CN217422080U

CN217422080U - Planetary roller screw pair and assembly tool thereof

Info

Publication number: CN217422080U
Application number: CN202220555417.4U
Authority: CN
Inventors: 钟坤; 周志勇
Original assignee: Hubei Kefeng Intelligent Transmission Co Ltd
Current assignee: Hubei Kefeng Intelligent Transmission Co Ltd
Priority date: 2022-03-10
Filing date: 2022-03-10
Publication date: 2022-09-13
Anticipated expiration: 2032-03-10

Abstract

The utility model provides a planet roller screw is vice and assembly fixture thereof, planet roller screw is vice including planet lead screw, a plurality of planet roller, the planet nut, two ring gears, two holders and nut sleeve, planet lead screw is located the planet nut, install respectively in the inboard both ends of planet nut in two ring gears, a plurality of planet rollers are installed in planet lead screw uniformly, between the planet nut, and with planet lead screw, the ring gear meshes mutually, install respectively in the both ends of planet nut for two holders, each holder all is connected with a plurality of planet roller, the planet nut passes through the locking nut axial and is positioned in the nut sleeve. Through set up nut socket structure outside the planet nut, avoid the nut directly to be connected with external mechanism, simplified the external structure of nut when the protection nut, reduced the processing degree of difficulty, also need not set up extra spare part and use rather than the cooperation in external mechanism simultaneously, only need with nut muffjoint can.

Description

Planetary roller screw pair and assembly tool thereof

Technical Field

The utility model relates to a roller screw's technical field especially relates to a planet roller screw is vice and assembly fixture thereof.

Background

A planetary roller screw is a new type of transmission that can convert rotary motion into linear motion. The planet roller screw has higher shock resistance than the traditional ball screw, the static load of the planet roller screw is about twice of that of the traditional ball screw, and the service life of the planet roller screw is about 15 times of that of the traditional ball screw. And the planetary roller screw can have higher rotating speed and rotating acceleration, so that the planetary roller screw is widely applied to the fields of precision instruments, weaponry, industrial robots, aerospace and the like.

The existing standard planetary roller screw comprises a screw rod, rollers and a nut, and on one hand, due to the fact that the rollers are numerous, the engagement of the rollers with the nut and the screw thread of the screw rod and the engagement of the rollers with the gear teeth of a gear ring need to be guaranteed simultaneously; the uneven circumferential clearance and the poor meshing position of the rollers can cause the rollers to be difficult to be sleeved with the retainer, and the factors cause the mounting efficiency of the rollers to be very low. On the other hand, the meshing state of each roller is difficult to unify and is in a random state, so that the loading of the rollers is uneven, and the running stability of the whole screw pair is affected.

In addition, the standard planetary roller screw consisting of the screw rod, the roller and the nut converts the rotary motion into linear motion, the nut and an external structure are often required to be fixedly installed in the using process, in the installation process, in order to install and fix the nut and the external structure, a plurality of parts are additionally required to be additionally arranged to be connected with the nut in a matched mode, or the external shape of the nut is arranged to be more complex, the processing difficulty is increased, the use complexity of the planetary roller screw is increased, and the convenience is reduced.

SUMMERY OF THE UTILITY MODEL

In view of this, the embodiment of the utility model provides a planetary roller screw pair and assembly fixture thereof.

An embodiment of the utility model provides a planet roller screw is vice, including planet lead screw, a plurality of planet roller, planet nut, two ring gears, two holders and nut sleeve, the planet lead screw is located in the planet nut, two the ring gear install respectively in the inboard both ends of planet nut, it is a plurality of the planet roller install uniformly in the planet lead screw between the planet nut, and with the planet lead screw the ring gear meshes mutually, two the holder install respectively in the both ends of planet nut, each the holder all with a plurality of the planet roller is connected, in order to guarantee a plurality of the planet roller is in the circumferencial direction evenly distributed of planet lead screw, the planet nut passes through the locking nut axial positioning in the nut sleeve.

Optionally, a first groove is formed in one end surface of each planetary roller, a plurality of second grooves are formed in one end surface of each planetary nut at intervals in the circumferential direction, and the first grooves and the second grooves are arranged in a straight line, so that when each planetary roller is installed in the planetary nut, the corresponding first grooves and the corresponding second grooves extend in the same direction.

Optionally, the outer side of the planetary roller is provided with a single-start thread, the outer side of the planetary screw and the inner side of the planetary nut are both provided with a multi-start thread, and the number of the screw starts is the same.

Optionally, the thread forms of the planetary screw and the planetary nut are both triangular, and the thread form of the planetary roller is a convex arc.

Optionally, one end of the planetary lead screw is provided with a gear for connecting with an external driving mechanism.

Optionally, one end of the nut sleeve is provided with a thread for connection with an external mechanism.

Optionally, a boss or a groove is arranged on an outer circle of the end part at the other end of the nut sleeve and used for circumferential limiting.

The utility model also provides an assembly fixture that is used for as above planetary roller screw pair, include:

the roller stop lever assembly comprises a first roller stop lever and a second roller stop lever, the radial sections of the first roller stop lever and the second roller stop lever are both in a fan shape, the radius of the fan shape is equal, the fan shapes are combined into a whole circle, the central angle of the radial section of the first roller stop lever is larger than that of the radial section of the second roller stop lever, the roller stop lever assembly comprises a first cylindrical surface, a conical surface and a second cylindrical surface which are sequentially connected, the diameter of the second cylindrical surface is smaller than that of the first cylindrical surface, and the diameter of the first cylindrical surface is matched with the outer diameter of the planetary screw; and the number of the first and second groups,

the roller ejector rod comprises a cylinder and a boss which are sequentially connected, the diameter of the cylinder is matched with the inner diameter of the nut sleeve, the end face, far away from one end of the boss, of the cylinder is a supporting face, the supporting face is used for supporting the planetary rollers, a cylindrical groove is formed in the center of the supporting face, and the inner diameter of the cylindrical groove is matched with the diameter of the second cylindrical surface, so that the second cylindrical surface is inserted into the cylindrical groove.

Optionally, the first roller bar has a radial cross-section with a central angle of any value of 205 ° -215 °.

Optionally, the roller stop lever assembly and the roller ejector rod are made of polymer plastic materials.

The embodiment of the utility model provides a beneficial effect that technical scheme brought is: the utility model discloses an in the planet roller lead screw pair through having set up nut socket structure outside the planet nut, avoided the nut directly to be connected with external mechanism, simplified the exterior structure of nut when having protected the nut, reduced the processing degree of difficulty, also need not set up extra spare part in external mechanism simultaneously and use rather than the cooperation, only need with nut muffjoint can.

Drawings

Fig. 1 is a half-sectional perspective view of an embodiment of a planetary roller screw pair provided by the present invention;

fig. 2 is a schematic axial sectional view of a planetary roller screw sub-belt assembling tool according to an embodiment of the present invention;

FIG. 3 is an isometric view of an assembly tool for a planetary roller screw set provided by the present invention;

FIG. 4 is a schematic view of the planetary roller arrangement of FIG. 1;

FIG. 5 is a schematic view of the planetary roller and planetary nut mounting alignment of FIG. 1;

FIG. 6 is a first schematic view of the roller assembly process of FIG. 2;

fig. 7 is a second schematic view of the roller assembly process of fig. 2.

In the figure: the planetary roller screw pair comprises a planetary roller screw pair 100, a planetary screw 1, a gear 11, a planetary roller 2, a first groove 21, a planetary nut 3, a second groove 31, an inner gear ring 4, a retainer 5, a nut sleeve 6, a thread 61, an assembly tool 200 for the planetary roller screw pair, a roller stop lever assembly 210, a first roller stop lever 211, a second roller stop lever 212, a first cylindrical surface 213, a conical surface 214, a second cylindrical surface 215, a roller top lever 220, a cylinder 221, a boss 222, a supporting surface 223 and a cylindrical groove 224.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, embodiments of the present invention will be further described below with reference to the accompanying drawings.

Referring to fig. 1-7, an embodiment of the present invention provides a planetary roller screw assembly 100, which includes a planetary screw 1, a plurality of planetary rollers 2, a planetary nut 3, two inner gear rings 4, two retainers 5 and a nut sleeve 6, the planet screw 1 is positioned in the planet nut 3, the two inner gear rings 4 are respectively arranged at two ends of the inner side of the planet nut 3, the plurality of planet rollers 2 are uniformly arranged between the planet screw 1 and the planet nut 3, and is engaged with the planetary screw 1 and the inner gear ring 4, two retainers 5 are respectively arranged at two ends of the planetary nut 3, each retainer 5 is connected with a plurality of planetary rollers 2, so as to ensure that the planetary rollers 2 are uniformly distributed in the circumferential direction of the planetary screw 1, and the planetary nut 3 is axially positioned in the nut sleeve 6 through a locking nut.

Compare in traditional planet roller lead screw pair 100, the utility model discloses set up nut sleeve 6 structure outside planetary nut 3, avoided the nut directly to be connected with external mechanism, simplified the external structure of nut when having protected the nut, reduced the processing degree of difficulty, also need not set up extra spare part simultaneously in external mechanism and use rather than cooperating, only need with nut sleeve 6 be connected can.

Referring to fig. 4 and 5, a first groove 21 is formed in one end surface of the planetary roller 2, a plurality of second grooves 31 are circumferentially spaced from one end surface of the planetary nut 3, and the first groove 21 and the second grooves 31 are both arranged in a straight shape, so that when each planetary roller 2 is installed in the planetary nut 3, the corresponding first groove 21 and the corresponding second groove 31 extend in the same direction.

Through the first recess 21 of a style of calligraphy of processing at planet roller 2's an axial end face, also set up the second recess 31 of a style of calligraphy at the terminal surface of planet nut 3, be convenient for planet roller 2 align through first recess 21 and second recess 31 and mark in the assembling process, the angle of quick adjustment circumferencial direction can guarantee that the axle portion terminal surface is in the unified meshing state of coplanar when planet roller 2 all accomplishes the meshing, guarantees that planet roller 2 bears the load evenly when helping improving planet roller 2's installation effectiveness.

Further, referring to fig. 1, the outer side of the planetary roller 2 is provided with a single-start thread, the outer side of the planetary screw 1 and the inner side of the planetary nut 3 are both provided with a multi-start thread, and the number of the thread starts is the same. In the circumferential direction, the motion among the planetary screw 1, the planetary rollers 2 and the planetary nut 3 is pure rolling, and the helix angles of the planetary rollers 2 and the planetary nut 3 are the same. More specifically, the screw thread directions and the screw pitches on the planet rollers 2, the planet screw 1 and the planet nuts 3 are all the same, and the tooth numbers and the modules of the gears 11 at the two ends of the inner gear ring 4 and the planet rollers 2 are all the same. The thread forms of the planetary screw rod 1 and the planetary nut 3 are both triangular, and the thread form of the planetary roller 2 is in a convex arc shape.

Further, referring to fig. 1, one end of the planetary screw 1 is provided with a gear 11 for connecting with an external driving mechanism. One end of the nut socket 6 is provided with a thread 61 for connection with an external mechanism. And a boss 222 or a groove is arranged on the excircle of the end part at the other end of the nut sleeve 6 and used for circumferential limiting. In this embodiment, the threads 61 at one end of the sleeve of the threads 61 are disposed in the sleeve and are internal threads 61. In addition, the excircle of the opposite end is also provided with a flat key-shaped boss 222 structure for limiting in the circumferential direction.

Here, the end of the planetary screw 1 is not limited to the gear 11, which is a driving mechanism for connecting to the outside, and may be provided in a manner such that a shaft provided with a key connection structure is connected to an external driving motor or a synchronous pulley. The end of the nut sleeve 6 is not limited to be connected with the thread 61, and can be fixedly connected with an external mechanism by providing the boss 222, a threaded hole, interference fit and the like.

Referring to fig. 2 and 3, the present invention further provides an assembly fixture 200 for a planetary roller screw assembly, including a roller stop lever assembly 210 and a roller push rod 220, where the roller stop lever assembly 210 includes a first roller stop lever 211 and a second roller stop lever 212, radial cross sections of the first roller stop lever 211 and the second roller stop lever 212 are both fan-shaped, and the fan-shaped radii are equal, the fan-shaped combination is a complete circle, a central angle of the radial cross section of the first roller stop lever 211 is greater than a central angle of the radial cross section of the second roller stop lever 212, the roller stop lever assembly 210 includes a first cylindrical surface 213, a conical surface 214, and a second cylindrical surface 215 connected in sequence, a diameter of the second cylindrical surface 215 is smaller than a diameter of the first cylindrical surface 213, and a diameter of the first cylindrical surface 213 is matched with an outer diameter of the planetary screw 1; the roller push rod 220 comprises a cylindrical body 221 and a boss 222 which are connected in sequence, the diameter of the cylindrical body 221 is matched with the inner diameter of the nut sleeve 6, the end surface of the cylindrical body 221, which is far away from one end of the boss 222, is a supporting surface 223, the supporting surface 223 is used for supporting a plurality of planet rollers 2, a cylindrical groove 224 is arranged at the center of the supporting surface 223, and the inner diameter of the cylindrical groove 224 is matched with the diameter of the second cylindrical surface 215, so that the second cylindrical surface 215 is inserted into the cylindrical groove 224.

By arranging the roller stop lever assembly 210 to comprise the first cylindrical surface 213, the conical surface 214 and the second cylindrical surface 215 which are sequentially connected, when the rollers are assembled, the planetary rollers 2 are firstly placed in the planetary nuts 3 to be meshed with the planetary nuts 3 and the inner gear ring 4, then the roller stop lever assembly 210 is sequentially and gradually inserted into the planetary nuts 3 from one end of the second cylindrical surface 215, the conical surface 214 can push the disengaged planetary rollers 2 back to a meshed state, and then the first cylindrical surface 213 enters the planetary nuts 3, so that the planetary rollers 2 can be kept in the meshed state. The roller stop lever assembly 210 comprises a first roller stop lever 211 and a second roller stop lever 212, the radial interfaces of the first roller stop lever 211 and the second roller stop lever 212 are combined and can be spliced into a whole circle, so that part of the planetary rollers 2 can be assembled firstly in the assembling process, then the first roller stop lever 211 fixes the planetary rollers in a meshing state, the rest of the planetary rollers 2 are assembled, and then the second roller stop lever 212 fixes the planetary rollers 2, the assembling efficiency can be improved, the plurality of planetary rollers 2 are assembled twice, the insertion of the planetary rollers 2 and the roller stop lever assembly 210 is facilitated, and the linkage influence between the planetary rollers 2 caused when the position of a single planetary roller 2 is adjusted in the assembling process is avoided. The meshing state of the other planetary rollers 2 is broken. The roller push rod 220 comprises a cylinder and a boss 222 and is used for supporting the planet roller 2, so that the end surface of the shaft of the planet roller 2 can be ensured not to be in direct contact with the end surface of the retainer 5, and the end surface of the retainer 5 is prevented from being extruded to the inner side surface of the nut sleeve 6 by the planet roller 2 to increase friction.

Through setting up assembly fixture, can accomplish the meshing assembly of planet roller 2 fast and the registrate of planet roller 2 and holder 5, improve assembly efficiency, and can guarantee that every roller has the same meshing state, and the loading is even, promotes the vice 100 operating stability of planet roller lead screw. This assembly fixture may also be used for assembly of structures similar to the planetary roller screw pair 100 provided by the present invention.

Further, the central angle of the radial section of the first roller bar 211 is any value of 205 ° to 215 °. The central angle is related to the number of planetary rollers 2 and may be set according to the actual situation so that the first roller bar 211 and the second roller bar 212 correspond to the number of planetary rollers 2, respectively. For example, in the present embodiment, the planetary roller screw pair 100 has 10 planetary rollers 2 in total, and preferably, the first roller stopper 211 has a radial cross-sectional central angle of 210 ° corresponding to 6 adjacent planetary rollers 2, and the second roller stopper 212 has a radial cross-sectional central angle of 150 ° corresponding to the remaining 4 adjacent planetary rollers 2.

Further, the roller stopper assembly 210 and the roller push rod 220 are made of polymer plastic materials. The polymer plastic material has the characteristics of soft hardness and wear resistance, can protect the planet roller 2 and is convenient for assembly.

The use of the assembly tool in the assembly of the planetary roller screw assembly 100 and the method of assembling the planetary roller screw assembly 100 in the present embodiment will be described by taking an example in which the planetary roller screw assembly 100 has 10 planetary rollers 2 in total, the first roller stopper 211 has a radial sectional central angle of 210 °, corresponding to 6 adjacent planetary rollers 2, and the second roller stopper 212 has a radial sectional central angle of 150 °.

S1: taking the planetary nut 3, respectively installing an inner gear ring 4 at two ends of the planetary nut and fixing the inner gear ring 4, and ensuring that any tooth socket of the inner gear ring 4 is aligned with the linear second groove 31 on the end surface of the planetary nut 3; taking a nut sleeve 6, installing a first retainer 5, and then installing the assembled planetary nut 3 and inner gear ring 4 assembly, wherein a 1mm movable gap is formed in the axial direction of the retainer 5;

s2: taking the roller mandril 220, and plugging in from the internal thread 61 end of the nut sleeve 6; taking a planet roller 2, inserting the planet roller in alignment with the circumferential hole of the first retainer 5, and enabling the end surface to abut against and be jacked up by the supporting surface 223 of the roller mandril 220 without contacting with the end surface of the first retainer 5; the first groove 21 of the straight line shape of the planet roller 2 is used for rotating the planet roller 2 by a tool, the meshing position is adjusted, the thread and the gear teeth are meshed synchronously, and finally the first groove 21 of the straight line shape is aligned with the second groove 31, namely, the meshing assembly of the first roller is completed.

S3: taking five planetary rollers 2, and sequentially loading the five planetary rollers into the planetary nut 3 according to the method in S2; the first roller stopper 211 is taken and inserted into the cylindrical groove 224 of the roller top bar 220, and six engaged planetary rollers 2 are stopped and restrained, as shown in fig. 6 and 7. Taking the remaining four planetary rollers 2, and sequentially loading the four planetary rollers into the planetary nut 3 according to the method in S2; the second roller stop lever 212 is taken and inserted into the cylindrical groove 224 of the roller top rod 220, and the ten planetary rollers 2 are completely engaged and are stopped and limited and cannot move circumferentially or radially.

S4: taking a second retainer 5, and easily and completely sleeving the ten rollers; screwing a locking nut into the sleeve to abut against the planetary nut 3; taking a planetary lead screw 1 to be meshed with the planetary roller 2 and slowly screwing in.

In this document, the terms front, back, upper and lower are used to define the components in the drawings and the positions of the components relative to each other, and are used for clarity and convenience of the technical solution. It is to be understood that the use of the directional terms should not be taken to limit the scope of the claims.

The features of the embodiments and embodiments described herein above may be combined with each other without conflict.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A planetary roller screw pair is characterized by comprising a planetary screw, a plurality of planetary rollers, a planetary nut, two inner gear rings, two retainers and a nut sleeve, wherein the planetary screw is positioned in the planetary nut, the two inner gear rings are respectively installed at two ends of the inner side of the planetary nut, the planetary rollers are uniformly installed between the planetary screw and the planetary nut and are meshed with the planetary screw and the inner gear rings, the two retainers are respectively installed at two ends of the planetary nut, each retainer is connected with the planetary rollers so as to ensure that the planetary rollers are uniformly distributed in the circumferential direction of the planetary screw, and the planetary nut is axially positioned in the nut sleeve through a locking nut.

2. A planetary roller screw set as claimed in claim 1, wherein a shaft end surface of the planetary roller is provided with a first groove, a shaft end surface of the planetary nut is provided with a plurality of second grooves at intervals in a circumferential direction, and the first and second grooves are arranged in a straight line such that the first and second grooves corresponding to each of the planetary rollers are in the same direction of extension when each of the planetary rollers is mounted in the planetary nut.

3. The planetary roller screw pair of claim 1, wherein the outer side of the planetary roller is provided with a single start thread, the outer side of the planetary screw and the inner side of the planetary nut are both provided with a multiple start thread, and the number of the start threads is the same.

4. The planetary roller screw set of claim 3, wherein the planetary screw and the planetary nut have triangular thread profiles and the planetary roller has a convex arc thread profile.

5. A planetary roller screw set according to claim 1, wherein the planetary screw is provided with a gear at one end for connection with an external drive mechanism.

6. A planetary roller screw set according to claim 1, wherein one end of the nut sleeve is threaded for connection with an external mechanism.

7. A planetary roller screw set according to claim 6, wherein the nut socket is provided with a boss or a groove on the outer circumference of the end portion at the other end thereof for circumferential limitation.

8. An assembly tool for a planetary roller screw pair according to any one of claims 1 to 7, comprising:

the roller ejector rod comprises a cylinder and a boss which are sequentially connected, the diameter of the cylinder is matched with the inner diameter of the nut sleeve, the end face, far away from one end of the boss, of the cylinder is a supporting face, the supporting face is used for supporting a plurality of planet rollers, a cylindrical groove is formed in the center of the supporting face, and the inner diameter of the cylindrical groove is matched with the diameter of the second cylindrical surface, so that the second cylindrical surface is inserted into the cylindrical groove.

9. The assembly fixture of a planetary roller screw pair according to claim 8, wherein a central angle of a radial cross section of the first roller stopper is any value of 205 ° to 215 °.

10. The assembly fixture of a planetary roller screw pair according to claim 8, wherein the roller stopper assembly and the roller carrier rod are made of a polymer plastic material.