Design method of variable-gap differential structure and variable-gap differential structure thereof

Abstract

The invention discloses a design method of a variable-clearance differential structure, which is characterized in that the internal space of a shell can be effectively utilized through the layout of the positions of a planetary gear shaft, a planetary bevel gear and a half shaft bevel gear in cooperation with a special-shaped elastic planetary gear gasket; the matching relation between the planetary gear shaft and the planetary bevel gear adopts a variable-gap conical structure, the performance of parts is effectively utilized, and the requirements of new energy for high rotating speed, high torque and long service life are met. The two sides of the variable-gap conical structure 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 which are alternately arranged, the arc sections on the two sides are attached to the spherical surface of the planetary bevel gear, the middle of the special-shaped elastic planetary gear gasket is drum-shaped, and an inner hole of the gasket is a flat slotted hole and is matched with the planetary gear shaft to form a limiting rotation structure.

Description

Technical Field

[0001] The present invention belongs to the technical field of gear differentials, and more specifically, relates to a design method for a variable clearance differential structure and the variable clearance differential structure. Background Art

[0002] Gearboxes and reduction gearboxes are important transmission parts of automobiles. The differential, an important component, not only transmits torque, but also realizes the speed difference between the two vehicles to complete the turning action. The variable clearance differential is based on the free rotation of the planetary gears and the connection of the half-shaft gears. When the car turns or drives on uneven roads, the differential ensures that the drive wheels on both sides can rotate at different speeds to adapt to different driving conditions. This design allows the inner and outer wheels to adjust according to the different road surfaces, reducing tire wear and power consumption.

[0003] In recent years, new energy vehicles have developed rapidly, and traditional differential design schemes have gradually fallen behind. New energy vehicles have put forward the "three highs" requirements for differentials: high speed, high strength, and high life, and have high requirements for planetary gear shafts and semi-bevel gears; the traditional differential design scheme is to improve the safety factor of the differential and achieve the requirement of long life, but this method is achieved at the cost of large space, large weight, and high cost, which runs counter to the low cost and lightweight requirements of new energy, and is a design scheme that is gradually being eliminated.

[0004] After searching, 202310171860.0 discloses a same-side output friction plate limited slip differential and its application, wherein a transmission gear is provided between the housing and the support seat of the limited slip differential, a planetary bevel gear set is installed in the housing, and a half-shaft gear 1 and a half-shaft gear 2 are respectively provided on both sides of the star bevel gear set to mesh with the star bevel gear, and the half-shaft gear 1 drives the transmission shaft 1 to output, and the half-shaft gear 2 is fitted on the transmission shaft 1, and serves as the transmission shaft 2 and the transmission shaft 1 to output on the same side, and a friction plate group is provided between the end face of the half-shaft gear 1 and the housing, and between the end face of the half-shaft gear 2 and the support seat, which solves the problem that the existing differential is output by two end shafts 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 half-shaft gears. This technology also solves the problem of improving the life of the variable gap structure differential.

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

[0006] In view of the deficiencies of the above-mentioned prior art, the present invention provides a design method for a variable clearance differential structure and a variable clearance differential structure thereof, wherein 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 conventionally repaired; 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 present invention is achieved through the following technical solutions: Disclosed is a design method for a variable clearance differential structure. By arranging the positions of a planetary gear shaft, a planetary bevel gear and a half-shaft bevel gear in combination with a special-shaped elastic planetary gear gasket, the internal space of a housing can be effectively utilized. The matching relationship between the planetary gear shaft and the planetary bevel gear adopts a variable clearance conical structure to effectively utilize the performance of the parts and meet the requirements of high speed, high torque and high life of new energy.

[0008] The variable clearance differential structure includes a planetary gear shaft, a planetary bevel gear and a half-shaft bevel gear installed in an outer shell, the outer shell includes a split-flap shell one and a split-flap shell two, the split-flap shell one and the split-flap shell two are connected by a connecting structure, so that a containing cavity is formed in the outer shell; a planetary gear shaft is arranged at the center of the containing cavity, the planetary gear shaft includes a shaft portion extending outward from the center, the shaft portion is conical, and a planetary bevel gear is installed at the end of the shaft portion; the planetary bevel gear is meshed with the half-shaft bevel gear; a special-shaped elastic planetary gear gasket is arranged on the outside of the planetary gear shaft, the special-shaped elastic planetary gear gasket includes 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] Furthermore, the special-shaped elastic planetary gear gasket structure includes arc segments AB and arc segments CD on both sides, the drum-shaped arc BC connects the arc segments AB and CD, the bulging height H of the drum-shaped arc BC is 0mm-1mm, and the thickness of the special-shaped elastic planetary gear gasket is T; the outer shell includes an inner spherical surface, and the size of the inner spherical surface = the design size SR of the planetary bevel gear spherical surface + the thickness T of the special-shaped elastic planetary gear gasket + the bulging height H of the drum-shaped arc BC. The special-shaped elastic planetary gear gasket structure is designed according to the structure of the planetary bevel gear, and the requirements of high speed or high torque, low speed or low torque can be met by alternating the arrangement of arc segments and drum-shaped arc segments.

[0010] Furthermore, the matching position between the planetary gear shaft and the planetary bevel gear adopts a conical structure with a cone angle of 5°-10°.

[0011] Furthermore, the cone angle of the inner hole of the planetary bevel gear is 5°-10°.

[0012] Furthermore, the shaft parts are connected via a cylindrical block arranged in the center; the shaft parts are provided with a limiting surface, and the limiting surface is a horizontal surface extending from the center to the outside and having the same height as the bottom surfaces on both sides.

[0013] Furthermore, the shaft portion of the planetary gear shaft is centrally symmetrically arranged, and the shaft portion is cross-shaped or straight-shaped.

[0014] Furthermore, the center hole of the special-shaped elastic planetary gear gasket 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.

[0015] 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.

[0016] 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.

[0017] Furthermore, the connection structure includes mounting holes and fixing bolts arranged on the edge of the shell, which are used to fix the split-flap shell one and the split-flap shell two into one body.

[0018] The variable clearance differential structure works in the following state at low speed and low torque: the planetary bevel gear transmits small torque, low speed, small centrifugal force, the planetary bevel gear contacts with the special-shaped elastic planetary gear gasket close to the natural state, 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 cooperate with small clearance, and the meshing position of the planetary bevel gear and the half-shaft bevel gear is on the small end, which is transmitted to the contact fatigue point of the planetary gear shaft. At this time, the meshing point of the planetary shaft is point F, the gasket cooperation is on the inner and outer sides, and the meshing point of the planetary bevel gear and the half-shaft gear tooth surface is on the small end.

[0019] When the differential works at high speed or high torque, the planetary bevel gear transmits large torque, high speed, large centrifugal force, and the planetary bevel gear flattens the special-shaped elastic planetary gear gasket. The contact area is the entire sphere, the planetary gear centrifugal offset H, and the clearance between the planetary gear shaft and the planetary gear increases by H*tanα, which is conducive to the differential lubrication of the planetary bevel gear; the meshing position of the planetary bevel gear and the half-shaft bevel gear is biased to the large end, and the meshing spot is offset by L relative to the small end, and the contact fatigue point transmitted to the planetary gear shaft is point G. The gasket fit is in the middle, the meshing point of the planetary bevel gear and the half-shaft gear tooth surface is biased to the large end, and the distance between the two working conditions on the planetary shaft is FG distance = H + L * sinA, A is the cone angle of the bevel gear pitch.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The variable clearance differential structure of the present invention 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 with special-shaped elastic planetary gear gaskets, 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 parts and meeting the requirements of high speed, high torque and long life of new energy.

[0021] The special-shaped elastic planetary gear gasket structure of the present invention is designed according to the structure of the planetary bevel gear. The requirements of high speed or high torque, low speed or low torque can be met by alternating the arrangement of arc segments and drum-shaped arc segments. When running at low torque and low speed, the planetary bevel gear contacts and cooperates with both sides of the special elastic gasket, the planetary shaft and the planetary bevel gear cooperate with a small gap, and the planetary bevel gear and the small end of the half-shaft gear are meshed; when running at high torque and high speed, the planetary bevel gear compresses the drum-shaped amount in the middle of the special elastic gasket, the planetary shaft and the planetary bevel gear cooperate with a large gap, and the planetary bevel gear and the large end of the half-shaft gear are meshed. The changes in the force points under different working conditions can meet the requirements of high speed, high torque and long life of the differential. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the variable clearance differential structure of the present invention.

[0023] Figure 2 It is a schematic cross-sectional structure diagram of the variable clearance differential structure of the present invention.

[0024] Figure 3 It is a schematic diagram of the internal structure of the variable clearance differential structure of the present invention.

[0025] 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.

[0026] Figure 5 It is a schematic diagram of the overall structure of the special-shaped elastic planetary gear gasket of the variable clearance differential structure of the present invention.

[0027] Figure 6 for Figure 5 A schematic side view of the structure of the special-shaped elastic planetary gear gasket of the variable clearance differential structure.

[0028] 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.

[0029] 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.

[0030] Fig. 9A 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 high speed or high torque.

[0031] Fig.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.

[0032] 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-semi-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

[0033] For the convenience of explaining and understanding the present invention, the following Figure 1-Figure 10 The embodiments of the present invention are described in detail. Example 1

[0034] like Figure 1-Figure 3 As shown, the variable clearance differential structure of this embodiment uses a design method of a variable clearance differential structure. By arranging the positions of the planetary gear shaft 2, the planetary bevel gear 3 and the half-shaft bevel gear 4, and matching the special-shaped elastic planetary gear gasket 6, the internal space of the housing can be effectively utilized; the matching relationship between the planetary gear shaft 2 and the planetary bevel gear 3 adopts a variable clearance conical structure to effectively utilize the performance of the parts and meet the requirements of high speed, high torque and long life of new energy.

[0035] 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 petal housing 1 11 and a petal housing 2 12. The petal housing 1 11 and the petal housing 2 12 are connected by a connecting structure 5. The connecting structure 5 includes a mounting hole 51 and a fixing bolt 52 arranged at the edge of the housing 1, which are used to fix the petal housing 1 11 and the petal housing 2 12 as a whole. A housing cavity is formed in the housing 1. A planetary gear shaft 2 is installed at the center of the housing 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 installed with a planetary bevel gear 3. The planetary gear shaft 2 can be a straight-line or cross-shaped structure, and a cross-shaped structure is used in this embodiment. The cross-shaped planetary gear shaft is arranged symmetrically at the center, and can be subjected to uniform force during use, thereby ensuring connection reliability and service life.

[0036] The planetary bevel gear 3 is meshed with the half-shaft bevel gear 4; the shaft portion 22 is a structure with a gradually decreasing diameter from the center to the outside. Figure 4As shown, the shaft 22 of this embodiment is connected by a cylindrical block 21 arranged in the center; the shaft 22 is provided with a limiting surface 221, which is a horizontal surface extending from the center to the outside and having the same height as the bottom surfaces on both sides. The shaft 22 is a tapered shaft with a thickness of 0-0.2D symmetrically milled on both sides. That is, the two ends of the planetary gear shaft 2 adopt a tapered structure, the two sides are milled flat, and a planetary bevel gear 3 is installed; the planetary bevel gear 3 is meshed with the half-shaft bevel gear 4; the outer side of the planetary gear shaft 2 is provided with a special-shaped elastic planetary gear gasket 6, and the inner hole of the special-shaped elastic planetary gear gasket 6 is a flat slot hole structure, which cooperates with the planetary gear shaft 2 to form a limited rotation structure.

[0037] The shaft 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.

[0038] 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 special-shaped elastic planetary gear gasket 6 is designed according to the structure of the planetary bevel gear 3. The requirements of high speed or high torque, low speed or low torque can be met by alternating the arrangement of arc segments and drum-shaped arc segments. The special-shaped elastic planetary gear gasket 6 includes arc segments and drum-shaped arc segments arranged alternately, and the arc segments on both sides have the same slope as the spherical surface of the planetary bevel gear. The special-shaped elastic planetary gear gasket 6 in this embodiment is an annular sheet structure, and the center hole of the special-shaped elastic planetary gear gasket 6 adopts a flat slot hole structure. Cooperating with the planetary gear shaft, the gasket is limited to rotate and the wear between the gasket and the differential housing is reduced.

[0039] The center of the special-shaped elastic planetary gear gasket 6 is a through hole sleeved on the inner hole of the planetary bevel gear 3, and the outer edge diameter is greater than or equal to the large end face diameter of the planetary bevel gear 3. The special-shaped elastic planetary gear gasket 6 includes arc segments AB and CD on both sides, and the drum-shaped arc BC connects the arc segments AB and CD. The bulging height H of the drum-shaped arc BC is 0mm-1mm, and the thickness of the special-shaped elastic planetary gear gasket is T; the housing 1 includes an inner spherical surface, wherein the size of the inner spherical surface = the design size SR of the planetary bevel gear spherical surface + the thickness T of the special-shaped elastic planetary gear gasket + the bulging height H of the drum-shaped arc BC.

[0040] The matching position of 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°. The inner hole cone angle of the planetary bevel gear 3 is 5°-10°.

[0041] 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 half-shaft bevel gear 4. The large end face 41 of the half-shaft bevel gear 4 is non-contactly matched 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.

[0042] The variable clearance differential structure works in the following state 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 with the shaped elastic planetary gear gasket close to the natural state, and the 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 gear are matched with a small clearance, and the meshing position of the planetary bevel gear and the half-shaft bevel gear is smaller than the small end. Figure 7 , transmitted to the contact fatigue point of the planetary gear shaft such as Figure 8 .

[0043] When the differential operates at high speed or high torque, the planetary bevel gears transmit large torque, high speed, large centrifugal force, and the planetary bevel gears flatten the special-shaped elastic planetary gear gaskets. The contact area is the entire spherical surface. The planetary bevel gears are centrifugally offset by H, and the clearance between the planetary gear shaft and the planetary bevel gear 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. Fig. 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. Fig.10 . FG distance = H + L * sinA, A is the pitch angle of the bevel gear.

[0044] The variable clearance differential has a compact structure: the structure of the entire differential is very compact, which can effectively save space. Good stability: Since the contact area between the planetary gear shaft 2 and the special-shaped elastic planetary gear gasket 6 is relatively large, the friction between them is also relatively large, thereby ensuring the stability and smoothness of the vehicle's driving. High transmission efficiency: Since the planetary bevel gear differential uses the special-shaped elastic planetary gear gasket 6 as a transmission component, its transmission efficiency is higher than that of the open differential.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention.

Claims

1. A design method for a variable clearance differential structure, characterized in that: By arranging the positions of the planetary gear shaft (2), the planetary bevel gear (3) and the half-shaft bevel gear (4) in combination with the special-shaped elastic planetary gear gasket (6), the internal space of the housing can be effectively utilized; the matching relationship between the planetary gear shaft (2) and the planetary bevel gear (3) adopts a variable clearance cone structure to effectively utilize the performance of the parts and meet the requirements of high speed, high torque and high life of new energy.

2. The design method of the variable clearance differential structure according to claim 1, characterized in that: The planetary gear shaft (2) comprises a shaft portion (22) extending outward from the center, the shaft portion (22) being conical, and a planetary bevel gear (3) being mounted on the end of the shaft portion (22); the planetary bevel gear (3) being meshed with the half-shaft bevel gear (4); and a special-shaped elastic planetary gear gasket (6) is arranged on the outer side of the planetary gear shaft (2), the special-shaped elastic planetary gear gasket (6) comprising 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.

3. The design method of the variable clearance differential structure according to claim 2, characterized in that: The special-shaped elastic planetary gear gasket (6) comprises 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, and the bulging height H of the drum-shaped arc BC is 0 mm-1 mm; the thickness of the special-shaped elastic planetary gear gasket is T; the planetary gear shaft (2), the planetary bevel gear (3) and the half-shaft bevel gear (4) are installed in the housing (1), and the housing (1) comprises an inner spherical surface, and the size of the inner spherical surface = the design size SR of the planetary bevel gear spherical surface + the thickness T of the special-shaped elastic planetary gear gasket + the bulging height H of the drum-shaped arc BC.

4. The design method of the variable clearance differential structure according to claim 3 is 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.

5. The design method of the variable clearance differential structure according to claim 4, 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.

6. The design method of the variable clearance 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.

7. The design method of the variable clearance differential structure according to claim 6, 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).

8. The design method of the variable clearance differential structure according to claim 7, characterized in that: When the differential operates at high speed or high torque, the planetary bevel gear flattens the special-shaped elastic planetary gear gasket (6), the contact area is the entire spherical surface, the planetary gear is eccentrically offset by H, and the clearance between the planetary gear shaft and the planetary gear increases by H*tanα, which is beneficial to the differential lubrication of the planetary bevel gear.

9. The design method of the variable clearance differential structure according to claim 8, characterized in that: The meshing position of the planetary bevel gear and the half-shaft bevel gear is biased towards the large end, and the meshing spot is offset by L relative to the small end. The contact fatigue point transmitted to the planetary gear shaft is point G; the meshing point of the planetary bevel gear and the half-shaft gear tooth surface is biased towards the large end, and the distance between the two working force points on the planetary shaft is FG distance = H + L * sinA, where A is the pitch angle of the bevel gear.

10. A variable clearance differential structure prepared using the design method for a variable clearance differential structure according to any one of claims 1 to 9.

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