Lead offset prepressing ball screw nut

Abstract

The utility model discloses a lead offset prepressing ball screw nut which comprises a first nut and a second nut which are matched with a lead screw, and a piston guiding piece is arranged between the adjacent ends of the first nut and the second nut and used for providing guiding and buffering when the first nut and the second nut move relatively. A first connecting ring is arranged at the other end of the first nut, a second connecting ring is arranged at the other end of the second nut, and a plurality of prestressed springs are arranged between the first connecting ring and the second connecting ring and are uniformly distributed on the first connecting ring and the second connecting ring; and a protective sleeve is arranged outside the first nut and the second nut. According to the scheme, the guide piston piece is arranged between the double lead screw nuts, the guide effect is provided when axial movement is generated, and the lead screw nuts are prevented from inclining; the pre-stress spring provides pre-pressure between the double-screw nut and can help the ball screw to eliminate the back clearance.

Description

Technical Field

[0001] The utility model relates to the field of ball screw structures, and particularly relates to a lead offset preloaded ball screw nut. Background Art

[0002] Precision ball screws are an important transmission device. Due to their advantages such as high load capacity, high precision, and high speed, they are widely used in various mechanical equipment, such as numerical control machine tools, precision tool machines, industrial robots, electronic machinery, conveying machinery, the aerospace industry, and other industrial equipment and precision instruments such as actuators used in antennas and valve switching devices.

[0003] However, for precision ball screws, the axial force generated by external driving force and internal pre-pressure can cause two types of clearances between the screw and the ball screw nut. One is the positive clearance generated by the manufacturing clearance between the balls and the ball grooves, and the other is the clearance between the double-nut ball screw nuts. When the clearances accumulate to a certain extent, the transmission efficiency of the screw decreases, and the "out-of-step" phenomenon occurs, thus affecting normal operation. In traditional technologies, shims are used in double nuts. Due to the influence of the flatness of the shims and the perpendicularity of the nuts, the nuts are inclined, and the contact angle deviation occurs on the internal ball contact surface, thus affecting the rotation performance and reducing the precision of the lead period error. Summary of the Utility Model

[0004] In view of the above deficiencies of the prior art, the utility model provides a lead offset preloaded ball screw nut.

[0005] To achieve the above invention purpose, the technical solution adopted by the utility model is as follows:

[0006] Provide a lead offset preloaded ball screw nut, which includes a first nut and a second nut that cooperate with the screw rod. A piston guide is provided between one ends of the first nut and the second nut adjacent to each other, which is used to provide guidance and buffering when the first nut and the second nut move relative to each other. A first connection ring is provided at the other end of the first nut, and a second connection ring is provided at the other end of the second nut. A number of prestressed springs are provided between the first connection ring and the second connection ring, and the number of prestressed springs is evenly distributed on the first connection ring and the second connection ring; a protective sleeve is provided outside the first nut and the second nut.

[0007] Further, the piston guide includes a movable ring provided at the end of the first nut. A counterbore that cooperates with the movable ring is provided at the end of the second nut. The size of the counterbore is larger than the size of the threaded hole of the second nut. A step is formed at the bottom of the counterbore. The movable ring is slidably connected with the counterbore, and an elastic buffer ring is provided at the end of the movable ring, and the end of the buffer ring abuts against the step.

[0008] Further, the buffer ring is made of rubber.

[0009] Further, one end of the prestressed spring is fixed on the second connecting ring, and a connecting rod member is arranged at the other end, and the connecting rod member is fixed in a through hole arranged on the first connecting ring.

[0010] Further, the connecting rod member passes through a through hole arranged on the first connecting ring, and a threaded hole is arranged at the end of the connecting rod member, and a pin is threadedly connected in the threaded hole, and the pin is used for limiting the prestressed spring.

[0011] Further, the second connecting ring is fixed on the connecting disc, one end of the protective sleeve is connected to the connecting disc, and the first connecting ring is in clearance fit with the inner wall of the protective sleeve.

[0012] The beneficial effects of the present utility model are as follows: In this solution, a guiding piston member is arranged between the double lead screw nuts to provide a guiding function during axial movement, avoiding the inclination of the lead screw nuts. At the same time, the buffer ring provides buffering for the impact generated by the relative movement of the double lead screw nuts, which can effectively reduce the damage caused by the impact between the double lead screw nuts and increase the service life.

[0013] The prestressed spring provides a pre-pressure between the double lead screw nuts. When the ball screw is used improperly, resulting in an excessive axial clearance between the internal balls and the raceways, the prestressed spring starts to work. The prestressed spring has a rated preloading function, which can help the ball screw to eliminate the backlash (the clearance between the balls and the raceways), making the mechanical transmission accuracy between the lead screw nut and the lead screw more stable, and improving the rigidity of the mechanical transmission structure. When the preloading is too large, it will reduce the mechanical efficiency of the lead screw, and also cause problems such as temperature rise and reduced service life. At this time, the prestressed spring can expand automatically to both sides to adjust the pre-pressure to achieve an appropriate pre-pressure effect and avoid negative impacts on the lead screw. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the internal structure diagram of the lead screw nut with offset preloading for the lead.

[0015] Figure 2 It is the structure diagram of the piston guiding member between the first nut and the second nut.

[0016] Figure 3 It is the structure diagram of the buffer ring.

[0017] Among them, 1. Connecting disc, 2. Second connecting ring, 3. Second nut, 4. Prestressed spring, 5. First nut, 6. First connecting ring, 7. Protective sleeve, 8. Movable ring, 9. Buffer ring, 10. Counterbore, 11. Connecting rod member, 12. Pin. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The specific embodiments of the present utility model will be described below to facilitate those skilled in the art of this technology to understand the present utility model. However, it should be clear that the present utility model is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of this technology, as long as various changes are within the spirit and scope of the present utility model defined and determined by the appended claims, these changes are obvious, and all utility models created using the concept of the present utility model are within the scope of protection.

[0019] As Figures 1 - 3 shown, a lead offset preloaded ball screw nut includes a first nut 5 and a second nut 3 that cooperate with the screw rod. A piston guide is provided between one ends of the first nut 5 and the second nut 3, so that the ends of the first nut 5 and the second nut 3 are connected through the piston guide, which is used to provide guidance and buffering when the first nut 5 and the second nut 3 move relative to each other. A first connecting ring 6 is provided at the other end of the first nut 5, and a second connecting ring 2 is provided at the other end of the second nut 3. A number of prestressed springs 4 are provided between the first connecting ring 6 and the second connecting ring 2, and the number of prestressed springs 4 are evenly distributed on the first connecting ring 6 and the second connecting ring 2; A protective sleeve 7 is provided outside the first nut 5 and the second nut 3.

[0020] In this embodiment, the piston guide includes a movable ring 8 provided at the end of the first nut 5. A counterbore 10 that cooperates with the movable ring 8 is provided at the end of the second nut 3. The size of the counterbore 10 is larger than the size of the threaded hole of the second nut 3. The counterbore 10 extends inward from the end of the second nut, so that a step is formed at the bottom of the counterbore 10. The movable ring 8 is slidably connected with the counterbore 10 to achieve a sliding fit, and an elastic buffer ring 9 is provided at the end of the movable ring 8. The end of the buffer ring 9 abuts against the step, and the extrusion between the step and the buffer ring 9 achieves a buffering effect. Preferably, the buffer ring 9 is made of rubber material to provide a good buffering effect.

[0021] This solution provides a guiding function when axial movement occurs by providing a guiding piston between the double screw nuts, avoiding the inclination of the screw nut. At the same time, the buffer ring 9 provides buffering for the impact generated by the relative movement of the double screw nuts, which can effectively reduce the damage caused by the impact between the double screw nuts and increase the service life.

[0022] The prestressed spring 4 provides a pre-pressure between the double lead screws and nuts. When the ball screw is used improperly, resulting in an excessive axial clearance between the internal balls and the raceways, the prestressed spring 4 starts to work. The prestressed spring 4 has a rated preloading function, which can help the ball screw to eliminate backlash (the clearance between the balls and the raceways), making the mechanical transmission accuracy between the lead screw and nut more stable and increasing the rigidity of the mechanical transmission structure. When the preloading is too large, it will reduce the mechanical efficiency of the lead screw, cause temperature rise problems and shorten the service life. At this time, the prestressed spring 4 can expand automatically to both sides to adjust the pre-pressure, achieving an appropriate pre-pressure effect and avoiding negative impacts on the lead screw.

[0023] In this embodiment, one end of the prestressed spring 4 is fixed on the second connection ring 2, and a connecting rod member 11 is provided at the other end. The connecting rod member 11 is fixed in the through hole provided on the first connection ring 6. The connecting rod member 11 passes through the through hole provided on the first connection ring 6, and a threaded hole is provided at the end of the connecting rod member 11. A pin 12 is threadedly connected in the threaded hole, and the pin 12 is used to limit the stress spring. During the assembly process, it is convenient to assemble the prestressed spring 4, ensuring that the prestressed spring 4 is stably connected between the second connection ring 2 and the first connection.

[0024] In this embodiment, the second connection ring 2 is fixed on the connection disk 1. One end of the protective sleeve 7 is connected to the connection disk 1, and the first connection ring 6 has a clearance fit with the inner wall of the protective sleeve 7; the protective sleeve 7 is used to provide protection for the double lead screws and nuts and the prestressed spring 4.

Claims

1. A lead offset preloaded ball screw nut, characterized in that: It includes a first nut and a second nut that cooperate with the screw rod, a piston guide is arranged between the adjacent ends of the first nut and the second nut, which is used to provide guidance and buffering during the relative movement between the first nut and the second nut, a first connecting ring is arranged at the other end of the first nut, and a second connecting ring is arranged at the other end of the second nut, a plurality of prestressed springs are arranged between the first connecting ring and the second connecting ring, and the plurality of prestressed springs are evenly distributed on the first connecting ring and the second connecting ring; a protective cover is arranged outside the first nut and the second nut.

2. The lead offset preloaded ball screw nut according to claim 1, characterized in that: The piston guide includes a movable ring arranged at the end of the first nut, and a countersunk hole matching the movable ring is arranged at the end of the second nut. The size of the countersunk hole is larger than the size of the threaded hole of the second nut. A step is formed at the bottom of the countersunk hole. The movable ring is slidably connected to the countersunk hole, and an elastic buffer ring is arranged at the end of the movable ring, and the end of the buffer ring is against the step.

3. The lead offset preloaded ball screw nut according to claim 2, characterized in that: The buffer ring is made of rubber.

4. The lead offset preloaded ball screw nut according to claim 1, characterized in that: One end of the prestressed spring is fixed on the second connecting ring, and the other end is provided with a connecting rod, and the connecting rod is fixed in a through hole provided on the first connecting ring.

5. The lead offset preloaded ball screw nut according to claim 4, characterized in that: The connecting rod passes through a through hole provided on the first connecting ring, and a threaded hole is provided at the end of the connecting rod. A pin is threadedly connected in the threaded hole, and the pin is used to limit the stress spring.

6. The lead offset preloaded ball screw nut according to claim 1, characterized in that: The second connecting ring is fixed on the connecting disk, one end of the protective sleeve is connected to the connecting disk, and the first connecting ring is gap-matched with the inner wall of the protective sleeve.

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