Planetary gearset limiting device and apparatus using planetary gearset limiting device

Abstract

Disclosed in the present application are a planetary gearset limiting device and an apparatus using a planetary gearset limiting device. In the planetary gearset limiting device, a first angular contact ball bearing and a second angular contact ball bearing, which are fixedly arranged, axially and radially limit a sun gear shaft; a third angular contact ball bearing and a first thrust bearing, which are fixed, axially limit a ring gear, and the first thrust bearing abuts against the side of the ring gear facing away from the sun gear shaft, so as to radially limit the ring gear; and a second thrust bearing and a third thrust bearing, which are fixedly arranged, respectively abut against two sides of a planet carrier in an axial direction, so as to axially limit the planet carrier, and planetary gears are meshed between a sun gear and the ring gear so as to radially limit the planet carrier. The apparatus using a planetary gearset limiting device comprises a planetary gearset limiting device. The planetary gearset limiting device and the apparatus using a planetary gearset limiting device provided in the present application improve the meshing precision between gears of a planetary gearset, improve the precision of transmission, and reduce axial displacement noise of the planetary gearset.

Description

A planetary gear limiting device and equipment using the same

[0001] This application claims priority to an authorized Chinese invention patent filed with the Patent Office of China on August 14, 2023, with application number 202311019955.7 and invention name “A planetary gear limit device and a device using a planetary gear limit device”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of mechanical transmission technology, and in particular to a planetary gear limiting device and equipment using the planetary gear limiting device. Background Art

[0003] The use of a planetary gear in a speed change mechanism can significantly reduce the size and weight of the speed change mechanism. When a speed change mechanism equipped with a planetary gear is used in equipment requiring mechanical transmission, such as vehicles, it is also beneficial to save space in the above equipment.

[0004] A planetary gear set typically consists of a sun gear, a planet carrier, and gears. During operation, one of these components must be fixed, while the other two components are floating, ensuring precise meshing between the three gears. The inventors discovered during the development of their invention that, in actual operation, axial and radial displacement between components in the planetary gear set can reduce meshing precision and increase transmission error. Furthermore, axial movement of floating components can generate noise, impacting performance.

[0005] Summary of the Invention

[0006] The purpose of the present application is to provide a planetary gear limiting device and equipment using the planetary gear limiting device to axially and radially limit the floating parts in the planetary gear, improve the meshing accuracy between the internal gears of the planetary gear, increase the transmission accuracy, and reduce the axial movement noise of the planetary gear.

[0007] The present application provides a planetary gear limiting device, comprising: a sun gear assembly, a ring gear, a planetary gear assembly and a limiting assembly; the sun gear assembly comprises a sun gear shaft and a sun gear fixedly connected, a limiting portion being provided on the sun gear shaft; the ring gear is sleeved on the sun gear shaft, and a supporting wall is provided on the ring gear; the planetary gear assembly comprises a planetary gear and a planetary gear shaft fixedly connected, and a planetary carrier connected to the planetary gear shaft; in the limiting assembly: a first angular contact ball bearing and a second angular contact ball bearing fixedly arranged are both sleeved on the sun gear shaft and abut against the limiting portion along the axis thereof, respectively. The two sides of the axial direction are used to limit the sun gear shaft axially and radially; the third angular contact ball bearing fixed on the sun gear shaft and the fixed first thrust bearing respectively abut against the two sides of the support wall along the axial direction to limit the axial position of the ring gear, and the first thrust bearing simultaneously abuts against the side of the ring gear facing away from the sun gear shaft to limit the radial position of the ring gear; the fixed second thrust bearing and the third thrust bearing respectively abut against the two sides of the planet carrier along the axial direction to limit the axial position of the planet carrier, and the planet gear is engaged between the sun gear and the ring gear to limit the radial position of the planet carrier.

[0008] Optionally, the limiting portion includes an input gear fixedly arranged on the sun gear shaft; the first angular contact ball bearing axially abuts against one side of the input gear, or the first angular contact ball bearing axially abuts against one side of the input gear through a thrust sleeve; the second angular contact ball bearing axially abuts against the other side of the input gear.

[0009] Optionally, the ring gear also includes an engaging portion and a positioning portion, the engaging portion is engaged with the planetary gear, the positioning portion is sleeved on the sun gear shaft, and the engaging portion and the positioning portion are respectively connected to both sides of the support wall along the axial direction; the first thrust bearing abuts against the side of the positioning portion facing away from the sun gear shaft.

[0010] Optionally, a limiting step is provided at a connection between the support wall and the positioning portion on a side facing away from the sun gear shaft, and the first thrust bearing abuts against the limiting step.

[0011] Optionally, the positioning portion extends toward the limiting portion and a needle bearing is provided between the positioning portion and the sun gear shaft.

[0012] Optionally, an abutment portion disposed opposite to the sun gear shaft is provided on the support wall, and the third angular contact ball bearing is radially confined between the abutment portion and the sun gear shaft.

[0013] Optionally, the planetary carrier is located at one end of the sun gear shaft, and a limiting groove is provided on the planetary carrier facing the end face of the sun gear shaft. One side of the second thrust bearing is arranged in the limiting groove and axially abuts against the bottom of the limiting groove, and the other side of the second thrust bearing axially abuts against the end face of the sun gear shaft.

[0014] Optionally, the outer periphery of the end portion of the planetary carrier facing away from the sun gear shaft is axially recessed to define a positioning step, and the third thrust bearing abuts axially against the end face of the positioning step, and the third thrust bearing abuts radially against the side face of the positioning step.

[0015] Optionally, a synchronizer is provided on the sun gear shaft, and the synchronizer is located between the limiting portion and the support wall. A differential is provided at the end of the sun gear shaft.

[0016] The present application provides a device using a planetary gear limiting device, including any one of the planetary gear limiting devices described above.

[0017] The above technical solution has the following beneficial effects:

[0018] The planetary gear limiting device and the equipment using the planetary gear limiting device provided in the present application limit the sun gear shaft axially and radially by means of a fixed first angular contact ball bearing and a fixed second angular contact ball bearing, so that the sun gear fixed to the sun gear shaft has only one rotational degree of freedom. A third angular contact ball bearing fixed to the sun gear shaft and a fixed first thrust bearing limit the ring gear axially and radially, so that the ring gear has only one rotational degree of freedom. A second thrust bearing and a third thrust bearing are fixed to limit the planet carrier axially, and the planetary gear meshes between the sun gear and the ring gear to limit the planet carrier radially, so that the planet carrier has only one rotational degree of freedom. By limiting the floating parts in the planetary gear, the meshing accuracy between the internal gears of the planetary gear is effectively improved, the transmission accuracy is increased, the axial movement noise of the planetary gear is reduced, and the use effect is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a schematic structural diagram of a planetary gear limiting device in one embodiment of the present application.

[0020] FIG2 is a partial enlarged view of A in FIG1 .

[0021] Reference numerals: 1-sun gear shaft, 10-sun gear, 11-limiting portion, 12-thrust sleeve; 2-ring gear, 20-support wall, 21-engaging portion; 22-positioning portion, 23-limiting step, 24-abutting portion; 3-planet carrier, 30-planet gear, 31-planet gear shaft, 32-limiting groove, 33-positioning step; 4-first angular contact ball bearing, 40-second angular contact ball bearing, 41-third angular contact ball bearing; 5-first thrust bearing, 50-second thrust bearing, 51-third thrust bearing; 6-needle roller bearing; 7-synchronizer; 8-differential. DETAILED DESCRIPTION

[0022] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0023] It is easy to understand that according to the technical solution of the present invention, a variety of structural modes and implementation modes can be replaced with each other by those skilled in the art without changing the essential spirit of the present invention. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solution of the present invention and should not be regarded as the entire invention or as a limitation or restriction of the technical solution of the invention.

[0024] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly mentioned in this specification are defined relative to the structure shown in the drawings. They are relative concepts and may vary depending on the location and usage of the device. Therefore, these or other directional terms should not be interpreted as restrictive.

[0025] Please refer to Figure 1 , the present application provides a planetary gear limiting device, including: a sun gear assembly, a ring gear 2, a planetary gear assembly and a limiting assembly.

[0026] It should be noted that, in the present application, “axial direction” refers to the axial direction of the sun gear shaft 1 , and “radial direction” refers to the radial direction of the sun gear shaft 1 .

[0027] Referring to Figure 1 , the sun gear assembly includes a sun gear 10 and a sun gear shaft 1, which are fixedly connected. A limiter 11 is provided on the sun gear shaft 1. Sun gear 10 is secured to the sun gear shaft 1 via a spline connection, interference fit, or integral molding. A ring gear 2 is sleeved on the sun gear shaft 1 and is provided with a support wall 20. The planetary gear assembly includes planetary gears 30 and planetary shafts 31, which are fixedly connected, and a planet carrier 3, which is mated with the planetary shaft 31.

[0028] In the limiting assembly, the first and second angular contact ball bearings 4 and 40 are both fixedly mounted on the sun gear shaft 1 and respectively abut against the two axial sides of the limiting portion 11 to limit the sun gear shaft 1 axially and radially. The first and second angular contact ball bearings 4 and 40 can be fixedly mounted on the outer transmission housing or other fixed structural components to achieve positioning. Referring to Figure 1, the first and second angular contact ball bearings 4 and 40 are mounted on the sun gear shaft 1 to achieve radial positioning of the sun gear shaft 1. The first and second angular contact ball bearings 4 and 40 abut against the two axial sides of the limiting portion 11 to achieve axial positioning of the sun gear shaft 1, thereby limiting the sun gear shaft 1 to only rotational freedom.

[0029] In the limiting assembly, the third angular contact ball bearing 41 fixed to the sun gear shaft 1 and the fixed first thrust bearing 5 respectively abut against the support wall 20 on both sides along the axial direction to limit the ring gear 2 axially. The first thrust bearing 5 also abuts against the side of the ring gear 2 facing away from the sun gear shaft 1 to limit the ring gear 2 radially. The first thrust bearing 5 can be fixedly mounted on the outer transmission housing or other fixed structural components to achieve positioning. Referring to Figure 1, the third angular contact ball bearing 41 is fixed to the sun gear shaft 1 for positioning, and together with the first thrust bearing 5, limits the ring gear 2 along the axial direction of the sun gear shaft 1. The first thrust bearing 5 and the sun gear shaft 1 jointly limit the ring gear 2 along the radial direction of the sun gear shaft 1, so that the ring gear 2 has only rotational freedom.

[0030] In the limiting assembly, the second and third thrust bearings 50, 51 are fixedly mounted on opposite sides of the planet carrier 3 along the axial direction to limit the axial position of the planet carrier 3. The planetary gears 30 engage between the sun gear 10 and the ring gear 2 to limit the radial position of the planet carrier 3. Referring to Figure 1 , the second and third thrust bearings 50, 51 are fixedly mounted on the outer housing or other fixed structural member for positioning. The second and third thrust bearings 50, 51 are respectively mounted on opposite sides of the planet carrier 3 along the axial direction to limit the axial position of the planet carrier 3, so that the planet carrier 3 has only rotational freedom.

[0031] The planetary gear limiting device provided in the embodiment of the present application uses a first angular contact ball bearing 4 and a second angular contact ball bearing 40 fixedly mounted to limit the sun gear shaft 1 axially and radially, so that the sun gear 10 fixed to the sun gear shaft 1 has only one degree of rotational freedom. The third angular contact ball bearing 41 fixedly mounted to the sun gear shaft 1 and the first thrust bearing 5 fixedly mounted to the sun gear shaft 1 limit the ring gear 2 axially and radially, so that the ring gear 2 has only one degree of rotational freedom. The planetary carrier 3 is axially limited by the second thrust bearing 50 and the third thrust bearing 51 fixedly mounted to the sun gear shaft 1, and the planetary carrier 3 is radially limited by the planetary gear 30 meshing between the sun gear 10 and the ring gear 2, so that the planetary carrier 3 has only one degree of rotational freedom. By limiting the floating parts in the planetary gear, the meshing accuracy between the internal gears of the planetary gear is effectively improved, the transmission accuracy is increased, the axial movement noise of the planetary gear shaft is reduced, and the use effect is improved.

[0032] As an optional embodiment, the limiting portion 11 includes an input gear fixedly mounted on the sun gear shaft 1, the first angular contact ball bearing 4 axially abuts against one side of the input gear, or the first angular contact ball bearing 4 axially abuts against one side of the input gear through the thrust sleeve 12; the second angular contact ball bearing 40 axially abuts against the other side of the input gear of the sun gear shaft 1. The input gear can provide power input for the sun gear shaft 1, and the input gear can be integrally formed with the sun gear shaft 1 to ensure the transmission accuracy between the input gear and the sun gear shaft 1. When there is an axial installation distance between the fixed first angular contact ball bearing 4 and the input gear, the thrust sleeve 12 axially abuts between the first angular contact ball bearing 4 and the input gear to compensate for the installation distance. In the embodiment of the present application, the first angular contact ball bearing 4 and the second angular contact ball bearing 40 can be fixed to the housing by a pairing method to increase the stability of the limit.

[0033] As an optional embodiment, the ring gear 2 further includes a meshing portion 21 and a positioning portion 22. The meshing portion 21 meshes with the planetary gears 30, and the positioning portion 22 is sleeved on the sun gear shaft 1. The meshing portion 21 and the positioning portion 22 are respectively connected to opposite axial sides of the support wall 20. The first thrust bearing 5 abuts the side of the positioning portion 22 facing away from the sun gear shaft 1. Referring to FIG1 , the meshing portion 21 can be a sleeve-like structure with a gear disposed on its inner ring, and the positioning portion 22 is also a sleeve-like structure. The meshing portion 21 and the positioning portion 22 are respectively disposed on opposite axial sides of the support wall 20, and the ring gear 2 is sleeved on the sun gear shaft 1 via the positioning portion 22. Referring to FIG1 and FIG2 , the first thrust bearing 5 also abuts the side of the positioning portion 22 facing away from the sun gear shaft 1 to radially position the positioning portion 22, thereby radially limiting the ring gear 2. In the embodiment of the present application, the third angular contact ball bearing 41 may also be fixed on the sun gear shaft 1 to achieve stable positioning of the support wall 20 .

[0034] Furthermore, the outer diameter of the positioning portion 22 is smaller than the outer diameter of the meshing portion 21, the support wall 20 and the positioning portion 22 are bent at the connection, the first thrust bearing 5 abuts against the side of the support wall 20 and the positioning portion 22 at the bent connection facing away from the sun gear shaft 1, and the third angular contact ball bearing 41 abuts against the side of the support wall 20 and the positioning portion 22 at the bent connection facing the sun gear shaft 1, so as to jointly limit the support wall 20 axially.

[0035] As an optional embodiment, a limiting step 23 is provided at the connection between the support wall 20 and the positioning portion 22 on the side facing away from the sun gear shaft 1, and the first thrust bearing 5 abuts against the limiting step 23. Referring to Figures 1 and 2 , the support wall 20 and the positioning portion 22 are connected by an arc transition on the side facing away from the sun gear shaft 1. The provided limiting step 23 provides an effective abutment surface for the first thrust bearing 5, which helps to enhance the limiting effect of the first thrust bearing 5 on the support wall 20.

[0036] As an optional embodiment, the positioning portion 22 extends toward the limiting portion 11 and a needle roller bearing 6 is disposed between the positioning portion 22 and the sun gear shaft 1. The positioning portion 22 may be a sleeve-shaped structure. The positioning portion 22 is rotatably mounted on the sun gear shaft 1 via the needle roller bearing 6. This prevents the portion of the ring gear 2 extending from the sun gear shaft 1 from tilting, thereby improving the stability of the ring gear 2.

[0037] As an optional embodiment, the support wall 20 is provided with an abutment portion 24 positioned opposite the sun gear shaft 1. The third angular contact ball bearing 41 is radially confined between the abutment portion 24 and the sun gear shaft 1. Referring also to Figure 1 , the abutment portion 24 can be a cylindrical structure. The third angular contact ball bearing 41 supports the ring gear 2 circumferentially via the abutment portion 24, thereby enhancing the operational stability of the ring gear 2. Confining the third angular contact ball bearing 41 within the annular space defined by the abutment portion 24, the support wall 20, and the sun gear shaft 1 also enhances the operational stability and reliability of the third angular contact ball bearing 41.

[0038] As an optional embodiment, the planet carrier 3 is located at one end of the sun gear shaft 1. A retaining groove 32 is defined on the end surface of the planet carrier 3 facing the sun gear shaft 1. One side of the second thrust bearing 50 is disposed within the retaining groove 32 and axially abuts against the bottom of the retaining groove 32. The other side of the second thrust bearing 50 axially abuts against the end surface of the sun gear shaft 1. Referring also to Figure 1 , the retaining groove 32 ensures a suitable installation space for the second thrust bearing 50, thereby axially limiting the planet carrier 3. Furthermore, the abutment of the other side of the second thrust bearing 50 against the end surface of the sun gear shaft 1 further enhances the axial retention of the sun gear shaft 1.

[0039] As an optional embodiment, the outer circumference of the end of the planet carrier 3 facing away from the sun gear shaft 1 is axially recessed to define a positioning step 33. The third thrust bearing 51 axially abuts the end face of the positioning step 33 and radially abuts the side face of the positioning step 33. Referring also to Figure 1 , the end face of the positioning step 33 is formed by the outer circumferential recess of the end face of the planet carrier 3 and is perpendicular to the axial direction of the sun gear shaft 1. The side face of the positioning step 33 is formed by the outer circumferential recess of the end face of the planet carrier 3 and is parallel to the axial direction of the sun gear shaft 1. The third thrust bearing 51 axially abuts the end face of the positioning step 33 and, together with the second thrust bearing 50, axially limits the planet carrier 3. By abutting the side face of the positioning step 33, the third thrust bearing 51 provides auxiliary radial positioning for the planet carrier 3, thereby increasing its stability.

[0040] As an optional embodiment, a synchronizer 7 is provided on the sun gear shaft 1, located between the stop 11 and the support wall 20. A differential 8 is provided at the end of the sun gear shaft 1. The synchronizer 7 in this embodiment is sleeved and mounted on the sun gear shaft 1, located between the support wall 20 and the stop 11, resulting in a compact, stable, and reliable structure. The synchronizer 7 in this embodiment can selectively disconnect the differential 8 from the sun gear shaft 1 to provide a neutral mode, or connect the differential 8 to the sun gear shaft 1 to provide a power transmission mode.

[0041] Please refer to Figure 1 at the same time. The differential 8 abuts against the end of the planet carrier 3 in the axial direction. The outer side surface of the abutment between the differential 8 and the planet carrier 3 is flush with the side surface of the positioning step 33. The third thrust bearing 51 abuts against the outer side surface of the differential 8 and the side surface of the positioning step 33 at the same time, and can also play a role in radial limiting the differential 8.

[0042] The present application also provides a device using a planetary gear limiter, including the planetary gear limiter described in any of the above embodiments. In the present application, the device using the planetary gear limiter may include vehicles (fuel vehicles, electric vehicles, etc.), heavy machinery, medical equipment, robots, ships, aircraft, spacecraft, and other equipment requiring mechanical transmission.

[0043] Please refer to Figure 1, taking the device using the planetary gear limit device as a vehicle as an example, the power output end of the sun gear shaft 1 is connected to the differential 8, the sun gear shaft 1 coaxially drives one input end of the differential 8, and the other input end of the differential 8 coaxially drives the clutch component or the brake component to achieve differential drive.

[0044] The device using a planetary gear limiting device provided in the embodiment of the present application axially and radially limits the sun gear shaft 1 by means of a fixed first angular contact ball bearing 4 and a fixed second angular contact ball bearing 40, so that the sun gear 10 fixed on the sun gear shaft 1 has only one rotational degree of freedom; axially and radially limits the ring gear 2 by means of a fixed third angular contact ball bearing 41 and a fixed first thrust bearing 5 on the sun gear shaft 1, so that the ring gear 2 has only one rotational degree of freedom; axially limits the planetary carrier 3 by means of a fixed second thrust bearing 50 and a third thrust bearing 51, radially limits the planetary carrier 3 by means of a planetary gear 30 meshing between the sun gear 10 and the ring gear 2, so that the planetary carrier 3 has only one rotational degree of freedom, thereby limiting the floating parts in the planetary gear set, effectively improving the meshing accuracy between the internal gears of the planetary gear set, increasing the accuracy of the transmission, reducing the axial movement noise of the planetary gear set, and improving the use effect.

[0045] The above are only the principles and preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several other variations can be made based on the principles of the present invention, which should also be considered as the scope of protection of the present invention.

Claims

1. A planetary gear limit device, characterized in that: include: Sun gear assembly, ring gear, planetary gear assembly and limit assembly; The sun gear assembly comprises a sun gear shaft and a sun gear that are fixedly connected, and a limiting portion is provided on the sun gear shaft; The gear ring is sleeved on the sun gear shaft, and a supporting wall is provided on the gear ring; The planetary gear assembly comprises a planetary gear and a planetary gear shaft that are fixedly connected, and a planetary carrier that is cooperatively connected to the planetary gear shaft; In the limiter assembly: The first angular contact ball bearing and the second angular contact ball bearing are fixedly mounted on the sun gear shaft and respectively abut against two sides of the limiting portion in the axial direction to limit the sun gear shaft in the axial direction and in the radial direction; The third angular contact ball bearing fixed on the sun gear shaft and the first thrust bearing fixedly arranged are respectively abutted against two sides of the support wall in the axial direction to limit the axial position of the gear ring, and the first thrust bearing is simultaneously abutted against a side of the gear ring facing away from the sun gear shaft to limit the radial position of the gear ring; The second thrust bearing and the third thrust bearing are fixedly arranged to respectively abut against two sides of the planet carrier in the axial direction to limit the axial position of the planet carrier, and the planet gear is meshed between the sun gear and the ring gear to limit the radial position of the planet carrier; The limiting part includes an input gear fixedly arranged on the sun gear shaft; The first angular contact ball bearing abuts against one side of the input gear in the axial direction, or the first angular contact ball bearing abuts against one side of the input gear in the axial direction through a thrust sleeve; The second angular contact ball bearing abuts against the other side of the input gear in the axial direction.

2. The planetary gear limiting device according to claim 1, characterized in that: The gear ring further comprises a meshing portion and a positioning portion, wherein the meshing portion meshes with the planetary gear, the positioning portion is sleeved on the sun gear shaft, and the meshing portion and the positioning portion are respectively connected to two sides of the support wall along the axial direction; The first thrust bearing abuts against a portion of the positioning portion facing away from the sun gear shaft. side.

3. The planetary gear limiting device according to claim 2, characterized in that: A limiting step is provided at a connection between the support wall and the positioning portion on a side facing away from the sun gear shaft, and the first thrust bearing abuts against the limiting step.

4. The planetary gear limiting device according to claim 2, characterized in that: The positioning portion extends toward the limiting portion and a needle bearing is disposed between the positioning portion and the sun gear shaft.

5. The planetary gear limiting device according to claim 2, characterized in that: The support wall is provided with an abutment portion which is arranged opposite to the sun gear shaft, and the third angular contact ball bearing is radially limited between the abutment portion and the sun gear shaft.

6. The planetary gear limiting device according to claim 1, characterized in that: The planet carrier is located at one end of the sun gear shaft, and a limiting groove is provided on the planet carrier toward the end face of the sun gear shaft. One side of the second thrust bearing is arranged in the limiting groove and axially abuts against the bottom of the limiting groove, and the other side of the second thrust bearing axially abuts against the end face of the sun gear shaft.

7. The planetary gear limiting device according to claim 6, characterized in that: The outer periphery of the end of the planet carrier facing away from the sun gear shaft is axially concave to define a positioning step, and the third thrust bearing abuts against the end face of the positioning step axially and the side face of the positioning step radially.

8. The planetary gear limiting device according to any one of claims 1 to 7, characterized in that: A synchronizer is arranged on the sun gear shaft, and the synchronizer is located between the limiting portion and the supporting wall. A differential is arranged at the end of the sun gear shaft.

9. A device using a planetary gear limiter, characterized in that: It comprises the planetary gear limiting device as described in any one of claims 1 to 8.

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