Planetary roller screw pair with ease of machining

Abstract

The utility model relates to the technical field of roller screw pair, and disclose a kind of planet roller screw pair of being convenient for processing, the planet roller screw pair of being convenient for processing, including center screw rod.The planet roller screw pair of being convenient for processing, through the mounting plate and installation slot on cover plate, it is convenient for processing, when center screw rod rotates, planet roller is engaged by thread, first will spin, rotate around its own axis, driven by center screw rod thread, second will revolve, planet roller does the "planetary" circular motion around center screw rod axis, it is constrained by the inner tooth ring in the first bearing, gear on planet roller engages inner tooth ring, planet roller is set in cover plate interior by second bearing, since planet roller and nut are engaged by thread, and planet roller is limited axial displacement, so that nut will be linear motion along center screw rod axial with the helical motion of planet roller, and the point contact bearing capacity of ball screw is stronger, and the rigidity is higher.

Description

Technical Field

[0001] This utility model relates to the field of roller screw pair technology, specifically to a planetary roller screw pair that is easy to manufacture. Background Technology

[0002] In the field of mechanical transmission, the lead screw pair, as the core component for realizing the conversion between rotary motion and linear motion, is widely used in many scenarios such as CNC machine tools, aerospace equipment, precision instruments and automated production lines. As industrial manufacturing continues to develop towards high precision, high load capacity and high reliability, the market has put forward increasingly stringent requirements for the performance of lead screw pairs.

[0003] Planetary roller screw pairs, with their line contact transmission structure, have significant advantages over traditional ball screws in terms of load-bearing capacity and stiffness, and are gradually becoming an important choice in the high-end transmission field. Their ease of processing and motion stability have also become research hotspots in the industry.

[0004] Existing planetary roller screw pairs still have certain shortcomings in practical applications. On the one hand, the cover plate and nut of some products adopt an integrated or complex fixed structure design, which makes it difficult to disassemble and assemble the cover plate. On the other hand, the support and positioning design of the planetary rollers in some structures is not reasonable enough, making it difficult to ensure the synchronization of their rotation and revolution, which can easily lead to problems such as transmission jamming and uneven wear, affecting the transmission accuracy of the screw pair. In view of this, we propose a planetary roller screw pair that is easy to manufacture. Utility Model Content

[0005] The purpose of this invention is to provide a planetary roller screw pair that is easy to manufacture, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A planetary roller screw pair that is easy to process includes a central screw, a nut, a cover plate, a mounting plate, a mounting groove, a first bearing, an internal gear ring, planetary rollers, a second bearing, and a gear. The mounting plate is fixed on the cover plate, and the mounting groove is formed on the mounting plate. Fasteners pass through the mounting groove and are threadedly engaged with the nut to realize a detachable connection between the cover plate and the nut. The first bearing is fixed inside the nut, the internal gear ring is fixedly installed inside the first bearing, the planetary roller is sleeved inside the cover plate through the second bearing, the planetary roller is threadedly engaged with the central screw and the nut, and the gear is fixed on the planetary roller and engages with the internal gear ring, thereby restricting the axial displacement of the planetary roller.

[0007] In a further embodiment, the mounting plate and the cover plate are integrally formed.

[0008] In a further embodiment, the mounting plates are evenly distributed along the outer circumference of the cover plate to achieve line contact transmission.

[0009] In a further embodiment, the inner tooth surface of the internal gear ring meshes with the outer tooth surface of the gear.

[0010] In a further embodiment, both ends of the planetary rollers are connected to the cover plate via second bearings, which facilitates machining.

[0011] In a further embodiment, the gear is coaxially arranged with the planetary rollers, which has a stronger load-bearing capacity and higher rigidity than the point contact bearing capacity of the ball screw.

[0012] In a further embodiment, multiple planetary rollers are provided, and the multiple planetary rollers are evenly distributed circumferentially along the central lead screw, with multiple gears correspondingly installed on each planetary roller.

[0013] Compared with the prior art, this utility model provides a planetary roller screw pair that is easy to manufacture, and has the following beneficial effects: This easily machinable planetary roller screw assembly uses a mounting plate on the cover plate to allow fasteners to pass through mounting slots and threadedly engage with the nut, facilitating cover plate assembly and disassembly and machining. When the central screw rotates, the planetary rollers engage with the screw threads, resulting in two simultaneous motions: first, they rotate on their own axis, driven by the central screw threads; second, they revolve around the central screw axis, performing a planetary circular motion constrained by an internal gear ring inside the first bearing. Gears on the planetary rollers mesh with the internal gear ring, and the planetary rollers are fitted inside the cover plate via a second bearing. Because the planetary rollers and nut engage with the screw threads, and the axial displacement of the planetary rollers is restricted, the nut will move linearly along the central screw axis following the helical motion of the planetary rollers. Conversely, if the nut is driven to move linearly, it can also drive the central screw to rotate through the planetary rollers, thus achieving line contact transmission, which has a stronger load-bearing capacity and higher rigidity than the point contact of ball screws. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the overall structure of the present invention from another perspective; Figure 3 This is a schematic diagram of part of the structure of this utility model; Figure 4 This is a cross-sectional view of the nut of this utility model; Figure 5 This utility model Figure 4 Enlarged structural diagram of region A in the middle; Figure 6 This is a cross-sectional view of part of the structure of this utility model.

[0015] Explanation of icon numbers: 100. Center lead screw; 101. Nut; 102. Cover plate; 103. Mounting plate; 104. Mounting groove; 105. First bearing; 106. Internal gear ring; 107. Planetary roller; 108. Second bearing; 109. Gear. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] In this application, the term "above" indicates the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. It is primarily used to better describe this application and its embodiments, and is not intended to limit the indicated device, element, or component to having a specific orientation, or to construct and operate in a specific orientation. Furthermore, the term "above" may also be used in certain circumstances to indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances.

[0018] Please see Figures 1-6 This utility model provides a technical solution: A planetary roller screw assembly that is easy to manufacture includes a central lead screw 100, a nut 101, a cover plate 102, a mounting plate 103, a mounting groove 104, a first bearing 105, an internal gear ring 106, planetary rollers 107, a second bearing 108, and a gear 109. The mounting plate 103 is fixed to the cover plate 102, and the mounting groove 104 is formed in the mounting plate 103. Fasteners pass through the mounting groove 104 and are threadedly engaged with the nut 101 to realize the connection between the cover plate 102 and the nut 101. The detachable connection with nut 101; the first bearing 105 is fixed inside nut 101, the internal gear ring 106 is fixedly installed inside the first bearing 105, the planetary roller 107 is sleeved inside cover plate 102 through second bearing 108, the planetary roller 107 is threadedly engaged with the central lead screw 100 and nut 101 respectively, and the gear 109 is fixed on the planetary roller 107 and engages with the internal gear ring 106, so that the axial displacement of planetary roller 107 is restricted.

[0019] In one embodiment of this utility model, the mounting plate 103 and the cover plate 102 are integrally formed. In addition, the mounting plate 103 is evenly distributed along the outer circumference of the cover plate 102 to achieve line contact transmission. Furthermore, the inner tooth surface of the internal gear ring 106 meshes with the outer tooth surface of the gear 109. In addition, both ends of the planetary roller 107 are connected to the cover plate 102 through the second bearing 108, which facilitates processing.

[0020] In one embodiment of this utility model, the gear 109 is coaxially arranged with the planetary roller 107, which has a stronger point contact load-bearing capacity and higher rigidity than the ball screw. In addition, multiple planetary rollers 107 are provided, and the multiple planetary rollers 107 are evenly distributed circumferentially along the central screw 100. Each planetary roller 107 is equipped with multiple gears 109.

[0021] Working principle: The cover plate 102 is detachably connected to the nut 101 via a mounting plate 103 fixed thereon. Fasteners pass through the mounting groove 104 on the mounting plate 103 and threadedly engage with the nut 101. This connection method facilitates the assembly and subsequent maintenance of moving parts while ensuring structural stability during movement. The planetary rollers 107 are fitted inside the cover plate 102 via second bearings 108, with both ends connected to the cover plate 102 by the second bearings 108. The second bearings 108 ensure flexible rotation of the planetary rollers 107 and provide reliable support and positioning. When the central lead screw 100 rotates under external drive, the threaded engagement between the planetary rollers 107 and the central lead screw 100 generates a driving force on the planetary rollers 107, causing the planetary rollers 107 to undergo two movements simultaneously: (1) Rotation motion: Under the direct drive of the central screw 100 thread, the planetary roller 107 rotates around its own axis. The presence of the second bearing 108 reduces the frictional resistance between the planetary roller 107 and the cover plate 102 when it rotates, ensuring the smoothness of the rotation. (2) Revolutionary motion: The gear 109 fixed on the planetary roller 107 meshes with the internal gear ring 106 fixedly installed on the inner side of the first bearing 105. The internal gear ring 106 provides circumferential constraint for the gear 109. When the planetary roller 107 rotates, the gear 109 will generate a circular motion around the axis of the central screw 100 under the constraint of the tooth surface of the internal gear ring 106, that is, the "planetary" revolution of the planetary roller 107. Multiple planetary rollers 107 are evenly distributed around the central screw 100, and the gear 109 on each planetary roller 107 meshes with the internal gear ring 106, ensuring the synchronization and stability of the revolutionary motion. (3) Linear motion of nut 101: Since planetary roller 107 meshes with nut 101 through threads, and the meshing of internal gear ring 106 and gear 109 restricts the axial displacement of planetary roller 107, the helical motion of planetary roller 107 cannot extend axially. Instead, it will transmit the driving force to nut 101 through the thread tooth surface, pushing nut 101 to make a smooth linear motion along the axis of central screw 100.

[0022] When the nut 101 is driven by an external force to move linearly along the axial direction, the nut 101 transmits force to the planetary rollers 107 through threaded engagement, causing the planetary rollers 107 to rotate. At the same time, the gear 109 on the planetary rollers 107, under the constraint of the internal gear ring 106, drives the planetary rollers 107 to revolve around the axis of the central screw 100. The rotation and revolution of the planetary rollers 107 work together, and through their threaded engagement with the central screw 100, the linear motion is converted into the rotational motion of the central screw 100. Throughout the transmission process, the central screw 100 and the planetary rollers 107, and the planetary rollers 107 and the nut 101, are all in line contact. Compared with the point contact of the ball screw, this contact method greatly increases the force-bearing area, thus giving it a stronger load-bearing capacity and higher structural rigidity.

[0023] All standard parts used in this application can be purchased from the market, and the specific connection methods of each part are all conventional methods such as riveting and welding that are mature in the existing technology, which will not be described in detail here.

[0024] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the protection scope of the present invention.

Claims

1. A planetary roller screw pair that is easy to manufacture, comprising a central screw (100), characterized in that: It also includes a nut (101), a cover plate (102), a mounting plate (103), a mounting groove (104), a first bearing (105), an internal gear ring (106), a planetary roller (107), a second bearing (108), and a gear (109). The mounting plate (103) is fixed on the cover plate (102), and the mounting groove (104) is opened on the mounting plate (103). Fasteners pass through the mounting groove (104) and are threadedly engaged with the nut (101) to realize the detachable connection between the cover plate (102) and the nut (101). The first bearing (105) is fixed inside the nut (101), the internal gear ring (106) is fixedly installed inside the first bearing (105), the planetary roller (107) is sleeved inside the cover plate (102) through the second bearing (108), the planetary roller (107) is threadedly engaged with the central lead screw (100) and the nut (101), and the gear (109) is fixed on the planetary roller (107) and engages with the internal gear ring (106), thereby restricting the axial displacement of the planetary roller (107).

2. The easily manufacturable planetary roller screw pair according to claim 1, characterized in that: The mounting plate (103) and the cover plate (102) are integrally formed.

3. The easily manufacturable planetary roller screw pair according to claim 2, characterized in that: The mounting plate (103) is evenly distributed along the outer circumference of the cover plate (102).

4. The easily manufacturable planetary roller screw pair according to claim 1, characterized in that: The inner tooth surface of the internal gear ring (106) meshes with the outer tooth surface of the gear (109).

5. The easily manufacturable planetary roller screw pair according to claim 1, characterized in that: Both ends of the planetary roller (107) are connected to the cover plate (102) via a second bearing (108).

6. The easily manufacturable planetary roller screw pair according to claim 1, characterized in that: The gear (109) is coaxially arranged with the planetary roller (107).

7. The easily manufacturable planetary roller screw pair according to claim 1, characterized in that: The planetary rollers (107) are provided in multiple ways, and the multiple planetary rollers (107) are evenly distributed circumferentially along the central lead screw (100). Each planetary roller (107) is equipped with multiple gears (109).

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