves as transmission shaft 2 for same-side output with transmission shaft 1. Friction plate groups are provided between the end face of axle gear 1 and the housing, and between the end face of axle gear 2 and the support seat. This solves the problem that the existing differential has two-end shaft output and cannot meet the same-side output requirements of wheel-side drive vehicles. With this technology, the limited slip differential will not slip. It mainly focuses on the axle gears. This technology also solves the problem of improving the life of variable gap structure differentials.

[0005] How to design a variable clearance differential structure to effectively utilize component performance and meet the requirements of high speed, high torque and long life of new energy has great practical significance and economic value. Utility Model Content

[0006] In response to the deficiencies of the above-mentioned prior art, the utility model provides a variable-clearance differential structure, in which a variable-clearance conical structure is adopted for the matching relationship between the planetary gear shaft and the planetary bevel gear, a special-shaped elastic planetary gear gasket is adopted, and the planetary bevel gear and the half-shaft bevel gear are subjected to conventional drum repairing. The requirements of high speed, high torque and long life of the differential can be met, and compared with the traditional design differential, it has important advantages in terms of lightweight and low cost.

[0007] The utility model is achieved through the following technical solutions:

[0008] Disclosed is a variable-clearance differential structure, comprising a planetary gear shaft, planetary bevel gears and half-shaft bevel gears installed in an outer shell, the outer shell comprising a first petal-type housing and a second petal-type housing, the first petal-type housing and the second petal-type housing being connected by a connecting structure to form an accommodating cavity in the outer shell; a planetary gear shaft is arranged at the center of the accommodating cavity, the planetary gear shaft comprises a shaft portion extending outward from the center, the shaft portion is conical, and planetary bevel gears are installed at the end of the shaft portion; the planetary bevel gears are meshed with the half-shaft bevel gears; a special-shaped elastic planetary gear gasket is arranged on the outside of the planetary gear shaft, the special-shaped elastic planetary gear gasket comprises arc segments and drum-shaped arc segments arranged alternately, and the arc segments on both sides have the same radius as the spherical surface of the planetary bevel gear.

[0009] The variable clearance differential structure of the utility model can effectively utilize the internal space of the shell by arranging the positions of the planetary gear shaft, planetary bevel gears and half-shaft bevel gears, and cooperating with the special-shaped elastic planetary gear gasket, so that the matching relationship between the planetary gear shaft and the planetary bevel gear adopts a variable clearance conical structure, effectively utilizing the performance of the parts and meeting the requirements of high speed, high torque and long life of new energy.

[0010] Furthermore, the irregularly shaped elastic planetary gear washer structure comprises two circular arc segments AB and CD, with a drum-shaped arc BC connecting them. The drum-shaped arc BC has a bulge height H of 0-1 mm, and the thickness of the irregularly shaped elastic planetary gear washer is T. The outer shell includes an inner spherical surface, the dimensions of which equal the design dimension SR of the planetary bevel gear sphere + the thickness T of the irregularly shaped elastic planetary gear washer + the bulge height H of the drum-shaped arc BC. This irregularly shaped elastic planetary gear washer structure is designed based on the structure of the planetary bevel gear. By alternating the circular arc segments and the drum-shaped arc segments, it can meet the requirements of different conditions, such as high speed or high torque and low speed or low torque.

[0011] Furthermore, the planetary gear shaft and the planetary bevel gear are matched at a conical structure with a cone angle of 5°-10°.

[0012] Furthermore, the cone angle of the inner hole of the planetary bevel gear is 5°-10°.

[0013] Furthermore, the shaft portions are connected via a cylindrical block arranged in the center; the shaft portions are provided with a limiting surface, which is a horizontal surface extending from the center to the outside and having the same height as the bottom surfaces on both sides.

[0014] Furthermore, the shaft portion of the planetary gear shaft is centrally symmetrically arranged, and the shaft portion is cross-shaped or straight-shaped.

[0015] Furthermore, the center hole of the special-shaped elastic planetary gear gasket adopts a flat slot structure, which cooperates with the planetary gear shaft to limit the rotation of the gasket and reduce the wear between the gasket and the differential housing.

[0016] Furthermore, a mounting groove is provided on the inner wall of the housing, and the mounting groove is provided with a stepped inner hole for mounting and positioning the half-shaft bevel gear.

[0017] Furthermore, the large end surface of the half-shaft bevel gear is in non-contact fit with the inner wall of the housing, and a gasket is provided at the shaft diameter of the half-shaft bevel gear.

[0018] Furthermore, the connection structure includes mounting holes and fixing bolts provided on the edge of the shell, for fixing the first and second petal-type shells into one body.

[0019] The variable clearance differential structure works as follows at low speed and low torque: the planetary bevel gear transmits small torque, the speed is low, the centrifugal force is small, the planetary bevel gear contacts the nearly natural-shaped elastic planetary gear gasket, and the special-shaped elastic planetary gear gasket cannot be flattened. The contact area can meet the low torque and low speed requirements of the parts. The planetary gear shaft and the planetary bevel gear fit together with a small clearance, and the meshing position of the planetary bevel gear and the axle bevel gear is biased towards the small end, which is transmitted to the contact fatigue point of the planetary gear shaft. At this time, the planetary shaft meshing point is point F, the gasket fits on both the inside and outside, and the meshing point of the planetary bevel gear and the axle gear tooth surface is biased towards the small end.

[0020] When the differential operates at high speed or high torque, it operates as follows: the planetary bevel gears transmit high torque, resulting in high speed and centrifugal force. The planetary bevel gears flatten the shaped elastic planetary gear gaskets, and the contact area covers the entire sphere. The planetary gears are centrifugally offset by H, and the clearance between the planetary gear shaft and the planetary gear increases by H*tanα, which facilitates differential lubrication of the planetary bevel gears. The meshing position of the planetary bevel gears and the axle bevel gears is offset from the large end, with the meshing point offset from the small end by L. The contact fatigue point transmitted to the planetary gear shaft is point G. The gasket engagement is in the middle, and the meshing point between the planetary bevel gear and the axle gear tooth surface is offset from the large end. The distance between the two working force points on the planetary shaft is FG (distance = H + L*sinA), where A is the bevel gear pitch angle.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The variable clearance differential structure of the utility model can effectively utilize the internal space of the shell by arranging the positions of the planetary gear shaft, planetary bevel gears and half-shaft bevel gears, and cooperating with the special-shaped elastic planetary gear gasket, so that the matching relationship between the planetary gear shaft and the planetary bevel gear adopts a variable clearance conical structure, effectively utilizing the performance of the parts and meeting the requirements of high speed, high torque and long life of new energy.

[0023] The special-shaped elastic planetary gear washer structure of the utility model is designed based on the structure of the planetary bevel gear. By alternating the arrangement of circular arc segments and drum-shaped circular arc segments, it can meet the requirements of different conditions of high speed or high torque, and low speed or low torque. During low-torque and low-speed operation, the planetary bevel gear contacts and fits with both sides of the special-shaped elastic washer, the planetary shaft and the planetary bevel gear have a small clearance, and the planetary bevel gear meshes with the small end of the axle gear. During high-torque and high-speed operation, the planetary bevel gear compresses the drum-shaped portion of the special-shaped elastic washer, the planetary shaft and the planetary bevel gear have a large clearance, and the planetary bevel gear meshes with the large end of the axle gear. The change of the force point under different operating conditions can meet the high speed, high torque, and long life requirements of the differential. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the variable gap differential structure of the utility model.

[0025] Figure 2 It is a schematic cross-sectional view of the variable gap differential structure of the present invention.

[0026] Figure 3 This is a schematic diagram of the internal structure of the variable gap differential structure of the present utility model.

[0027] Figure 4 This is a schematic diagram of the overall structure of the planetary gear shaft of the variable clearance differential structure of the present invention.

[0028] Figure 5 This is a schematic diagram of the overall structure of the special-shaped elastic planetary gear gasket of the variable clearance differential structure of the utility model.

[0029] Figure 6 for Figure 5 A schematic side view of the structure of the special-shaped elastic planetary gear spacer of the variable clearance differential structure.

[0030] Figure 7 A schematic diagram of the meshing position of the planetary bevel gear and the half-shaft bevel gear of the variable clearance differential structure of the present invention at low speed and low torque.

[0031] Figure 8 A schematic diagram of the contact fatigue point of the planetary gear shaft of the variable clearance differential structure of the present invention at low speed and low torque.

[0032] Figure 9 A schematic diagram of the meshing positions of the planetary bevel gears and the half-shaft bevel gears of the variable clearance differential structure of the present invention at high speed or high torque.

[0033] Figure 10 A schematic diagram of the contact fatigue point of the planetary gear shaft of the variable clearance differential structure of the present invention at high speed or high torque.

[0034] Among them, 1-housing, 11-split housing one, 12-split housing one, 2-planetary gear shaft, 21-cylindrical block, 22-shaft, 211-limiting surface, 3-planetary bevel gear, 4-half-shaft bevel gear, 41-large end face, 42-shaft diameter, 5-connecting structure, 51-mounting hole, 52-fixing bolt 6-special-shaped elastic planetary gear gasket, 7-mounting groove, 8-gasket. DETAILED DESCRIPTION

[0035] In order to facilitate the explanation and understanding of the present invention, the following Figures 1-10 The embodiments of the present utility model are described in detail. Example 1

[0036] like Figure 1-Figure 3 As shown, the variable clearance differential structure of this embodiment includes a planetary gear shaft 2, a planetary bevel gear 3, and a half-shaft bevel gear 4 installed in a housing 1. The housing 1 includes a split housing 11 and a split housing 2 12. The split housing 1 11 and the split housing 2 12 are connected by a connecting structure 5. The connecting structure 5 includes a mounting hole 51 and a fixing bolt 52 provided on the edge of the housing 1 for fixing the split housing 1 11 and the split housing 2 12 into one body. A receiving cavity is formed in the housing 1. A planetary gear shaft 2 is installed in the center of the receiving cavity. The planetary gear shaft 2 includes a cylindrical block 21 and a shaft portion 22 extending outward from the cylindrical block 21. The end of the shaft portion 22 is mounted with a planetary bevel gear 3. The planetary gear shaft 2 can be in a straight line or a cross shape. In this embodiment, it is a cross shape. The cross-shaped planetary gear shaft is arranged symmetrically at the center, which can be evenly stressed during use, ensuring connection reliability and service life.

[0037] The planetary bevel gear 3 is meshed with the half-shaft bevel gear 4; the shaft 22 is a structure with a gradually decreasing diameter from the center to the outside. Figure 4As shown, the shaft portion 22 of this embodiment is connected via a centrally positioned cylindrical block 21. The shaft portion 22 is provided with a limiting surface 221, which is a horizontal surface extending outward from the center and aligned with the bottom surface height on both sides. The shaft portion 22 is a tapered shaft portion symmetrically milled to a thickness of 0-0.2D on both sides. Specifically, the planetary gear shaft 2 has a tapered structure at both ends, flattened on both sides, and mounted with planetary bevel gears 3. These mesh with the axle bevel gears 4. A specially shaped elastic planetary gear washer 6 is installed on the outside of the planetary gear shaft 2. The inner hole of this washer is a flat slot, which cooperates with the planetary gear shaft to form a limited rotation structure.

[0038] The shaft portion 22 of the planetary gear shaft 2 is symmetrically arranged along the cylindrical block 21. Symmetrical half-shaft bevel gears 4 are arranged on both sides of the bottom surface of the cylindrical block 21. The half-shaft bevel gears 4 include a large end face 41 and an axis diameter 42. The large end face 41 is parallel to the bottom surface of the cylindrical structure.

[0039] The outer side of the planetary gear shaft 2 is provided with a special-shaped elastic planetary gear gasket 6, such as Figure 5 and Figure 6 As shown, the structure of the shaped elastic planetary gear washer 6 is designed based on the structure of the planetary bevel gear 3. By alternating circular arc segments and drum-shaped circular arc segments, it can meet the requirements of different conditions, such as high speed or high torque, and low speed or low torque. The shaped elastic planetary gear washer 6 includes alternating circular arc segments and drum-shaped circular arc segments, with the arc segments on both sides having the same inclination as the spherical surface of the planetary bevel gear. In this embodiment, the shaped elastic planetary gear washer 6 is an annular sheet structure, and the center hole of the shaped elastic planetary gear washer 6 adopts a flat slot structure. It cooperates with the planetary gear shaft to limit the washer's rotation and reduce wear between the washer and the differential housing.

[0040] The shaped elastic planetary gear washer 6 has a central through-hole and fits over the inner hole of the planetary bevel gear 3. Its outer diameter is equal to or greater than the diameter of the larger end face of the planetary bevel gear 3. This shaped elastic planetary gear washer 6 comprises two side arc segments AB and CD, connected by a drum-shaped arc BC. The drum-shaped arc BC has a bulge height H of 0mm-1mm, and the thickness of the shaped elastic planetary gear washer is T. The housing 1 includes an inner spherical surface, the dimensions of which are calculated as the design dimensions SR of the planetary bevel gear sphere, the thickness T of the shaped elastic planetary gear washer, and the bulge height H of the drum-shaped arc BC.

[0041] The planetary gear shaft 2 and the planetary bevel gear 3 are matched at a conical structure with a cone angle of 5°-10°. The inner hole cone angle of the planetary bevel gear 3 is also 5°-10°.

[0042] The inner wall of the housing 1 is provided with a mounting groove 7, which is provided with a stepped inner hole for mounting and positioning the axle bevel gear 4. The large end face 41 of the axle bevel gear 4 is non-contactingly fitted with the inner wall of the housing 1, and a gasket 8 is provided at the shaft diameter 42 of the axle bevel gear 4.

[0043] The variable clearance differential structure works as follows at low speed and low torque: the planetary bevel gears transmit small torque, low speed, small centrifugal force, and the planetary bevel gears are in contact with the nearly natural shaped elastic planetary gear gaskets, which cannot be flattened. The contact area can meet the low torque and low speed requirements of the parts. The planetary gear shaft and the planetary gears have a small clearance, and the meshing position of the planetary bevel gears and the half-shaft bevel gears is at the small end. Figure 7 , transmitted to the contact fatigue point of the planetary gear shaft such as Figure 8 .

[0044] When the differential operates at high speed or high torque, the planetary bevel gears transmit large torque, high speed, and large centrifugal force. The planetary bevel gears flatten the special-shaped elastic planetary gear gaskets, and the contact area is the entire sphere. The planetary bevel gears are centrifugally offset by H, and the clearance between the planetary gear shaft and the planetary bevel gears increases by H*tanα, which is beneficial to the differential lubrication of the planetary bevel gears. The meshing position of the planetary bevel gears and the half-shaft bevel gears is biased to the large end. Figure 9 , the relative small end meshing spot is offset by L, and the contact fatigue point transmitted to the planetary gear shaft is point G. Figure 10 . FG distance = H + L * sinA, A is the pitch angle of the bevel gear.

[0045] This variable-clearance differential features a compact structure: The entire differential is very compact, effectively saving space. It also offers excellent stability: The large contact area between the planetary gear shafts 2 and the shaped elastic planetary gear washers 6 results in high friction, ensuring stable and smooth driving. High transmission efficiency: Because the planetary bevel gear differential utilizes shaped elastic planetary gear washers 6 as its transmission components, its transmission efficiency is higher than that of an open differential.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of the present invention.

Claims

1. A variable gap differential structure, characterized in that: The invention comprises a planetary gear shaft (2), a planetary bevel gear (3) and a half-shaft bevel gear (4) installed in a housing (1), wherein the housing (1) comprises a first split-type housing (11) and a second split-type housing (12), wherein the first split-type housing (11) and the second split-type housing (12) are connected via a connecting structure (5) so that a receiving cavity is formed in the housing (1); a planetary gear shaft (2) is provided at the center of the receiving cavity, wherein the planetary gear shaft (2) comprises a shaft portion (22) extending outward from the center, wherein the shaft portion (22) is conical, and a planetary bevel gear (3) is installed at the end of the shaft portion (22); the planetary bevel gear (3) is meshed with the half-shaft bevel gear (4); a special-shaped elastic planetary gear gasket (6) is provided on the outer side of the planetary gear shaft (2), wherein the special-shaped elastic planetary gear gasket (6) comprises circular arc segments and drum-shaped circular arc segments arranged alternately, and the circular arc segments on both sides have the same radius as the spherical surface of the planetary bevel gear.

2. The variable gap differential structure according to claim 1, characterized in that: The special-shaped elastic planetary gear gasket (6) includes two side arc segments AB and an arc segment CD, the drum-shaped arc BC connects the arc segment AB and the arc segment CD, the bulging height H of the drum-shaped arc BC is 0 mm-1 mm, and the thickness of the special-shaped elastic planetary gear gasket is T; the housing (1) includes an inner spherical surface, the size of the inner spherical surface = the design size SR of the planetary bevel gear sphere + the thickness T of the special-shaped elastic planetary gear gasket + the bulging height H of the drum-shaped arc BC.

3. The variable gap differential structure according to claim 1, characterized in that: The matching position between the planetary gear shaft (2) and the planetary bevel gear (3) adopts a conical structure, and the cone angle of the conical structure is 5°-10°.

4. The variable gap differential structure according to claim 1, characterized in that: The inner hole cone angle of the planetary bevel gear (3) is 5°-10°.

5. The variable gap differential structure according to any one of claims 1 to 4, characterized in that: The shaft portion (22) is connected via a cylindrical block (21) arranged at the center; the shaft portion (22) is provided with a limiting surface (221), and the limiting surface (221) is a horizontal surface extending from the center to the outside and having the same height as the bottom surfaces on both sides.

6. The variable gap differential structure according to claim 5, characterized in that: The shaft portion (22) of the planetary gear shaft (2) is centrally symmetrically arranged, and the shaft portion (22) is cross-shaped or straight-shaped.

7. The variable gap differential structure according to claim 5, characterized in that: The center hole of the special-shaped elastic planetary gear gasket (6) adopts a flat slot hole structure, which cooperates with the planetary gear shaft to limit the rotation of the gasket and reduce the wear between the gasket and the differential housing.

8. The variable gap differential structure according to claim 7, characterized in that: The inner wall of the housing (1) is provided with a mounting groove (7), and the mounting groove (7) is provided with a stepped inner hole for mounting and positioning the half-shaft bevel gear (4).

9. The variable gap differential structure according to claim 8, characterized in that: The large end surface (41) of the half-shaft bevel gear (4) is in non-contact engagement with the inner wall of the housing (1), and a gasket (8) is provided at the shaft diameter (42) of the half-shaft bevel gear (4).

10. The variable gap differential structure according to claim 9, characterized in that: The connection structure (5) comprises a mounting hole (51) and a fixing bolt (52) provided on the edge of the housing (1), and is used to fix the first petal-type housing (11) and the second petal-type housing (12) into one body.

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