A planetary reduction gear and a starter

Abstract

The present invention provides a planetary reduction device, which includes a sun gear, a planetary gear, an internal gear ring, a one-way clutch, a combined shock pad and a housing. The sun gear, the planetary gear and the internal gear ring are meshed with each other in a planetary gear set structure. The one-way clutch is the planet carrier of the planetary gear. The combined shock pad is arranged between the internal gear ring and the housing. An axial boss is provided on the outer wall of the internal gear ring. A through hole corresponding to the boss is provided on the combined shock pad. The boss passes through the through hole and protrudes from the outer wall of the combined shock pad. A groove for accommodating the boss is provided on the inner wall of the housing. A first elastic element, a second elastic element, a first stop block and a second stop block are arranged in the groove. The first stop block limits the internal gear ring within a first limit when torque is output by the one-way clutch. The second stop block limits the internal gear ring within a second limit when torque is input to the one-way clutch. A starter is also provided.

Description

Technical Field

[0001] The invention belongs to the technical field of starters, and in particular relates to a planetary reduction gear with a protection function and a starter comprising the planetary reduction gear. Background Art

[0002] In the prior art, the starter deceleration system includes a planetary gear, an inner gear ring, a gear ring seat, and a combined shock-absorbing pad arranged between the inner gear ring and the gear ring seat. The combined shock-absorbing pad mainly plays a buffering role when the starter starts to crank the engine, reduces the current at that moment, and protects the mechanical part of the starter. In the prior art, the combined shock-absorbing pad material is made of rubber material. If the hardness is too high, the shock-absorbing effect is not obvious. If the hardness is too low, the combined shock-absorbing pad will break and fail. In addition, under the action of a large instantaneous impact force from the outside, the rubber combined shock-absorbing pad is also prone to crush failure.

[0003] The invention patent "Planetary gear reducer type automobile starter with torque limiting device", authorization announcement number CN1118623C, discloses an automobile starter with a motor, the output shaft of the motor rotates and drives a coaxial clutch through a planetary gear reducer, the reducer has a cylindrical housing, a toothed ring gear is rotatably mounted on the housing, the internal ring gear is connected to the housing through a torque limiting friction device, the torque limiting device is axially mounted between the ring gear and a side plate of the housing, the torque limiting device is composed of at least one annular friction side surface of the ring gear, and the side surface is axially elastically supported on a reaction surface connected to the housing.

[0004] The invention "Reducer with retarder for starter", publication number: CN1594871A, discloses a reducer for starter, which is composed of a housing and a reduction gear ring, the reduction gear ring is fixed in the housing, and also includes a buffer claw, a buffer member, and a buffer chamber opened at the contact between the outer wall of the reduction gear ring and the inner wall of the housing, the buffer claw and the buffer member are combined into a buffer device and inserted into the buffer chamber. During use, the invention partially relieves the workload increased at the start of the starter by deformation of the buffer member, thereby protecting the motor and other components.

[0005] In addition, the reduction gear is an important part of the starter transmission system, and its normal operation is directly related to the normal use of the starter. During the starting process, some parts of the reduction gear will generate a high speed, and there are transmissions between gears and rotating supports of bearings, and the internal cleanliness must be kept high. The transmission shock absorber also has great deficiencies in protecting the system. Summary of the invention

[0006] In view of the above problems, the present invention provides a planetary reduction device, which includes a sun gear, a planetary gear, an internal gear ring, a one-way clutch, a combined shock pad, and a housing. The sun gear, the planetary gear, and the internal gear ring are meshed with each other in a planetary gear set structure. The one-way clutch serves as the planet carrier of the planetary gear. The combined shock pad is disposed between the internal gear ring and the housing. An axial boss is provided on the outer wall of the internal gear ring. A through hole corresponding to the boss is provided on the combined shock pad. The boss passes through the through hole and protrudes from the outer wall of the combined shock pad. A groove for accommodating the boss is provided on the inner wall of the housing. The space between the first inner side surface of the groove and the first outer side surface of the boss is the first space. A first elastic element and a first stop block are arranged in the first space. The two ends of the first elastic element respectively contact the first inner side surface and the first outer side surface. The first stop block limits the internal gear ring within the first limit when torque is output by the one-way clutch. The space between the second inner side surface of the groove and the second outer side surface of the boss is the second space. A second elastic element and a second stop block are arranged in the second space. The two ends of the second elastic element respectively contact the second inner side surface and the second outer side surface. The second stop block limits the internal gear ring within the second limit when torque is input to the one-way clutch.

[0007] Further, the available compression stroke of the first elastic element is less than or equal to the available compression stroke of the second elastic element.

[0008] Preferably, the first elastic element and the second elastic element are compression springs or elastic blocks.

[0009] Preferably, the first elastic element and the second elastic element are arranged on the outer wall of the combined shock pad.

[0010] Preferably, the first stop block and the second stop block are arranged on the outer wall of the combined shock pad.

[0011] Preferably, the first stop block and the second stop block are respectively arranged on the first outer side surface and the second outer side surface.

[0012] Preferably, the first stop block and the second stop block are respectively arranged on the first inner side surface and the second inner side surface.

[0013] Preferably, a plurality of such bosses are circumferentially arranged on the outer wall of the internal gear ring. The housing is correspondingly provided with a plurality of such grooves, and the combined shock pad is correspondingly provided with a plurality of such through holes.

[0014] Preferably, the plurality of bosses are evenly distributed on the outer wall of the internal gear ring.

[0015] Preferably, the combined shock pad further includes a bottom ring. The bottom ring of the combined shock pad has a clearance fit with the one-way clutch. At least one circumferential sealing rib is provided on the inner side surface of the bottom ring.

[0016] The present invention further provides a starter, comprising: an electric motor; a planetary reduction gear as described above, wherein the sun gear of the planetary reduction gear is connected to the drive shaft of the electric motor, and the one-way clutch of the planetary reduction gear has a gear shaft, and a drive gear for outputting torque is provided at the output end of the gear shaft; a clutch device, comprising an electromagnetic switch and a fork cam disc, the fork cam disc is arranged at the output end, and the electromagnetic switch drives the fork cam disc to connect the drive gear with the output end for torque output, or disconnect the drive gear from the output end to cut off torque output. Description of the Drawings

[0017] Figure 1 is a three-dimensional assembly drawing of the starter of the present invention.

[0018] Figure 2 is a schematic structural diagram of the internal gear ring and the combined shock pad of the present invention.

[0019] Figure 3 is a schematic structural diagram of the planetary reduction gear of the present invention.

[0020] Figure 4 is a schematic diagram of the stop block arrangement in the first embodiment of the present invention.

[0021] Figure 5 is a schematic diagram of the stop block arrangement in the second embodiment of the present invention.

[0022] Figure 6 is a schematic diagram of the stop block arrangement in the third embodiment of the present invention.

[0023] Figure 7 is a schematic diagram of the sealing fit between the combined shock pad and the one-way clutch in the fourth embodiment of the present invention.

[0024] Among them, the reference numerals are:

[0025] 1: C snap ring 2: drive gear 3: meshing spring

[0026] 4: electromagnetic switch fastening screw 5: drive end cover 6: pivot pin seat

[0027] 7: fork cam disc 8: shaft circlip 9: retaining plate

[0028] 10: one-way clutch 10-1: gear shaft 11: middle cover

[0029] 11-1: groove 12: planetary gear 13: combined shock pad

[0030] 13-1: through hole 13-2: first elastic element 13-3: second elastic element

[0031] 13-4: bottom ring 13-5: sealing rib 14: internal gear ring

[0032] 14 - 1: Boss 15: Electromagnetic switch 15 - 1: Plunger

[0033] 16: Motor 17: Through bolt 18: Sun gear

[0034] 19 - 1: First stop block 19 - 2: Second stop block Detailed implementation manners

[0035] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further details the planetary reduction gear device with protection function and the starter of the present invention in conjunction with the accompanying drawings. It should be understood that the specific implementation methods described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] The technical problem to be solved by the present invention is: to provide a planetary reduction gear device for application in a starter to avoid the problem that the impact is too large when the starter starts to crank the engine instantaneously and damages the combined shock pad of the ring gear seat. The planetary reduction gear device realizes advantages such as more convenient adjustment of the elastic coefficient and longer service life than traditional rubber shock absorption by embedding elastic elements in the combined shock pad, so as to achieve the purpose of effective shock absorption. At the same time, by means of the stop blocks that limit the clockwise and counterclockwise rotation amplitudes of the internal gear ring, the service life of the elastic elements is prevented from being damaged by excessive impact, and the design of the bidirectional rotation stop blocks can meet the starters with different steering outputs. The present invention also designs a sealing rib at the place where the combined shock pad contacts the one - way clutch, which can ensure that the grease in the working area of the planetary gear will not be thrown out, and can also ensure that impurities will not enter this area and affect its service life.

[0037] Figure 1 is the three - dimensional assembly drawing of the starter of the present invention. As Figure 1As shown in the figure, the starter of the present invention includes: a C snap ring 1, a drive gear 2, an engagement spring 3, an electromagnetic switch fastening screw 4, an end cover 5, a pivot seat 6, a fork cam disc 7, a shaft circlip 8, a retaining plate 9, a one-way clutch 10, a middle cover 11, a planetary gear 12, a combined shock pad 13, an internal gear ring 14, an electromagnetic switch 15, a motor 16, a through bolt 17, and a sun gear 18; wherein, the planetary gear 12, the internal gear ring 14, and the sun gear 18 are meshed with each other in a planetary gear set structure, the one-way clutch 10 is the planet carrier of the planetary gear set structure, and the planetary gear 12 is arranged on the one-way clutch 10 to form a planetary reduction gear; in the starter of the present invention, power is input from the sun gear 18 and output from the one-way clutch 10, and the internal gear ring 14 is locked relative to the middle cover 11; the gear shaft 10-1 of the one-way clutch 10 passes through the retaining plate 9, the fork cam disc 7, the shaft circlip 8, the drive end cover 5, the engagement spring 3, the drive gear 2 and is connected to the C snap ring 1; the middle cover 11 and the drive end cover 5 are assembled together to form the housing of the planetary reduction gear, and a combined shock pad 13 is arranged between the internal gear ring 14 and the middle cover 11; the motor 16 is connected to the drive end cover 5 and the middle cover 11 through the through bolt 17, and the drive shaft of the motor 16 is connected to the sun gear 18; the electromagnetic switch 15 is connected to the drive end cover 5 and the middle cover 11 through the electromagnetic switch fastening screw 4, and the plunger 15-1 of the electromagnetic switch 15 pushes the pivot seat 6 to drive the fork cam disc 7 to perform the clutch operation on the drive gear 2.

[0038] When the starter of the present invention is working, the motor 16 outputs power to drive the sun gear 18 to rotate. Since the internal gear ring 14 is locked relative to the middle cover 11, the power generated by the motor 16 is decelerated by the planetary gear set structure composed of the planetary gear 12, the internal gear ring 14, and the sun gear 18 and then output by the gear shaft 10-1 of the one-way clutch 10. The fork cam disc 7 is arranged at the output end of the gear shaft 10-1. The electromagnetic switch 15 drives the plunger 15-1 to push the fork cam disc 7 to connect the drive gear 2 to the output end of the gear shaft 10-1 for torque output, or to disconnect the drive gear 2 from the output end of the gear shaft 10-1 to cut off the torque output.

[0039] Figure 2 is a schematic diagram of the internal gear ring and the combined shock pad structure of the present invention. As Figure 2As shown, in the planetary reduction gear of the present invention, a combined shock pad 13 is provided between the internal gear ring 14 and the middle cover 11. Among them, a boss 14-1 is provided on the outer wall of the internal gear ring 14. The boss 14-1 extends along the axial direction of the internal gear ring 14. The thickness of the boss 14-1 is generally not greater than the thickness of the internal gear ring 14. The boss 14-1 can be one or more, and the distance between the bosses is equidistant or set according to the working condition index; the combined shock pad 13 wraps the internal gear ring 14. A through hole 13-1 corresponding to the boss 14-1 is provided on the combined shock pad 13. After the combined shock pad 13 and the internal gear ring 14 are combined, the boss 14-1 passes through the through hole 13-1 and partially protrudes from the outer wall of the combined shock pad 13. A first elastic element 13-2 and a second elastic element 13-3 are provided on the combined shock pad 13, and are respectively arranged on both sides of the through hole 13-1. One end of the first elastic element 13-2 contacts the outer side surface of the boss 14-1, and one end of the second elastic element 13-3 also contacts the outer side surface of the boss 14-1; the combined shock pad 13 is further provided with a bottom ring 13-4, and a circumferential sealing rib 13-5 is provided on the inner side surface of the bottom ring 13-4. The first elastic element 13-2 and the second elastic element 13-3 can be compression springs or elastic blocks, such as elastic rubber blocks, etc.; the first elastic element 13-2 and the second elastic element 13-3 can be embedded on the combined shock pad 13, or can be independently arranged and installed on the combined shock pad 13. The circumferential lengths of the first elastic element 13-2 and the second elastic element 13-3 can be set to be equal or unequal according to the industrial control index of the starter. The present invention is not limited thereto.

[0040] Figure 3 is a schematic structural diagram of the planetary reduction gear of the present invention. As Figure 3As shown, in the planetary reduction device of the present invention, the planetary gears 12, the inner ring gear 14 and the sun gear 18 are meshed with each other in a planetary gear set structure, the one-way device 10 is a planetary carrier of the planetary gear set structure, and the planetary gears 12 are arranged on the one-way device 10; the inner wall of the middle cover 11 is provided with a groove 11-1 corresponding to the boss 14-1, and the circumferential width of the groove 11-1 is greater than the circumferential width of the boss 14-1. After the planetary reduction device is assembled, the combination of the combined shock-absorbing pad 13 and the inner ring gear 14 is placed in the package of the middle cover 11, the boss 14-1 of the inner ring gear 14 is placed in the groove 11-1, and the groove 11-1 is divided into two spaces along the circumferential direction of the inner ring gear 14, the first elastic element 13-2 and the second elastic element 13-3 are respectively accommodated in the two spaces, the other end of the first elastic element 13-2 contacts the inner side surface of the groove 11-1, and the other end of the second elastic element 13-3 also contacts the inner side surface of the groove 11-1, so that The boss 14-1 is restricted by the first elastic element 13-2 and the second elastic element 13-3 to the middle or near the middle of the groove 11-1. When the inner gear ring 14 has a clockwise or counterclockwise rotation tendency, the impact of the inner gear ring 14 on the center cover 11 can be mitigated by the elastic deformation of the first elastic element 13-2 or the second elastic element 13-3. The planetary reduction device of the present invention is also provided with a stopper, which is arranged between the outer side surface of the boss 14-1 and the inner side surface of the groove 11-1. For example, a first stopper 19-1 is arranged corresponding to the first elastic element 13-2, and a second stopper 19-2 is arranged corresponding to the second elastic element 13-3. The stopper limits the relative position of the boss 14-1 and the groove 11-1, so that the distance between the outer side surface of the boss 14-1 and the inner side surface of the groove 11-1 is greater than a certain distance value, and this distance value is greater than the minimum compression value of the elastic element, so that the elastic element will not be damaged or fail or reduce the service life due to extreme compression.

[0041] When the motor 16 outputs power, it will drive the inner gear ring 14 to rotate or have a tendency to rotate. The generated torque is transmitted to the middle cover 11 through the boss 14-1 to compress the first elastic element 13-2 or the second elastic element 13-3, so that the elastic deformation of the first elastic element 13-2 or the second elastic element 13-3 plays a buffering role, reduces the current of the motor 16, and protects the middle cover 11 and the inner gear ring 14. At the same time, the first stop block 19-1 or the second stop block 19-2 limits the rotation of the inner gear ring 14, so that the first elastic element 13-2 or the second elastic element 13-3 will not exceed the available compression stroke when compressed, thereby preventing the first elastic element 13-2 or the second elastic element 13-3 from being crushed and failing.

[0042] Figure 4 Schematic diagram of the block arrangement of the first embodiment of the present invention. Figure 4As shown, in this embodiment, the first stop block 19-1 and the second stop block 19-2 are disposed in the groove 11-1 of the middle cover 11 and are respectively located on both sides of the boss 14-1. The first stop block 19-1 and the first elastic element 13-2 are in the same space, and the second stop block 19-2 and the second elastic element 13-3 are in the same space. The first stop block 19-1 and the second stop block 19-2 contact the inner side surface of the groove 11-1. The first stop block 19-1 has a circumferential width d1, and the second stop block 19-2 has a circumferential width d2. Therefore, in the space where the boss 14-1 is located in the first stop block 19-1, the distance from the inner side surface of the groove 11-1 is not less than d1, and in the space where the second stop block 19-2 is located, the distance from the inner side surface of the groove 11-1 is not less than d2; d1 and d2 are set according to the circumferential lengths and available compression strokes of the first elastic element 13-2 and the second elastic element 13-3.

[0043] Figure 5 It is a schematic diagram of the stop block setting in the second embodiment of the present invention. As Figure 5 shown, continuing from the first embodiment, the first stop block 19-1 and the first elastic element 13-2 are in the same space, and the second stop block 19-2 and the second elastic element 13-3 are in the same space. By limiting the boss 14-1 with the first stop block 19-1 and the second stop block 19-2, in the space where the boss 14-1 is located in the first stop block 19-1, the distance from the inner side surface of the groove 11-1 is not less than the circumferential width of the first stop block 19-1, and in the space where the second stop block 19-2 is located, the distance from the inner side surface of the groove 11-1 is not less than the circumferential width of the second stop block 19-1; the difference from the first embodiment is that the first stop block 19-1 and the second stop block 19-2 in this embodiment are disposed on the outer wall of the internal gear ring 14 and are divided into both sides of the boss 14-1. The first stop block 19-1 and the second stop block 19-2 contact the outer side surface of the boss 14-1 to limit the relative position between the boss 14-1 and the groove 11-1.

[0044] Figure 6 It is a schematic diagram of the stop block setting in the third embodiment of the present invention. As Figure 6As shown, continuing from the first embodiment, the first stopper 19-1 and the first elastic element 13-2 are in the same space, and the second stopper 19-2 and the second elastic element 13-3 are in the same space. By limiting the boss 14-1 with the first stopper 19-1 and the second stopper 19-2, the boss 14-1 is in the space where the first stopper 19-1 is located, and the distance from the inner side surface of the groove 11-1 is not less than the circumferential width of the first stopper 19-1. In the space where the second stopper 19-2 is located, the distance from the inner side surface of the groove 11-1 is not less than the circumferential width of the second stopper 19-1. The difference from the first embodiment is that the first stopper 19-1 and the second stopper 19-2 of this embodiment are arranged on the combined shock pad 13 and are located on both sides of the boss 14-1 to limit the relative position between the boss 14-1 and the groove 11-1.

[0045] Figure 7 is a schematic diagram of the sealing cooperation between the combined shock pad and the one-way clutch in the fourth embodiment of the present invention. As Figure 7 shown, when the planetary reduction gear is assembled, the bottom ring 13-4 of the combined shock pad 13 is in clearance fit with the one-way clutch 10. The inner side surface of the bottom ring 13-4 is provided with a circumferential sealing rib 13-5. There is at least one sealing rib 13-5. Through the sealing rib 13-5, impurities are prevented from entering the side of the planetary gear 12 from the side of the one-way clutch 10 of the middle cover 11, which affects the working life of the planetary reduction gear. At the same time, it is ensured that the grease in the area of the planetary gear 12 will not be thrown out. Figure 7 In [the figure], there are two sealing ribs 13-5, and the cross-sectional shape is circular. It can also be other cross-sectional shapes suitable for sealing.

[0046] After adopting the above technical solutions, the beneficial effects of the present invention are:

[0047] 1. In the planetary reduction gear of the present invention, the combined shock pad is pre-embedded with elastic elements. Compared with the traditional rubber shock absorption, the elastic elements have the characteristics of convenient adjustment of the elastic coefficient and high service life. The elastic coefficient can be adjusted according to the actual use conditions to achieve the purpose of effective shock absorption. At the same time, a sealing rib is designed at the contact place between the combined shock pad and the one-way clutch, which can effectively ensure that no impurities enter the area where the planetary gear works, affecting its working life.

[0048] 2. In the planetary reduction gear of the present invention, a stopper for restricting the clockwise and counterclockwise rotation amplitudes of the internal gear ring is designed. Its function is to prevent the elastic element from being damaged due to excessive impact, and the design of the two-way rotation stopper can meet the starters with different steering outputs.

[0049] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention. The patent protection scope of the present invention shall be defined by the claims.

Claims

1. A planetary reduction gear device, comprising a sun gear, planetary gears, an internal gear ring, a one-way clutch, a combined shock pad, and a housing. The sun gear, the planetary gears, and the internal gear ring are meshed with each other in a planetary gear set structure. The one-way clutch is the planet carrier of the planetary gears. The combined shock pad is arranged between the internal gear ring and the housing. It is characterized in that An axial boss is provided on the outer wall of the internal gear ring. A through hole corresponding to the boss is provided on the combined shock pad. The boss passes through the through hole and protrudes from the outer wall of the combined shock pad. A groove for accommodating the boss is provided on the inner wall of the housing. The space between the first inner side surface of the groove and the first outer side surface of the boss is the first space. A first elastic element and a first stop block are arranged in the first space. The two ends of the first elastic element respectively contact the first inner side surface and the first outer side surface. The first stop block limits the internal gear ring within a first limit when torque is output by the one-way clutch. The space between the second inner side surface of the groove and the second outer side surface of the boss is the second space. A second elastic element and a second stop block are arranged in the second space. The two ends of the second elastic element respectively contact the second inner side surface and the second outer side surface. The second stop block limits the internal gear ring within a second limit when torque is input to the one-way clutch.

2. The planetary reduction gear according to claim 1, characterized in that, The available compression stroke of the first elastic element is less than or equal to the available compression stroke of the second elastic element.

3. The planetary reduction gear according to claim 1, characterized in that, The first elastic element and the second elastic element are compression springs or elastic blocks.

4. The planetary reduction gear according to claim 1, characterized in that, The first elastic element and the second elastic element are arranged on the outer wall of the combined shock pad.

5. The planetary reduction gear according to claim 1, characterized in that, The first stop block and the second stop block are arranged on the outer wall of the combined shock pad.

6. The planetary reduction gear according to claim 1, characterized in that, The first stop block and the second stop block are respectively arranged on the first outer side surface and the second outer side surface.

7. The planetary reduction gear according to claim 1, characterized in that, The first stop block and the second stop block are respectively arranged on the first inner side surface and the second inner side surface.

8. The planetary reduction gear according to claim 1, characterized in that, A plurality of the bosses are circumferentially arranged on the outer wall of the internal gear ring. The housing is correspondingly provided with a plurality of the grooves, and the combined shock pad is correspondingly provided with a plurality of the through holes.

9. The planetary reduction gear according to claim 8, wherein, The plurality of bosses are evenly distributed on the outer wall of the internal gear ring.

10. The planetary reduction gear according to claim 1, characterized in that, The combined shock pad further includes a bottom ring. The bottom ring of the combined shock pad has a clearance fit with the one-way clutch. At least one circumferential sealing rib is provided on the inner side surface of the bottom ring.

11. A starter, comprising: a motor; the planetary reduction gear device according to any one of claims 1-10, wherein the sun gear of the planetary reduction gear device is connected to the drive shaft of the motor. The one-way clutch of the planetary reduction gear device has a gear shaft, and a drive gear for outputting torque is provided at the output end of the gear shaft. a clutch device, comprising an electromagnetic switch and a fork cam disc. The fork cam disc is arranged at the output end of the gear shaft. The electromagnetic switch drives the fork cam disc to connect the drive gear to the output end of the gear shaft for torque output, or to disconnect the drive gear from the output end of the gear shaft to cut off torque output.

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