Differential mechanism and power system
By using needle roller bearings in the differential to connect the planet wheel and the planetary pin shaft to replace sliding friction, the problems of large friction and ablation in the existing differential are solved, and the effect of reducing friction and ablation is achieved, which is suitable for high-speed differential and large torque conditions.
Patent Information
- Application Number
- CN202421408020.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-19
- Publication Date
- 2025-03-18
- Estimated Expiration
- 2034-06-19
AI Technical Summary
In the existing differential structure, the sliding friction pair coefficient between the planetary gear and the planet pin shaft is relatively large, resulting in a greater frictional work under high speed difference and large torque conditions, which is easy to cause ablation. At the same time, the rigidity of the cantilever planetary gear is weak, which is easy to cause frictional ablation.
Needle roller bearings are used to connect the planet wheel and the planetary pin assembly to replace sliding friction and reduce friction work. By setting multiple needle roller bearings and retaining rings, the contact area and limit effect are increased, and friction ablation is reduced.
It effectively reduces the frictional work of the planet wheel when it rotates, reduces the ablation of the planet wheel and planet pin shafts, improves the rigidity and reliability of the overall structure, and is especially suitable for high-speed differential and large torque conditions.
Smart Images
Figure CN222633767U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of differentials, in particular to a differential and a power system. Background Art
[0002] The rear axle of the tractor is generally equipped with a differential structure, which can realize the differential of the cruise ship during normal driving or working. In addition, when the tractor is stuck in the ground, the differential lock can be used to cancel the differential of the cruise ship, thereby helping the tractor to get out of trouble.
[0003] However, in the existing differential structure, the planetary gear and the planetary pin are sliding friction pairs, and the friction coefficient of the sliding friction pair is relatively large. Under the condition of high speed difference and large torque, the planetary gear will generate large friction work when it rotates differentially, which is easy to cause the planetary gear and the planetary pin to burn. In addition, the planetary gears of the existing differential are generally cantilevered, and the rigidity of the cantilever structure is relatively weak. When the planetary gears are meshed and stressed, it is easy to cause the planetary pin to have a large deflection change. This deflection deformation will further weaken the contact area of the friction pair between the planetary pin and the planetary gear, which is easy to cause stress concentration and lead to friction burning. Utility Model Content
[0004] The utility model provides a differential and a power system, which are used to reduce the friction work of the differential and reduce the ablation of planetary wheels and planetary pin shafts.
[0005] In a first aspect, the utility model provides a differential, comprising a differential housing, a planetary pin assembly, a plurality of planetary gears, two half-shaft gears and two sun gear shafts;
[0006] The plurality of planetary gears are located between the two side-shaft gears, and each of the planetary gears is respectively connected to the two side-shaft gears in a transmission manner;
[0007] The planetary pin assembly is fixedly connected to the differential housing, and each of the planetary wheels is connected to the planetary pin assembly through at least two needle bearings, the at least two needle bearings are arranged along the axial direction of the planetary wheel, and both ends of each needle bearing are provided with retaining rings;
[0008] The two sun gear shafts are fixedly connected to the two side gears respectively.
[0009] The differential provided by the utility model utilizes needle roller bearings to connect the planetary gear and the planetary pin shaft assembly, and replaces the existing sliding friction with rolling friction, which is beneficial to reducing the friction work when the planetary gear rotates and reducing the ablation of the planetary gear and the planetary pin shaft assembly. Since two or more needle roller bearings are provided, there are multiple contact areas between the multiple needle roller bearings and the planetary pin shaft assembly, which can effectively reduce the impact of the reduction in contact area caused by the deflection deformation of the planetary pin shaft, thereby further reducing friction ablation. By respectively providing retaining rings at both ends of the needle roller bearing, the retaining rings can be used to limit the needle roller bearing, avoiding the displacement of the needle roller relative to the planetary pin shaft, which leads to a reduction in contact area, thereby further reducing friction ablation. Therefore, the differential in the utility model can reduce the friction work when the planetary gear rotates and reduce the friction ablation of the planetary gear and the planetary pin shaft.
[0010] In some possible implementation schemes, in the at least one needle bearing connected to each of the planetary gears, two adjacent needle bearings share one retaining ring.
[0011] In some possible implementations, the planetary pin assembly includes a first planetary pin, two second planetary pins, and a cross sleeve;
[0012] The two second planetary pins are respectively located on two opposite sides of the first planetary pin, and the second planetary pin is perpendicular to the first planetary pin;
[0013] The two ends of the first planetary pin are respectively fixedly connected to the differential housing, the cross sleeve is fixedly connected to the middle of the first planetary pin, the first end of the second planetary pin is fixedly connected to the differential housing, and the second end of the second planetary pin is fixedly connected to the cross sleeve.
[0014] In some possible embodiments, a lubricating oil groove is provided between the cross shaft sleeve and the first planetary pin shaft, and a lubricating oil groove is provided between the cross shaft sleeve and the second planetary pin shaft, and the lubricating oil grooves are interconnected. A lubricating oil channel is provided inside at least one of the sun gear shafts, and the lubricating oil channel is connected to the lubricating oil groove.
[0015] In some possible implementation schemes, a nozzle is provided at one end of the lubricating oil channel close to the cross sleeve, and one end of the nozzle is located inside the cross sleeve and communicated with the lubricating oil groove.
[0016] In some possible implementation schemes, the first planetary pin shaft is connected to the differential housing via an elastic pin.
[0017] In some possible implementation schemes, the invention further includes a differential end cover and a bevel gear, wherein the differential end cover is fixedly connected to the differential housing, and the bevel gear is arranged on the differential end cover;
[0018] The bevel gear is drivingly connected to the half-shaft gear to output power to the half-shaft gear.
[0019] In some possible implementation schemes, a planetary wheel ball pad is provided between the planetary wheel and the differential housing.
[0020] In some possible implementation schemes, a gasket is provided between the side gear and the differential housing.
[0021] In a second aspect, the utility model provides a power system, comprising a differential as described in any possible implementation scheme of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 A schematic cross-sectional structure diagram of a differential in an embodiment of the utility model;
[0023] Figure 2 It is a schematic cross-sectional structure diagram of the differential at another angle in the embodiment of the utility model.
[0024] In the figure:
[0025] 10-differential case; 20-differential end cover; 30-planetary pin assembly; 31-first planetary pin; 32-second planetary pin; 33-cross sleeve; 40-planetary gear; 50-semi-axle gear; 60-sun gear shaft; 61-lubricating oil channel; 62-nozzle; 70-bevel gear; 80-needle bearing; 90-retaining ring; 100-planetary ball pad; 110-gasket; 120-elastic pin. DETAILED DESCRIPTION
[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0027] refer to Figure 1 and Figure 2 The differential in the embodiment of the utility model may include a differential case 10, a differential end cover 20, a planetary pin assembly 30, a plurality of planetary gears 40, two half-shaft gears 50, two sun gear shafts 60 and a bevel gear 70, wherein the differential end cover 20 is fixedly connected to the differential case 10.
[0028] A plurality of planetary gears 40 are located between the two side gears 50, and each planetary gear 40 is respectively meshed with the left and right side gears 50 to achieve transmission connection between the planetary gears 40 and the side gears 50. The number of planetary gears 40 can be designed according to actual needs. In this embodiment, four planetary gears 40 are arranged between the two side gears 50, and the four planetary gears 40 can be evenly distributed along the circumferential direction.
[0029] The planetary pin assembly 30 is fixedly connected to the differential housing 10. Specifically, Figure 2 As shown, the planetary pin assembly 30 may include a first planetary pin 31, two second planetary pins 32 and a cross sleeve 33. The two ends of the first planetary pin 31 are respectively fixedly connected to the differential case 10. For example, the first planetary pin 31 may be fixed to the differential case 10 by an elastic pin 120 to ensure a stable connection between the first planetary pin 31 and the differential case 10.
[0030] The two second planetary pins 32 are respectively located on opposite sides of the first planetary pin 31, and the second planetary pins 32 are perpendicular to the first planetary pin 31. The cross sleeve 33 is fixedly connected to the middle of the first planetary pin 31, and the first end of each second planetary pin 32 is fixedly connected to the differential case 10, and the second end is fixedly connected to the cross sleeve 33. In this way, the first planetary pin 31 and the two second planetary pins 32 form a structurally stable "cross" structure under the fixing action of the differential case 10 and the cross sleeve 33, thereby improving the overall rigidity of the planetary pin assembly 30.
[0031] In this embodiment, the length of the first planetary pin 31 is greater than that of the second planetary pin 32. Among the four planetary gears 40, two planetary gears 40 are respectively sleeved on the first planetary pin 31 at the two sides of the cross sleeve 33, and each planetary gear 40 can rotate around the axis of the first planetary pin 31 relative to the first planetary pin 31. The other two planetary gears 40 are respectively sleeved on the two second planetary pins 32, and each planetary gear 40 can rotate around the axis of the second planetary pin 32 relative to the second planetary pin 32.
[0032] In addition, continue to refer to Figure 2 Each planetary gear 40 sleeved on the first planetary pin 31 is connected to the first planetary pin 31 through at least two needle bearings 80, and a retaining ring 90 is provided at both ends of each needle bearing 80. The planetary gear 40 sleeved on the second planetary pin 32 is connected to the second planetary pin 32 through at least two needle bearings 80, and a retaining ring 90 is also provided at both ends of each needle bearing 80. Each retaining ring 90 is sleeved on the planetary pin and fixedly connected to the planetary pin to ensure that the retaining ring 90 and the planetary pin are relatively fixed, so that the two retaining rings 90 have a good limiting effect on the needle bearing 80.
[0033] As an optional embodiment, Figure 2 As shown, two needle bearings 80 are provided between the planetary gear 40 and the first planetary pin 31, and the two needle bearings 80 are arranged along the axial direction of the first planetary pin 31. At this time, the two needle bearings 80 can share a retaining ring 90. Similarly, two needle bearings 80 are provided between the planetary gear 40 and the second planetary pin 32, and the two needle bearings 80 are arranged along the axial direction of the second planetary pin 32. At this time, the two needle bearings 80 can also share a retaining ring 90. In this embodiment, by respectively providing retaining rings 90 at both ends of the needle bearing 80, the retaining rings 90 can be used to ensure the relative position between each needle bearing 80 and the planetary pin, thereby preventing the needle roller from being displaced and affecting the contact area between the needle roller and the planetary pin.
[0034] In some other embodiments, the number of needle bearings 80 connected between each planetary gear 40 and the planetary pin can also be three, four, etc. The number of needle bearings 80 can be designed according to actual needs. In addition, the plurality of needle bearings 80 are arranged along the axial direction of the planetary gear 40, and each two adjacent needle bearings 80 can share a retaining ring 90, thereby saving costs.
[0035] It should be understood that in this embodiment, the planetary gear 40 and the planetary pin shaft are connected through the needle roller bearing 80, and the sliding friction in the prior art is replaced by rolling friction, which greatly reduces the friction work when the planetary gear 40 rotates, thereby reducing the ablation of the planetary gear and the planetary pin shaft. Secondly, since the overall rigidity of the planetary pin shaft assembly 30 in this embodiment is good, when the planetary gear 40 is engaged, the deflection deformation of the planetary pin shaft is reduced, thereby reducing the impact of the reduction in the contact area of the friction pair caused by the deflection deformation of the planetary pin shaft, and further reducing friction ablation. In addition, since the planetary pin shaft is subjected to the radial force of the planetary gear 40, it is inevitable that deflection deformation will occur, thereby reducing the contact area between the needle roller and the planetary pin shaft and increasing the contact stress. When two or more needle roller bearings 80 are provided, the contact area between the needle roller and the planetary pin shaft can be increased, thereby further reducing the impact of the reduction in the contact area caused by the deflection deformation of the planetary pin shaft, and increasing reliability.
[0036] It is worth noting that a plurality of needle roller bearings 80 are provided in the present embodiment, which can withstand large torque at low speed. Therefore, the solution in the present embodiment is particularly suitable for working conditions of high speed difference and large torque.
[0037] Further, continue to refer to Figure 1, the two sun gear shafts 60 are fixedly connected to the two side gears 50 respectively. Specifically, in each pair of sun gear shafts 60 and side gears 50, the side gear 50 is sleeved on one end of the sun gear shaft 60, and the side gear 50 and the sun gear shaft 60 can rotate synchronously around the axis of the sun gear shaft 60. The bevel gear 70 is arranged on the differential end cover 20, and the bevel gear 70 is meshed with one of the side gears 50, so that the bevel gear 70 and the side gear 50 can achieve transmission connection, and the bevel gear 70 can output power to the side gear 50 meshed with it, so that the power is output through the sun gear shaft 60 connected to the side gear 50. At the same time, the side gear 50 outputs power to the other side gear 50 through the power transmission of the planetary gear 40, so that the power is output through the other sun gear shaft 60.
[0038] At least one sun gear shaft 60 is provided with a lubricating oil passage 61 inside, and the lubricating oil passage 61 extends along the axial direction of the sun gear shaft 60. A lubricating oil groove (not shown in the figure) is provided between the cross shaft sleeve 33 and the first planetary pin shaft 31 and the second planetary pin shaft 32. Specifically, a lubricating oil groove is provided between the cross shaft sleeve 33 and the first planetary pin shaft 31, and a lubricating oil groove is also provided between the cross shaft sleeve 33 and the second planetary pin shaft 32, and the lubricating oil grooves are connected to each other. In addition, each lubricating oil groove is provided with an opening at one end facing the planetary gear 40, and one end of the lubricating oil passage 61 can be connected to one of the lubricating oil grooves, and the lubricating oil in the lubricating oil passage 61 can enter the lubricating oil groove, and then flow from each lubricating oil groove to each planetary gear 40, thereby realizing fixed-point lubrication of the needle bearings 80 connected to each planetary gear 40, so as to further reduce friction ablation.
[0039] Specifically, a nozzle 62 is provided at one end of the lubricating oil passage 61, and one end of the nozzle 62 can extend into the cross sleeve 33 and communicate with the lubricating oil passage 61. The nozzle 62 can be used to control the amount of lubricating oil, which can not only improve the lubrication effect of the needle bearing 80, but also increase the amount of lubricating oil for the differential system as a whole.
[0040] As an optional implementation scheme, both sun gear shafts 60 are provided with lubricating oil channels 61 , and each end of the lubricating oil channel 61 is provided with a nozzle 62 to improve the lubrication efficiency and ensure that the amount of lubricating oil in each needle bearing 80 is uniform.
[0041] Further, continue to refer to Figure 1 A planetary wheel ball washer 100 is provided between the planetary wheel 40 and the differential housing 10 to facilitate the rotation of the planetary wheel 40 relative to the differential housing 10. Similarly, a washer 110 is provided between the side gear 50 and the differential housing 10 to facilitate the rotation of the side gear 50 relative to the differential housing 10, thereby improving the stability of the overall structure of the differential.
[0042] Based on the same design concept, an embodiment of the utility model can also provide a power system, which includes a differential as described in the above embodiment.
[0043] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.
Claims
1. A differential, characterized in that: It includes a differential case, a planetary pin assembly, a plurality of planetary gears, two half-shaft gears and two sun gear shafts; The plurality of planetary gears are located between the two side-shaft gears, and each of the planetary gears is respectively connected to the two side-shaft gears in a transmission manner; The planetary pin assembly is fixedly connected to the differential housing, and each of the planetary wheels is connected to the planetary pin assembly through at least two needle bearings, the at least two needle bearings are arranged along the axial direction of the planetary wheel, and both ends of each needle bearing are provided with retaining rings; The two sun gear shafts are fixedly connected to the two side gears respectively.
2. The differential according to claim 1, characterized in that: Among the at least two needle roller bearings connected to each of the planetary gears, two adjacent needle roller bearings share one retaining ring.
3. The differential according to claim 1, characterized in that: The planetary pin assembly comprises a first planetary pin, two second planetary pins and a cross sleeve; The two second planetary pins are respectively located on two opposite sides of the first planetary pin, and the second planetary pin is perpendicular to the first planetary pin; The two ends of the first planetary pin are respectively fixedly connected to the differential housing, the cross sleeve is fixedly connected to the middle of the first planetary pin, the first end of the second planetary pin is fixedly connected to the differential housing, and the second end of the second planetary pin is fixedly connected to the cross sleeve.
4. The differential according to claim 3, characterized in that: A lubricating oil groove is provided on the cross shaft sleeve and the first planetary pin shaft, and a lubricating oil groove is provided between the cross shaft sleeve and the second planetary pin shaft, and the lubricating oil grooves are interconnected. A lubricating oil channel is provided inside at least one of the sun gear shafts, and the lubricating oil channel is connected to the lubricating oil groove.
5. The differential according to claim 4, characterized in that: A nozzle is provided at one end of the lubricating oil passage close to the cross sleeve, and one end of the nozzle is located inside the cross sleeve and communicated with the lubricating oil groove.
6. The differential according to claim 3, characterized in that: The first planetary pin shaft is connected to the differential housing through an elastic pin.
7. The differential according to claim 1, characterized in that: It also includes a differential end cover and a bevel gear, wherein the differential end cover is fixedly connected to the differential housing, and the bevel gear is arranged on the differential end cover; The bevel gear is drivingly connected to the half-shaft gear to output power to the half-shaft gear.
8. The differential according to claim 1, characterized in that: A planetary wheel ball pad is provided between the planetary wheel and the differential housing.
9. The differential according to claim 1, characterized in that: A gasket is provided between the side gear and the differential housing.
10. A power system, characterized in that: It comprises a differential as claimed in any one of claims 1 to 9.