Cylindrical cage and ball screw

Abstract

The utility model discloses a cylindrical retainer, the cylindrical retainer is arranged between transmission shaft and nut, the cylindrical retainer has the accommodating hole for setting ball, the circumferential direction of accommodating hole is equipped with the camber that projects along the radial direction of accommodating hole outward, the clearance for remaining lubricating oil film is formed between the camber and the outer wall of ball, the both ends of cylindrical retainer are equipped with the incomplete thread along the circumferential direction, and the incomplete thread is cooperated with the channel thread of transmission shaft to assemble cylindrical retainer. The utility model discloses cylindrical retainer and ball screw, utilize the cylindrical retainer with the guide structure to accommodate ball, can reduce the friction between ball, reduce the noise in the working process, and the convenient installation and replacement.

Description

Technical Field

[0001] This utility model relates to the field of transmission structure technology, specifically to ball screws, and more particularly to a cylindrical cage and a ball screw. Background Technology

[0002] Miniature bushing guide assemblies are suitable for high-precision CNC machine tools, industrial robots, and other high-precision equipment, meeting the requirements for high precision and high performance. Existing miniature bushing guide assemblies consist of inner and outer sleeves, balls, and a cage. The inner and outer sleeves lack helical grooves; the balls only roll when external force is applied to the guide assembly. The contact between the balls and the inner and outer sleeves is at two points, limiting their load-bearing capacity and making them unsuitable for high-speed, high-temperature, and high-pressure environments.

[0003] A conventional ball screw consists of a screw, nut, balls, and a reversing mechanism. To ensure the balls can smoothly return to the raceway via the reversing mechanism, the structure and precision requirements for the reversing mechanism are high. This makes the manufacturing of the reversing mechanism difficult, which is detrimental to improving product production and assembly efficiency. Due to its structure, existing ball screws cannot be miniaturized, failing to meet the demand for miniaturized ball screws in high-precision equipment. Utility Model Content

[0004] The technical problem to be solved by this utility model is: in order to solve the technical problem that ball screws cannot be miniaturized in the prior art, this utility model provides a cylindrical cage and a ball screw. The cylindrical cage with a guide structure is used to accommodate the balls, which can reduce the friction between the balls, reduce the noise during operation, and facilitate installation and replacement.

[0005] The technical solution adopted by this utility model to solve its technical problem is: a cylindrical retainer, wherein the cylindrical retainer is disposed between the drive shaft and the nut, the cylindrical retainer has a receiving hole for holding balls, the receiving hole has an arc surface that protrudes radially outward in the circumferential direction, the arc surface and the outer wall of the ball form a gap for retaining a lubricating oil film, and the two ends of the cylindrical retainer are provided with incomplete threads in the circumferential direction, the incomplete threads are engaged with the groove threads of the drive shaft to assemble the cylindrical retainer.

[0006] This utility model features a cylindrical cage that uses holes to keep the balls moving in the grooves. A lubricating oil film can be retained between the arc surface and the balls, which can reduce the friction between the balls and reduce the noise generated by the balls during operation. The cylindrical cage can be quickly assembled with the incomplete thread, and the connection strength of the cylindrical cage can be improved.

[0007] Furthermore, in order to achieve higher precision linear motion and positioning control, the plurality of receiving holes are evenly spaced along the spiral trajectory of the drive shaft groove.

[0008] Furthermore, in order to achieve lubrication and positioning of the balls, the radius of the arc surface is larger than the radius of the balls.

[0009] Furthermore, to further ensure the lubrication effect, the arc surfaces are symmetrically formed on the left and right sides of the receiving hole.

[0010] Furthermore, in order to ensure the connection strength of the cylindrical cage, the incomplete thread starts in the non-receiving hole area of ​​the cylindrical cage and is adjacent to the outermost receiving hole of the cylindrical cage.

[0011] Furthermore, to further stabilize the cylindrical cage connection, the incomplete thread is offset in the circumferential direction.

[0012] Furthermore, in order to separate the balls, the cylindrical cage is provided with a segment protruding from the side wall of the cylindrical cage, the segment being connected between two adjacent receiving holes to separate the balls.

[0013] The technical solution adopted by this utility model to solve its technical problem is a ball screw, wherein the above-mentioned cylindrical retainer is provided between the nut and the transmission shaft, and the two ends of the transmission shaft are connected with baffles for limiting the axial displacement of the cylindrical retainer.

[0014] Furthermore, to facilitate the assembly of the baffle, threaded holes are provided at both ends of the drive shaft, and the baffle is connected to the drive shaft through threaded connectors and threaded holes.

[0015] Furthermore, in order to effectively eliminate gaps and improve load capacity, the grooves of the drive shaft and nut are Gothic grooves.

[0016] Compared with the prior art, the beneficial effects of this utility model are: 1. The present invention relates to a cylindrical cage and a ball screw, which uses the equally spaced staggered holes of the cylindrical cage to install the balls, thereby maintaining the balls in the groove at equal intervals. A lubricating oil film can be retained between the arc surface and the balls, which can reduce the friction between the balls, reduce the noise generated by the balls during operation, and provide high-precision linear motion and positioning control.

[0017] 2. The cylindrical cage and ball screw of this utility model have an incomplete thread to enable quick assembly of the cylindrical cage and nut, which facilitates subsequent installation and replacement. In addition, the incomplete thread can also ensure the connection strength of the cylindrical cage and ensure stable operation.

[0018] 3. The cylindrical cage and ball screw of this utility model are equipped with baffles at both ends of the transmission shaft. The baffles restrict the cylindrical cage in the axial direction to prevent the cylindrical cage from slipping out.

[0019] 4. The cylindrical cage and ball screw of this utility model adopt Gothic grooves for the drive shaft and nut, forming four-point contact with the balls, which can effectively eliminate gaps, improve load capacity, and enhance the product's load-bearing capacity. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a schematic diagram of the cylindrical retainer of this utility model; Figure 2 for Figure 1 Side view; Figure 3 This is a cross-sectional view of a ball screw; Figure 4 for Figure 3 The exposed photo; Figure 5 This is a cross-sectional view of a cylindrical cage.

[0022] In the diagram: 1. Cylindrical cage, 11. Receiving hole, 12. Arc surface, 13. Segment, 14. Incomplete thread, 15. Area without receiving hole, 2. Ball, 3. Nut, 4. Drive shaft, 41. Threaded hole, 42. Groove, 5. Baffle, 6. Threaded connector. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0024] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] Example 1, as Figure 1 and Figure 2 As shown, a cylindrical retainer 1 is disposed between the drive shaft 4 and the nut 3.

[0027] Specifically, the cylindrical cage 1 has receiving holes 11 for housing the balls 2. The receiving holes 11 are evenly spaced along the helical trajectory of the groove 42 of the drive shaft 4. Because the receiving holes 11 are arranged in an equally spaced and staggered manner, the balls 2 can be kept running at equal intervals on the drive shaft 4.

[0028] Preferably, the receiving hole 11 has a circumferentially circumferentially provided arc surface 12 that protrudes radially outward along the receiving hole 11, and a gap is formed between the arc surface 12 and the outer wall of the ball 2 for retaining a lubricating oil film. The arc surface 12 has two functions. First, it can limit the ball 2 to prevent the ball 2 from falling out of the receiving hole 11. Second, after the cylindrical cage 1 is assembled and sealed with lubricating oil, a certain amount of lubricating oil film can be retained between the arc surface 12 and the ball 2, reducing the friction between the ball 2 and the cage, and improving the service life and reliability.

[0029] Preferably, the arc surfaces 12 are symmetrically formed on the left and right sides of the receiving hole 11. The arc surfaces 12 on the left and right sides can effectively limit the movement of the ball 2. At the same time, the radius of the arc surface 12 must be larger than the radius of the ball 2, such as... Figure 5 As shown, the gap between the ball 2 and the arc surface 12 can retain a sufficient lubricating oil film to ensure the lubrication effect.

[0030] Specifically, the cylindrical cage 1 has incomplete threads 14 at both ends along the circumference. The incomplete threads 14 engage with the grooves 42 of the drive shaft 4 to assemble the cylindrical cage 1. During assembly, the incomplete threads 14 are directly screwed into the grooves 42 of the drive shaft 4, making assembly very convenient. At the same time, the incomplete threads 14 can also provide support for the cylindrical cage 1, ensuring the structural strength of the cylindrical cage 1 and the connection strength between the cylindrical cage 1 and the drive shaft 4, thereby improving stability.

[0031] Preferably, the incomplete thread 14 is offset circumferentially. Since a complete receiving hole needs to be cut out in the cylindrical cage, the incomplete thread 14 begins in the area where a complete receiving hole cannot be cut out, i.e., the area without a receiving hole 15, and ends at the first receiving hole 11 of the cylindrical cage 1. The length of the incomplete thread needs to take into account both the lead angle and the number of steel balls it carries.

[0032] In Embodiment 2, based on Embodiment 1, the cylindrical cage 1 is further provided with a segment 13 protruding from the side wall of the cylindrical cage 1. The segment 13 connects between two adjacent receiving holes 11 to separate the balls. The segment 13 protrudes relative to the side of the cylindrical cage 1, thus forming a blocking structure for the balls, confining the balls inside the receiving holes 11, preventing the balls from falling out, and effectively separating the balls.

[0033] Example 3, as Figure 3 and Figure 4 As shown, a ball screw has a cylindrical cage 1 between the nut 3 and the drive shaft 4, as described above. Both ends of the drive shaft 4 are connected to baffles 5 to limit the axial displacement of the cylindrical cage 1. When the balls and the cylindrical cage 1 reciprocate on the drive shaft 4, the baffles 5 can axially limit the cylindrical cage 1, preventing it from slipping out.

[0034] Specifically, threaded holes 41 are provided at both ends of the drive shaft 4, and the baffle 5 is connected to the drive shaft 4 through threaded connectors 6 and threaded holes 41. The baffle 5 is placed at both ends of the drive shaft 4 and fixed by screws and threaded holes 41. Of course, in other embodiments, the baffle 5 and screws can be set as an integral structure, and the assembly of the baffle 5 can also be achieved by directly threading the baffle 5 to the threaded holes 41.

[0035] In Example 4, based on Example 3, the groove 42 of the drive shaft 4 and the nut 3 is a Gothic groove. The ball and the Gothic groove can form a four-point contact, which changes the two-point contact to a four-point contact compared to the miniature bushing guide assembly. This can effectively eliminate gaps, provide higher precision guidance, improve load capacity, and enhance the product's load-bearing capacity.

[0036] Compared with standard ball screws, the ball screw in this embodiment adopts a non-circulating structure, which can still complete reciprocating motion without the need for a circulator, making it particularly suitable for scenarios that require miniature ball screws.

[0037] In summary, the cylindrical cage and ball screw of this invention utilize a cylindrical cage with a guiding structure to accommodate the balls, which can reduce friction between the balls, reduce noise during operation, and facilitate installation and replacement.

[0038] The above description is based on the preferred embodiments of this utility model. Through the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined by the scope of the claims.

Claims

1. A cylindrical retainer, said cylindrical retainer (1) being disposed between a drive shaft (4) and a nut (3), characterized in that, The cylindrical cage (1) has a receiving hole (11) for setting the ball (2). The receiving hole (11) has an arc surface (12) that protrudes radially outward along the circumferential direction. The arc surface (12) and the outer wall of the ball (2) form a gap for retaining a lubricating oil film. The two ends of the cylindrical cage (1) are provided with incomplete threads (14) along the circumferential direction. The incomplete threads (14) are threaded with the groove (42) of the drive shaft (4) to assemble the cylindrical cage (1).

2. The cylindrical retainer according to claim 1, characterized in that, The plurality of receiving holes (11) are evenly spaced along the spiral trajectory of the channel (42) of the drive shaft (4).

3. The cylindrical retainer according to claim 1, characterized in that, The radius of the arc surface (12) is greater than the radius of the ball (2).

4. The cylindrical retainer according to claim 3, characterized in that, The arc surface (12) is symmetrically opened on the left and right sides of the receiving hole (11).

5. The cylindrical retainer according to claim 1, characterized in that, The incomplete thread (14) begins in the non-receiving hole area of ​​the cylindrical retainer (1) and is adjacent to the outermost receiving hole (11) of the cylindrical retainer (1).

6. The cylindrical retainer according to claim 5, characterized in that, The incomplete thread (14) is offset in the circumferential direction.

7. The cylindrical retainer according to claim 1, characterized in that, The cylindrical retainer (1) is further provided with a segment (13) protruding from the side wall of the cylindrical retainer (1), the segment (13) being connected between two adjacent receiving holes (11) to divide the balls (2).

8. A ball screw, characterized in that, It includes a nut (3) and a drive shaft (4), and a cylindrical retainer (1) as described in any one of claims 1-7 is provided between the nut (3) and the drive shaft (4). Both ends of the drive shaft (4) are connected to baffles (5) for limiting the axial displacement of the cylindrical retainer (1).

9. The ball screw according to claim 8, characterized in that, The drive shaft (4) has threaded holes (41) at both ends, and the baffle (5) is connected to the drive shaft (4) through the threaded connector (6) and the threaded holes (41).

10. The ball screw according to claim 8, characterized in that, The grooves (42) of the drive shaft (4) and nut (3) are Gothic grooves.

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