Roller screw rod with built-in bearings

Abstract

The invention discloses a roller screw rod with a built-in bearing, and belongs to the field of screw rods. A first row of outer ring raceways are arranged on the inner side of the bearing outer ring and are in contact with the first row of rolling bodies; the first row of rolling bodies are in contact with the first row of inner ring raceways, and the first row of inner ring raceways are located on the outer surface of the planetary roller screw rod inner gear ring shaft; a second-row outer ring raceway is arranged on the inner side of the bearing outer ring and is in contact with a second-row rolling body; the second row of rolling bodies are in contact with the second row of inner ring raceways, and the second row of inner ring raceways are located on the outer surface of the planetary roller screw rod inner gear ring shaft; a lead screw through inner thread is integrated on the inner side of the planetary roller lead screw inner gear ring shaft and connected with a roller. Pin roller retainers are arranged on the side edges of the pin rollers; the planetary roller, the lead screw component and the bearing are integrally designed and manufactured, a cantilever supporting structure is adopted, components such as a coupler are reduced, and the size is further reduced.

Description

Technical Field

[0001] This application relates to the field of lead screws, and more specifically, to a roller lead screw with an integrated bearing. Background Technology

[0002] Planetary roller screws are precision transmission mechanisms that convert rotary motion into linear motion. Their core principle is the efficient and high-precision force transmission achieved through the rolling engagement of planetary rollers between the screw and nut. These characteristics make them widely used in CNC machine tools, industrial robots, aerospace, and medical devices.

[0003] However, existing technologies have the following problems: using reversible roller screws requires couplings and bearings, resulting in a lengthy and bulky device that does not align with the compact advantage of current robots. Furthermore, the lengthy device requires numerous tolerances and considerations, making installation inconvenient. Summary of the Invention

[0004] The summary section of this application is intended to provide a brief overview of the concepts, which will be described in detail in the detailed description section below. This summary section is not intended to identify key or essential features of the claimed technical solutions, nor is it intended to limit the scope of the claimed technical solutions.

[0005] To address the technical problems mentioned in the background section, some embodiments of this application provide a ball screw with an integrated bearing, comprising: a bearing outer ring; a first row of outer ring raceways on the inner side of the bearing outer ring, the first row of outer ring raceways contacting a first row of rolling elements; the first row of rolling elements contacting a first row of inner ring raceways, the first row of inner ring raceways located on the outer surface of the planetary ball screw internal gear ring shaft; a second row of outer ring raceways on the inner side of the bearing outer ring, the second row of outer ring raceways contacting a second row of rolling elements; the second row of rolling elements contacting a second row of inner ring raceways, the second row of inner ring raceways located on the outer surface of the planetary ball screw internal gear ring shaft; an integrated ball screw thread on the inner side of the planetary ball screw internal gear ring shaft, the ball screw thread being connected to a roller; a roller cage on the side of the roller; and the roller being connected to the ball screw.

[0006] Furthermore, The contact angle B formed by the straight line connecting the contact point between the rolling element and the raceway of the outer ring of the bearing and the raceway of the inner gear ring of the planetary roller screw, and the perpendicular line to the axis of the inner gear ring of the planetary roller screw, is 30±5°.

[0007] Furthermore, The lead screw is a stepped shaft, with a larger diameter on the left side and an external thread on the outer diameter surface. The thread length of the lead screw is the same as that of the roller thread.

[0008] Furthermore, The roller cage is interference-fitted with the lead screw, and the roller cage and the lead screw have a clearance through internal thread.

[0009] Furthermore, The rolling elements are evenly separated by a rolling element cage. There are seals on the left side of the first row of rolling elements and the right side of the second row of rolling elements. The seals are connected to the outer ring and the internal gear ring shaft of the planetary roller screw.

[0010] The beneficial effects of this application are as follows: the present invention integrates the planetary roller, lead screw components and bearings into a single design and manufacture, and adopts a cantilever support structure to reduce components such as couplings, thereby further reducing the volume; The present invention integrates the bearing inner ring raceway and the ball screw outer ring into one outer diameter surface. This allows the existing tools to machine the planetary ball screw internal gear ring shaft with only one clamping turning and grinding, without the need to change the reference surface, thus ensuring machining accuracy, measurement and matching assembly with small error. The present invention adopts an integrated ball bearing design with an internal contact angle of 30±5°. This contact angle allows the bearing to withstand a certain radial force while bearing a relatively large axial force. Compared with conventional bearing structures, it can significantly improve the axial load capacity of the entire device. The internal "o"-shaped arrangement with a contact angle of 30±5° enhances axial rigidity, and the support points of the overall rotor shaft are extended to both sides, improving the rotor's anti-overturning ability. This invention integrates two rows of rolling bearings into a single design and manufacture. Compared with conventional bearings, it can increase the storage space for grease inside the bearing, and fill the interior with a large amount of high-quality grease suitable for the working conditions, thus extending the lubrication life of the components. The present invention adopts a "V" seal structure on both sides of the rolling bearing, which is beneficial for protecting against external foreign objects and providing a more suitable axial displacement seal, which is beneficial for product assembly and greatly reduces the entry of external foreign objects into the screw cavity. Attached Figure Description

[0011] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application.

[0012] Furthermore, throughout the accompanying drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the elements are not necessarily drawn to scale.

[0013] In the attached diagram: Figure 1 This is a semi-sectional three-dimensional schematic diagram according to an embodiment of this application; Figure 2 This is a full sectional view according to an embodiment of this application; Figure 3 This is a schematic diagram of the internal contact angle portion of this application; Figure 4 yes Figure 2 A magnified structural diagram of point A in the middle.

[0014] Figure label: 1. Bearing outer ring; 2. First row of rolling elements; 3. Planetary roller screw internal gear ring shaft; 4. Roller; 5. Screw; 6. Roller cage; 7. Seal; 8. Roller element cage; 9. Second row of rolling elements; 101. First row of outer ring raceway; 102. Second row of outer ring raceway; 301. First row of inner ring raceway; 302. Second row of inner ring raceway; 303. Screw internal thread; 501. Screw external thread. Detailed Implementation

[0015] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0016] It should also be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other.

[0017] It should be noted that the concepts of "one" and "two" mentioned in this disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0018] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0019] This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] Example 1: Refer to Figures 1-4A planetary roller screw with an internal bearing includes: a bearing outer ring 1; a first row of outer ring raceways 101 on the inner side of the bearing outer ring 1, the first row of outer ring raceways 101 contacting a first row of rolling elements 2; the first row of rolling elements 2 contacting a first row of inner ring raceways 301, the first row of inner ring raceways 301 being located on the outer surface of the planetary roller screw internal gear ring shaft 3; a second row of outer ring raceways 102 on the inner side of the bearing outer ring 1, the second row of outer ring raceways 102 contacting a second row of rolling elements 15; the second row of rolling elements 15 contacting a second row of inner ring raceways 302, the first row of outer ring raceways 102 contacting a second row of rolling elements 15, ... first row of outer ring raceways 102 being located on the outer surface of the planetary roller screw internal gear ring shaft 301; a second row of outer ring raceways 102 on the inner side of the bearing outer ring 1, the second row of outer ring raceways 102 contacting a second row of rolling elements 15, the second row of rolling elements 15 contacting a second row of inner ring raceways 302, the first row of outer ring raceways 102 contacting a second row of rolling elements 15, the first row of outer ring raceways 102 being located on the outer surface of the planetary roller The two inner raceways 302 are located on the outer surface of the planetary roller screw internal gear ring shaft 3; the inner side of the planetary roller screw internal gear ring shaft 3 is integrated with a screw through thread 303, which is connected to the roller 4; the roller 4 has a roller retainer 6 on its side; the roller 4 is also threadedly connected to the screw 5; this application adopts a cantilever support structure, which can reduce the volume, increase the power density, and integrate the planetary roller screw structure and rolling bearing into one unit, cleverly reducing the volume of the entire device, and can also improve the coaxiality between the motor and the roller screw, and improve the screw accuracy.

[0021] The contact angle B formed by the straight line formed by the contact point between the rolling element 2 and the raceway of the outer ring 1 of the bearing and the raceway of the inner gear ring shaft 3 of the planetary roller screw and the perpendicular line to the axis of the inner gear ring shaft 3 of the planetary roller screw is 30°±5°.

[0022] The lead screw 5 is a stepped shaft. The left side of the lead screw 5 has a larger diameter and the outer diameter surface has an external thread 501. The thread length of the lead screw 5 is the same as that of the roller 4.

[0023] The roller retainer 6 is interference-fitted with the lead screw 5, and there is a gap between the roller retainer 6 and the inner thread 303 of the planetary roller lead screw internal gear ring shaft 3.

[0024] The rolling elements 2 are evenly separated by a rolling element cage 8. There are seals 7 on the left side of the first row of rolling elements 2 and the right side of the second row of rolling elements 9. The seals 7 are connected to the outer ring 1 and the internal gear ring shaft 3 of the planetary roller screw.

[0025] The above description is merely a selection of preferred embodiments of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of this disclosure.

Claims

1. A roller screw with a built-in bearing, comprising: The bearing outer ring (1) is characterized by: A roller screw with a built-in bearing also includes, The first row of outer ring raceways (101) is located inside the outer ring (1) of the bearing. The second row of outer ring raceways (102) is located inside the outer ring (1) of the bearing. The planetary roller screw internal gear ring shaft (3) is located in the inner cavity of the outer ring (1) of the bearing. The first inner raceway (301) is located on the outer surface of the planetary roller screw internal gear ring shaft (3); The second row of inner raceway (302) is located on the outer surface of the planetary roller screw inner gear ring shaft (3); The first row of rolling elements (2) is tactilely connected between the first row of outer raceway (101) and the first row of inner raceway (301); The second row of rolling elements (15) is tactilely connected between the second row of outer raceway (102) and the second row of inner raceway (302); The lead screw has a through internal thread (303), which is located inside the internal gear ring shaft (3) of the planetary roller lead screw. The roller (4) is provided with multiple threaded connections to the screw's through-core internal thread (303); A roller retainer (6) is rotatably connected to one side of the plurality of rollers (4); The lead screw (5) is rotatably connected to the roller cage (6). The planetary roller screw internal gear ring shaft (3) coincides with the axis of the bearing outer ring (1), and the roller (4) is threadedly connected to the screw (5).

2. The roller screw with built-in bearing according to claim 1, characterized in that: The contact angle B formed by the straight line formed by the contact point between the rolling element (2) and the raceway of the outer ring (1) of the bearing and the raceway of the inner gear shaft (3) of the planetary roller screw and the perpendicular line formed by the line perpendicular to the axis of the inner gear shaft (3) of the planetary roller screw is 30°±5°.

3. A roller screw with an internal bearing according to claim 1, characterized in that: The lead screw (5) is a stepped shaft, and the left side of the lead screw (5) has a larger diameter.

4. A roller screw with an internal bearing according to claim 3, characterized in that: The lead screw (5) has an external thread (501) on its left outer diameter surface that is threaded with the roller (4), and the length of the external thread (501) is the same as the length of the thread of the roller (4).

5. A roller screw with an internal bearing according to claim 1, characterized in that: The roller retainer (6) is interference-fitted with the lead screw (5).

6. A roller screw with an internal bearing according to claim 1, characterized in that: The roller retainer (6) has a clearance with the inner screw thread (303) of the planetary roller screw internal gear ring shaft (3).

7. A roller screw with an internal bearing according to claim 1, characterized in that: A roller screw with a built-in bearing also includes, A rolling element cage (8) is located between the rolling elements (2). The seal (7) is located on the left side of the first row of rolling elements (2) and on the right side of the second row of rolling elements (9). The seal (7) is in contact with the outer ring (1) and the planetary roller screw internal gear ring shaft (3), and the rolling element cage (8) evenly divides the rolling elements (2).

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