Reciprocating roller type linear torque transmission bearing

Abstract

The application discloses a reciprocating roller type linear torque transmission bearing, which comprises an inner shaft, a retainer and an outer ring coaxially sleeved; the outer surface of the inner shaft and the inner surface of the outer ring are both rolling surface, the rolling surface comprises a planar rolling surface section and a circular arc surface rolling surface section which axially extend along the inner shaft; the retainer is located between the inner shaft and the outer ring, and the cross-sectional shape of the retainer is matched with the rolling surface of the inner shaft and the outer ring respectively; the rolling body is arranged in the rolling body pocket of the retainer, and the rolling body at least comprises a roller corresponding to the planar rolling surface section, the circumferential surface of the roller is in contact with the rolling surface of the inner shaft and the outer ring respectively, and the axis of the roller is perpendicular to the axis of the inner shaft; the axial length of the retainer is smaller than the axial length of the rolling surface of the outer ring, so that the retainer has an axial stroke in the outer ring. The reciprocating roller type linear torque transmission bearing can meet the requirements of torque transmission and linear motion at the same time, and has the performance advantages of high transmission accuracy, low friction, high bearing capacity and high space utilization.

Description

Technical Field

[0001] This utility model relates to the field of bearing technology, specifically to a reciprocating roller linear torque transmission bearing. Background Technology

[0002] In mechanical structures, parts that can simultaneously achieve torque transmission and linear motion typically need to meet the following two functions: (1) transmitting rotational power; (2) allowing axial relative motion. Among known mechanical structures, parts that can achieve the above functions include: splines (rectangular splines, involute splines, ball splines, helical splines), ball screws, and component-type mechanisms. Among them, rectangular splines and involute splines have the characteristics of high load-bearing capacity, but have shortcomings such as high sliding friction resistance, low precision, and poor flexibility; while ball splines, helical splines, and ball screws have the characteristics of low friction and high precision, but have shortcomings such as low load-bearing capacity, high processing difficulty, and large space occupation. Utility Model Content

[0003] The purpose of this invention is to propose a reciprocating roller linear torque transmission bearing that can simultaneously meet the requirements of torque transmission and linear motion, while integrating the performance advantages of high transmission accuracy, low friction, high load capacity and high space utilization.

[0004] The technical solution adopted by this utility model is: a reciprocating roller linear torsion bearing, including an inner shaft, a cage and an outer ring coaxially sleeved; the outer surface of the inner shaft and the inner surface of the outer ring are both raceway surfaces, and the raceway surfaces include a planar raceway section extending axially along the inner shaft and an arc-shaped raceway section. The cage is located between the inner shaft and the outer ring, and the cross-sectional shape of the cage is adapted to the raceway surfaces of the inner shaft and the outer ring, respectively; The cage has rolling elements in the rolling element pocket. The rolling elements include at least rollers corresponding to the planar raceway section. The circumferential surface of the rollers contacts the raceway surfaces of the inner shaft and the outer ring, respectively, and the axis of the rollers is perpendicular to the axis of the inner shaft. The axial length of the cage is less than the axial length of the raceway surface of the outer ring, so that the cage has axial travel within the outer ring, and the end of the outer ring is provided with a stop to restrict the axial disengagement of the cage.

[0005] As a preferred option, the rolling elements corresponding to the arc-shaped raceway section are rollers or steel balls.

[0006] As a preferred embodiment, the stop member includes retaining rings and shoulders located at both ends of the outer ring, and the corresponding ends of the outer ring are provided with retaining grooves for installing the retaining rings.

[0007] As a preferred embodiment, both ends of the inner shaft extend to the outer side of the outer ring.

[0008] As a preferred option, the outer surface of the outer ring is provided with a transmission keyway.

[0009] As a preferred option, the two ends of the roller circumference have shaping sections.

[0010] As a preferred option, the shaping curve of the shaping segment is an eccentric circular arc or a logarithmic spiral curve.

[0011] As a preferred embodiment, the axial length L1 of the outer ring raceway surface, the axial length L2 of the cage, and the bearing stroke T satisfy the following relationship: L1-L2=mT, where 1≤m≤2.

[0012] As a preferred option, the cage is fitted with the raceway surfaces of the inner shaft and the outer ring with clearance.

[0013] As a preferred option, the rolling elements on the cage are fitted with the rolling element pockets with clearance. The rolling elements on the cage have small clearance or transition fits with the inner shaft and outer ring, respectively.

[0014] Compared with the prior art, the beneficial effects of this utility model are: 1. This reciprocating roller linear torque bearing can withstand radial loads and torque loads in two directions. It can transmit torque between the inner shaft and the outer ring, and at the same time, they can perform linear motion relative to each other. 2. Torque transmission is achieved by using rollers. The raceway surfaces of the inner shaft and outer ring are flat, eliminating the need for ball grooves on the inner shaft and outer ring, reducing the machining accuracy of the inner shaft and outer ring. At the same time, since there is no need to design grooves, the inner shaft and outer ring can be designed as thin-walled structures, increasing the roller size and thus increasing the bearing load capacity. 3. The cage can maintain movement within its stroke range, thereby reducing cage wear. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a partial cross-sectional view of the present invention; Figure 2 This is a schematic cross-sectional view of the present invention; Figure 3 This is a schematic diagram of the cage in this utility model; Figure 4 This is a schematic diagram showing the fit between the rollers and the cage in this utility model; Figure 5 This is a schematic diagram showing the fit between the steel ball and the cage in this utility model; Figure 6 This is a schematic diagram of the retaining ring in this utility model; Figure 7 This is a side view of the roller in this utility model.

[0017] Reference numerals: 1. Inner shaft, 101. Flat raceway section, 102. Arc raceway section, 2. Outer ring, 3. Cage, 301. Steel ball pocket, 302. Roller pocket, 4. Roller, 401. Shaped section, 5. Steel ball, 6. Snap ring, 7. Shoulder, 8. Transmission keyway. Detailed Implementation

[0018] The present invention will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0019] It should be noted that, unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "a," "an," or "the," etc., used in this utility model patent application specification and claims do not express a quantity limitation, but rather indicate the presence of at least one; the terms "first," "second," and "third," as used herein, should not be considered as a limitation on the order of components, but are merely for distinguishing different components; the terms "comprising" or "including," etc., indicate that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects having the same function.

[0020] To more clearly describe the specific structural composition of this reciprocating roller linear torsion bearing, in conjunction with the attached... Figure 1-7 This embodiment is described as follows: like Figure 1-7 As shown, a reciprocating roller linear torsion bearing includes an inner shaft 1, a cage 3, and an outer ring 2 coaxially mounted, i.e., the three are arranged coaxially; both ends of the inner shaft 1 extend to the outer side of the end of the outer ring 2, and the outer surface of the inner shaft 1 and the inner surface of the outer ring 2 are both raceway surfaces, which include a planar raceway section extending axially along the inner shaft 1 and a circular arc raceway section; the cage 3 is located between the inner shaft 1 and the outer ring 2, and the cross-sectional shape of the cage 3 is adapted to the raceway surfaces of the inner shaft 1 and the outer ring 2 respectively; The rolling element pocket of the cage 3 is provided with rolling elements. The rolling elements include at least rollers 4 corresponding to the planar raceway section, and also rollers 4 or steel balls 5 corresponding to the arc raceway section. The circumferential surface of the rollers 4 contacts the raceway surfaces of the inner shaft 1 and the outer ring 2 respectively, and the axis of the rollers 4 is perpendicular to the axis of the inner shaft 1. The axial length of the cage 3 is less than the axial length of the raceway surface of the outer ring 2, so that the cage 3 has axial travel within the outer ring 2. The end of the outer ring 2 is provided with a stop to restrict the axial disengagement of the cage 3.

[0021] See Figure 2 It shows the planar raceway section 101 and the arc-shaped raceway section 102 of the inner shaft 1. The two raceway sections are staggered and symmetrical in the circumferential direction of the inner shaft 1. In a specific embodiment, two rows of rollers are used to bear the torque in the planar raceway section and two rows of steel balls are used for support in the arc-shaped raceway section, which can reduce the friction of the bearing. Furthermore, according to the magnitude of the torque transmission and the friction requirements, the arc-shaped raceway section and the corresponding steel balls can be replaced with the planar raceway section and the rollers, respectively.

[0022] A transmission keyway 8 is provided on the outer surface of the outer ring 2. Specifically, the transmission keyway 8 can be a flat keyway. When torque is applied to the inner shaft 1 and it moves linearly, the torque is transmitted to the outer ring 2 through the roller 4, and the torque is output by the outer ring 2 through the flat key.

[0023] See Figure 3-5 The cage 3 is made of copper or steel. The cage 3 is provided with rolling element pockets, which are divided into steel ball pockets 301 and roller pockets 302. The pockets have inner pockets and outer locking openings. After the rollers 4 or steel balls 5 are installed on the outside of the pockets, the outer locking openings are stamped to ensure that the steel balls 5 and rollers 4 will not separate, which facilitates installation and disassembly.

[0024] The cage 3 has a clearance fit with the raceway surfaces of the inner shaft 1 and the outer ring 2; the rolling elements on the cage 3 have a clearance fit with the rolling element pockets in which they are located; the rolling elements on the cage 3 have a small clearance fit with the inner shaft 1 and the outer ring 2, respectively.

[0025] See Figure 7 In one specific embodiment, a modified section 401 is designed at both ends of the circumferential surface of the roller 4 to prevent stress concentration at both ends of the roller 4 during torque transmission, thereby improving the bearing capacity and service life of the bearing; specifically, the modified curve of the modified section 401 is designed according to the requirements, and can be an eccentric circular arc or a logarithmic spiral curve.

[0026] See Figure 1In one specific embodiment, the stop includes a retaining ring 6 and a shoulder 7 located at both ends of the outer ring 2. The corresponding ends of the outer ring 2 are provided with a groove for installing the retaining ring 6. The retaining ring 6 is a single-layer earless retaining ring. The inner diameter of the retaining ring 6 is larger than the outer diameter of the inner shaft 1. The inner side of the retaining ring 6 is provided with a groove to facilitate its disassembly. After the retainer 3 is inserted into the outer ring 2 from one side of the retaining ring 6, the retaining ring 6 is installed in the groove. The retaining ring 6 and the shoulder 7 respectively limit the two ends of the retainer 3 to prevent the retainer 3 from falling out.

[0027] The cage 3 has a bearing stroke due to the constraint of the retaining ring 6 and the shoulder 7. Specifically, the axial length L1 of the raceway surface of the outer ring 2, the axial length L2 of the cage 3, and the bearing stroke T satisfy the following relationship: L1-L2=mT, where m is a coefficient, 1≤m≤2. Driven by friction, the cage 3, rollers 4, and steel balls 5 move linearly along the direction of the inner shaft. After the inner shaft reaches the specified stroke, since the difference between the width of the inner raceway surface of the outer ring 2 and the width of the cage 3 is equal to twice the bearing stroke, the cage 3 can maintain movement within the stroke range, thereby reducing the wear of the cage 3 and improving the service life of the bearing.

[0028] The parts not described in detail in the above embodiments are existing technologies.

[0029] It should be noted that although the present invention has been described through the above embodiments, there may be other various embodiments of the present invention. Without departing from the spirit and scope of the present invention, those skilled in the art can obviously make various corresponding changes and modifications to the present invention, but all such changes and modifications should fall within the scope of protection of the appended claims and their equivalents.

Claims

1. A reciprocating roller linear torsion bearing, characterized in that: It includes an inner shaft (1), a cage (3), and an outer ring (2) that are coaxially fitted together; The outer surface of the inner shaft (1) and the inner surface of the outer ring (2) are both raceway surfaces. The raceway surfaces include a planar raceway section extending axially along the inner shaft (1) and a circular arc raceway section. The cage (3) is located between the inner shaft (1) and the outer ring (2), and the cross-sectional shape of the cage (3) is adapted to the raceway surfaces of the inner shaft (1) and the outer ring (2), respectively; The rolling element pocket of the cage (3) is provided with rolling elements, and the rolling elements include at least rollers (4) corresponding to the planar raceway section. The circumferential surface of the rollers (4) is in contact with the raceway surfaces of the inner shaft (1) and the outer ring (2) respectively, and the axis of the rollers (4) is perpendicular to the axis of the inner shaft (1). The axial length of the cage (3) is less than the axial length of the raceway surface of the outer ring (2), so that the cage (3) has axial travel within the outer ring (2), and the end of the outer ring (2) is provided with a stop to restrict the axial disengagement of the cage (3).

2. The reciprocating roller linear torsion bearing according to claim 1, characterized in that: The rolling elements corresponding to the arc-shaped raceway section are rollers (4) or steel balls (5).

3. The reciprocating roller linear torsion bearing according to claim 1, characterized in that: The stop includes a retaining ring (6) and a shoulder (7) located at both ends of the outer ring (2), and the corresponding ends of the outer ring (2) are provided with a groove for installing the retaining ring (6).

4. A reciprocating roller linear torque transmission bearing according to claim 1, characterized in that: Both ends of the inner shaft (1) extend to the outer side of the end of the outer ring (2).

5. A reciprocating roller linear torque transmission bearing according to claim 1, characterized in that: The outer surface of the outer ring (2) is provided with a transmission keyway (8).

6. A reciprocating roller linear torsion bearing according to claim 1, characterized in that: The roller (4) has a trimmed section (401) at both ends of its circumferential surface.

7. A reciprocating roller linear torsion bearing according to claim 6, characterized in that: The shaping curve of the shaping segment (401) is an eccentric circular arc or a logarithmic spiral curve.

8. A reciprocating roller linear torsion bearing according to claim 1, characterized in that: The axial length L1 of the raceway surface of the outer ring (2), the axial length L2 of the cage (3) and the bearing stroke T satisfy the following: L1-L2=mT, where 1≤m≤2.

9. A reciprocating roller linear torsion bearing according to claim 1, characterized in that: The cage (3) is clearance-fitted with the raceway surfaces of the inner shaft (1) and the outer ring (2).

10. A reciprocating roller linear torsion bearing according to claim 1, characterized in that: The rolling elements on the cage (3) are clearance-fitted with the rolling element pockets in which they are located; The rolling elements on the cage (3) have small clearance or transition fits with the inner shaft (1) and the outer ring (2), respectively.

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