A method for assembling a reverse planetary roller screw pair

Abstract

The present application relates to the technical field of planetary roller screw assembly method, and particularly relates to an assembly method of a reverse planetary roller screw pair. In view of the technical problem of defects in the existing assembly method of the planetary roller screw pair, the present application simplifies the assembly process by using a radial retainer and a circumferential retainer, that is, the screw and the roller are quickly assembled into an integrated module, and then the integrated module is quickly assembled with the nut. This form can efficiently and conveniently realize the assembly of the screw and the roller, while ensuring the transmission accuracy and performance of the reverse planetary roller screw pair, and improving the overall assembly efficiency of the reverse planetary roller screw pair. Moreover, the radial retainer and the circumferential retainer have simple structures and simple assembly processes, and are easy to be matched with intelligent equipment such as a mechanical arm, so as to realize the automatic assembly of industrialization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of planetary roller screw assembly methods, in particular to an assembly method of a reverse planetary roller screw pair. BACKGROUND

[0002] The planetary roller screw pair is a kind of rolling screw transmission mechanism for converting linear and rotary motion, and its basic principle is to transmit power through multi-point thread contact between multiple rollers, a screw and a nut raceway. In recent years, with the rapid development of humanoid robots, planetary roller screw pairs have been applied in robot joints. Among them, the reverse planetary roller screw pair, as a commonly used planetary roller screw pair in the field of humanoid robots, has the advantages of high load capacity, high precision, high efficiency, no pollution, easy maintenance, etc. In the reverse planetary roller screw pair, the two ends of the threaded segment on the roller are combined with gears to form the end tooth segment of the roller, and the two ends of the threaded segment on the screw are also provided with gears to form the end tooth segment of the screw. The gear meshing between the end tooth segments of the screw and the roller can limit the roller and prevent it from tilting.

[0003] However, the industrial field automation assembly problem of the reverse planetary roller screw pair is one of the reasons that hinder the further mass production of the reverse planetary roller screw pair. The existing assembly method and operation cannot ensure the transmission accuracy and performance of the planetary roller screw pair while having high assembly efficiency, and the equipment and labor cost is high. SUMMARY

[0004] In view of the technical problem of defects in the existing assembly method of the planetary roller screw pair, the present application provides an assembly method of a reverse planetary roller screw pair, which uses radial retainers and circumferential retainers to efficiently and conveniently assemble the screw and the roller, ensures the transmission accuracy and performance of the reverse planetary roller screw pair, and improves the overall assembly efficiency of the reverse planetary roller screw pair.

[0005] The technical scheme provided by the application is a reverse type planetary roller screw pair assembly method, comprising the following steps: S1, preparing a radial retainer and a circumferential retainer; the radial retainer is in a cylindrical shape, and a through gap is arranged on the radial retainer; the circumferential retainer comprises a barrel body, one side of the barrel body is fixedly provided with an end block, and open limiting grooves are uniformly arranged on the end block in the circumferential direction, and the number of the limiting grooves is consistent with the number of rollers; S2, arranging two circumferential retainers on both sides of one radial retainer respectively; ensuring that the end block on any circumferential retainer is adjacent to the radial retainer; and ensuring that the center plane P1 of the limiting groove corresponding to the gap on any circumferential retainer is coincident with the center plane P2 of the gap; S3, assembling a screw into the radial retainer and the circumferential retainer, ensuring coaxial cooperation of the screw, the radial retainer and the circumferential retainer, ensuring that the center plane P2 is coincident with the plane P3 where the thread starting point R1 of the screw is located, and clamping the screw to ensure that the screw is fixed; S4, pushing a roller into the gap until the optical axis segment of the roller is clamped into the limiting groove, and ensuring that the end tooth segment of the roller is cooperated with the end tooth segment of the screw, and the thread segment of the roller is cooperated with the thread segment of the screw at the same time; S5, rotating the two circumferential retainers synchronously by a fixed angle, and rotating the roller at the same time, leaving the gap, and ensuring that the center plane P1 of the limiting groove corresponding to the gap is coincident with the center plane P2 of the gap; S6, repeating S4 and S5 until all rollers are assembled; S7, removing the circumferential retainer on one side, and sequentially assembling a retainer and an elastic check ring on the side, and then removing the circumferential retainer on the other side, and sequentially assembling a retainer and an elastic check ring on the side, so that the screw, the roller, the retainer and the elastic check ring form an integrated module; and S8, rotating the integrated module into a nut, and completing the assembly of the reverse type planetary roller screw pair.

[0006] Optionally, for step S4, during the process of pushing the roller into the gap, the thread starting point R1 of the screw is ensured to be in the same plane as the thread starting point R2 of the roller, so that the end tooth segment of the roller is cooperated with the end tooth segment of the screw, and the thread segment of the roller is cooperated with the thread segment of the screw at the same time.

[0007] Optionally, for step S5, the single rotation angle of the two circumferential retainers is θ=360° / N, wherein N is the number of rollers.

[0008] Optionally, for step S7, when the retainer is assembled, the retainer is ensured to be coaxial with the screw, and each retaining hole on the retainer is coaxial with the corresponding roller.

[0009] Optionally, an elastic clamping piece is arranged at the opening of the limiting groove, and the distance between the two elastic clamping pieces in the same limiting groove is less than the diameter of the optical axis segment of the roller.

[0010] Optionally, the limiting groove is provided with a mounting groove, and the elastic card is fixedly arranged in the mounting groove.

[0011] Optionally, the outer diameter of the end block is smaller than the inner diameter of the radial retainer.

[0012] Optionally, the distance between the radial retainer and the lead screw is greater than the outer diameter of the roller.

[0013] Compared with the prior art, the technical scheme provided by the present application has the following beneficial effects: In view of the technical problem of defects in the existing assembly method of the planetary roller screw pair, the present application simplifies the assembly process by using a radial retainer and a circumferential retainer: the lead screw and the roller are quickly assembled into an integrated module, and then the integrated module and the nut are quickly assembled. This form can efficiently and conveniently realize the assembly of the lead screw and the roller, while ensuring the transmission accuracy and performance of the reverse planetary roller screw pair, and improving the overall assembly efficiency of the reverse planetary roller screw pair. Moreover, the radial retainer and the circumferential retainer have simple structure and simple assembly process, and are easy to be matched with intelligent equipment such as a mechanical arm, so as to realize industrialized automatic assembly. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 One of the layout schematic diagrams of the radial retainer and the circumferential retainer proposed by the embodiment of the present application.

[0015] Figure 2 The second layout schematic diagram of the radial retainer and the circumferential retainer proposed by the embodiment of the present application.

[0016] Figure 3 One of the assembly method schematic diagrams of the reverse planetary roller screw pair proposed by the embodiment of the present application.

[0017] Figure 4 The second assembly method schematic diagram of the reverse planetary roller screw pair proposed by the embodiment of the present application.

[0018] Figure 5 One of the assembly position relationship diagrams of the lead screw and the roller proposed by the embodiment of the present application.

[0019] Figure 6 The second assembly position relationship diagram of the lead screw and the roller proposed by the embodiment of the present application.

[0020] Figure 7 The structural explosion schematic diagram of the reverse planetary roller screw pair proposed by the embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to further understand the content of the present application, the present application is described in detail in combination with the drawings and embodiments.

[0022] The application will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related application, and not to limit the application. In addition, it should be noted that only the parts related to the application are shown in the drawings for ease of description. The terms first, second, etc. used in the application are set for the convenience of describing the technical solutions of the application, and have no specific limiting effect, and all refer to the technical solutions of the application. It should be noted that the embodiments and features in the embodiments in the application can be combined with each other without conflict. In the description of the application, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the application. In addition, the terms "first", "second", "third" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance. Unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication between two elements inside. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances. The technical solutions in the same embodiment and the technical solutions in different embodiments can be arranged and combined to form new technical solutions without contradiction or conflict, which are within the scope of the application.

[0023] In combination with the drawings Figure 1 to the drawings Figure 7 The embodiment provides an assembly method of a reverse type planetary roller screw pair, which comprises the following steps: S1, in combination with the drawings Figure 1 and the drawings Figure 2 As shown in the drawings, a radial retainer 1 and a circumferential retainer 2 are prepared: the radial retainer 1 is in a cylindrical shape, and the radial retainer 1 is provided with a through gap 10; the circumferential retainer 2 comprises a barrel 20, one side of the barrel 20 is fixedly provided with an end block 21, and the end block 21 is uniformly provided with an open limiting groove 22 in the circumferential direction, and the number of the limiting grooves 22 is consistent with the number of rollers 30.

[0024] In the embodiment, the circumferential retainer 2 drives the roller 30 to move circumferentially around the screw 31; the radial retainer 1 ensures that the roller 30 does not disengage from the meshing with the screw 31 when moving circumferentially around the screw 31.

[0025] The size of the radial retainer 1 and the circumferential retainer 2 mentioned in this embodiment is replaced according to the size of the different lead screws 31, and the shape of the radial retainer 1 and the circumferential retainer 2 can be adjusted according to the actual assembly line clamping device.

[0026] S2, combined with Figure 1 and Figure 2 , two circumferential retainers 2 are arranged on both sides of a radial retainer 1 respectively: ensure that the end block 21 on any circumferential retainer 2 is adjacent to the radial retainer 1; at the same time, ensure that the center face P1 of the limiting groove 22 corresponding to the notch 10 on any circumferential retainer 2 coincides with the center face P2 of the notch 10.

[0027] S3, combined with Figure 3 and Figure 4 , the lead screw 31 is loaded into the radial retainer 1 and the circumferential retainer 2 through a mechanical arm or other clamping device, ensuring that the lead screw 31, the radial retainer 1 and the circumferential retainer 2 are coaxially matched, ensuring that the end tooth section on both sides of the lead screw 31 is flush with the end face of the end block 21 on the circumferential retainer 2, and ensuring that the center face P2 coincides with the plane P3 where the thread starting point R1 of the lead screw 31 is located. After ensuring the above conditions, the lead screw 31 is clamped to ensure that the lead screw 31 is fixed.

[0028] S4, a roller 30 is pushed into the notch 10 until the optical axis section of the roller 30 is clamped into the limiting groove 22, and the end tooth section of the roller 30 is matched with the end tooth section of the lead screw 31, and the thread section of the roller 30 is matched with the thread section of the lead screw 31 at the same time.

[0029] In order to ensure that the end tooth section of the roller 30 is matched with the end tooth section of the lead screw 31, and the thread section of the roller 30 is matched with the thread section of the lead screw 31 at the same time during assembly, it is necessary to ensure that the thread starting point R1 of the lead screw 31 and the thread starting point R2 of the roller 30 are in the same plane during the process of pushing the roller 30 into the notch 10. The assembly position relationship of the lead screw 31 and the roller 30 can be referred to the drawings Figure 5 and Figure 6 .

[0030] In a further embodiment, a resilient card 4 is provided at the opening of the limiting groove 22, and the distance between the two resilient clamping pieces in the same limiting groove 22 is less than the diameter of the optical axis section of the roller 30. In this embodiment, when the roller 30 is pushed into the notch 10 of the radial retainer 1 through an automatic clamping device, the optical axis section of the roller 30 will compress the resilient card 4. After the roller 30 enters the limiting groove 22, the resilient card 4 gradually expands and returns to its original state, so as to clamp the roller 30 when the optical axis section of the roller 30 is completely assembled into the limiting groove 22.

[0031] For the assembly of the elastic card 4, an installation groove 5 can be arranged on the limiting groove 22, and the elastic card 4 is fixedly arranged in the installation groove 5, so as to realize the assembly of the elastic card 4 and the circumferential retainer 2.

[0032] In addition, in order to facilitate the clamping of the roller 30 into the limiting groove 22, the outer diameter of the end block 21 is smaller than the inner diameter of the radial retainer 1, so that the size of the limiting groove 22 is not too large, and the stroke of the optical axis segment of the roller 30 in the limiting groove 22 is smaller, and the limiting groove 22 and the roller 30 are more easily separated from each other in the subsequent step.

[0033] S5, the two circumferential retainers 2 are synchronously rotated by a fixed angle, and simultaneously drive the rollers 30 to rotate, so as to vacate the gap 10, and ensure that the central surface P1 of the limiting groove 22 corresponding to the gap 10 is coincident with the central surface P2 of the gap 10. In a more preferred embodiment, the single rotation angle of the two circumferential retainers 2 is θ = 360° / N, wherein N is the number of the rollers 30.

[0034] S6, repeating S4 and S5 until all the rollers 30 are assembled.

[0035] In steps S4 and S6, the continuous transmission of the rollers 30 can be transmitted by a protractor or a belt drive, and the feeding process of the rollers 30 can be realized by a mechanical arm or other intelligent equipment.

[0036] S7, taking out one side of the circumferential retainer 2, and sequentially loading the retainer 33 and the elastic retainer ring 34 on this side by a mechanical hand or other intelligent equipment, and then taking out the other side of the circumferential retainer 2, and sequentially loading the retainer 33 and the elastic retainer ring 34 on this side, so as to form an integrated module composed of the lead screw 31, the roller 30, the retainer 33 and the elastic retainer ring 34.

[0037] For step S7, when the retainer 33 is loaded, it is necessary to ensure that the retainer 33 is coaxial with the lead screw 31, and each retaining hole on the retainer 33 is coaxial with the corresponding roller 30, so as to ensure the assembly accuracy.

[0038] S8, the integrated module can be clamped by a mechanical hand or other intelligent equipment, and taken out to the radial retainer 1 in the axial direction, and then the integrated module is screwed into the nut 32, and the reverse planetary roller screw pair assembly is completed.

[0039] It can be understood that, in order to facilitate the integrated module to be easily separated from the radial retainer 1, the distance between the radial retainer 1 and the lead screw 31 should be greater than the outer diameter of the roller 30.

[0040] In view of the technical problem that the existing assembly mode of the planetary roller screw pair has defects, the embodiment simplifies the assembly process by using the radial retainer 1 and the circumferential retainer 2, that is, the screw 31 and the roller 30 are quickly assembled into an integrated module, and then the integrated module and the nut 32 are quickly assembled. This form can efficiently and conveniently realize the assembly of the screw 31 and the roller 30, while ensuring the transmission accuracy and performance of the reverse planetary roller screw pair, and improving the overall assembly efficiency of the reverse planetary roller screw pair. Moreover, the radial retainer 1 and the circumferential retainer 2 have simple structures and simple assembly processes, and are easy to be matched with intelligent equipment such as a mechanical arm, so as to realize the automatic assembly of industrialization.

[0041] The above describes the present application and its embodiments in a schematic manner, which is not restrictive, and the drawings only show one of the embodiments of the present application, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired thereby, without departing from the purpose of the present application, similar structural modes and embodiments can be designed without creativity, which shall belong to the protection scope of the present application.

Claims

1. A method of assembling a reverse planetary roller screw pair, characterized in that, The application relates to a reverse type planetary roller screw assembly. S1, preparing a radial retainer (1) and a circumferential retainer (2): the radial retainer (1) is in a cylindrical shape, and through gaps (10) are arranged on the radial retainer (1); the circumferential retainer (2) comprises a barrel body (20), one side of the barrel body (20) is fixedly provided with an end block (21), and open limiting grooves (22) are uniformly arranged on the end block (21) in the circumferential direction; the number of the limiting grooves (22) is consistent with the number of rollers (30); S2, arranging two circumferential retainers (2) on the two sides of one radial retainer (1) respectively: ensuring that the end block (21) on any circumferential retainer (2) is adjacent to the radial retainer (1); meanwhile, ensuring that the center face P1 of the limiting groove (22) corresponding to the gap (10) on any circumferential retainer (2) is coincident with the center face P2 of the gap (10); S3, assembling a lead screw (31) into the radial retainer (1) and the circumferential retainer (2), ensuring coaxial cooperation of the lead screw (31), the radial retainer (1) and the circumferential retainer (2), ensuring that the center face P2 is coincident with a plane P3 where a thread starting point R1 of the lead screw (31) is located, and clamping the lead screw (31) to ensure that the lead screw (31) is fixed and immovable; S4, pushing one roller (30) into the gap (10) until the optical axis segment of the roller (30) is clamped into the limiting groove (22), and ensuring that the end tooth segment of the roller (30) is simultaneously matched with the end tooth segment of the lead screw (31), and the thread segment of the roller (30) is simultaneously matched with the thread segment of the lead screw (31); S5, synchronously rotating the two circumferential retainers (2) by a fixed angle, simultaneously driving the roller (30) to rotate, leaving the gap (10), and ensuring that the center face P1 of the limiting groove (22) corresponding to the gap (10) is coincident with the center face P2 of the gap (10); S6, repeating S4 and S5 until all the rollers (30) are assembled; S7, removing one circumferential retainer (2) on one side, and sequentially assembling a retainer (33) and an elastic retainer ring (34) on the side, and then removing the circumferential retainer (2) on the other side, and sequentially assembling the retainer (33) and the elastic retainer ring (34) on the side, so that the lead screw (31), the roller (30), the retainer (33) and the elastic retainer ring (34) form an integrated module; S8, rotating the integrated module into a nut (32), and completing the reverse type planetary roller screw assembly.

2. The assembly method of a reverse type planetary roller screw pair according to claim 1, characterized in that, For step S4, during the process of pushing the roller (30) into the gap (10), the thread starting point R1 of the lead screw (31) is ensured to be in the same plane as the thread starting point R2 of the roller (30), so that the end tooth segment of the roller (30) is simultaneously matched with the end tooth segment of the lead screw (31), and the thread segment of the roller (30) is simultaneously matched with the thread segment of the lead screw (31).

3. The assembly method of a reverse type planetary roller screw pair according to claim 1, wherein For step S5, the single rotation angle of the two circumferential retainers (2) is theta=360 degrees / N, wherein N is the number of the rollers (30).

4. The assembly method of a reverse type planetary roller screw pair according to claim 1, wherein For step S7, when the holder (33) is loaded, the holder (33) needs to be coaxial with the lead screw (31), and each holding hole on the holder (33) is coaxial with the corresponding roller (30).

5. The assembly method of a reverse type planetary roller screw pair according to claim 1, wherein An elastic clamping piece (4) is arranged at the opening of the limiting groove (22), and the distance between the two elastic clamping pieces in the same limiting groove (22) is less than the diameter of the optical axis segment of the roller (30).

6. A method of assembling a reverse planetary roller screw pair according to claim 5, characterized in that An installation groove (5) is arranged on the limiting groove (22), and the elastic clamping piece (4) is fixedly arranged in the installation groove (5).

7. The assembly method of a reverse type planetary roller screw pair according to claim 1, wherein The outer diameter of the end block (21) is less than the inner diameter of the radial holder (1).

8. The assembly method of a reverse type planetary roller screw pair according to claim 1, wherein The distance between the radial holder (1) and the lead screw (31) is greater than the outer diameter of the roller (30).

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