Anti-backlash transmission device for feeding of grinding machine

Abstract

The invention relates to the field of machine tool transmission, in particular to an anti-backlash transmission device for grinding machine feeding, which comprises a base, a workbench and a transmission lead screw, an anti-backlash mechanism is connected between the transmission lead screw and the workbench, and the anti-backlash mechanism comprises a connecting sleeve seat, a lead screw nut fixedly mounted on the connecting sleeve seat and an anti-backlash nut movably mounted on the connecting sleeve seat; the connecting sleeve seat is fixedly mounted at the bottom of the workbench; the lead screw nut and the anti-backlash nut are both nested on the transmission lead screw; a spring is nested between the clearance eliminating nut and the lead screw nut or between the clearance eliminating nut and the connecting sleeve seat, and the spring provides elastic force for the clearance eliminating nut to be away from the lead screw nut. The anti-backlash nut and the lead screw nut are always opened on the transmission lead screw and keep a one-way approaching trend, so that the transmission gap between the transmission lead screw and the nut is effectively eliminated and compensated, and the stability and the repeated positioning precision are improved.

Description

Technical Field

[0001] This invention relates to the field of machine tool transmission, specifically a backlash-free transmission device for grinding machine feed. Background Technology

[0002] The feed transmission system of CNC machine tools usually adopts the form of servo motor + reducer + ball screw. During the machining process, due to the gap between the ball screw and the ball screw nut, the diameter of the machined parts cannot meet the high precision requirements.

[0003] From the perspective of mechanical transmission principles, there must be a gap as long as there is relative motion between two objects. The transmission accuracy of ball screw pairs is much higher than that of ordinary screw pairs, but it also has a certain gap. When the machine tool is grinding the workpiece or repeatedly feeding, the grinding state of the machine tool is not very stable and the repeated feed accuracy is poor due to the gap of the ball screw pair, resulting in low consistency of the workpiece grinding dimensions. Summary of the Invention

[0004] To address the above problems, the present invention provides a backlash-free transmission device for grinding machine feed.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a backlash-eliminating transmission device for grinding machine feed, comprising a base, a worktable slidably mounted on the base, and a transmission screw rotatably mounted within the base. A drive motor is fixedly mounted within the base to drive the transmission screw to rotate. A backlash-eliminating mechanism connects the transmission screw and the worktable, and the transmission screw converts its rotational motion into the translational motion of the worktable on the base through the backlash-eliminating mechanism. The backlash-eliminating mechanism includes a connecting sleeve, a screw nut fixedly mounted on the connecting sleeve, and a backlash-eliminating nut movably mounted on the connecting sleeve. The connecting sleeve is fixedly mounted on the bottom of the worktable. Both the screw nut and the backlash-eliminating nut are nested on the transmission screw. A spring is nested between the backlash-eliminating nut and the screw nut or the connecting sleeve, and the spring provides a spring force to the backlash-eliminating nut away from the screw nut.

[0006] Furthermore, the connecting sleeve has a through hole in the middle for the transmission screw to pass through, and the front end of the connecting sleeve has a movable hole with a diameter larger than the through hole. A top seat is slidably nested inside the movable hole. The top seat retains the degree of freedom to move along the axis of the transmission screw within the movable hole. The backlash-eliminating nut is fixed on the top seat, and the spring abuts against the top seat within the movable hole.

[0007] Furthermore, the top seat is clearance-fitted with the movable hole, and the movable hole is provided with a planar inner limiting step surface, which is parallel to the axis of the transmission screw. The top seat is provided with a planar outer limiting step surface, which fits against the inner limiting step surface to restrict the degree of freedom of rotation of the top seat within the movable hole.

[0008] Furthermore, the inner side of the top seat is provided with a number of slots spaced around it, and the gap-eliminating nut is provided with an annular recessed diameter reduction groove, in which a ratchet spring is engaged; the ratchet spring is strip-shaped, and an arc-shaped connecting ring is connected to the root of the ratchet spring, the connecting ring is nested in the diameter reduction groove, and the head of the ratchet spring is used to abut against the diameter reduction groove.

[0009] Furthermore, the backlash-free nut on the transmission screw has a tendency to move closer to and away from the screw nut by rotation, and the ratchet spring is used to restrict the degree of freedom of the backlash-free nut to rotate away from the screw nut on the transmission screw in the reduced diameter groove.

[0010] Furthermore, the head of the ratchet spring faces the opposite direction to the rotational motion of the backlash-free nut as it moves closer to the lead screw nut on the transmission screw.

[0011] Furthermore, an annular recessed pry slot is provided on the side where the top seat and the gap-eliminating nut fit together.

[0012] Furthermore, the top seat is provided with threaded locking holes around its perimeter, and the gap-eliminating nut is provided with bolt through holes around its perimeter. The gap-eliminating nut is locked and fixed to the threaded locking holes of the top seat by passing a bolt through the bolt through holes.

[0013] Furthermore, an operating boss is provided on the outer side of the gap-eliminating nut, and the operating boss is hexagonal prism shaped.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes the spring force of a lead screw nut fixed on a connecting sleeve and a movable backlash-eliminating nut, which, in conjunction with the spring force of a spring, ensures that the backlash-eliminating nut and the lead screw nut are always spread apart on the transmission lead screw and maintain a unidirectional tendency to move closer together. This effectively eliminates and compensates for the transmission backlash between the transmission lead screw and the nut, improving stability and repeatability.

[0015] Furthermore, this invention utilizes a ratchet spring that automatically engages with the top seat groove during installation, allowing the backlash-free nut to be easily screwed into the compression spring and temporarily fixed during installation using its one-way locking characteristic. This achieves pre-installation similar to tightening a screw, followed by final fixing via bolt tightening, facilitating disassembly and maintenance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of a backlash-eliminating transmission device for grinding machine feed according to the present invention.

[0017] Figure 2 This is a side sectional view of the gap-eliminating mechanism of the present invention.

[0018] Figure 3 This is a three-dimensional structural schematic diagram of the gap-eliminating mechanism of the present invention.

[0019] Figure 4 This is a front cross-sectional schematic diagram of the backlash-free nut and the top seat of the present invention being engaged by a ratchet spring.

[0020] In the diagram: 1. Base; 2. Worktable; 3. Lead screw; 4. Drive motor; 5. Backlash elimination mechanism; 11. Bearing; 12. Slide rail; 13. Slider; 51. Lead screw nut; 52. Connecting sleeve; 53. Backlash-free nut; 54. Top seat; 55. Spring; 521. Movable hole; 522. Inner limiting step surface; 531. Operating boss; 532. Reduction groove; 533. Ratchet spring; 534. Connecting ring bar; 541. Outer limiting step surface; 542. Slot; 543. Threaded lock hole; 544. Prying aid slot. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Examples, such as Figures 1-4 As shown: This invention provides a backlash-eliminating transmission device for grinding machine feed, including a base 1, a worktable 2 slidably mounted on the base 1, and a transmission screw 3 rotatably mounted inside the base 1. A slide rail 12 is fixedly mounted on the base 1, and a slider 13 is fixedly mounted on the bottom of the worktable 2. The slider 13 is slidably nested on the slide rail 12, thereby allowing the worktable 2 to slide on the base 1. Bearings 11 are provided on both sides of the base 1, and the two ends of the transmission screw 3 are nested in the bearings 11, thereby rotating inside the base 1. A drive motor 4 is fixedly mounted inside the base 1, and the drive motor 4 is connected to the transmission screw 3 through a coupling to drive the transmission screw 3 to rotate. A backlash-eliminating mechanism 5 is connected between the transmission screw 3 and the worktable 2, and the transmission screw 3 converts its rotational motion into the translational motion of the worktable 2 on the base 1 through the backlash-eliminating mechanism 5.

[0023] The backlash elimination mechanism 5 includes a connecting sleeve 52, a lead screw nut 51 fixedly installed on the connecting sleeve 52, and a backlash elimination nut 53 movably installed on the connecting sleeve 52. The connecting sleeve 52 is fixedly installed at the bottom of the workbench 2. The connecting sleeve 52 has a through hole in the middle for the transmission lead screw 3 to pass through. The lead screw nut 51 and the backlash elimination nut 53 are both nested on the transmission lead screw 3. The top seat 54 has a through hole in the middle for the backlash elimination nut 53 to pass through. The top seat 54 has threaded locking holes 543 around its perimeter. The backlash elimination nut 53 has bolt through holes around its perimeter. The backlash elimination nut 53 is locked and fixed with the threaded locking holes 543 of the top seat 54 by passing a bolt through the bolt through hole. A spring 55 is nested between the backlash-eliminating nut 53 and the lead screw nut 51 or the connecting sleeve 52. The front end of the connecting sleeve 52 has a movable hole 521 with a diameter larger than the through hole. A top seat 54 is slidably nested inside the movable hole 521. The backlash-eliminating nut 53 is fixed on the top seat 54. The spring 55 abuts against the top seat 54 inside the movable hole 521. The spring 55 provides the backlash-eliminating nut 53 with a spring force away from the lead screw nut 51, thereby spreading the backlash-eliminating nut 53 and the lead screw nut 51 on the transmission lead screw 3. This ensures that when the two nuts move, there is always a force that moves towards one side. This relatively reduces the transmission backlash between the transmission lead screw and the nut, and improves the feeding accuracy of the feeding mechanism.

[0024] It should be noted that the top seat 54 is clearance-fitted with the movable hole 521. The movable hole 521 is provided with a planar inner limiting step surface 522, which is parallel to the axis of the transmission screw 3. The top seat 54 is provided with a planar outer limiting step surface 541. The outer limiting step surface 541 fits against the inner limiting step surface 522 to restrict the degree of freedom of rotation of the top seat 54 in the movable hole 521, so that the top seat 54 retains only the degree of freedom to move along the axis of the transmission screw 3 in the movable hole 521.

[0025] In this embodiment, in addition, the inner side of the top seat 54 is provided with a number of slots 542 at intervals, and the gap-free nut 53 is provided with an annular recessed diameter reduction groove 532. A ratchet spring 533 is engaged in the diameter reduction groove 532. Furthermore, the ratchet spring 533 is strip-shaped, and an arc-shaped connecting ring 534 is connected to the root of the ratchet spring 533. The connecting ring 534 is nested in the diameter reduction groove 532, and the head of the ratchet spring 533 is used to abut against the diameter reduction groove 532. It should be noted that, since the backlash-eliminating nut 53 has a tendency to move closer to and away from the lead screw nut 51 by rotating on the lead screw 3, that is, the backlash-eliminating nut 53 moves closer to and away from the lead screw nut 51 by rotating on the lead screw 3, the ratchet spring 533 is used on the reduced diameter groove 532 to restrict the degree of freedom of the backlash-eliminating nut 53 to move away from the lead screw nut 51 on the lead screw 3. Specifically, the head of the ratchet spring 533 faces the opposite direction to the direction of the rotational movement of the backlash-eliminating nut 53 to move closer to the lead screw nut 51 on the lead screw 3. For example, if the backlash-eliminating nut 53 moves closer to the lead screw nut 51 by rotating to the right on the lead screw 3, then the head of the ratchet spring 533 faces to the left, thereby abutting against the slot 542 on the left side to restrict the degree of freedom of the backlash-eliminating nut 53 to rotate to the left.

[0026] In summary, during the specific implementation, the lead screw nut 51 is nested on the transmission lead screw 3, and then the connecting sleeve 52 is fitted onto the transmission lead screw 3, fixing the lead screw nut 51 onto the connecting sleeve 52. This completes the basic installation. Afterward, the spring 55 and the top block are sequentially fitted onto the transmission lead screw 3, with a portion of the top block engaging the movable hole 521. At this point, the backlash-eliminating nut 53 is installed. The backlash-eliminating nut 53 is nested on the transmission lead screw 3, rotating as it moves closer to the top block. After the backlash-eliminating nut 53 is embedded in the top block, the inclined portion of the ratchet spring 533 contacts the top block. As the backlash-eliminating nut 53 rotates further, the ratchet spring 533 is pressed against the inside of the slot 542 and holds the slot 542 in place. Then, the backlash-eliminating nut 53 continues to rotate, eliminating the backlash... As the nut 53 penetrates further, it gradually begins to compress the spring 55 along with the top block. The spring 55 provides the force for the top block and the backlash-free nut 53 to move outward. However, for the backlash-free nut 53 to move outward, it needs to rotate in the opposite direction on the transmission screw 3. The degree of freedom of rotation in the opposite direction is blocked by the ratchet spring 533, preventing the backlash-free nut 53 from disengaging outward. Thus, the backlash-free nut 53 can be easily installed onto the top block like a screw, and the spring 55 is compressed to reach its working state. Then, the bolt through hole of the backlash-free nut 53 is aligned with the threaded locking hole 543 of the top block and fixed by passing the bolt through. Since the contact between the backlash-free nut 53 and the top block is already fixed, it is no longer important whether the ratchet spring 533 is exactly aligned in the slot 542.

[0027] In this embodiment, an annular recessed pry slot 544 is provided on the side where the top seat 54 and the backlash-eliminating nut 53 fit together. This allows the top block to be pushed further inward by a tool inserted into the pry slot 544 during maintenance and disassembly of the backlash-eliminating nut 53, thereby disengaging the slot 542 from the ratchet spring 533 and facilitating the removal of the backlash-eliminating nut 53.

[0028] In this embodiment, an operating boss 531 is provided on the outer side of the backlash-eliminating nut 53. The operating boss 531 is hexagonal prism-shaped, which makes it easy to use a wrench to rotate the backlash-eliminating nut 53 on the top block, thereby reducing the workload of overcoming the elastic force of the spring 55 by using tools.

[0029] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A backlash-free transmission for a grinding machine feed, characterized by: The utility model provides a workbench, including base (1), workbench (2) of sliding installation on base (1) and rotation installation in base (1) transmission screw rod (3), fixedly install drive motor (4) in base (1) for driving transmission screw rod (3) to carry out rotation, be connected with the anti backlash mechanism (5) between transmission screw rod (3) and workbench (2), transmission screw rod (3) is converted through anti backlash mechanism (5) the rotation of itself into the translational motion of workbench (2) on base (1), The anti backlash mechanism (5) includes connecting sleeve (52), screw nut (51) of fixed installation on connecting sleeve (52) and movable installation anti backlash nut (53) on connecting sleeve (52), connecting sleeve (52) is fixedly installed on the bottom of workbench (2), and the screw nut (51) and anti backlash nut (53) are nested on transmission screw rod (3), The spring (55) is nested between the anti backlash nut (53) and the screw nut (51) or the connecting sleeve (52), and provides the elastic force of the anti backlash nut (53) away from the screw nut (51).

2. A backlash-free transmission for a grinding machine feed according to claim 1, characterized in that: The connecting sleeve (52) is provided with a through hole in the middle for the transmission screw rod (3) to pass through, and the front end of the connecting sleeve (52) is provided with a movable hole (521) with a diameter larger than the through hole, the inside of the movable hole (521) is slidably nested with a top seat (54), the top seat (54) retains the freedom of movement along the axis direction of the transmission screw rod (3) in the movable hole (521), the anti backlash nut (53) is fixed on the top seat (54), and the spring (55) abuts against the top seat (54) in the movable hole (521).

3. A backlash-free transmission for a grinding machine feed according to claim 2, characterized in that: The top seat (54) is in clearance fit with the movable hole (521), the movable hole (521) is provided with a planar inner limiting step surface (522), the inner limiting step surface (522) is parallel to the axis of the transmission screw rod (3), the top seat (54) is provided with a planar outer limiting step surface (541), the outer limiting step surface (541) is attached to the inner limiting step surface (522) to limit the freedom of rotation of the top seat (54) in the movable hole (521).

4. A backlash-free transmission for a grinding machine feed according to claim 2, characterized in that: The inside of the top seat (54) is surrounded and spaced apart by a plurality of clamping grooves (542), the anti backlash nut (53) is provided with a ring-shaped recessed reduced diameter groove (532), and the reduced diameter groove (532) is clamped with a ratchet spring leaf (533). The ratchet spring leaf (533) is in strip shape, the ratchet spring leaf (533) is connected with a circular arc-shaped connecting ring strip (534) at the root, the connecting ring strip (534) is nested in the reduced diameter groove (532), and the head of the ratchet spring leaf (533) is used to abut against the reduced diameter groove (532).

5. A backlash-free transmission for a grinding machine feed according to claim 4, characterized in that: The anti backlash nut (53) has a moving trend of approaching and moving away from the screw nut (51) on the transmission screw rod (3) by rotation, and the ratchet spring leaf (533) is used to limit the freedom of rotational movement of the anti backlash nut (53) away from the screw nut (51) on the transmission screw rod (3) in the reduced diameter groove (532).

6. A backlash-free transmission for a grinding machine feed according to claim 5, characterized in that: The head of the ratchet spring leaf (533) is opposite to the direction of the rotational movement of the anti-backlash nut (53) on the transmission screw (3) moving close to the screw nut (51).

7. A backlash-free transmission for a grinding machine feed according to claim 2, characterized in that: The side of the top base (54) and the anti-backlash nut (53) is provided with a ring-shaped concave pry seam (544).

8. A backlash-free transmission for a grinding machine feed according to claim 2, characterized in that: The top base (54) is provided with a threaded lock hole (543) around, the anti-backlash nut (53) is provided with a bolt through hole around, and the anti-backlash nut (53) is locked and fixed with the threaded lock hole (543) of the top base (54) by passing through the bolt in the bolt through hole.

9. A backlash-free transmission for a grinding machine feed according to claim 2, characterized in that: The outer side of the anti-backlash nut (53) is provided with an operation boss (531), and the operation boss (531) is in the shape of a hexagonal prism.

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