Gearless planetary roller screw

Abstract

The utility model relates to the technical field of planetary roller screws, in particular to a gearless planetary roller screw, which comprises a nut, a screw and a plurality of rollers. Assembling sections are arranged on the pin rollers; when the lead screw is a driving part, one of the assembling section and the nut is provided with annular teeth, the other one of the assembling section and the nut is provided with an annular groove, and the annular groove is matched with the annular teeth in a meshed mode so that no relative axial displacement exists between the pin rollers and the nut. When the nut is a driving part, one of the assembling section and the lead screw is provided with annular teeth, the other one of the assembling section and the lead screw is provided with annular grooves, and the annular grooves are matched with the annular teeth in a meshed mode so that no relative axial displacement exists between the pin rollers and the lead screw. Aiming at the defects of the existing planetary roller screw, a gear structure is eliminated, burrs generated by gear machining are eliminated, the cleanliness level of the roller is improved, the influence of the burrs on thread meshing is reduced, and the overall service life of the planetary roller screw is prolonged; impact and noise caused by gear meshing are avoided, and the overall NVH level of the planetary roller screw is improved.

Description

Technical Field

[0001] This utility model relates to the field of planetary roller screw technology, and specifically to a gearless planetary roller screw. Background Technology

[0002] Currently, both common planetary roller screw designs incorporate gear structures, including standard planetary roller screws and reverse planetary roller screws. In particular, the gears on the rollers are designed as a combination of threads and gears, meaning that threads exist on both ends of the roller, as shown in the figure. Because the thread diameter of the conventional roller design matches the pitch circle of the gear, the gear portion of the roller needs to mesh with both the gear on the internal gear ring and the thread of the screw. This results in the gears at both ends of the roller requiring both gears and threads.

[0003] This structure ensures the normal transmission of the planetary roller screw, but the gear structure has many problems. For example, the gear structure is difficult to machine, resulting in burrs that are difficult to clean. Additionally, the presence of threads on the gear section leads to incomplete tooth profiles, reducing gear strength and increasing noise. Similarly, the presence of gears on the threads at both ends also results in incomplete thread sections, affecting thread strength and generating noise.

[0004] In summary, the main problems with the internal gear structure of planetary roller screws are high processing costs; the tendency to generate burrs, which affects the cleanliness of the assembly and thus exacerbates wear and affects service life; and the fact that the design of the gear tip circle is limited by the size of the thread major diameter, often resulting in low overlap, which leads to impact and noise during gear meshing. Utility Model Content

[0005] To address the technical problems of existing planetary roller screws, this invention provides a gearless planetary roller screw. It simplifies the roller structure by eliminating the gears on the rollers and correspondingly eliminating the gears on the screw or the internal gear ring on the nut. This eliminates burrs generated during gear machining, improves the cleanliness of the rollers, reduces the impact of burrs on thread engagement, and increases the overall lifespan of the planetary roller screw. Simultaneously, eliminating gear meshing reduces the impact and noise caused by gear meshing, improving the overall NVH level of the planetary roller screw, and reducing overall machining difficulty and cost.

[0006] The technical solution provided by this utility model is as follows: a gearless planetary roller screw, comprising a nut, a screw, and a plurality of rollers; the nut is disposed on the outside of the screw, the plurality of rollers are evenly distributed circumferentially between the screw and the nut, the nut is provided with an internal thread, the outer wall of the screw is provided with an external thread, and the middle part of the roller is provided with a mating thread; the internal thread meshes with the mating thread, and the external thread meshes with the mating thread; the roller is provided with an assembly section, the assembly section being located at both ends of the mating thread. When the lead screw is the driving component, one of the assembly section and the nut is provided with a ring tooth, and the other is provided with a ring groove. The ring groove meshes with the ring tooth to ensure that there is no relative axial displacement between the roller and the nut. When the nut is the driving component, one of the assembly section and the lead screw is provided with a ring tooth, and the other is provided with a ring groove. The ring groove meshes with the ring tooth to ensure that there is no relative axial displacement between the roller and the lead screw. The ring tooth or ring groove on the lead screw is located at both ends of the external thread.

[0007] Optionally, a multi-groove retainer is provided between the nut and the lead screw, the multi-groove retainer having a plurality of through receiving grooves along the circumferential direction, and the roller being located in the receiving groove.

[0008] Optionally, the multi-groove retainer is clearance-fitted with the nut and the lead screw.

[0009] Optionally, the outer diameter of the assembly section is smaller than the outer diameter of the mating thread.

[0010] Optionally, the tooth profile of the ring tooth or ring groove is consistent with the thread profile of the mating thread.

[0011] Optionally, the tooth profile of the ring tooth includes a triangular or arc-shaped shape.

[0012] Optionally, the tooth profile of the annular groove includes a triangular or circular arc shape.

[0013] Optionally, at least one pair of ring teeth and ring grooves are provided.

[0014] Optionally, the length of the roller is less than or equal to the length of the nut.

[0015] Beneficial effects

[0016] Compared with the prior art, the technical solution provided by this utility model has the following beneficial effects: Addressing the technical problems of defects in existing planetary roller screws, this utility model simplifies the roller structure by eliminating the roller gears and correspondingly eliminating the gears on the screw or the internal gear ring on the nut. This eliminates burrs generated during gear machining, improves the cleanliness level of the rollers, reduces the impact of burrs on thread meshing, and increases the overall lifespan of the planetary roller screw. Simultaneously, eliminating gear meshing avoids the impact and noise caused by gear meshing, improving the overall NVH level of the planetary roller screw; and reducing the overall processing difficulty and cost. Attached Figure Description

[0017] Figure 1 This is one of the embodiments of the gearless planetary roller screw proposed in this utility model.

[0018] Figure 2 for Figure 1 An exploded view of the structure of the embodiment shown.

[0019] Figure 3 This is the second embodiment of the gearless planetary roller screw proposed in this utility model.

[0020] Figure 4 for Figure 3 An exploded view of the structure of the embodiment shown. Detailed Implementation

[0021] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0022] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the relevant utility model and not intended to limit the utility model. Furthermore, it should be noted that, for ease of description, only the parts related to the utility model are shown in the accompanying drawings. The terms "first," "second," etc., used in this utility model are provided for the convenience of describing the technical solution of this utility model and have no specific limiting effect; they are all general terms and do not constitute a limitation on the technical solution of this utility model. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions that do not contradict or conflict, all of which are within the scope of protection claimed by this utility model.

[0023] Example 1

[0024] Combined with appendix Figure 1-2 This embodiment proposes a gearless planetary roller screw, including a nut 1, a screw 2, and a plurality of rollers 3. The nut 1 is disposed on the outside of the screw 2, and the plurality of rollers 3 are evenly distributed circumferentially between the screw 2 and the nut 1. The nut 1 is provided with an internal thread, the outer wall of the screw 2 is provided with an external thread 20, and the middle part of the roller 3 is provided with a mating thread 30; the internal thread meshes with the mating thread 30, and the external thread 20 meshes with the mating thread 30.

[0025] The roller 3 is provided with an assembly section 31, which is located at both ends of the mating thread 30. In this embodiment, the lead screw 2 is the driving component. One of the assembly section 31 and the nut 1 is provided with a ring tooth 4, and the other is provided with a ring groove 5. The ring groove 5 meshes with the ring tooth 4 to ensure that there is no relative axial displacement between the roller 3 and the nut 1.

[0026] The gearless planetary roller screw proposed in this embodiment is in the form of a standard planetary roller screw, where the screw 2 is the driving component and the nut 1 is the output component. The rotation of the screw 2 is transmitted to the nut 1 through the rollers 3, forming the linear motion output of the nut 1. To ensure the proper fit between the nut 1 and the rollers 3, the length of the rollers 3 is generally less than or equal to the length of the nut 1.

[0027] In this embodiment, the structure of roller 3 is simplified by eliminating the gear, and correspondingly, the structure of nut 1 is also simplified by eliminating the internal gear ring. This eliminates burrs generated during gear machining, improves the cleanliness of roller 3, reduces the impact of burrs on thread engagement, and increases the overall lifespan of the planetary roller screw. Simultaneously, eliminating gear meshing avoids the impact and noise caused by gear meshing, improving the overall NVH level of the planetary roller screw. Furthermore, eliminating gear machining significantly reduces machining difficulty and cost.

[0028] In a further embodiment, a multi-groove retainer 6 is provided between the nut 1 and the lead screw 2. The multi-groove retainer 6 has several through-grooves 60 arranged circumferentially, and the roller 3 is located in the receiving grooves 60. During the operation of the roller 3, the helix angle will cause the roller 3 to tilt. The multi-groove retainer 6 added in this embodiment has good rigidity and can cooperate with the roller 3 to prevent the roller 3 from tilting, thus playing the role of a gear. In addition, in order to avoid interference and ensure effective cooperation between the lead screw 2, the nut 1 and the roller 3, the multi-groove retainer 6 adopts a clearance fit with the nut 1 and the lead screw 2.

[0029] In addition, in order to avoid the engagement of the ring groove 5 and the ring tooth 4 affecting the meshing of the mating thread 30 on the roller 3 with the nut 1 and the lead screw 2, the outer diameter of the assembly section 31 is smaller than the outer diameter of the mating thread 30.

[0030] Furthermore, to achieve efficient meshing between the annular groove 5 and the annular tooth 4, the tooth profile of the annular tooth 4 can be triangular or arc-shaped, etc., and correspondingly, the tooth profile of the annular groove 5 can also be triangular or arc-shaped, etc. Here, the tooth profile of the annular tooth 4 refers to the cross-sectional shape of the annular tooth 4, and the tooth profile of the annular groove 5 refers to the cross-sectional shape of the annular groove 5. In one embodiment, the tooth profile of the annular tooth 4 or the annular groove 5 is consistent with the thread profile of the mating thread 30.

[0031] Understandably, the ring groove 5 and ring tooth 4 are designed to replace traditional gear meshing. Therefore, the number of ring grooves 5 and ring teeth 4 can also affect the replacement effect. Generally, at least one pair of ring grooves 5 and ring teeth 4 should be provided. Obviously, within a certain range, the more ring grooves 5 and ring teeth 4 there are, the better the effect of limiting the relative axial displacement between the roller 3 and the nut 1. Therefore, the number of ring grooves 5 and ring teeth 4 can be adjusted according to the actual situation.

[0032] Example 2

[0033] Combined with appendix Figure 3-4 This embodiment proposes a gearless planetary roller screw, which also includes a nut 1, a screw 2, and several rollers 3. The nut 1 is located on the outside of the screw 2, and the several rollers 3 are evenly distributed circumferentially between the screw 2 and the nut 1. The nut 1 has an internal thread, the outer wall of the screw 2 has an external thread 20, and the middle of the roller 3 has a mating thread 30; the internal thread meshes with the mating thread 30, and the external thread 20 meshes with the mating thread 30. The roller 3 has an assembly section 31 located at both ends of the mating thread 30.

[0034] This embodiment is generally similar to Embodiment 1, but the difference is that: in this embodiment, the nut 1 is the driving part, and one of the assembly section 31 and the lead screw 2 is provided with a ring tooth 4, and the other is provided with a ring groove 5. The ring groove 5 and the ring tooth 4 mesh with each other so that there is no relative axial displacement between the roller 3 and the lead screw 2; and the ring tooth 4 or the ring groove 5 on the lead screw 2 is located at both ends of the external thread 20.

[0035] The gearless planetary roller screw proposed in this embodiment is in the form of a reverse planetary roller screw, that is, the screw 2 is the driving member and the nut 1 is the output member. The rotation of the screw 2 is transmitted to the nut 1 through the roller 3, forming the linear motion output of the nut 1.

[0036] Similar to the aforementioned standard planetary roller screw, the reverse planetary roller screw in this embodiment also simplifies the structure of roller 3 by eliminating the gear of roller 3, and correspondingly simplifies the structure of screw 2 by eliminating the external gear of screw 2.

[0037] Compared to the traditional reverse planetary roller screw, in this embodiment, the external gear of the screw 2 is also eliminated (there is no internal gear ring on the nut 1). Through the cooperation of the ring tooth 4 and the ring groove 5, it is ensured that there is no relative axial displacement between the roller 3 and the screw 2.

[0038] This eliminates burrs generated during gear machining, improves the cleanliness of roller 3, reduces the impact of burrs on thread engagement, and extends the overall lifespan of the planetary roller screw. Simultaneously, eliminating gear meshing avoids the impact and noise associated with it, improving the overall NVH (noise, vibration, and harshness) level of the planetary roller screw. Furthermore, the elimination of gear machining significantly reduces machining difficulty and cost.

[0039] Similar to Embodiment 1, in this embodiment, a multi-groove retainer 6 is also provided between the nut 1 and the lead screw 2. The multi-groove retainer 6 has several through-grooves 60 arranged circumferentially, and the roller 3 is located in the receiving grooves 60. During the operation of the roller 3, the helix angle will cause the roller 3 to tilt. The multi-groove retainer 6 added in this embodiment has good rigidity and can cooperate with the roller 3 to prevent the roller 3 from tilting, thus playing the role of a gear. In addition, in order to avoid interference and ensure effective cooperation between the lead screw 2, the nut 1 and the roller 3, the multi-groove retainer 6 adopts a clearance fit with the nut 1 and the lead screw 2.

[0040] In addition, in order to avoid the engagement of the ring groove 5 and the ring tooth 4 affecting the meshing of the mating thread 30 on the roller 3 with the nut 1 and the lead screw 2, the outer diameter of the assembly section 31 is smaller than the outer diameter of the mating thread 30.

[0041] Furthermore, to achieve efficient meshing between the annular groove 5 and the annular tooth 4, the tooth profile of the annular tooth 4 can also be triangular or arc-shaped, etc. Correspondingly, the tooth profile of the annular groove 5 can also be triangular or arc-shaped, etc. In one embodiment, the tooth profile of the annular tooth 4 or the annular groove 5 is consistent with the thread profile of the mating thread 30.

[0042] Furthermore, this embodiment also includes at least one pair of annular grooves 5 and annular teeth 4, and the specific number of annular grooves 5 and annular teeth 4 can be adjusted according to the actual situation.

[0043] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited to this. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A gearless planetary roller screw, characterized in that, Includes a nut (1), a lead screw (2), and several rollers (3); The nut (1) is disposed on the outside of the lead screw (2), and a plurality of rollers (3) are evenly distributed circumferentially between the lead screw (2) and the nut (1). The nut (1) is provided with an internal thread, the outer wall of the lead screw (2) is provided with an external thread (20), and the middle part of the roller (3) is provided with a mating thread (30); the internal thread meshes with the mating thread (30), and the external thread (20) meshes with the mating thread (30); The roller (3) is provided with an assembly section (31), which is located at both ends of the mating thread (30); When the lead screw (2) is the driving component, one of the assembly section (31) and the nut (1) is provided with a ring tooth (4), and the other is provided with a ring groove (5). The ring groove (5) meshes with the ring tooth (4) so ​​that there is no relative axial displacement between the roller (3) and the nut (1). When the nut (1) is the driving component, one of the assembly section (31) and the lead screw (2) is provided with a ring tooth (4), and the other is provided with a ring groove (5). The ring groove (5) meshes with the ring tooth (4) so ​​that there is no relative axial displacement between the roller (3) and the lead screw (2); and the ring tooth (4) or the ring groove (5) on the lead screw (2) is located at both ends of the external thread (20).

2. The gearless planetary roller screw according to claim 1, characterized in that, A multi-groove retainer (6) is provided between the nut (1) and the lead screw (2). The multi-groove retainer (6) has several through-groove receiving grooves (60) arranged in the circumferential direction. The roller (3) is located in the receiving grooves (60).

3. The gearless planetary roller screw according to claim 2, characterized in that, The multi-groove retainer (6) is clearance-fitted with the nut (1) and the lead screw (2).

4. The gearless planetary roller screw according to claim 1, characterized in that, The outer diameter of the assembly section (31) is smaller than the outer diameter of the mating thread (30).

5. A gearless planetary roller screw according to claim 1, characterized in that, The tooth profile of the ring tooth (4) or the ring groove (5) is consistent with the thread profile of the mating thread (30).

6. A gearless planetary roller screw according to claim 1 or 5, characterized in that, The tooth shape of the ring tooth (4) includes a triangle or an arc.

7. A gearless planetary roller screw according to claim 1 or 5, characterized in that, The tooth shape of the annular groove (5) includes a triangle or an arc.

8. A gearless planetary roller screw according to claim 1, characterized in that, At least one pair of ring teeth (4) and ring grooves (5) are provided.

9. A gearless planetary roller screw according to claim 1, characterized in that, The length of the roller (3) is less than or equal to the length of the nut (1).

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