Flexible lead screw mechanism

Abstract

The invention belongs to the technical field of large planetary roller lead screw structures, and discloses a flexible lead screw mechanism. The flexible lead screw mechanism comprises a roller lead screw component, a driving end support, a driven end support and a driving motor, the two ends of the roller lead screw component are movably arranged on the driving end support and the driven end support correspondingly, and the output end of the driving motor is connected with the roller lead screw component located at one end of the driving end support. The roller lead screw component comprises a follow-up support used for guaranteeing radial loading safety of a roller nut, a driven end support is arranged below the driven end support, and the driven end support is arranged on the driven end support in the axial direction in a sliding mode. According to the flexible lead screw mechanism, follow-up supporting of the nut is added, the design is reasonable, the flexible lead screw mechanism can adapt to structural displacement caused by part linear expansion speed difference under the condition of uneven temperature change or inconsistent cooling speed, the structural safety of the planetary roller lead screw can still be guaranteed under the condition of great radial loading, and the flexible lead screw mechanism has engineering practical value.

Description

Technical Field

[0001] The invention belongs to the technical field of large planetary roller screw structures, and in particular relates to a flexible screw mechanism. Background Art

[0002] Planetary roller screws have the combined characteristics of thread transmission and rolling screw transmission. Compared with ball screw transmission, its rolling elements are not multiple balls, but multiple roller bodies with threads. Around the main thread screw, multiple roller screws are arranged on the planet to convert the rotational motion of the motor into the linear motion of the screw or nut. The standard planetary roller screw is mainly composed of a screw, roller, nut, spur teeth, internal gear ring, roller cage and spring retaining ring. Among them, the screw is a multi-start thread with a tooth angle of 90°; the roller is a single-start thread with the same tooth angle; the nut is an internal thread with the same number of heads and tooth shape as the screw.

[0003] In order to eliminate the tilting torque caused by the helix angle of the screw on the roller, straight teeth are machined on both ends of the roller to mesh with the inner gear ring to ensure that the roller axis rolls normally parallel to the thread axis; the roller cage is used to ensure that the rollers are evenly distributed along the circumference; the roller cage is axially positioned by the elastic tube retaining ring.

[0004] The working principle of the planetary roller screw is: the screw driven by the motor uses the friction torque to drive the roller to rotate, and then converts the rotational motion of the screw into the linear reciprocating motion of the nut.

[0005] When the overall structure of the existing planetary roller screw changes temperature within a large temperature range, it cannot adapt to the difference in linear expansion speed of parts caused by uneven temperature changes or inconsistent cooling speeds, resulting in structural displacement.

[0006] Currently, there is an urgent need to develop a flexible screw mechanism. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a flexible lead screw mechanism.

[0008] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions: The flexible screw mechanism of the present invention includes a roller screw component, a driving end support, a driven end support and a driving motor. The two ends of the roller screw component are movably arranged on the driving end support and the driven end support respectively. The output end of the driving motor is connected to the roller screw component located at one end of the driving end support. The roller screw component includes a follower support for ensuring the radial load safety of the roller nut. A driven end support is arranged below the driven end support, and the driven end support is axially slidably arranged on the driven end support.

[0009] Specifically, in addition to the conventional drive end support and driven end support, this technical solution adds a nut follower support to ensure that the planetary roller screw structure is safe under extremely large radial load conditions. Through the non-fixed support of the driven end, the additional bearing allows the screw to expand and contract to a certain extent in the axial direction. When the entire structure changes temperature within a large temperature range, the structure can adapt to the structural displacement caused by the difference in linear expansion speed of parts due to uneven temperature changes or inconsistent cooling speeds. At the same time, ball bearings and spherical supports are arranged at the drive end, so that when the roller nut is loaded at the same time in the above situation, the screw can deflect a certain amount in the load direction to reduce the radial load. This technical solution also arranges an additional additional structure (follower support) at the roller nut. The follower support can move with the roller nut and has an independent heavy-duty track, which can fully share the remaining radial load of the screw, making the planetary roller screw structure stable.

[0010] The structural arrangement of the planetary roller screw component of the technical solution can make the structural size and working stroke of the planetary roller screw exceed the existing maximum size. The planetary roller screw with an operating temperature range of below -170°C to room temperature and a working pressure range from vacuum to positive pressure, the overall height of the planetary roller screw component of the technical solution is more than 4 meters, and it is an extra-large planetary roller screw component with a working stroke of more than 3 meters. The planetary roller screw structure can adapt to large structural deformation.

[0011] In one embodiment, the roller screw component includes a main thread screw, a plurality of roller screws arranged in a planetary manner around the main thread screw, and a roller nut, wherein the plurality of roller screws are sleeved in the roller nut, and the follower support cooperates with the roller nut.

[0012] In one embodiment, the number of roller screws is 6 to 12.

[0013] In one embodiment, it also includes a motor support, and the drive end support and the drive motor are both arranged on the motor support.

[0014] In one embodiment, the driving end support includes a first bearing seat, a first bearing sleeved in the first bearing seat, a dustproof shell sleeved outside the first bearing seat, a fixing ring for fixing the first bearing seat on the motor support, and a coupling connected to the output end of the driving motor, and one end of the main threaded screw passes through the inner ring of the first bearing and is connected to the coupling.

[0015] In one embodiment, the dustproof housing includes a pressure cover mounted on the first bearing seat and a dustproof cover detachably connected to the pressure cover. A circular opening is provided on the side of the pressure cover close to the coupling, and the dustproof cover is connected to the circular opening through a bolt assembly.

[0016] In one embodiment, a locking assembly for locking the main threaded screw on the inner ring of the first bearing is provided between the first bearing and the dust cover.

[0017] Specifically, the locking assembly includes a first round nut, a second round nut and a clamping nut arranged in parallel, the main threaded screw near the end of the drive motor is a stepped shaft, the large end of the stepped shaft abuts against one side of the inner ring of the first bearing, the small end of the stepped shaft passes through the inner ring of the first bearing, and the first round nut, the second round nut and the clamping nut are locked on the small end of the stepped shaft. A bearing retaining ring and a fixing flange are also arranged on the inner side of the fixing ring.

[0018] In one embodiment, the driven end support includes a second bearing seat, a second bearing sleeved in the second bearing seat, a sleeve arranged on one side of the second bearing, and a second clamping nut arranged on the other side of the second bearing. The main thread screw passes through the sleeve and the second bearing inner ring in sequence at one end away from the drive motor, and the main thread screw is locked on the second bearing inner ring by the second clamping nut.

[0019] In one embodiment, an upper bearing shell and a lower bearing shell are respectively disposed at the upper and lower ends of the second bearing seat.

[0020] In one embodiment, two second bearings are arranged side by side in the second bearing seat, and an inner spacer ring and an outer spacer ring are arranged between the two second bearings.

[0021] The flexible screw mechanism of the present invention adds a follow-up support for the nut and has a reasonable design. It can adapt to the structural displacement caused by the difference in linear expansion speed of parts due to uneven temperature changes or inconsistent cooling speeds. Under extremely large radial loads, it can still ensure the safety of the planetary roller screw structure and has practical engineering value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the flexible screw mechanism of the present invention; Figure 2 It is a structural schematic diagram of the driving end support in the flexible screw mechanism of the present invention; Figure 3 It is a schematic structural diagram of the driven end support in the flexible screw mechanism of the present invention.

[0023] In the figure, 1. driving motor; 2. driving end support; 21. coupling; 22. dust cover; 23. first round nut; 24. pressure cover; 25. first bearing seat; 26. first bearing; 27. fixing ring; 28. bearing retaining ring; 29. ​​clamping nut; 210. fixing flange; 211. second round nut; 3. roller nut; 4. driven end support; 41. bushing; 42. upper bearing shell; 43. second bearing; 44. outer spacer ring; 45. second bearing seat; 46. second clamping nut; 47. lower bearing shell; 48. inner spacer ring; 5. driven end support; 6. follower support; 7. motor support; 8. main thread screw. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In addition, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0027] In the description of the embodiments of the present invention, it should be noted that the terms "inside", "outside", "upper", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] Example 1: Figure 1~Figure 3As shown, this embodiment provides a flexible screw mechanism, including a roller screw component, a driving end support 2, a driven end support 4 and a driving motor 1, the two ends of the roller screw component are movably arranged on the driving end support 2 and the driven end support 4 respectively, the output end of the driving motor 1 is connected to the roller screw component located at one end of the driving end support 2, the roller screw component includes a follower support 6 for ensuring the radial load safety of the roller nut 3, a driven end support 5 is arranged below the driven end support 4, and the driven end support 4 is axially slidably arranged on the driven end support 5.

[0029] Specifically, in addition to the conventional driving end support 2 and the driven end support 4, this embodiment adds a nut follower support 6 to ensure that the planetary roller screw structure is safe under extremely large radial load conditions. Through the non-fixed support of the driven end, the additional bearing allows the screw to expand and contract to a certain extent in the axial direction. When the entire structure changes temperature within a large temperature range, the structure can adapt to the structural displacement caused by the difference in linear expansion speed of parts caused by uneven temperature changes or inconsistent cooling speeds. At the same time, a ball bearing and a spherical support are arranged at the driving end, so that when the roller nut 3 is loaded at the same time in the above situation, the screw can deflect a certain amount in the load direction to reduce the radial load. In this embodiment, an additional additional structure (follower support 6) is arranged at the roller nut 3. The follower support 6 can move with the roller nut 3 and has an independent heavy-duty track, which can fully share the remaining radial load of the screw, making the planetary roller screw structure stable.

[0030] The structural arrangement of the star roller screw component of this embodiment can make the structural size and working stroke of the planetary roller screw exceed the existing maximum size. The planetary roller screw with an operating temperature range of below -170°C to room temperature and a working pressure range from vacuum to positive pressure, the overall height of the star roller screw component is more than 4 meters, and it is an extra-large planetary roller screw component with a working stroke of more than 3 meters. A planetary roller screw structure that can adapt to large structural deformation.

[0031] Example 2: Figure 1~Figure 3 As shown, this embodiment provides a flexible screw mechanism, including a roller screw component, a driving end support 2, a driven end support 4 and a driving motor 1, the two ends of the roller screw component are movably arranged on the driving end support 2 and the driven end support 4 respectively, the output end of the driving motor 1 is connected to the roller screw component located at one end of the driving end support 2, the roller screw component includes a follower support 6 for ensuring the radial load safety of the roller nut 3, a driven end support 5 is arranged below the driven end support 4, and the driven end support 4 is axially slidably arranged on the driven end support 5.

[0032] The roller screw component includes a main thread screw 8, a plurality of roller screws arranged in a planetary manner around the main thread screw 8, and a roller nut 3. The plurality of roller screws are sleeved in the roller nut 3, and the follower support 6 cooperates with the roller nut 3.

[0033] The number of roller screws is 6 to 12.

[0034] It also includes a motor support 7, on which the drive end support 2 and the drive motor 1 are both arranged.

[0035] Example 3: Figure 2 As shown, this embodiment is further optimized on the basis of Embodiment 2, specifically: The driving end support 2 includes a first bearing seat 25, a first bearing 26 sleeved in the first bearing seat 25, a dustproof shell sleeved outside the first bearing seat 25, a fixing ring 27 fixing the first bearing seat 25 on the motor support 7, and a coupling 21 connected to the output end of the driving motor 1. One end of the main threaded screw 8 passes through the inner ring of the first bearing 26 and is connected to the coupling 21.

[0036] The dustproof housing includes a pressure cover 24 sleeved on the first bearing seat 25 and a dust cover detachably connected to the pressure cover 24. A circular opening is provided on the side of the pressure cover 24 close to the coupling 21, and the dust cover is connected to the circular opening through a bolt assembly.

[0037] A locking assembly for locking the main threaded screw 8 on the inner ring of the first bearing 26 is provided between the first bearing 26 and the dust cover.

[0038] Specifically, the locking assembly includes a first round nut 23, a second round nut 211 and a clamping nut 29 arranged in parallel, the main threaded screw 8 is close to the drive motor 1. The end of the step shaft is a stepped shaft, the large end of the step shaft abuts against the inner ring of the first bearing 26, and the small end of the step shaft passes through the inner ring of the first bearing 26. The first round nut 23, the second round nut 211 and the clamping nut 29 are locked on the small end of the step shaft. A bearing retaining ring 28 and a fixing flange 210 are also arranged inside the fixing ring 27.

[0039] Example 4: Figure 3 As shown, this embodiment is further optimized on the basis of Embodiment 2, specifically: The driven end support 4 includes a second bearing seat 45, a second bearing 43 sleeved in the second bearing seat 45, a sleeve 41 arranged on one side of the second bearing 43, and a second clamping nut 46 arranged on the other side of the second bearing 43. The end of the main threaded screw 8 away from the drive motor 1 passes through the sleeve 41 and the inner ring of the second bearing 43 in sequence, and the main threaded screw 8 is locked on the inner ring of the second bearing 43 by the second clamping nut 46.

[0040] An upper bearing bush 42 and a lower bearing bush 47 are respectively disposed at the upper and lower ends of the second bearing seat 45 .

[0041] Two second bearings 43 are arranged in parallel in the second bearing seat 45 , and an inner spacer ring 48 and an outer spacer ring 44 are arranged between the two second bearings 43 .

Claims

1. A flexible screw mechanism, characterized in that: The invention comprises a roller screw component, a driving end support (2), a driven end support (4) and a driving motor (1), wherein the two ends of the roller screw component are movably arranged on the driving end support (2) and the driven end support (4), respectively, and the output end of the driving motor (1) is connected to the roller screw component located at one end of the driving end support (2). The roller screw component comprises a follower support (6) for ensuring the radial load safety of the roller nut (3). A driven end support (5) is arranged below the driven end support (4), and the driven end support (4) is axially slidably arranged on the driven end support (5).

2. A flexible screw mechanism according to claim 1, characterized in that: The roller screw component comprises a main thread screw (8), a plurality of roller screws arranged in a planetary pattern around the main thread screw (8), and a roller nut (3); the plurality of roller screws are sleeved in the roller nut (3), and the follower support (6) cooperates with the roller nut (3).

3. A flexible screw mechanism according to claim 2, characterized in that: The number of the roller screws is 6 to 12.

4. A flexible screw mechanism according to claim 2, characterized in that: It also includes a motor support (7), and the drive end support (2) and the drive motor (1) are both arranged on the motor support (7).

5. A flexible screw mechanism according to claim 4, characterized in that: The drive end support (2) comprises a first bearing seat (25), a first bearing (26) sleeved in the first bearing seat (25), a dustproof housing sleeved outside the first bearing seat (25), a fixing ring (27) fixing the first bearing seat (25) on the motor support (7), and a coupling (21) connected to the output end of the drive motor (1); one end of the main threaded screw (8) passes through the inner ring of the first bearing (26) and is connected to the coupling (21).

6. A flexible screw mechanism according to claim 5, characterized in that: The dustproof housing comprises a pressure cover (24) sleeved on the first bearing seat (25), and a dustproof cover (22) detachably connected to the pressure cover (24); a circular opening is provided on a side of the pressure cover (24) close to the coupling (21); and the dustproof cover (22) is connected to the circular opening via a bolt assembly.

7. A flexible screw mechanism according to claim 6, characterized in that: A locking assembly for locking the main threaded screw (8) onto the inner ring of the first bearing (26) is provided between the first bearing (26) and the dust cover (22).

8. A flexible screw mechanism according to claim 4, characterized in that: The driven end support (4) comprises a second bearing seat (45), a second bearing (43) sleeved in the second bearing seat (45), a sleeve (41) arranged on one side of the second bearing (43), and a second clamping nut (46) arranged on the other side of the second bearing (43); an end of the main threaded screw (8) away from the drive motor (1) passes through the sleeve (41) and the inner ring of the second bearing (43) in sequence, and the main threaded screw (8) is locked on the inner ring of the second bearing (43) by the second clamping nut (46).

9. A flexible screw mechanism according to claim 8, characterized in that: An upper bearing shell (42) and a lower bearing shell (47) are respectively arranged at the upper and lower ends of the second bearing seat (45).

10. A flexible screw mechanism according to claim 8, characterized in that: Two second bearings (43) are arranged in parallel in the second bearing seat (45), and an inner spacer ring (48) and an outer spacer ring (44) are arranged between the two second bearings (43).

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