A planetary roller screw assembly tooling and assembly method suitable for multiple sizes

Abstract

The present application relates to the field of planetary roller screw assembly, and specifically discloses a planetary roller screw assembly tool suitable for multiple sizes, which comprises a horizontally placed base, the base is provided with a slide table movable along the radial direction thereof, and the slide table is fixed through pressing blocks and pressing bolts; the slide table is provided with a clamping mechanism for clamping the planetary roller screw, the clamping mechanism is provided with a trapezoidal screw, and the rotation of the trapezoidal screw drives the up-down movement of the trapezoidal screw nut sleeve to realize the support and clamping of the planetary roller screw; the present application further discloses a method for assembling the planetary roller screw by using the above-mentioned assembly tool. The planetary roller screw assembly tool provided by the present application is simple and reliable in structure, can adapt to the assembly requirements of planetary roller screws of different sizes, effectively improves the assembly efficiency, reduces the cost, and the assembly method of the present application is efficient and easy to operate, has strong repeatability, and is helpful to improve the assembly accuracy and the qualified rate of the planetary roller screw.

Description

Technical Field

[0001] This invention relates to the field of planetary roller screw assembly, and more particularly to a tooling and assembly method for planetary roller screws of various sizes. Background Technology

[0002] A planetary roller screw is a mechanical device that converts rotary and linear motion into each other. Its core components consist of a screw, rollers, and a nut, with multiple rollers evenly distributed around the screw. The screw inputs torque, driving the rollers in planetary motion, and the transmission of motion and power is achieved through threaded contact. Furthermore, to ensure the roller axis does not tilt during movement and to reduce sliding friction, gear pairs are installed at both ends of the rollers, achieving linkage between threaded and gear drives through parameter matching. Benefiting from numerous contact points, planetary roller screws offer significant advantages over other linear transmission mechanisms, including high operating accuracy, high load-bearing capacity, impact resistance, and strong environmental adaptability. They are widely used in aerospace, weaponry, heavy engineering machinery, medical equipment, and other fields. With the trend towards full electrification of mechanical equipment, their application prospects will undoubtedly expand further.

[0003] Assembly accuracy is the primary prerequisite for ensuring the performance of planetary roller screws. However, due to the large number of parts in planetary roller screws, their assembly is difficult and inefficient. The main problems are as follows: (1) In order to simultaneously meet the correct meshing of threads and gears, each roller needs to be repeatedly tested to find the correct mating position, resulting in low assembly efficiency; (2) During assembly, the rollers are in a moving state, and the assembly space is usually small. When assembling some rollers, the assembled rollers may tilt or skip teeth, which will disrupt their normal meshing; (3) Because the cage is designed with an axial floating clearance between the internal gear ring and the elastic retaining ring, the rollers are prone to axial movement after assembly, resulting in inconsistent end face heights, increasing the risk of excessive wear on the end face of the cage and uneven load on the rollers, which affects the smooth operation of the planetary roller screw.

[0004] In addition, manual assembly can lead to problems such as low repeatability and poor consistency. Existing assembly fixtures are usually customized for specific models of planetary roller screws. When the size changes, the fixtures need to be redesigned and reprocessed, which increases the assembly cost and cycle. Therefore, it is necessary to propose assembly fixtures and corresponding assembly methods that can be applied to various sizes based on the structural characteristics of planetary roller screws, so as to improve assembly efficiency and assembly accuracy and promote the further development of planetary roller screw assembly technology. Summary of the Invention

[0005] To address the aforementioned problems, the objective of this invention is to provide an assembly fixture suitable for planetary roller screws of various sizes. The technical solution adopted by this invention is as follows:

[0006] This invention proposes an assembly fixture for planetary roller screws of various sizes, comprising a horizontally placed base with multiple radially movable slides arranged in a circular array on the base. Each slide is equipped with a clamping mechanism for clamping the planetary roller screw. The clamping mechanism includes a base plate fixedly connected to the slides. A vertically arranged trapezoidal screw is arranged on the inner side of the base plate. An upper bearing seat and a lower bearing seat with bearings are respectively provided at both ends of the trapezoidal screw, and both the upper and lower bearing seats are fixedly connected to the base plate. A trapezoidal screw nut is provided on the trapezoidal screw, and a trapezoidal screw nut sleeve is provided on the outer side of the trapezoidal screw nut. The trapezoidal screw nut sleeve slides up and down and is engaged with the base plate. A bracket is provided on the inner side of both the trapezoidal screw nut sleeve and the lower bearing seat. An upper support head and a lower support head for supporting the planetary roller screw are respectively provided on the facing surfaces of the two brackets.

[0007] Preferably, the top of the trapezoidal lead screw is provided with a locking structure that can restrict its rotational movement.

[0008] Preferably, the locking structure includes a locking seat, which has a circular hole with a notch, the circular hole being fitted onto the trapezoidal lead screw, and a locking bolt being provided at the notch of the locking seat.

[0009] Preferably, the inner side of the base plate is provided with a vertically arranged guide groove, and the trapezoidal lead screw nut sleeve is provided with a boss on the side near the base plate, the boss being slidably engaged in the guide groove.

[0010] Preferably, the upper support head and the lower support head are detachably connected to the corresponding brackets via a threaded structure.

[0011] Preferably, the head ends of the upper support head and the lower support head are spherical.

[0012] Preferably, the top of the trapezoidal lead screw is provided with a hand-tightening head.

[0013] Preferably, the base has a plurality of radially arranged grooves in a circular array, and a matching slider is arranged in the groove. The top of the slider is connected to the slide table, and a pressure block is provided at the rear of the slide table. The pressure block is connected to the slider by a clamping bolt.

[0014] Preferably, limit bolts are provided at both ends of the slide.

[0015] This invention also provides a method for assembling planetary roller screws, utilizing the aforementioned assembly fixture suitable for planetary roller screws of various sizes. The method includes the following steps:

[0016] Step 1: Install the two internal gear rings into both ends of the nut respectively, and insert the locating pins to fix the internal gear rings in the nut to ensure that the gears of the two internal gear rings are in phase.

[0017] Step 2: Insert the first retainer into one end of the nut and install the first elastic retaining ring to prevent the retainer from falling off. The retainer is provided with multiple positioning holes.

[0018] Step 3: Place the nut vertically with the end containing the cage facing down, and push the slide table to the appropriate position to ensure that the lower support head is accurately inserted into the positioning hole of the cage. Repeat this step until all the lower support heads are inserted into the corresponding positioning holes. At this time, the planetary roller screw is placed stably on the assembly fixture.

[0019] Step 4: Place the slotted retainer into the upper end of the nut. The slotted retainer and the retainer have the same positioning hole. The difference between the two is that the mounting hole of the slotted retainer is provided with an inward opening slot. The slotted retainer ensures that the axis does not tilt or skip teeth when the roller is inserted, and also leaves enough space for adjusting the meshing position of the roller.

[0020] Step 5: Rotate the trapezoidal screw to move the upper support head up and down, accurately insert the upper support head into the positioning hole of the slotted retainer, and make it have a certain clamping force to ensure that the retainer and the slotted retainer are in close contact with the end faces of the internal gear rings at both ends. Repeat this step until all the upper support heads are inserted into the positioning holes corresponding to the slotted retainers.

[0021] Step 6: Insert multiple rollers into the mounting holes of the cage in sequence. Rotate the rollers at one end of the slotted cage to make them properly mesh with the threads of the nut and the gear of the internal gear ring. At the same time, in order to avoid disrupting the meshing state of the rollers installed earlier when adjusting the rollers, when half of the rollers are installed, install half of the split cage above the slotted cage. After all the rollers are installed, install the other half of the split cage.

[0022] Step 7: Rotate the trapezoidal lead screw to move the upper support head to a suitable position, and remove the nut with the roller assembly completed from the tooling, while keeping one end of the slotted retainer facing upwards.

[0023] Step 8: Screw the lead screw in from the bottom of the nut. You can press the split cage slightly to prevent the cage from slipping when the lead screw is engaged. After engaging for an appropriate distance, remove the split cage and the slotted cage. At this point, all rollers are properly engaged with the nut and the lead screw, and the second cage can be easily inserted. At the same time, install the second elastic retaining ring, and then continue to screw in the lead screw to complete the assembly.

[0024] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0025] The assembly fixture structure of the present invention is simple and reliable, and can adapt to the assembly requirements of planetary roller screws of different sizes, effectively improving assembly efficiency and reducing costs. Moreover, the assembly method of the present invention is efficient, easy to operate, and highly repeatable, which helps to improve the assembly accuracy and pass rate of planetary roller screws. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings.

[0027] Figure 1 A schematic diagram of the structure of the planetary roller screw assembly tooling provided for a specific embodiment of the present invention;

[0028] Figure 2 A schematic diagram of the clamping mechanism provided for a specific embodiment of the present invention;

[0029] Figure 3 A schematic diagram of the structure of the locking seat provided for a specific embodiment of the present invention;

[0030] Figure 4 A schematic diagram of the trapezoidal lead screw nut sleeve provided for a specific embodiment of the present invention;

[0031] Figure 5 A schematic diagram of the structure of the base and the slide provided for a specific embodiment of the present invention;

[0032] Figure 6 A schematic diagram of the slide table provided for a specific embodiment of the present invention;

[0033] Figure 7 A schematic diagram of the overall structure of the planetary roller screw provided for a specific embodiment of the present invention;

[0034] Figure 8 A schematic diagram of a retainer with positioning holes provided for a specific embodiment of the present invention;

[0035] Figure 9 A schematic diagram of a retainer with an open slot provided for a specific embodiment of the present invention;

[0036] Figure 10 A schematic diagram showing the assembled open slot retainer and rollers according to a specific embodiment of the present invention;

[0037] Figure 11 A schematic diagram of a split cage provided for a specific embodiment of the present invention.

[0038] Explanation of reference numerals in the attached drawings: 1. Base; 101. Slide groove; 102. Limit bolt; 2. Slide table; 201. Pressure block; 202. Clamping bolt; 203. Slider; 3. Clamping mechanism; 301. Base plate; 302. Trapezoidal lead screw; 303. Upper bearing seat; 304. Lower bearing seat; 305. Locking seat; 305-1. Round hole; 306. Locking bolt; 307. Trapezoidal lead screw nut; 308. Trapezoidal lead screw nut sleeve; 3 08-1, Boss; 309, Guide groove; 310, Upper support head; 311, Lower support head; 312, Bracket; 313, Hand-tightening head; 4, Planetary roller screw; 401, Nut; 402, Roller; 403, Internal gear ring; 404, Locating pin; 405, Cage; 405-1, Locating hole; 406, Elastic retaining ring; 407, Screw; 5, Slotted cage; 501, Open slot; 6, Split cage. Detailed Implementation

[0039] To make the technical problems, technical solutions, and beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0040] like Figure 1 and 2 As shown in the figure, this embodiment discloses a planetary roller screw assembly fixture applicable to multiple sizes, including a horizontally placed base 1, on which a plurality of slides 2 are arranged in a ring array and can move radially thereon, and each slide 2 can be provided with a clamping mechanism 3 for clamping the planetary roller screw 4.

[0041] The clamping mechanism 3 includes a base plate 301 that is fixedly connected to the slide table 2 by bolts. A vertically arranged trapezoidal lead screw 302 is provided on the inner side of the base plate 301. A hand-tightening head 313 is provided at the top of the trapezoidal lead screw 302. An upper bearing seat 303 and a lower bearing seat 304 with bearings are respectively provided at both ends of the trapezoidal lead screw 302. The upper bearing seat 303 and the lower bearing seat 304 are both fixedly connected to the base plate 301 by bolts. A trapezoidal lead screw nut 307 that cooperates with the trapezoidal lead screw 302 is provided on the outer side of the trapezoidal lead screw nut 307. The trapezoidal lead screw nut sleeve 308 slides up and down and is engaged with the base plate 301. A bracket 312 is provided on the inner side of both the trapezoidal lead screw nut sleeve 308 and the lower bearing seat 304. An upper support head 310 and a lower support head 311 for supporting the planetary roller lead screw 4 are respectively provided on the facing surfaces of the two brackets 312.

[0042] In this embodiment, the upper support head 310 and the lower support head 311 are connected to the corresponding bracket 312 by a threaded structure, which facilitates the replacement of the support head in the future. The head ends of the upper support head 310 and the lower support head 311 are spherical, which makes it easy to insert them into the corresponding holes during assembly.

[0043] To prevent the trapezoidal lead screw nut 307 from slipping after reaching the predetermined position, a locking structure is provided at the top of the trapezoidal lead screw 302 to restrict its rotational movement, such as... Figure 2 and 3 As shown, in this embodiment, the locking structure includes a locking seat 305, which is fixedly connected to the base plate 301 by bolts. The locking seat 305 has a circular hole 305-1 with a straight notch, which is fitted onto the trapezoidal lead screw 302. A locking bolt 306 is provided at the straight notch of the locking seat 305. The trapezoidal lead screw 302 can be locked by tightening the locking bolt 306.

[0044] The trapezoidal lead screw nut sleeve 308 slides and engages with the base plate 301, thus both restricting the circumferential rotation of the trapezoidal lead screw nut 307 and providing linear guidance. Figure 2 and 4 As shown, in this embodiment, a boss 308-1 is provided on the side of the trapezoidal screw nut sleeve 308 near the base plate 301, and a vertically arranged guide groove 39 is provided on the inner side of the base plate 31. The boss 308-1 is slidably engaged in the guide groove 309.

[0045] like Figure 1 , 5 As shown in Figure 6, the base 1 has multiple radially arranged grooves 101 arranged in a circular array. Matching sliders 203 are arranged in the grooves 101. The top of the sliders 203 is connected to the slide table 2. When planetary roller screws of different diameters are assembled, they are matched by moving the slide table 2. In this embodiment, the groove 101 is a dovetail groove. This structure ensures that the slide table 2 will not tilt when sliding in the groove 101. At the same time, in order to prevent the slide table 2 from sliding out of the groove 11 and falling off, limit bolts 102 are provided at both ends of the groove 11.

[0046] A pressure block 201 is provided at the rear of the slide table 2. The pressure block 201 is connected to the slider 203 by a clamping bolt 202. When the slide table 2 moves, the pressure block 201 moves with it. When the slide table 2 moves to a certain position, the pressure block 201 is pressed against the base 1 by tightening the clamping bolt 202, thereby fixing the slide table 2.

[0047] Based on the aforementioned planetary roller screw assembly fixture, this embodiment also discloses a method for assembling planetary roller screws using a planetary roller screw assembly fixture applicable to multiple sizes. This method includes the following steps:

[0048] Step 1, as follows Figure 7 As shown, two internal gear rings 403 are respectively installed into the two ends of the nut 401, and the locating pins 404 are inserted to fix the internal gear rings 403 in the nut 401 to ensure that the gear phases of the two internal gear rings 403 are consistent.

[0049] Step two: Insert the first retainer 405 into one end of the nut 401 and install the first elastic retaining ring 406 to prevent the retainer 405 from falling off. Figure 8 As shown, unlike conventional cages, the cage 405 in this embodiment is provided with three positioning holes 405-1 for precise positioning of the support head of the assembly tooling.

[0050] Step 3: Place the nut 401 vertically with the end containing the retainer 405 facing down, and push the slide 2 to the appropriate position to ensure that the lower support head 311 is accurately inserted into the positioning hole 405-1 of the retainer 405. Then tighten the clamping bolt 202 to fix the position of the slide 2. Repeat this step until all the lower support heads 311 are inserted into the corresponding positioning holes 405-1. At this time, the planetary roller screw is placed stably on the assembly fixture.

[0051] Step four, as Figure 9 As shown, the slotted retainer 5 is placed on the upper end of the nut 401. The slotted retainer 5 and the retainer 405 have the same positioning hole 405-1. The difference between the two is that the mounting hole of the slotted retainer 5 is provided with an inward opening slot 501. The slotted retainer 5 ensures that the axis does not tilt or skip teeth when the roller 402 is inserted, and also leaves enough space for adjusting the meshing position of the roller 402.

[0052] Step 5: Rotate the trapezoidal lead screw 302 to move the upper support head 310 up and down, accurately inserting the upper support head 310 into the positioning hole 405-1 of the slotted retainer 5, and applying a certain clamping force to ensure that the retainer 405 and the slotted retainer 5 are in close contact with the end faces of the internal gear rings 403 at both ends. This can minimize or even eliminate the problem of axial movement of the roller 402 after assembly, improving assembly consistency and quality. At the same time, tighten the locking bolt 306 to maintain a constant clamping force. Repeat this step until all the upper support heads 310 are inserted into the corresponding positioning holes 405-1 of the slotted retainer 5.

[0053] Step six, as follows Figure 10 As shown, multiple rollers 402 are sequentially inserted into the mounting holes of the cage 405. By rotating one end of the slotted cage 5, the rollers 402 are correctly engaged with the threads of the nut 401 and the gear of the internal gear ring 403. To avoid disrupting the engagement of the previously installed rollers 402 when adjusting the installation of the next roller, half of the split cage 6 is installed above the slotted cage 5 after half of the rollers 402 have been installed. The other half of the split cage 6 is installed after all the rollers 402 have been installed. Figure 11 As shown, the split retainer 6 in this embodiment has the same basic dimensions as the retainer 405. The difference between the two is that the split retainer 6 has the outer part of the mounting hole of the retainer 405 cut off and is split in half.

[0054] Step 7: Rotate the trapezoidal lead screw 302 to move the upper support head 310 to a suitable position, and remove the nut 401 with the roller 402 assembled from the tooling. At this time, keep one end of the slotted retainer 5 facing upward.

[0055] Step 8: Screw the lead screw 407 into the lower end of the nut 401. You can press the split retainer 6 slightly to prevent the retainer from slipping when the lead screw 407 is engaged. After engaging for an appropriate distance, remove the split retainer 6 and the slotted retainer 5. At this time, all rollers 402 are correctly engaged with the nut 401 and the lead screw 407. The second retainer 405 can be easily inserted. At the same time, install the second elastic retaining ring 406. Then continue to screw the lead screw in to complete the assembly.

[0056] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A tooling fixture suitable for assembling planetary roller screws of various sizes, characterized in that: It includes a horizontally placed base (1), on which a plurality of slides (2) are arranged in a ring array that can move radially thereon, and each slide (2) can be provided with a clamping mechanism (3) for clamping the planetary roller screw (4). The clamping mechanism (3) includes a base plate (301) fixedly connected to the slide table (2). A vertically arranged trapezoidal lead screw (302) is provided on the inner side of the base plate (301). An upper bearing seat (303) and a lower bearing seat (304) with bearings are respectively provided at both ends of the trapezoidal lead screw (302). The upper bearing seat (303) and the lower bearing seat (304) are both fixedly connected to the base plate (301). A trapezoidal lead screw that cooperates with the trapezoidal lead screw (302) is provided on the trapezoidal lead screw (302). The trapezoidal screw nut (307) is provided with a trapezoidal screw nut sleeve (308) on its outer side. The trapezoidal screw nut sleeve (308) is slidably engaged with the base plate (301). The trapezoidal screw nut sleeve (308) and the lower bearing seat (304) are both provided with brackets (312). The two brackets (312) are respectively provided with an upper support head (310) and a lower support head (311) for supporting the planetary roller screw (4) on their opposing surfaces.

2. The planetary roller screw assembly fixture applicable to multiple sizes according to claim 1, characterized in that: The trapezoidal lead screw (302) is provided with a locking structure at the top to restrict its rotational movement.

3. The planetary roller screw assembly fixture applicable to multiple sizes according to claim 2, characterized in that: The locking structure includes a locking seat (305), which has a circular hole (305-1) with a notch in the shape of a straight line. The circular hole (305-1) is fitted onto the trapezoidal lead screw (302), and a locking bolt (306) is provided at the notch in the shape of the straight line of the locking seat (305).

4. The planetary roller screw assembly fixture applicable to multiple sizes according to claim 1, characterized in that: The inner side of the base plate (301) is provided with a vertically arranged guide groove (309), and the trapezoidal screw nut sleeve (308) is provided with a boss (308-1) on the side near the base plate (301), and the boss (308-1) is slidably engaged in the guide groove (309).

5. The planetary roller screw assembly fixture applicable to multiple sizes according to claim 1, characterized in that: The upper support head (310) and the lower support head (311) are detachably connected to the corresponding bracket (312) through a threaded structure.

6. The planetary roller screw assembly fixture applicable to multiple sizes according to claim 5, characterized in that: The head ends of the upper support head (310) and the lower support head (311) are spherical.

7. The planetary roller screw assembly fixture applicable to multiple sizes according to claim 1, characterized in that: The top of the trapezoidal lead screw (302) is provided with a hand-tightening head (313).

8. The planetary roller screw assembly fixture applicable to multiple sizes according to claim 1, characterized in that: The base (1) has a plurality of radially arranged grooves (101) arranged in a ring array. Matching sliders (203) are arranged in the grooves (101). The top of the sliders (203) is connected to the slide table (2). A pressure block (201) is arranged at the rear of the slide table (2). The pressure block (201) is connected to the sliders (203) by a clamping bolt (202).

9. The planetary roller screw assembly fixture applicable to multiple sizes according to claim 8, characterized in that: Limit bolts (102) are provided at both ends of the slide (101).

10. A method for assembling a planetary roller screw, utilizing the planetary roller screw assembly fixture applicable to multiple sizes as described in any one of claims 1 to 9, characterized in that: The method includes the following steps: Step 1: Install the two internal gear rings (403) into the two ends of the nut (401) respectively, and insert the positioning pin (404) to fix the internal gear rings (403) in the nut (401) to ensure that the gear phases of the two internal gear rings (403) are consistent. Step 2: Insert the first retainer (405) into one end of the nut (401) and install the first elastic retaining ring (406) to prevent the retainer (405) from falling off. The retainer (405) is provided with multiple positioning holes (405-1). Step 3: Place the nut (401) vertically with the end containing the retainer (405) facing down, and push the slide (2) to the appropriate position to ensure that the lower support head (311) is accurately inserted into the positioning hole (405-1) of the retainer (405). Repeat this step until all the lower support heads (311) are inserted into the corresponding positioning holes (405-1). At this time, the planetary roller screw is placed stably on the assembly fixture. Step 4: Place the slotted retainer (5) into the upper end of the nut (401). The slotted retainer (5) and the retainer (405) have the same positioning hole (405-1). The difference between the two is that the mounting hole of the slotted retainer (5) is provided with an inward opening slot (501). The slotted retainer (5) ensures that the axis does not tilt or skip teeth when the roller (402) is placed, and also leaves enough space for adjusting the meshing position of the roller (402). Step 5: Rotate the trapezoidal lead screw (302) to move the upper support head (310) up and down, accurately insert the upper support head (310) into the positioning hole (405-1) of the slotted retainer (5), and make it have a certain clamping force to ensure that the retainer (405) and the slotted retainer (5) are in close contact with the end faces of the internal gear rings (403) at both ends respectively. Repeat this step until all the upper support heads (310) are inserted into the corresponding positioning holes (405-1) of the slotted retainer (5); Step six: Insert multiple rollers (402) into the mounting holes of the cage (405) in sequence. Rotate the rollers (402) at one end of the slotted cage (5) to make them properly mesh with the threads of the nut (401) and the gear of the internal gear ring (403). At the same time, in order to avoid disrupting the meshing state of the rollers (402) installed earlier when adjusting the rollers (402), when half of the rollers (402) are installed, install half of the split cage (6) above the slotted cage (5). After all the rollers (402) are installed, install the other half of the split cage (6). Step 7: Rotate the trapezoidal lead screw (302) to move the upper support head (310) to a suitable position, and remove the nut (401) that has completed the roller (402) assembly from the tooling. At this time, keep one end of the slotted retainer (5) facing upward. Step 8: Screw the screw (407) into the lower end of the nut (401). You can press the split retainer (6) slightly to prevent the retainer from slipping when the screw (407) is engaged. After engaging for an appropriate distance, remove the split retainer (6) and the slotted retainer (5). At this time, all rollers (402) are properly engaged with the nut (401) and the screw (407). The second retainer (405) can be easily inserted. At the same time, the second elastic retaining ring (406) is installed. Then continue to screw the screw in to complete the assembly.

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