A standard planetary roller screw without straight-tooth engagement

Abstract

The utility model relates to the field of mechanical drive, specifically disclose a kind of standard planetary roller screw without straight-tooth engagement, including transmission screw, retainer, several rollers and nut cover, roller and retainer are arranged in nut cover, the outer circumferential surface of retainer is equipped with assembly space, assembly space is same with roller quantity, assembly space is equipped with rotation space and assembly slot, roller is equipped with threaded section and rotation section, rotation section is limited rotation in assembly slot, threaded section rotates in rotation space, threaded section is screwed with transmission screw, nut cover cooperation.This utility model is by setting integrated retainer, screw stud both ends and retainer cooperation transmission, when screw stud transmission, retainer can rotate integrally, integral retainer both ensure that screw stud will not be inclined in transmission process, and simplify integral structure, to solve the problem of unbalanced transmission, improve the integrity of action transmission between screw stud and retainer.

Description

Technical Field

[0001] This utility model relates to the field of mechanical transmission, and in particular to a standard planetary roller screw that does not require spur gear meshing. Background Technology

[0002] A planetary roller screw is a mechanical transmission device that can convert between rotary and linear motion, possessing characteristics of both threaded and rolling helical drives. Unlike ball screw drives, its rolling elements are not multiple spheres, but multiple threaded rollers. In a standard planetary roller screw drive mechanism, both the screw and the nut cap have multi-start threads with triangular tooth profiles. The rollers have single-start threads with a spherical profile. To eliminate the tilting torque generated by the screw helix angle on the rollers, straight teeth are machined at both ends of the rollers, meshing with an internal gear ring installed in the nut cap to ensure that the roller axis is parallel to the screw axis for normal rolling.

[0003] However, in current standard planetary roller screws, the internal gear rings at both ends of the rollers are set separately. Due to the transmission gap during screw transmission, there is still a slight asynchrony between the internal gear rings at both ends of the rollers, causing the rollers to tilt slightly. This results in uneven force on each roller, unstable transmission, and reduced transmission efficiency and accuracy.

[0004] The technical problem to be solved by this application is: how to reduce the transmission instability of rollers during the transmission process. Utility Model Content

[0005] In order to overcome the shortcomings of the existing technology, the purpose of this utility model is to provide a standard planetary roller screw that does not require spur gear meshing.

[0006] The technical solution adopted by this utility model is as follows: a standard planetary roller screw that does not require spur gear meshing, including a transmission screw, a cage, several rollers and a nut cover. The rollers and the cage are disposed inside the nut cover. The outer circumferential surface of the cage is provided with an assembly space, which is arranged in accordance with the number of rollers. The assembly space is provided with a rotation space and an assembly groove. The rollers are provided with a threaded section and a rotating section. The rotating section rotates within the assembly groove and the threaded section rotates within the rotation space. The threaded section is threadedly engaged with the transmission screw and the nut cover.

[0007] In some implementations, the diameter of the threaded section is larger than the diameter of the rotating section.

[0008] In some embodiments, the bottom of the assembly slot is arc-shaped and rotates inward with the rotating section, and the opening of the assembly slot faces outward from the cage.

[0009] In some embodiments, the mounting slot is located at the end of the cage, and the rotation space is located between two mounting slots on the same axis.

[0010] In some embodiments, an end cap is included, which is shaped like a "7". The end cap is disposed at the end of the cage and one side of the end cap is disposed around the opening of the mounting groove. One end of the end cap abuts against the end of the cage.

[0011] In some embodiments, the inner wall of the nut cover is provided with a fixing groove and a positioning groove arranged sequentially from the middle of the nut groove toward the end. Both the fixing groove and the positioning groove are annular grooves. The end cover is set in the fixing groove, and a positioning retaining ring is provided in the positioning groove. The positioning retaining ring is embedded in the positioning groove.

[0012] In some implementations, the fixing groove and the positioning groove form a stepped shape, and one side of the positioning retaining ring abuts against the end cap.

[0013] In some implementations, two end caps are respectively located at both ends of the cage.

[0014] In some implementations, the cage is shaped like a hollow cylinder.

[0015] In some implementations, the outer peripheral surface of the rotating section is smoothly configured, while the outer peripheral surface of the threaded section is configured as a thread.

[0016] The beneficial effects of this utility model are as follows:

[0017] This standard planetary roller screw, which does not require spur gear meshing, uses an integrated cage. The two ends of the stud cooperate with the cage for transmission. When the stud is in motion, the cage can rotate as a whole, avoiding the slight rotational difference between the two internal gear rings in the original separate design. The integrated cage not only ensures that the stud will not tilt during transmission, but also simplifies the overall structure, thereby solving the problem of transmission imbalance and improving the overall integrity of motion transmission between the stud and the cage. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 This is an exploded view of the structure of this utility model;

[0020] Figure 3 This is a schematic cross-sectional view of the structure of this utility model;

[0021] The labels and names in the diagram correspond as follows: 1. Lead screw; 2. Cage; 3. Roller; 4. Nut cap; 5. End cap; 6. Positioning retaining ring; 21. Connecting column; 22. Rotation space; 23. Assembly groove; 31. Threaded section; 32. Rotating section; 42. Fixed groove; 43. Positioning groove. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Please see Figure 1 This utility model provides a technical solution: a standard planetary roller screw that does not require spur gear meshing, comprising a drive screw 1, a cage 2, several rollers 3, a nut cover 4, and end caps 5. The rollers 3 and the cage 2 are disposed within the nut cover 4. The outer circumferential surface of the drive screw 1 is uniformly threaded, and the drive screw 1 passes through the nut cover 4. The rollers 3 are arranged around the drive screw 1, and the drive screw 1 and rollers 3 are threadedly engaged. Two end caps 5 are respectively disposed at both ends of the cage 2.

[0024] Please see Figure 2 The roller 3 is provided with a threaded section 31 and a rotating section 32. The two rotating sections 32 are respectively located at both ends of the threaded section 31. The outer circumferential surface of the rotating section 32 is smooth, and the outer circumferential surface of the threaded section 31 is threaded. The diameter of the threaded section 31 is larger than the diameter of the rotating section 32. The threaded section 31 is threadedly engaged with the nut cover 4 and the transmission screw 1.

[0025] Please see Figure 2 The cage 2 is shaped like a hollow cylinder. Its outer circumference has assembly spaces and connecting posts 21, which are alternately arranged. The number of assembly spaces is the same as the number of rollers 3. Several rollers 3 are evenly assembled on the cage 2, each roller located within its corresponding assembly space. The connecting posts 21 separate adjacent assembly spaces. Each assembly space has a rotation space 22 and an assembly groove 23. The assembly groove 23 is located at the end of the cage 2, and the rotation space 22 is located between two assembly grooves 23 on the same axis. The rotating section 32 of the roller 3 is limited to rotate within the assembly groove 23, while the threaded section 31 of the roller 3 rotates within the rotation space 22. The bottom of the assembly groove 23 is arc-shaped and accommodates the rotation of the rotating section 32. The opening of the assembly groove 23 faces outwards from the cage 2. Because the split internal gear ring has been eliminated, when the roller 3 is driven in conjunction with the transmission screw 1, the rotation of the screw forces the cage 2 to rotate as a whole due to the limiting effect of the nut cover 4. This avoids the asynchronous situation at both ends of the roller 3, and prevents the roller 3 from tilting slightly at both ends, which would ultimately lead to unstable transmission.

[0026] Please see Figure 3The end cap 5 is shaped like a "7". The end cap 5 is set at the end of the retainer 2 and one side of the end cap 5 is set around the groove of the assembly groove 23. One end of the end cap 5 abuts against the end of the retainer 2. The end cap 5 is set to prevent the roller 3 from disengaging from the assembly groove 23, and to ensure that there is no relative axial displacement between the retainer 2 and the nut cover 4.

[0027] Please see Figure 3 The inner wall of the nut cover 4 is provided with a fixing groove 42 and a positioning groove 43. The fixing groove 42 and the positioning groove 43 are arranged sequentially from the middle of the nut groove towards the end, and both the fixing groove 42 and the positioning groove 43 are annular grooves, forming a stepped shape. The end cover 5 is set in the fixing groove 42. A positioning retaining ring 6 is provided in the positioning groove 43. The positioning retaining ring 6 is embedded in the positioning groove 43, and one side of the positioning retaining ring 6 abuts against the end cover 5. The positioning retaining ring 6 can further axially position the retainer 2 and facilitate the assembly of the internal structure of the nut cover 4. The retainer 2, the end cover 5 and the positioning retaining ring 6 are sequentially placed into the nut cover 4.

[0028] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A standard planetary roller screw without straight-toothed engagement, characterized in that, The device includes a lead screw (1), a cage (2), several rollers (3) and a nut cover (4). The rollers (3) and the cage (2) are arranged inside the nut cover (4). The outer circumference of the cage (2) is provided with an assembly space. The assembly space is provided in accordance with the number of rollers (3). The assembly space is provided with a rotation space (22) and an assembly groove (23). The rollers (3) are provided with a threaded section (31) and a rotating section (32). The rotating section (32) rotates within the assembly groove (23) and the threaded section (31) rotates within the rotation space (22). The threaded section (31) is threadedly engaged with the lead screw (1) and the nut cover (4).

2. A standard planetary roller screw that does not require spur gear meshing according to claim 1, characterized in that, The diameter of the threaded section (31) is greater than the diameter of the rotating section (32).

3. A standard planetary roller screw that does not require spur gear meshing according to claim 1, characterized in that, The bottom of the assembly groove (23) is set to be arc-shaped and rotates inward with the rotating section (32), and the opening of the assembly groove (23) faces outward from the retainer (2).

4. A standard planetary roller screw that does not require spur gear meshing according to claim 1, characterized in that, The assembly slot (23) is located at the end of the retainer (2), and the rotation space (22) is located between the two assembly slots (23) on the same axis.

5. A standard planetary roller screw that does not require spur gear meshing according to claim 3, characterized in that, Includes an end cap (5), which is shaped like a "7". The end cap (5) is located at the end of the retainer (2) and one side of the end cap (5) is arranged around the opening of the assembly groove (23). One end of the end cap (5) abuts against the end of the retainer (2).

6. A standard planetary roller screw that does not require spur gear meshing according to claim 5, characterized in that, The inner wall of the nut cover (4) is provided with a fixing groove (42) and a positioning groove (43) arranged sequentially from the middle of the nut groove to the end. The fixing groove (42) and the positioning groove (43) are both annular grooves. The end cover (5) is set in the fixing groove (42). The positioning groove (43) is provided with a positioning retaining ring (6). The positioning retaining ring (6) is embedded in the positioning groove (43).

7. A standard planetary roller screw that does not require spur gear meshing according to claim 6, characterized in that, The fixing groove (42) and the positioning groove (43) form a stepped shape, and one side of the positioning retaining ring (6) abuts against the end cap (5).

8. A standard planetary roller screw that does not require spur gear meshing according to claim 6, characterized in that, The two end caps (5) are respectively disposed at both ends of the retainer (2).

9. A standard planetary roller screw that does not require spur gear meshing according to claim 1, characterized in that, The cage (2) has an overall shape like a hollow cylinder.

10. A standard planetary roller screw that does not require spur gear meshing according to claim 1, characterized in that, The outer circumferential surface of the rotating section (32) is smoothly arranged, and the outer circumferential surface of the threaded section (31) is threaded.

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