Reverse planetary roller screw rod based on flexible support

Abstract

The invention discloses a reverse planetary roller screw rod based on flexible support. The reverse planetary roller screw rod comprises a nut, a screw rod shaft, a roller and a planet carrier, a traditional left planet carrier and a traditional right planet carrier are designed into an integral structure, and a flexible supporting structure based on a flexible leaf spring is arranged between a screw rod shaft hole of the planet carrier and a roller hole. Therefore, the phenomenon that an original split type planet carrier structure is not synchronous in the left-right direction is avoided, the multiple sets of pin rollers are uniform in bearing and stable in transmission, the transmission efficiency is improved, the multiple sets of pin rollers can do planetary motion around the lead screw shaft in a self-adaptive mode in a flexible supporting mode, the situation that operation is not smooth due to the fact that part machining and assembling precision is not enough is made up, and the service life of the planet carrier is prolonged. Noise is reduced, and reliability is improved.

Description

Technical Field

[0001] The present invention particularly relates to a reverse planetary roller screw based on flexible support, belonging to the technical field of mechanical transmission. Background Art

[0002] The planetary roller screw is a transmission mechanism that can realize the mutual conversion between rotational motion and linear motion. As a new type of linear transmission mechanism, it is widely used in aerospace, weapons and equipment, humanoid robots and other fields. Compared with the traditional ball screw, it has many advantages such as high rigidity, high load-bearing capacity and smooth transmission. By evenly arranging several rollers around the screw, the planetary roller screw greatly increases the internal force area of ​​the structure, thus having the advantages of high load-bearing capacity and high reliability, and it is more suitable for high-speed and high-acceleration conditions. As aerospace vehicles and humanoid robot actuators continue to develop in the direction of high speed, high efficiency, miniaturization and lightweight, planetary roller screws have gradually replaced ball screws with their performance advantages and become the first choice for linear servo systems.

[0003] Among them, the reverse planetary roller screw is being widely used in the fields of humanoid robot linear drive joints due to its easy integration with motors and the output shaft can be made into an optical axis. However, the planetary cages on both sides of the rollers in the current reverse planetary roller screws are usually split. Although the synchronization of the planetary cages on both sides can be roughly maintained by the planetary gear mechanism, there is still a slight asynchrony between the planetary cages on both sides due to the transmission gap in the gear transmission, which causes the two sides of the roller to tilt, resulting in uneven force on each roller, unstable transmission, and low transmission efficiency. In addition, due to insufficient processing and assembly precision, in order to ensure smooth operation of the screw, the matching clearance between the planetary cage, roller, and screw is usually increased, resulting in parasitic power consumption between the components, increased wear, and reduced transmission efficiency and transmission precision. Summary of the invention

[0004] The main purpose of the present invention is to provide a reverse planetary roller screw based on flexible support, so as to overcome the shortcomings of the prior art.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0006] The embodiment of the present invention provides a reverse planetary roller screw based on flexible support, comprising: a nut, a screw shaft, a plurality of rollers, and a planet carrier, wherein the plurality of rollers and the planet carrier are arranged between the nut and the screw shaft, the plurality of rollers are assembled on the planet carrier and arranged around the screw shaft, the planet carrier is rotationally matched with the screw shaft and the rollers, the rollers are threadedly matched with the nut and the screw shaft, the screw shaft is also transmission-matched with the plurality of rollers at the same time, and when the screw shaft rotates, the rollers are driven to rotate and perform planetary rotation around the screw shaft together with the planet carrier;

[0007] The planetary carrier includes a screw shaft frame, a plurality of roller frames and a plurality of elastic mechanisms, wherein the plurality of roller frames are arranged at intervals along the circumference of the screw shaft frame, and each of the roller frames is fixedly connected to the screw shaft frame via an elastic mechanism, wherein the screw shaft frame has a screw shaft channel passing through the interior thereof, a portion of the screw shaft is arranged in the screw shaft channel and rotatably cooperates with the screw shaft frame, and both ends of each of the rollers are rotatably cooperated with a roller frame.

[0008] Compared with the prior art, the advantages of the present invention include:

[0009] An embodiment of the present invention provides a reverse planetary roller screw based on flexible support, which adopts an integral planetary frame structure, avoids the left and right slight asynchronism phenomenon existing in the split planetary frame structure, makes multiple groups of rollers evenly loaded, transmits smoothly, and improves transmission efficiency.

[0010] An embodiment of the present invention provides a reverse planetary roller screw based on flexible support, in which multiple groups of roller holes in an integral planetary frame are flexibly supported by flexible leaf springs, and the special design of the flexible leaf springs enables them to only produce circumferential elastic rotation around the center of the planetary frame, so that the multiple groups of rollers can adaptively perform planetary motion, compensating for the uneven load and uneven operation caused by insufficient precision in parts processing and assembly, while also reducing noise and improving reliability.

[0011] An embodiment of the present invention provides a reverse planetary roller screw based on flexible support, in which sliding bearings are arranged in the screw shaft hole and the roller hole of the planetary carrier, thereby reducing friction and improving transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is an overall cross-sectional view of a reverse planetary roller screw based on flexible support provided in a typical implementation case of the present invention;

[0013] Figure 2 It is a structural schematic diagram of a planet carrier in a reverse planetary roller screw based on flexible support provided in a typical implementation case of the present invention;

[0014] Figure 3 It is a side view of a planet carrier in a reverse planetary roller screw based on flexible support provided in a typical implementation case of the present invention;

[0015] Figure 4 yes Figure 3 A partial enlarged view of point I in the middle;

[0016] Figure 5 It is a stereoscopic diagram of a reverse planetary roller screw based on flexible support provided in a typical implementation case of the present invention with the nut removed;

[0017] Figure 6 yes Figure 5 A partial enlarged view of point II in the middle. DETAILED DESCRIPTION

[0018] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

[0019] The embodiment of the present invention provides a reverse planetary roller screw based on flexible support, comprising: a nut, a screw shaft, a plurality of rollers, and a planet carrier, wherein the plurality of rollers and the planet carrier are arranged between the nut and the screw shaft, the plurality of rollers are assembled on the planet carrier and arranged around the screw shaft, the planet carrier is rotationally matched with the screw shaft and the rollers, the rollers are threadedly matched with the nut and the screw shaft, the screw shaft is also transmission-matched with the plurality of rollers at the same time, and when the screw shaft rotates, the rollers are driven to rotate and perform planetary rotation around the screw shaft together with the planet carrier;

[0020] The planetary carrier includes a screw shaft frame, a plurality of roller frames and a plurality of elastic mechanisms, wherein the plurality of roller frames are arranged at intervals along the circumference of the screw shaft frame, and each of the roller frames is fixedly connected to the screw shaft frame via an elastic mechanism, wherein the screw shaft frame has a screw shaft channel passing through the interior thereof, a portion of the screw shaft is arranged in the screw shaft channel and rotatably cooperates with the screw shaft frame, and both ends of each of the rollers are rotatably cooperated with a roller frame.

[0021] Furthermore, the screw shaft frame is a cylindrical structure as a whole, and each of the elastic mechanisms includes two elastic components that are arranged at intervals along the circumference of the screw shaft frame and fixedly connected, and the elastic components extend radially along the screw shaft frame. The roller frame is arranged between the two elastic components, and the elastic components are fixedly connected to the screw shaft frame and the roller frame respectively.

[0022] Furthermore, the elastic component is a leaf spring.

[0023] Furthermore, the circumferential side surfaces of the screw shaft frame and the roller frame are hollow, and the threaded structures of the screw shaft and the roller are respectively exposed from the hollow parts of the screw shaft frame and the roller frame and threadedly engaged, and the threaded structure of the roller is also exposed from the hollow parts of the roller frame and threadedly engaged with the internal thread structure of the nut.

[0024] Furthermore, the screw shaft frame includes two screw shaft positioning rings and at least two rib plates, the two screw shaft positioning rings are fixedly connected via at least two rib plates, at least two rib plates are arranged at intervals along the circumference of the screw shaft positioning ring, the two screw shaft positioning rings and at least two rib plates enclose the screw shaft channel, a hollow structure for exposing the screw shaft is formed between two adjacent rib plates, and a plurality of elastic mechanisms are fixed on the outer ring surface of the screw shaft positioning ring.

[0025] Furthermore, each of the roller racks includes two roller positioning blocks, each of which is fixedly connected to a screw shaft positioning ring via an elastic mechanism, and a roller channel is provided on the roller positioning block. Both ends of each roller are arranged in the roller channel and rotatably cooperate with the roller positioning block.

[0026] Furthermore, the side surface of the roller positioning block is also provided with an assembly notch which is in communication with the roller channel, and the roller can be assembled into the roller channel from the assembly notch along the radial direction of the roller channel.

[0027] Furthermore, a first bearing is provided between the screw shaft and the screw shaft frame, and the screw shaft is rotatably matched with the screw shaft frame via the first bearing.

[0028] Furthermore, the first bearing is a sliding bearing.

[0029] Furthermore, a second bearing is provided between the roller and the roller rack, and the roller is rotationally engaged with the roller rack via the second bearing.

[0030] Furthermore, the second bearing is a sliding bearing.

[0031] Furthermore, two retaining rings are fixedly arranged on the screw shaft, and the planet carrier is restricted between the two retaining rings.

[0032] Furthermore, a first gear is fixed on the screw shaft, and a second gear is fixed on each of the rollers, and the first gear is meshed with multiple second gears at the same time.

[0033] The technical solution, its implementation process and principles, etc. will be further explained below in conjunction with the accompanying drawings and specific implementation cases. Unless otherwise specified, the screw shaft, nut, sliding bearing, gear, etc. used in the embodiments of the present invention are all known in the art and can be purchased commercially. Their specific structures and product models are not limited here.

[0034] Example

[0035] See also Figure 1 A reverse planetary roller screw based on flexible support, comprising a nut 10, a plurality of rollers 11, a screw shaft 12, a planet carrier 13, two first sliding bearings 14, two retaining rings 15 and a plurality of second sliding bearings 16, wherein the plurality of rollers 11 and the planet carrier 13 are arranged between the nut 10 and the screw shaft 12, the plurality of rollers 11 are assembled on the planet carrier 13 and arranged around the screw shaft 12, the first sliding bearing 14 is sleeved between the screw shaft 12 and the planet carrier 13, the screw shaft 12 and the planet carrier 13 are rotationally matched through the first sliding bearing 14, and the two retaining rings 15 are fixed on the screw shaft 12 at intervals along the axial direction of the screw shaft 12. On the rod shaft 12, the planet carrier 13 is arranged between the two retaining rings 15. In the axial direction of the screw shaft 12, the planet carrier 13 can be in active contact with the two retaining rings 15. The planet carrier 13 is restricted between the two retaining rings 15. Each second sliding bearing 16 is sleeved between a roller 11 and the planet carrier 13. The roller 11 and the planet carrier 13 are rotationally matched through the second sliding bearing 16. The roller 11 is threadedly matched with the nut 10 and the screw shaft 12. The screw shaft 12 is also transmission-matched with multiple rollers 11 at the same time. When the screw shaft 12 rotates, the roller 11 is driven to rotate and rotates around the screw shaft 12 together with the planet carrier 13.

[0036] In this embodiment, the nut 10 is a hollow structure, and an internal thread structure is provided on the inner wall of the nut 10. A part of the screw shaft 12 has an external thread structure, and the other part is a smooth axis structure. Both ends of the roller 11 are pivots, and the middle part has an external thread structure. Multiple rollers 11 are evenly arranged along the circumference of the screw shaft 12. The part of the screw shaft 12 with the smooth axis structure is rotatably matched with the planetary carrier 13, and the pivots at both ends of the roller 11 are rotatably matched with the planetary carrier 13. The external thread structure of the roller 11 is respectively adapted to mesh with the external thread structure of the screw shaft 12 and the internal thread structure of the nut 10. In addition, a first gear is also fixedly provided on the screw shaft 12, and a second gear is also fixedly provided on the roller 11. The first gear on the screw shaft 12 is simultaneously meshed with multiple second gears fixed on multiple rollers 11, thereby realizing synchronous transmission of the screw shaft 12 and multiple rollers 11.

[0037] In this embodiment, two first gears are preferably arranged on the screw shaft 12, the two first gears are arranged coaxially with the screw shaft 12, and the two first gears are preferably arranged at intervals along the axial direction of the screw shaft 12 on both sides of the external thread structure of the screw shaft 12. Correspondingly, two second gears are preferably arranged on each roller 11, the two second gears are arranged coaxially with the roller 11, and the two second gears are preferably arranged at intervals along the axial direction of the roller 11 on both sides of the external thread structure of the roller 11. In this embodiment, the nut 10 and the screw shaft 12 are preferably arranged coaxially, and the axial directions of the plurality of rollers 11 are parallel to the axial direction of the screw shaft 12.

[0038] In this embodiment, the planetary carrier 13 and the screw shaft 12 are rotatably matched, but the two should be kept relatively fixed as much as possible in the axial direction of the screw shaft 12. In order to achieve this effect, two retaining rings 15 are fixedly provided on the screw shaft 12. The two retaining rings 15 are arranged on both sides of the planetary carrier 13 at intervals along the axial direction of the screw shaft 12. Specifically, the retaining rings 15 can be in clearance fit with the planetary carrier 13, or can be in active contact with it.

[0039] In this example, see Figure 2 The planet carrier 13 includes a first flexible planet carrier 13.1, a second flexible planet carrier 13.3 and a rib plate 13.2. The first flexible planet carrier 13.1 and the second flexible planet carrier 13.3 are fixedly connected via the rib plate 13.2 to form an integral structure, wherein the number of the rib plates 13.2 is at least two, and at least two rib plates 13.2 are arranged at intervals along the circumference of the planet carrier 12. The planet carrier 13 is a hollow cylindrical structure as a whole, and at least two rib plates 13.2 are arranged at intervals along the circumference of the planet carrier 12, so that the side of the planet carrier 13 forms a hollow structure.

[0040] It should be noted that the rib plate 13.2 is mainly used to combine the rigid parts of the first flexible planetary carrier 13.1 and the second flexible planetary carrier 13.3 into one. The rib plate 13.2 is arranged between two adjacent rollers, but has no direct contact with the rollers. In the radial direction of the planetary carrier 13, the outer side surface of the rib plate 13.2 is located on the inner side of the outer peripheral surface of the roller, that is, the rib plate 13.2 will not interfere with the threaded connection and rotation between the roller and the nut.

[0041] In this embodiment, the structures of the first flexible planet carrier 13.1 and the second flexible planet carrier 13.3 are exactly the same. The specific structure of the first flexible planet carrier 13.1 is described below by taking the first flexible planet carrier 13.1 as an example, and those skilled in the art can understand the structure of the second flexible planet carrier 13.3 without any objection.

[0042] For details, please refer to Figure 2-Figure 6The first flexible planetary carrier 13.1 includes a screw shaft positioning ring, a plurality of roller positioning blocks and a plurality of elastic mechanisms 13.1.3. The plurality of elastic mechanisms 13.1.3 are fixed on the outer ring surface of the screw shaft positioning ring at circumferential intervals along the screw shaft positioning ring. Each roller positioning block is fixedly connected to an elastic mechanism 13.1.3. It can be understood that the plurality of roller positioning blocks are also distributed on the outer ring surface of the screw shaft positioning ring at circumferential intervals along the screw shaft positioning ring; the screw shaft 12 is rotationally matched with the screw shaft positioning ring, and the roller 11 is rotationally matched with the plurality of roller positioning blocks. The plurality of elastic mechanisms 13.1.3 enable the roller 11 to only generate elastic rotation around the circumference of the planetary carrier 13 while rotating.

[0043] Specifically, the screw shaft locating ring is an annular structure, the central area of ​​the screw shaft locating ring is the screw shaft hole 13.1.1, the roller locating block is an annular structure, the central area of ​​the roller locating block is the roller hole 13.1.2, the roller hole 13.1.2 and the axial direction of the screw shaft hole 13.1.1 are parallel, the screw shaft locating ring is fixedly connected to the rib plate 13.2, so that the screw shaft holes 13.1.1 of the two screw shaft locating rings of the first flexible planetary frame 13.1 and the second flexible planetary frame 13.3 jointly form a hollow screw shaft channel in the middle, and the multiple roller locating blocks included in the first flexible planetary frame 13.1 and the second flexible planetary frame 13.3 are one-to-one corresponding, respectively corresponding to the first and second flexible planetary frames 13.1 and 13.3. The roller holes of the two roller positioning blocks of the first flexible planetary frame 13.1 and the second flexible planetary frame 13.3 jointly form a hollow roller channel in the middle. The part of the screw shaft 12 with the optical axis structure is arranged in the screw shaft hole 13.1.1 of the screw shaft positioning ring and rotates with the screw shaft positioning ring. The pivots at both ends of each roller 11 are respectively arranged in the roller holes of the two roller positioning blocks of the first flexible planetary frame 13.1 and the second flexible planetary frame 13.3 and rotate with the two roller positioning blocks respectively. The external thread structure of the roller 11 and the external thread structure of the screw shaft 12 are exposed in the hollow part between the first flexible planetary frame 13.1 and the second flexible planetary frame 13.3.

[0044] Specifically, in order to achieve better rotational cooperation between the screw shaft 12 and the screw shaft positioning ring, a first sliding bearing 14 is arranged between the screw shaft 12 and the screw shaft positioning ring. More specifically, the first sliding bearing 14 is coaxially arranged in the screw shaft hole 13.1.1, and the part of the screw shaft 12 with the optical axis structure is coaxially arranged in the first sliding bearing 14. More specifically, in order to complete the assembly of the integral flexible planetary carrier, the diameter of the screw shaft hole 13.1.1 of the screw shaft positioning ring should be slightly larger than the diameter of the corresponding part of the screw shaft, so that the planetary carrier 13 can be installed from one end of the screw shaft 12; the first sliding bearing 14 is installed in the screw shaft hole 13.1.1.

[0045] Specifically, in order to achieve better rotational cooperation between the roller 11 and the roller positioning block, a second sliding bearing 16 is provided between the roller 11 and the roller positioning block. More specifically, the second sliding bearing 16 is coaxially arranged in the roller hole 13.1.2, and the pivots at both ends of the roller 11 are coaxially arranged in the second sliding bearing 16. In order to complete the assembly of the roller 11 based on the integral flexible planetary carrier, the roller hole 13.1.2 of the integral flexible planetary carrier 13 is a semi-open structure in the radial direction, that is, the side of the roller positioning block is provided with an assembly notch that is conductive with the roller hole 13.1.2, and the assembly notches of the roller positioning blocks on the first flexible planetary carrier 13.1 and the second flexible planetary carrier 13.3 are located on the side close to each other, and the size of the assembly notch is equal to or slightly larger than the diameter of the pivots at both ends of the roller 11 and smaller than the diameter of the second sliding bearing 16. The total length L0 (see FIG. 1 ) between the assembly notches of the roller positioning blocks on the first flexible planetary carrier 13.1 and the second flexible planetary carrier 13.3 is Figure 1 ) must be equal to or slightly greater than the total length of the roller 11; in this way, the roller 11 can be radially installed into the roller hole 13.1.2 from the assembly notch, and then the second sliding bearing 16 can be installed from both ends, thereby solving the problem of roller installation without sacrificing the rigidity of the integral flexible planetary carrier. After all parts are assembled on the screw shaft, the nut 10 is screwed into the internal thread structure of the nut from one side, and the assembly of the reverse planetary roller screw based on flexible support is completed.

[0046] Specifically, the first sliding bearing and the second sliding bearing reduce friction during the rotation process, thereby improving the overall transmission efficiency.

[0047] Specifically, each of the elastic mechanisms 13.1.3 includes two elastic components that are circumferentially spaced and fixedly connected along the screw shaft frame, and the elastic components extend radially along the screw shaft positioning ring. The roller positioning block is arranged between the two elastic components. More specifically, the center line of the elastic component passes through the central axis of the screw shaft positioning ring. Under the joint action of the two elastic components passing through the central axis of the screw shaft positioning ring, the roller 11 can only generate elastic rotation around the circumference of the planetary frame 13 while rotating on its own; preferably, the elastic component can be a flexible leaf spring, etc.

[0048] Specifically, a first gear is fixed on the screw shaft 12, and a second gear is fixed on each of the rollers 11, and the first gear is meshed with multiple second gears at the same time. Preferably, the pitch circle diameter of the first gear on the screw shaft 12 is equal to the middle diameter of the external thread structure on the screw shaft 12, and the pitch circle diameter of the second gear on the roller 11 is equal to the middle diameter of the external thread structure on the roller 11. More specifically, the transmission ratio of the first gear to the second gear is equal to the ratio of the number of heads of the thread structure on the screw shaft 12 to the number of heads of the thread structure on the roller 11.

[0049] It should be noted that due to problems such as processing and assembly, it is extremely difficult to ensure that the multiple rollers of the traditional planetary roller screw are completely parallel and evenly loaded. As a result, some rollers have very little load or even no load, while some rollers have a large load or even break. The present invention achieves the purpose of uniform load by designing a flexible planetary frame (providing a flexible connection between the roller bearing hole and the screw bearing hole). The center extension lines of the two flexible leaf springs of the present invention intersect at the center of the circle, forming an isosceles trapezoidal structure, so that the roller bearing hole can only produce elastic rotation around the center of the planetary frame, and the planetary frame roller bearing holes on the left and right sides (corresponding to the first and second planetary frames) can adaptively produce a small range of circumferential misalignment, so that the rollers can adaptively tilt in a small range, reducing the high demand for processing and assembly accuracy and improving the load-balancing performance of the planetary roller screw.

[0050] An embodiment of the present invention provides a reverse planetary roller screw based on flexible support, which adopts an integral planetary frame structure, avoids the left and right slight asynchronism phenomenon existing in the split planetary frame structure, makes multiple groups of rollers evenly loaded, transmits smoothly, and improves transmission efficiency.

[0051] An embodiment of the present invention provides a reverse planetary roller screw based on flexible support, in which multiple groups of roller holes in an integral planetary frame are flexibly supported by flexible leaf springs, and the special design of the flexible leaf springs enables them to only produce circumferential elastic rotation around the center of the planetary frame, so that the multiple groups of rollers can adaptively perform planetary motion, compensating for the uneven load and uneven operation caused by insufficient precision in parts processing and assembly, while also reducing noise and improving reliability.

[0052] An embodiment of the present invention provides a reverse planetary roller screw based on flexible support, in which sliding bearings are arranged in the screw shaft hole and the roller hole of the planetary carrier, thereby reducing friction and improving transmission efficiency.

[0053] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A reverse planetary roller screw based on flexible support, comprising: A nut, a screw shaft, a plurality of rollers, and a planet carrier, wherein the plurality of rollers and the planet carrier are arranged between the nut and the screw shaft, the plurality of rollers are assembled on the planet carrier and arranged around the screw shaft, the planet carrier is rotationally matched with the screw shaft and the rollers, the rollers are threadedly matched with the nut and the screw shaft, and the screw shaft is also transmission-matched with the plurality of rollers at the same time, and when the screw shaft rotates, the rollers are driven to rotate and perform planetary rotation around the screw shaft together with the planet carrier; It is characterized in that: the planetary carrier includes a screw shaft frame, a plurality of roller frames and a plurality of elastic mechanisms, the plurality of roller frames are arranged at intervals along the circumference of the screw shaft frame, each of the roller frames is fixedly connected to the screw shaft frame via an elastic mechanism, wherein the screw shaft frame has a screw shaft channel passing through the inside thereof, a portion of the screw shaft is arranged in the screw shaft channel and rotatably cooperates with the screw shaft frame, and both ends of each of the rollers are rotatably cooperated with a roller frame, wherein x≥2.

2. The reverse planetary roller screw based on flexible support according to claim 1, characterized in that: The screw shaft frame is a cylindrical structure as a whole, and each of the elastic mechanisms includes two elastic components that are arranged at intervals along the circumference of the screw shaft frame and fixedly connected. The elastic components extend radially along the screw shaft frame, and the roller frame is arranged between the two elastic components. The elastic components are fixedly connected to the screw shaft frame and the roller frame respectively.

3. The reverse planetary roller screw based on flexible support according to claim 1 or 2, characterized in that: The elastic member is a leaf spring.

4. The reverse planetary roller screw based on flexible support according to claim 2, characterized in that: The circumferential side surfaces of the screw shaft frame and the roller frame are hollow, and the threaded structures of the screw shaft and the roller are respectively exposed from the hollow parts of the screw shaft frame and the roller frame and threadedly engaged, and the threaded structure of the roller is also exposed from the hollow parts of the roller frame and threadedly engaged with the internal thread structure of the nut.

5. The reverse planetary roller screw based on flexible support according to claim 2 or 4, characterized in that: The screw shaft frame includes two screw shaft positioning rings and at least two rib plates, the two screw shaft positioning rings are fixedly connected via at least two rib plates, at least two rib plates are arranged at intervals along the circumference of the screw shaft positioning ring, the two screw shaft positioning rings and at least two rib plates enclose the screw shaft channel, a hollow structure for exposing the screw shaft is formed between two adjacent rib plates, and a plurality of elastic mechanisms are fixed on the outer ring surface of the screw shaft positioning ring.

6. The reverse planetary roller screw based on flexible support according to claim 5, characterized in that: Each of the roller racks includes two roller positioning blocks, each of which is fixedly connected to a screw shaft positioning ring via an elastic mechanism. A roller channel is provided on the roller positioning block, and both ends of each roller are arranged in the roller channel and rotatably cooperate with the roller positioning block.

7. The reverse planetary roller screw based on flexible support according to claim 6, characterized in that: The side surface of the roller positioning block is also provided with an assembly notch which is in communication with the roller channel, and the roller can be assembled into the roller channel from the assembly notch along the radial direction of the roller channel.

8. The reverse planetary roller screw based on flexible support according to claim 1, characterized in that: A first bearing is also provided between the screw shaft and the screw shaft frame, and the screw shaft is rotatably matched with the screw shaft frame via the first bearing; And / or, the first bearing is a sliding bearing; And / or, a second bearing is further provided between the roller and the roller rack, and the roller is rotationally engaged with the roller rack via the second bearing; And / or, the second bearing is a sliding bearing.

9. The reverse planetary roller screw based on flexible support according to claim 1, characterized in that: Two retaining rings are also fixedly arranged on the screw shaft, and the planet carrier is restricted between the two retaining rings.

10. The reverse planetary roller screw based on flexible support according to claim 1, characterized in that: A first gear is also fixed on the screw shaft, and a second gear is also fixed on each of the rollers. The first gear is meshed with a plurality of the second gears at the same time.

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