A sun gear assembly and cutting structure

Abstract

The present invention discloses a sun gear assembly cutting structure, which includes a sun gear and a connecting shaft; the sun gear includes a gear body and a wheel shaft coaxially connected to the gear body, the wheel shaft is sequentially provided with an external spline, an annular groove and a guide section in a direction away from the gear body, and a sharp cutting portion is formed at the connection between the wall surface where the annular groove and the external spline are connected and the external spline; the connecting shaft is provided with a connecting sleeve for connecting the wheel shaft; when the wheel shaft of the sun gear is connected to the connecting sleeve of the connecting shaft, the guide section, annular groove and external spline of the wheel shaft are sequentially inserted into the connecting sleeve, and the cutting portion of the wheel shaft cuts the inner wall of the connecting sleeve so that the inner wall of the connecting sleeve forms an internal spline that meshes with the external spline. The present invention can prevent the connecting sleeve from expanding and deforming when the wheel shaft is installed into the connecting sleeve, and prevent the wheel shaft from deforming under excessive pressure, while also ensuring that the external spline of the wheel shaft is tightly meshed with the internal spline of the connecting sleeve.

Description

Technical Field

[0001] The invention relates to the field of planetary reducers, in particular to a sun gear assembly and cutting structure. Background Art

[0002] In the structural design of the existing planetary reducer, the sun gear and the connecting shaft used to connect to the motor are matched through splines, wherein the axle of the sun gear is provided with an external spline, and the inner wall of the connecting sleeve of the connecting shaft is provided with an internal spline, the axle is inserted into the connecting sleeve and the external spline is engaged with the internal spline.

[0003] Currently, the connecting sleeve of the sun gear axle and the connecting shaft adopts an interference fit design structure, which has the following problems:

[0004] 1. When the sun gear axle and the connecting sleeve of the connecting shaft are assembled, it is easy to cause the connecting sleeve to expand and deform, making it difficult to insert the connecting sleeve into the inner ring of the bearing, affecting the assembly of the planetary reducer;

[0005] 2. When assembling the connecting sleeve of the sun gear axle and the connecting shaft, it is easy to apply too much force to the axle, which can easily cause the axle to deform and cause the concentricity of the sun gear and the connecting shaft to deteriorate, which can easily lead to problems such as the planetary reducer jamming and loud noise. Summary of the Invention

[0006] The object of the present invention is to provide a sun gear assembly cutting structure to overcome the deficiencies in the prior art.

[0007] In order to achieve the above object, the solution of the present invention is:

[0008] A sun gear assembly cutting structure comprises a sun gear and a connecting shaft; the sun gear comprises a gear body and a wheel shaft coaxially connected to the gear body, the wheel shaft is provided with an external spline, an annular groove and a guide section in sequence in the direction away from the gear body, the wall surface where the annular groove connects with the external spline is a cutting surface, the cutting surface is inclined outward in the direction from the external spline to the guide section, a sharp cutting portion is formed at the connection between the cutting surface and the external spline, and the outer diameter of the guide section is smaller than the outer diameter of the external spline; the connecting shaft is provided with a connecting sleeve for connecting the wheel shaft, the inner diameter of the connecting sleeve is larger than the outer diameter of the wheel shaft guide section and smaller than the outer diameter of the wheel shaft external spline; when the wheel shaft of the sun gear is connected to the connecting sleeve of the connecting shaft, the guide section, annular groove and external spline of the wheel shaft are inserted into the connecting sleeve in sequence, the cutting portion of the wheel shaft cuts the inner wall of the connecting sleeve to form an internal spline on the inner wall of the connecting sleeve, and the external spline of the wheel shaft meshes with the inner spline of the connecting sleeve.

[0009] The inclination angle of the cutting surface is 70° to 75°.

[0010] The inclination angle of the cutting surface is 75°.

[0011] The hardness of the wheel axle is greater than the hardness of the connecting sleeve.

[0012] The hardness of the wheel axle is HRC57-60 degrees; the hardness of the connecting sleeve is HRC48-50 degrees.

[0013] The wall surface where the annular groove of the wheel shaft connects with the guide section is a beveled surface parallel to the cutting surface.

[0014] An inclined guide surface is formed at the periphery of the end portion of the guide section of the wheel shaft away from the annular groove, and the inclined guide surface is inclined inwardly in a direction away from the annular groove.

[0015] The gear body and the axle of the sun gear are integrally formed.

[0016] After adopting the above scheme, the annular groove of the wheel shaft of the sun gear of the present invention is provided with a cutting surface, and a sharp cutting portion is formed at the connection between the cutting surface and the external spline. When the wheel shaft of the sun gear is connected to the connecting sleeve of the connecting shaft, the guide section, annular groove and external spline of the wheel shaft are inserted into the connecting sleeve in sequence, and the cutting portion of the wheel shaft cuts the inner wall of the connecting sleeve so that the inner wall of the connecting sleeve forms an internal spline that meshes with the external spline, so that when the wheel shaft is installed into the connecting sleeve, it will not cause the connecting sleeve to expand and deform, and the wheel shaft will not deform under excessive pressure, and at the same time it can ensure that the external spline of the wheel shaft is tightly meshed with the internal spline of the connecting sleeve; wherein, the cutting chips generated by the cutting portion of the wheel shaft cutting the inner wall of the connecting sleeve will enter the annular groove and will not affect the insertion of the wheel shaft into the connecting sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The structure of the sun gear of the present invention is shown in FIG. Figure 1 ;

[0018] Figure 2 The structure of the sun gear of the present invention is shown in FIG. Figure 2 ;

[0019] Figure 3 is a cross-sectional view of the sun gear of the present invention;

[0020] Figure 4 It is a structural schematic diagram of the connecting shaft of the present invention;

[0021] Figure 5 A schematic diagram of the combination of the sun gear and the connecting shaft of the present invention;

[0022] Figure 6 A combined sectional view of the sun gear and the connecting shaft of the present invention;

[0023] Description of labels:

[0024] Sun gear 1,

[0025] Gear body 11, teeth 111,

[0026] The wheel shaft 12, the cutting portion 120, the external spline 121, the annular groove 122, the cutting surface 1221, the beveled surface 1222, the guide section 123, the beveled guide surface 1231,

[0027] Connecting shaft 2, connecting sleeve 21, internal spline 211. DETAILED DESCRIPTION

[0028] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments.

[0029] like Figures 1 to 6 As shown, the present invention discloses a sun gear assembly cutting structure, which includes a sun gear 1 and a connecting shaft 2; the sun gear 1 includes a gear body 11 and a wheel shaft 12 coaxially connected to the gear body 11, the outer wall of the gear body 11 can form teeth 111, and the wheel shaft 12 is provided with an external spline 121, an annular groove 122 and a guide section 123 in sequence along the direction away from the gear body 11, the outer diameter of the guide section 123 is smaller than the outer diameter of the external spline 121, and the wall surface where the annular groove 122 connects with the external spline 121 is a cutting surface 1221, which is inclined outward from the direction from the external spline 121 to the guide section 123, so that a sharp cutting portion 120 is formed at the connection between the cutting surface 1221 and the external spline 121; the connecting shaft 2 is provided with a connecting sleeve 21 for connecting the wheel shaft 12, and the inner diameter of the connecting sleeve 21 is larger than the outer diameter of the guide section 123 of the wheel shaft 12 and smaller than the outer diameter of the external spline 121 of the wheel shaft 12.

[0030] In the present invention, the annular groove 122 of the wheel shaft 12 of the sun gear 1 is provided with a cutting surface 1221, and a sharp cutting portion 120 is formed at the connection between the cutting surface 1221 and the external spline 121. When the wheel shaft 12 of the sun gear 1 is connected to the connecting sleeve 21 of the connecting shaft 2, the guide section 123, the annular groove 122 and the external spline 121 of the wheel shaft 12 are sequentially inserted into the connecting sleeve 21, and the cutting portion 120 of the wheel shaft 12 cuts the inner wall of the connecting sleeve 21 so that the inner wall of the connecting sleeve 21 is formed. The internal spline 211 meshing with the external spline 121 ensures that the connecting sleeve 21 will not expand and deform when the wheel axle 12 is installed into the connecting sleeve 21, and the wheel axle 12 will not deform under excessive pressure. At the same time, it can ensure that the external spline 121 of the wheel axle 12 is tightly meshed with the internal spline 211 of the connecting sleeve 21; wherein, the cutting part 120 of the wheel axle 12 cuts the inner wall of the connecting sleeve 21, and the cutting chips generated will enter the annular groove 122 without affecting the insertion of the wheel axle 12 into the connecting sleeve 21. The specific assembly method of the wheel axle 12 of the sun gear 1 of the present invention and the connecting sleeve 21 of the connecting shaft 2 is: first insert the guide section 123 of the wheel axle 12 into the connecting sleeve 21 of the connecting shaft 2, and then use a pressing device such as a hydraulic press or a servo press to press the sun gear 1, so that the annular groove 122 and the external spline 121 of the wheel axle 12 are pressed into the connecting sleeve 21 of the connecting shaft 2, and at the same time, the cutting portion 120 of the wheel axle 12 cuts the inner wall of the connecting sleeve 21 so that the inner wall of the connecting sleeve 21 forms an internal spline 211 that meshes with the external spline 121.

[0031] In the present invention, the hardness of the wheel axle 12 is greater than the hardness of the connecting sleeve 21, which is conducive to the cutting part 120 cutting the inner wall of the connecting sleeve 21; the wheel axle 12 and the gear body 11 can be integrally formed, the hardness of the wheel axle 12 is HRC57~60 degrees, the material of the wheel axle 12 can be 20CrNiMo and the wheel axle 12 is carburized heat treated; the hardness of the connecting sleeve 21 is HRC48~50 degrees, the material of the connecting sleeve 21 can be 15CrMo and the connecting sleeve 21 is carburized heat treated.

[0032] In the present invention, the inclination angle θ of the cutting surface 1221 of the wheel shaft 12 is 70° to 75°, and the inclination angle θ of the cutting surface 1221 is preferably 75°, which can not only ensure the strength of the cutting part 120, but also help the cutting part 120 to cut the inner wall of the connecting sleeve 21 with less effort.

[0033] In the present invention, the wall surface where the annular groove 122 of the wheel shaft 12 connects with the guide section 123 is a bevel surface 1222 parallel to the cutting surface 1221. In this way, the present invention can use a milling cutter to mill the wheel shaft 12 and process the bevel surface 1222 parallel to the cutting surface 1221 of the annular groove 122 at one time, which is convenient for processing and production.

[0034] In the present invention, an inclined guide surface 1231 is formed on the periphery of the end of the guide section 123 of the axle 12 away from the annular groove 122. The inclined guide surface 1231 is inclined inward in a direction away from the annular groove 122. This inclined guide surface 1231 facilitates the insertion of the guide section 123 into the connecting sleeve 21. The surface of the guide section 123 of the axle 12 can be coated with sealant; when the axle 12 of the sun gear 1 is connected to the connecting sleeve 21 of the connecting shaft 2, the sealant seals the surface of the guide section 123 with the inner wall of the connecting sleeve 21, thereby preventing lubricating oil from the interior of the planetary reducer housing from leaking out through the gap between the surface of the guide section 123 and the inner wall of the connecting sleeve 21, thereby affecting the operation of the planetary reducer.

[0035] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. A sun gear assembly cutting structure, characterized in that: Including sun gear and connecting shaft; The sun gear includes a gear body and a wheel shaft coaxially connected to the gear body. The wheel shaft is provided with an external spline, an annular groove and a guide section in sequence in a direction away from the gear body. The wall surface where the annular groove connects with the external spline is a cutting surface. The cutting surface is inclined outward in the direction from the external spline to the guide section. A sharp cutting portion is formed at the connection between the cutting surface and the external spline. The outer diameter of the guide section is smaller than the outer diameter of the external spline. The connecting shaft is provided with a connecting sleeve for connecting to the wheel axle, the inner diameter of the connecting sleeve is larger than the outer diameter of the wheel axle guide section and smaller than the outer diameter of the wheel axle external spline; When the axle of the sun gear is connected to the connecting sleeve of the connecting shaft, the guide section, annular groove and external spline of the axle are inserted into the connecting sleeve in sequence, and the cutting part of the axle cuts the inner wall of the connecting sleeve to form an internal spline on the inner wall of the connecting sleeve, and the external spline of the axle engages with the internal spline of the connecting sleeve.

2. A sun gear assembly cutting structure according to claim 1, characterized in that: The inclination angle of the cutting surface is 70° to 75°.

3. A sun gear assembly cutting structure according to claim 2, characterized in that: The inclination angle of the cutting surface is 75°.

4. The sun gear assembly cutting structure according to claim 1, characterized in that: The hardness of the wheel axle is greater than the hardness of the connecting sleeve.

5. The sun gear assembly cutting structure according to claim 1, characterized in that: The hardness of the wheel axle is HRC57-60 degrees; the hardness of the connecting sleeve is HRC48-50 degrees.

6. The sun gear assembly cutting structure according to claim 1, characterized in that: The wall surface where the annular groove of the wheel shaft connects with the guide section is a beveled surface parallel to the cutting surface.

7. The sun gear assembly and cutting structure according to claim 1, characterized in that: An inclined guide surface is formed at the periphery of the end portion of the guide section of the wheel shaft away from the annular groove, and the inclined guide surface is inclined inwardly in a direction away from the annular groove.

8. A sun gear assembly and cutting structure according to any one of claims 1 to 7, characterized in that: The gear body and the axle of the sun gear are integrally formed.

9. The sun gear assembly and cutting structure according to claim 1, characterized in that: The guide section surface of the axle is coated with sealant; when the axle of the sun gear is connected to the connecting sleeve of the connecting shaft, the sealant seals the guide section surface and the inner wall of the connecting sleeve.

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