A planet carrier

Abstract

The present invention discloses a planet carrier, belonging to the technical field of planet carriers. The planet carrier includes two side plates and a plurality of columns. The plurality of columns are arranged at intervals and in a circular pattern between the two side plates. The two ends of the columns in the height direction are respectively connected to the two side plates. A connecting portion is provided on the side surface of the columns along the circumferential direction of the side plates. An unloading groove is recessed inwardly on the connecting portion. A fillet is provided between the columns and the side plates. The radius or equivalent curvature radius of the fillet is R, and the vertical distance between the bottom of the unloading groove and the side plate is W, where W < 3R. For the planet carrier of the present invention, by providing the unloading groove, the high stress at the root position of the columns is unloaded, the maximum stress acting on the roots of the columns is reduced, the stress-bearing capacity of the planet carrier is improved, and the applicability and design flexibility of the planet carrier are enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of planet carriers, and in particular to a planet carrier. Background Art

[0002] As Figure 1 shown, the planet carrier includes two side plates 1' and columns 2' connecting the two side plates 1'. Currently, most planet carriers of planetary transmissions are formed by casting, and the materials are mainly cast iron and cast steel. After being subjected to the input torque, the connection position between the side plate 1' and the column 2' is often the stress concentration area. To reduce the stress concentration, the root of the column 2' is set as a fillet 21'. However, many design schemes of planet carriers still cannot be used because the root stress exceeds the allowable stress of the material, which greatly limits the design and use of the planet carrier. Summary of the Invention

[0003] The purpose of the present invention is to provide a planet carrier, so that the high stress at the root position of the column is unloaded, the maximum stress acting on the root of the column is reduced, the stress-bearing capacity of the planet carrier is improved, and the applicability and design flexibility of the planet carrier are improved.

[0004] To achieve this purpose, the present invention adopts the following technical solutions:

[0005] A planet carrier includes two side plates and a plurality of columns. The plurality of columns are spaced apart and arranged in a ring between the two side plates. The two ends of the column in the height direction are respectively connected to the two side plates. A connecting portion is provided on the side surface of the column along the circumferential direction of the side plate. An unloading groove is recessed inward on the connecting portion. A fillet is provided between the column and the side plate. The radius or equivalent curvature radius of the fillet is R, and the vertical distance between the bottom of the unloading groove and the side plate is W, and W < 3R.

[0006] Optionally, one unloading groove is provided on the same connecting portion of the column, and the unloading groove is close to one of the side plates; or

[0007] Two unloading grooves are provided at intervals on the same connecting portion of the column, and the two unloading grooves are respectively close to the two side plates.

[0008] Optionally, when two unloading grooves are provided on the same connecting portion, a transition groove is provided between the two unloading grooves. The two ends of the transition groove are respectively connected to the two unloading grooves, and the transition groove and the unloading groove are integrally formed with the column.

[0009] Optionally, the bottom of the transition groove is an arc surface or a plane.

[0010] Optionally, the depth of the transition groove is not greater than the depth of the unloading groove.

[0011] Optionally, the depth of the unloading groove is h, where h > R / 3.

[0012] Optionally, the unloading groove is an arc groove, a tapered groove or a U-shaped groove.

[0013] Optionally, the column is provided with an inner side surface and an outer side surface in the radial direction. The circumferential length of the outer side surface is greater than the circumferential length of the inner side surface. The outer side surface and the inner side surface are connected by a connecting surface, and the connection part is formed at the junction of the connecting surface and the outer side surface.

[0014] Optionally, the connecting surface, the inner side surface and the outer side surface are all arc-shaped in cross-section. The connecting surface and the outer side surface are connected by an arc surface, and the arc surface is the connecting part.

[0015] Optionally, a pin shaft hole is provided on the side plate. The pin shaft hole is located between the two columns. The connecting surface is a concave circular arc in cross-section, and the circular arc of the connecting surface in cross-section is concentric with the pin shaft hole adjacent to the column; and / or

[0016] The side plate is a circular plate. The inner side surface is a concave circular arc in cross-section, and the circular arc of the inner side surface in cross-section is concentric with the side plate; and / or

[0017] The side plate is a circular plate. The outer side surface is a convex circular arc in cross-section, and the circular arc of the outer side surface in cross-section is concentric with the side plate.

[0018] Advantages of the present invention:

[0019] A planet carrier provided by the present invention unloads the local high stress received by the stress concentration area near the root of the column close to the side plate by providing a first unloading groove. The closer the first unloading groove is to the fillet, the better the unloading effect. W < 3R, which can obtain an obvious stress unloading effect, avoid large stress concentration at the root, improve the stress bearing capacity of the column root, and thus improve the stress bearing capacity of the planet carrier, as well as the applicability and design flexibility of the planet carrier. Description of the Drawings

[0020] Figure 1 is a schematic structural diagram of a planet carrier provided by the prior art;

[0021] Figure 2 is a schematic structural diagram of a planet carrier provided by Embodiment 1 of the present invention;

[0022] Figure 3 is a cross-sectional view of a planet carrier provided by Embodiment 1 of the present invention;

[0023] Figure 4It is a schematic structural diagram of the planet carrier provided by the second embodiment of the present invention;

[0024] Figure 5 It is a schematic structural diagram of the planet carrier provided by the third embodiment of the present invention.

[0025] In the figure:

[0026] 1', side plate; 2', column; 21', rounded corner;

[0027] 1, side plate; 11, pin shaft hole; 2, column; 21, rounded corner; 22, first unloading groove; 23, second unloading groove; 24, third unloading groove; 25, first transition groove; 26, second transition groove; 2A, inner side surface; 2B, outer side surface; 2C, connecting surface; 2D, connecting part. Detailed implementation manners

[0028] To make the technical problems solved, the technical solutions adopted, and the achieved technical effects of the present invention clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0029] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact of the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "above", and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "below", and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is lower than that of the second feature.

[0031] Embodiment 1

[0032] This embodiment provides a planet carrier, as Figure 2 andFigure 3 As shown, it includes two side plates 1 and a plurality of columns 2. The plurality of columns 2 are spaced apart and arranged in a ring between the two side plates 1. The two ends of the columns 2 in the height direction are respectively connected to the two side plates 1. A connecting portion 2D is provided on the side surface of the column 2 along the circumferential direction of the side plate 1. A first unloading groove 22 is recessed inward on the connecting portion 2D. A fillet 21 is provided between the column 2 and the side plate 1. The radius or equivalent curvature radius of the fillet 21 is R, and the vertical distance from the bottom of the first unloading groove 22 to the side plate 1 is W, and W < 3R.

[0033] By providing the first unloading groove 22, the local high stress in the stress concentration area near the root of the column 2 close to the side plate 1 is unloaded. The closer the first unloading groove 22 is to the fillet 21, the better the unloading effect. Since W < 3R, an obvious stress unloading effect can be obtained, avoiding large stress concentration at the root, improving the stress bearing capacity of the root of the column 2, and thus improving the stress bearing capacity of the planet carrier, as well as the applicability and design flexibility of the planet carrier.

[0034] Optionally, as Figure 3 shown, the column 2 is provided with an inner side surface 2A and an outer side surface 2B in the radial direction. The circumferential length of the outer side surface 2B is greater than the circumferential length of the inner side surface 2A. The outer side surface 2B and the inner side surface 2A are connected by a connecting surface 2C. By increasing the length of the outer side surface 2B, the cross-sectional area of the column 2 is increased, improving the structural strength. By reducing the length of the inner side surface 2A, the internal space of the planet carrier is increased. The junction of the connecting surface 2C and the outer side surface 2B forms the connecting portion 2D. The connecting portion 2D protrudes along the circumferential direction of the side plate 1. The concentrated stress received by the connecting portion 2D at the root is greater than that at other positions. By providing the first unloading groove 22 on the connecting portion 2D, the stress unloading effect can be significantly improved.

[0035] Optionally, as Figure 3 shown, the connecting surface 2C, the inner side surface 2A and the outer side surface 2B are all arc-shaped in the cross-section. The connecting surface 2C and the outer side surface 2B are connected by an arc surface, and the arc surface is the connecting portion 2D. By providing the arc surface, a pointed and protruding connecting portion 2D at the junction of the connecting surface 2C and the outer side surface 2B is avoided, preventing stress concentration at the connecting portion 2D and improving the reliability of the column 2. Specifically, the arc can be circular arc, elliptical arc, etc., without limitation. Specifically, each column 2 includes two connecting surfaces 2C and two arc surfaces.

[0036] In this embodiment, a pin shaft hole 11 is provided on the side plate 1. The pin shaft hole 11 is located between two columns 2. The connecting surface 2C is a concave circular arc in the cross-section. The circular arc of the connecting surface 2C in the cross-section is concentric with the adjacent pin shaft hole 11 of the column 2. When a gear is installed on the pin shaft, the connecting surface 2C can avoid the gear, increasing the installation space of the gear and facilitating the installation.

[0037] The side plate 1 and the column 2 form an internal space. In this embodiment, the side plate 1 is a circular plate, and the inner side surface 2A is a concave circular arc in cross-section. The circular arc of the inner side surface 2A in cross-section is concentric with the side plate 1, and the inner side surface 2A faces inward, which can increase the internal space and facilitate the utilization of the internal space.

[0038] In this embodiment, the side plate 1 is a circular plate, and the outer side surface 2B is a convex circular arc in cross-section. The circular arc of the outer side surface 2B in cross-section is concentric with the side plate 1, which increases the cross-sectional area of the column 2 and improves the structural strength.

[0039] Optionally, as Figure 2 shown, two first unloading grooves 22 are provided at intervals on the same connecting portion 2D of the column 2. The two first unloading grooves 22 are respectively arranged close to the two side plates 1, and the two first unloading grooves 22 are respectively used to unload the local high stress at the roots on both sides of the column 2.

[0040] In other embodiments, when the column 2 only receives a large concentrated stress at the root close to one of the side plates 1, one first unloading groove 22 is provided on the same connecting portion 2D of the column 2. The first unloading groove 22 is arranged close to one of the side plates 1 and is set according to the use requirements and its stress conditions.

[0041] Optionally, as Figure 2 shown, connecting portions 2D are respectively provided on the two side surfaces of the column 2 along the circumferential direction of the side plate 1, and the two connecting portions 2D are both recessed with first unloading grooves 22 to cope with the torque in two directions, further improving the applicability.

[0042] In other embodiments, when only the root on one side of the column 2 receives a large concentrated stress, the first unloading groove 22 can also be provided only on the side with the larger concentrated stress, and it is set according to the use requirements and its stress conditions.

[0043] Optionally, as Figure 2 shown, the depth of the first unloading groove 22 is h, and h > R / 3. By increasing the depth, the stress concentration of the first unloading groove 22 is improved, and the stress unloading effect is significantly improved. However, the depth cannot be too large to avoid affecting the structural strength of the column 2 at the position of the first unloading groove 22.

[0044] Optionally, the first unloading groove 22 is an arc groove or a tapered groove or a U-shaped groove. By forming a depression on the connecting portion 2D through the first unloading groove 22, the stress concentration effect at the first unloading groove 22 is improved. Further, the arc groove can be an elliptical arc or a circular arc, etc., which is not limited. In this embodiment, as Figure 2 shown, the arc groove is a circular arc groove.

[0045] Optionally, the connection structure of the two side plates 1 and the multiple columns 2 can be integrally formed by casting, and then a first unloading groove 22 is machined on the column 2.

[0046] Through simulation calculation, when the solution in the background technology is adopted, the maximum stress at the fillet 21 of the column 2 is 424 MPA, while when this solution is adopted, the maximum stress at the fillet 21 of the column 2 drops to 359 MPA, and the stress reduction amplitude is 15%, significantly reducing the stress concentration phenomenon at the root of the column 2.

[0047] Embodiment 2

[0048] The structure of this embodiment is basically the same as that of Embodiment 1, and the same structure will not be described in detail. The difference is only that, as Figure 4 shown, a first transition groove 25 is provided at the connection part 2D of the column 2. The two ends of the first transition groove 25 are respectively connected to two second unloading grooves 23. The first transition groove 25 and the second unloading grooves 23 are integrally formed with the column 2, which is convenient for overall casting and processing, and can also achieve the effect of unloading local high stress.

[0049] Further optionally, the depth of the first transition groove 25 is not greater than the depth of the second unloading groove 23, so that the maximum depth of the column 2 along the circumferential direction of the side plate 1 is located at the second unloading groove 23, realizing an obvious unloading effect. The depth of the second unloading groove 23 should not be too large to avoid reducing the structural strength of the column 2. Optionally, the first transition groove 25 is an arc-shaped groove, an elliptical arc-shaped groove, a conical groove or a U-shaped groove, etc.; in this embodiment, the bottom of the first transition groove 25 is a plane to avoid stress concentration, and the groove wall of the first transition groove 25 can be a plane, an inclined plane or an arc-shaped surface, etc., without limitation.

[0050] Through simulation calculation, when the solution in the background technology is adopted, the maximum stress at the fillet 21 of the column 2 is 424 MPA, while when this solution is adopted, the maximum stress at the fillet 21 of the column 2 drops to 343 MPA, and the stress reduction amplitude is 19%, significantly reducing the stress concentration phenomenon at the root of the column 2.

[0051] Embodiment 3

[0052] The structure of this embodiment is basically the same as that of Embodiment 1, and the same structure will not be described in detail. The difference is only that, as Figure 5 shown, a second transition groove 26 is provided at the connection part 2D of the column 2. The two ends of the second transition groove 26 are respectively connected to two third unloading grooves 24. The second transition groove 26 and the third unloading grooves 24 are integrally formed with the column 2, which is convenient for overall casting and processing, and can also achieve the effect of unloading local high stress.

[0053] Optionally, the depth of the second transition groove 26 is not greater than the depth of the third unloading groove 24, so that the maximum depth of the column 2 along the circumferential direction of the side plate 1 is located at the third unloading groove 24, achieving an obvious unloading effect. The depth of the third unloading groove 24 should not be too large to avoid reducing the structural strength of the column 2. Optionally, the second transition groove 26 is an arc-shaped groove, an elliptical arc-shaped groove, a conical groove or a U-shaped groove, etc.; in this embodiment, the bottom of the second transition groove 26 is an arc surface, and the groove wall of the second transition groove 26 is a plane, an inclined surface or an arc surface, etc., which is not limited; preferably, the second transition groove 26 is an arc groove or an elliptical arc-shaped groove.

[0054] Through simulation calculation, when the solution in the background technology is adopted, the maximum stress at the fillet 21 of the column 2 is 424 MPA, while when this solution is adopted, the maximum stress at the fillet 21 of the column 2 drops to 343 MPA, and the stress reduction amplitude is 19%, significantly reducing the stress concentration phenomenon at the root of the column 2.

[0055] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A planet carrier, characterized in that, it includes two side plates (1) and a plurality of columns (2). The plurality of columns (2) are arranged at intervals and in a circular pattern between the two side plates (1). The two ends of each column (2) in the height direction are respectively connected to the two side plates (1). A connecting portion (2D) is provided on the side surface of each column (2) along the circumferential direction of the side plate (1). An unloading groove is recessed inward on the connecting portion (2D). A fillet (21) is provided between the column (2) and the side plate (1). The radius or equivalent curvature radius of the fillet (21) is R, and the vertical distance between the bottom of the unloading groove and the side plate (1) is W, where W < 3R; Two unloading grooves are provided at intervals on the same connecting portion (2D) of the column (2), and the two unloading grooves are respectively arranged close to the two side plates (1); When two unloading grooves are provided on the same connecting portion (2D), a transition groove is provided between the two unloading grooves. The two ends of the transition groove are respectively connected to the two unloading grooves, and the transition groove and the unloading grooves are integrally formed with the column (2).

2. The planet carrier according to claim 1, characterized in that, the bottom of the transition groove is an arc surface or a flat surface.

3. The planet carrier according to claim 1, characterized in that, the depth of the transition groove is not greater than the depth of the unloading groove.

4. The planet carrier according to any one of claims 1 - 3, characterized in that, the depth of the unloading groove is h, where h > R / 3.

5. The planet carrier according to any one of claims 1 - 3, characterized in that, the unloading groove is an arc-shaped groove, a tapered groove or a U-shaped groove.

6. The planet carrier according to any one of claims 1 - 3, characterized in that, the column (2) is provided with an inner side surface (2A) and an outer side surface (2B) along the radial direction. The circumferential length of the outer side surface (2B) is greater than the circumferential length of the inner side surface (2A). The outer side surface (2B) and the inner side surface (2A) are connected by a connecting surface (2C), and the connecting portion (2D) is formed at the junction of the connecting surface (2C) and the outer side surface (2B).

7. The planet carrier according to claim 6, characterized in that, the connecting surface (2C), the inner side surface (2A) and the outer side surface (2B) are all arc-shaped in cross-section. The connecting surface (2C) and the outer side surface (2B) are connected by an arc surface, and the arc surface is the connecting portion (2D).

8. The planet carrier according to claim 7, characterized in that, a pin shaft hole (11) is provided on the side plate (1), and the pin shaft hole (11) is located between the two columns (2). The connecting surface (2C) is a concave circular arc in cross-section, and the circular arc of the connecting surface (2C) in cross-section is concentric with the pin shaft hole (11) adjacent to the column (2); and / or the side plate (1) is a circular plate, and the inner side surface (2A) is a concave circular arc in cross-section, and the circular arc of the inner side surface (2A) in cross-section is concentric with the side plate (1); and / or The side plate (1) is a circular plate, the outer side surface (2B) is a convex circular arc in cross-section, and the circular arc of the outer side surface (2B) in cross-section is concentric with the side plate (1).

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