A planetary gear reducer

Abstract

The planetary gear reducer provided by the present invention is provided with a first tooth meshing with the primary planet carrier and a second tooth meshing with the secondary planet wheel on the secondary center gear, and the radius of the tooth top circle of the second tooth is larger than the radius of the tooth top circle of the first tooth, so that when the secondary center gear moves axially to the left, the left end face of the second tooth is blocked by the right end face of the primary planet carrier; by providing a mounting hole on the end face of the secondary center gear close to the first tooth, and providing a pin hole extending outward and passing through the first tooth on the inner wall of the mounting hole, a pin is provided in the pin hole, so that the pin has a pin end protruding outward from the tooth top circle of the first tooth, and a groove for accommodating the pin end is provided on the end face of the primary planet carrier away from the second tooth, so that when the secondary center gear moves to the right, the pin is blocked by the bottom wall of the groove, thereby realizing axial limitation of the secondary center gear. Compared with the prior art, this method can shorten the axial dimension of the reducer and enhance the strength of the spline.

Description

Technical Field

[0001] The invention relates to the field of planetary gear reducers. Background Art

[0002] A planetary gear reducer is a device used to reduce rotational speed and increase torque. A general planetary gear reducer includes at least two stages of planetary transmission mechanisms. Each stage of the planetary transmission mechanism includes at least planetary wheels, a planetary carrier, a center gear, and a ring gear. The planetary wheels are meshed with the center gear and the ring gear at the same time. The secondary center gear must also be meshed with the primary planetary carrier to complete the power transmission. The axial movement of the secondary center gear will affect the transmission efficiency of the above power. Usually, a larger diameter wear-resistant pad plus a retaining spring structure is set at both ends of the secondary center gear to limit the axial movement of the secondary center gear. However, the larger diameter wear-resistant pad will increase the axial size of the planetary gear reducer and weaken the strength of the planetary carrier connecting spline. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a planetary gear reducer which can limit the axial movement of the secondary sun gear, reduce the axial size and enhance the strength of the planet carrier connection spline.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is a planetary gear reducer, comprising:

[0005] Body;

[0006] A primary planetary transmission mechanism, the primary planetary transmission mechanism is arranged in the body, the primary planetary transmission mechanism comprises a primary planet carrier, a primary planetary gear, a primary ring gear, and a primary sun gear, the primary planetary gear is rotatably arranged on the primary planet carrier, and the primary planetary gear is meshed with the primary ring gear and the primary sun gear at the same time;

[0007] A secondary planetary transmission mechanism, the secondary planetary transmission mechanism is arranged in the body, the secondary planetary transmission mechanism comprises a secondary planet carrier, a secondary planetary gear, a secondary ring gear, and a secondary sun gear, the secondary planetary gear is rotatably arranged on the secondary planet carrier, and the secondary planetary gear is meshed with the secondary ring gear and the secondary sun gear at the same time;

[0008] The secondary sun gear is meshed with the primary planet carrier;

[0009] The secondary central gear is provided with a first tooth meshing with the primary planet carrier and a second tooth meshing with the secondary planet gear, the first tooth and the second tooth are both located on the outer circumferential surface of the secondary central gear, and the radius of the tooth top circle of the second tooth is greater than the radius of the tooth top circle of the first tooth;

[0010] The end surface of the secondary sun gear close to the first tooth is provided with a mounting hole extending along the axial direction of the secondary sun gear, the inner wall of the mounting hole is provided with a pin hole extending outwardly perpendicular to the inner wall and penetrating the first tooth, a pin is provided in the pin hole, the pin has a pin end protruding outwardly from the tooth top of the first tooth, and the end surface of the primary planet carrier away from the second tooth is provided with a groove for accommodating the pin end;

[0011] A wear-resistant pad is arranged in the mounting hole to prevent the pin from falling out of the pin hole. The outer circumferential surface of the wear-resistant pad fits with the inner wall of the mounting hole, and the right end surface of the wear-resistant pad fits with the bottom wall of the mounting hole.

[0012] Preferably, the tooth height of the second teeth is higher than the tooth height of the first teeth.

[0013] Preferably, the radius of the second tooth root circle is equal to the radius of the first tooth root circle.

[0014] Preferably, there are a plurality of pin holes, and the plurality of pin holes are evenly distributed along the inner wall of the mounting hole.

[0015] Preferably, a top screw hole is provided on the wear-resistant pad.

[0016] Further preferably, the top screw hole is away from the center of the wear-resistant pad.

[0017] Further preferably, a protrusion protruding to the right is provided at the end of the first-stage central gear close to the first-stage planetary carrier, and the right end surface of the protrusion abuts against the middle part of the left end surface of the wear-resistant pad.

[0018] Further preferably, the diameter of the protrusion is smaller than the diameter of the wear-resistant pad.

[0019] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0020] The planetary gear reducer provided by the present invention is provided with a first tooth meshing with the primary planet carrier and a second tooth meshing with the secondary planet wheel on the secondary central gear, and the radius of the tooth top circle of the second tooth is greater than the radius of the tooth top circle of the first tooth, so that when the secondary central gear moves axially to the left, the left end face of the second tooth is blocked by the right end face of the primary planet carrier; a mounting hole is provided on the end face of the secondary central gear close to the first tooth, and a pin hole extending outwardly and penetrating the first tooth is provided on the inner wall of the mounting hole, a pin is provided in the pin hole, so that the pin has a pin end protruding outwardly from the tooth top circle of the first tooth, and a groove for accommodating the pin end is provided on the end face of the primary planet carrier away from the second tooth, so that when the secondary central gear moves to the right, the pin is blocked by the bottom wall of the groove, thereby realizing axial limitation of the secondary central gear. Compared with the structure of limiting the axial movement of the secondary central gear by providing a larger diameter wear-resistant pad plus a retaining spring, this method can shorten the axial size of the planetary gear reducer and enhance the strength of the connecting spline between the secondary central gear and the primary planet carrier. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a front view schematic diagram of the present invention, with a partial cross-section.

[0022] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0023] Figure 3 It is a schematic front view of a first-stage planet carrier in the present invention.

[0024] Figure 4 It is a cross-sectional schematic diagram of the secondary central gear in the present invention.

[0025] Figure 5 It is a schematic front view of the wear-resistant pad in the present invention.

[0026] Among them: 101. body; 200. primary planetary transmission mechanism; 201. primary planet carrier; 202. primary planetary gear; 203. primary ring gear; 204. primary central gear; 300. secondary planetary transmission mechanism; 301. secondary planet carrier; 302. secondary planetary gear; 303. secondary ring gear; 304. secondary central gear; 3041. first tooth; 3042. second tooth; 3043. mounting hole; 3044. pin hole; 3045. pin; 3046. wear-resistant pad. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings:

[0028] The left and right directions in the present invention refer to Figure 1 left and right direction in center.

[0029] like Figure 1 As shown, the planetary gear reducer provided by the present invention includes: a body 100, a primary planetary transmission mechanism 200, and a secondary planetary transmission mechanism 300, wherein the primary planetary transmission mechanism 200 and the secondary planetary transmission mechanism 300 are both arranged in the body 100, the primary planetary transmission mechanism 200 is located on the left side of the secondary planetary transmission mechanism 300, the primary planetary transmission mechanism 200 includes a primary planet carrier 201, a primary planetary wheel 202, a primary ring gear 203, and a primary sun gear 204, and the primary planetary wheel 202 is rotatably arranged on the On the primary planet carrier 201, the primary ring gear 203 is fixed on the inner wall of the body 100, the left end of the primary sun gear 204 is connected to the input shaft, and the primary planetary gear 202 is meshed with the primary ring gear 203 and the primary sun gear 204 at the same time. When the input shaft transmits external power to the primary sun gear 204, the primary sun gear 204 is driven to rotate, so that the primary planetary gear 202 rotates accordingly. When the primary planetary gear 202 rotates between the primary ring gear 203 and the primary sun gear 204, it will drive the primary planet carrier 201 to rotate;

[0030] The secondary planetary transmission mechanism 300 includes a secondary planet carrier 301, a secondary planetary gear 302, a secondary ring gear 303, and a secondary central gear 304. The secondary planetary gear 302 is rotatably arranged on the secondary planet carrier 301. The secondary planetary gear 302 is meshed with the secondary ring gear 303 and the secondary central gear 304 at the same time. The secondary central gear 304 is meshed with the primary planet carrier 201. When the primary planet carrier 201 rotates, the secondary central gear 304 is driven to rotate, so that the secondary planetary gear 302 rotates. When the secondary planetary gear 302 rotates between the secondary central gear 304 and the secondary ring gear 303, it drives the secondary planet carrier 301 to rotate, thereby transmitting the external power from the primary planet carrier 201 to the secondary planet carrier 301.

[0031] The secondary central gear 304 is provided with a first tooth 3041 meshing with the primary planet carrier 201 and a second tooth 3042 meshing with the secondary planetary gear 302. The first tooth 3041 and the second tooth 3042 are both located on the outer circumferential surface of the secondary central gear 304. The radius of the tooth top circle of the second tooth 3042 is greater than the radius of the tooth top circle of the first tooth 3041. The radius of the tooth root circle of the second tooth 3042 is equal to the radius of the tooth root circle of the first tooth 3041, so that the tooth height of the second tooth 3042 is higher than the tooth height of the first tooth 3041, that is, the tooth height of the second tooth 3042 is higher than the tooth height of the matching tooth on the primary planet carrier 201 matching with the first tooth 3041. The advantage of such a setting is that when the secondary central gear 304 is about to move to the left along its axial direction, the left end face of the second tooth 3042 will be blocked by the right end face of the primary planet carrier 201, so that the secondary central gear 304 cannot move to the left along its axial direction.

[0032] The left end face of the secondary central gear 304 is provided with a mounting hole 3043 extending to the right along its axial direction, and the inner wall of the mounting hole 3043 is provided with a pin hole 3044 extending outwardly perpendicular to the inner wall and penetrating the first tooth 3041. There are multiple pin holes 3044, and the pin holes 3044 are evenly distributed along the inner wall of the mounting hole 3043. The pin hole 3044 is a circular through hole, and a pin 400 is arranged in the pin hole 3044. The pin 400 has a pin end 401 protruding outwardly from the top of the first tooth 3041. The left end face of the primary planet carrier 202 is provided with a groove 2011 extending to the right for accommodating the pin end 401. The advantage of such a configuration is that when the secondary central gear 304 is about to be rotated along its axis, When moving to the right, the pin end 401 is blocked by the groove 2011, so that the secondary center gear 304 cannot move to the right along its axial direction. Compared with the structure with a larger diameter wear-resistant pad and a retaining spring, the axial dimension of the planetary gear reducer is greatly shortened. Since the pin 400 is arranged in the pin hole 3044 on the secondary center gear 304, and the pin end 401 of the pin 400 is inserted into the groove 2011 on the primary planet carrier 202, when the spline meshing between the secondary center gear 304 and the primary planet carrier 202 is destroyed, it is necessary to provide an additional force to cut off the pin 400, which is equivalent to enhancing the spline strength when the secondary center gear 304 is meshing with the primary planet carrier 202.

[0033] A wear-resistant pad 500 is also provided in the mounting hole 3043 for preventing the pin 400 from falling off the pin hole 3044. The outer circumferential surface of the wear-resistant pad 500 fits against the inner wall of the mounting hole 3043, and the right end face of the wear-resistant pad 500 fits against the bottom wall of the mounting hole 3043. A top screw hole 501 is provided at a position away from the center of the wear-resistant pad 500. The top screw hole 501 is used to remove the wear-resistant pad 500 from the mounting hole 3043. A protrusion 2041 protruding to the right is provided at the right end portion of the first-stage center gear 204. The right end face of the protrusion 2041 abuts against the middle part of the left end face of the wear-resistant pad 500, and the diameter of the protrusion 2041 is smaller than the diameter of the wear-resistant pad 500.

[0034] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A planetary gear reducer, comprising: Body; A primary planetary transmission mechanism, the primary planetary transmission mechanism is arranged in the body, the primary planetary transmission mechanism comprises a primary planet carrier, a primary planetary gear, a primary ring gear, and a primary sun gear, the primary planetary gear is rotatably arranged on the primary planet carrier, and the primary planetary gear is meshed with the primary ring gear and the primary sun gear at the same time; A secondary planetary transmission mechanism, the secondary planetary transmission mechanism is arranged in the body, the secondary planetary transmission mechanism comprises a secondary planet carrier, a secondary planetary gear, a secondary ring gear, and a secondary sun gear, the secondary planetary gear is rotatably arranged on the secondary planet carrier, and the secondary planetary gear is meshed with the secondary ring gear and the secondary sun gear at the same time; The secondary sun gear is meshed with the primary planet carrier; Features: The secondary central gear is provided with a first tooth meshing with the primary planet carrier and a second tooth meshing with the secondary planet gear, the first tooth and the second tooth are both located on the outer circumferential surface of the secondary central gear, and the radius of the tooth top circle of the second tooth is greater than the radius of the tooth top circle of the first tooth; A mounting hole extending along the axial direction of the secondary central gear is provided at the middle of the end surface of the secondary central gear close to the first tooth, a pin hole extending outwardly perpendicular to the inner wall and penetrating the first tooth is provided on the inner wall of the mounting hole, a pin is provided in the pin hole, and the pin has a pin end protruding outwardly from the tooth top of the first tooth, and a groove for accommodating the pin end is provided on the end surface of the primary planet carrier away from the second tooth; A wear-resistant pad is arranged in the mounting hole to prevent the pin from falling out of the pin hole. The outer circumferential surface of the wear-resistant pad fits with the inner wall of the mounting hole, and the right end surface of the wear-resistant pad fits with the bottom wall of the mounting hole.

2. The planetary gear reducer according to claim 1, characterized in that: The tooth height of the second tooth is higher than the tooth height of the first tooth.

3. The planetary gear reducer according to claim 1, characterized in that: The radius of the second tooth root circle is equal to the radius of the first tooth root circle.

4. The planetary gear reducer according to claim 1, characterized in that: There are multiple pin holes, and the multiple pin holes are evenly distributed along the inner wall of the mounting hole.

5. The planetary gear reducer according to claim 1, characterized in that: The wear-resistant pad is provided with a top screw hole.

6. The planetary gear reducer according to claim 5, characterized in that: The top screw hole is away from the center of the wear-resistant pad.

7. The planetary gear reducer according to any one of claims 1 to 6, characterized in that: A protrusion protruding to the right is arranged at the end of the primary central gear close to the primary planet carrier, and the right end surface of the protrusion abuts against the middle part of the left end surface of the wear-resistant pad.

8. The planetary gear reducer according to claim 7, characterized in that: The diameter of the protrusion is smaller than the diameter of the wear-resistant pad.

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