Anti-backlash structure of fixed shaft linear motor
By designing a gap-elimination structure including bearings, connectors, pretension springs, nuts and positioning sleeves, the problem of screws and nuts in fixed shaft linear motors is solved, and higher linear accuracy and lower cost of use is achieved.
Patent Information
- Application Number
- CN202421580174.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-04
- Publication Date
- 2025-04-18
- Estimated Expiration
- 2034-07-04
AI Technical Summary
The axial fit gap between the screw and the nut in a fixed shaft linear motor causes the linear accuracy to be affected, which cannot meet the special application environment where axial clearance is not allowed, increasing the customer's cost of use and the market competitiveness of the motor.
A gap-elimination structure is designed, including bearings, connectors, pre-tightening springs, nuts and positioning sleeves. The nut is topped by the pre-tightening springs to eliminate the gap between the internal thread of the nut and the external thread on the screw.
It effectively eliminates the axial clearance between the screw and the nut, improves the linear accuracy of the motor, meets the special application needs that do not allow the existence of axial clearance, reduces customer usage costs and improves the market competitiveness of the motor.
Smart Images
Figure CN222776061U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of motors, in particular to a backlash-eliminating structure of a fixed-axis linear motor. Background Art
[0002] The fixed-axis motor uses a screw and nut drive structure to directly convert the nut rotational motion into the screw linear motion, simplifying the conversion process from rotational motion to linear motion and simplifying the motor structure design. Due to its stable quality, small size, large thrust, and a variety of step length specifications to choose from, it is widely used in the market.
[0003] When the screw and nut inside the motor are driving, there will be a small axial clearance between the screw and the nut, which has a small impact on the linear accuracy of the motor. However, for special application environments where axial clearance is not allowed, this type of linear motor is not suitable. Customers need to use special mechanisms to eliminate the clearance between the motor screw and nut, which increases customer use costs, reduces motor market competitiveness, and restricts the market share of linear motors. Utility Model Content
[0004] The utility model provides a backlash elimination structure of a fixed-axis linear motor, which eliminates the matching gap between a screw rod and a nut.
[0005] The technical solutions to the above technical problems are as follows:
[0006] The anti-backlash structure of the fixed-axis linear motor includes a bearing that cooperates with the motor, and also includes a connector, a preload spring, a nut, and a positioning sleeve. One end of the bearing is provided with a first axial extension portion for extending to the outside of the motor, and the connector has an axial through hole. The connector is sleeved on the first axial extension portion and fixed to the first axial extension portion. The preload spring is located in the through hole on the connector, one end of the preload spring is abutted against the end of the first axial extension portion, one end of the nut is circumferentially fixed to the other end of the connector, the other end of the preload spring is abutted against the nut, the positioning sleeve is sleeved on the connector and the nut, one end of the positioning sleeve is fixed to the connector, and the other end of the positioning sleeve cooperates with the nut.
[0007] Furthermore, a first external thread is provided on the outer peripheral surface of the first axial extension portion, a first internal thread is provided on the inner wall surface of the connector, and the first internal thread on the connector is connected to the first external thread on the first axial extension portion.
[0008] Furthermore, the other end of the bearing is provided with a first support portion for connecting to the motor rotor assembly, and the other end of the positioning sleeve is clearance-matched with the nut.
[0009] Furthermore, a second external thread is provided on the outer circumferential surface of the connector, a second internal thread is provided on the inner circumferential surface of the positioning sleeve, and the second internal thread is connected to the second external thread to fix the positioning sleeve to the connector.
[0010] Furthermore, a tenon is provided at the other end of the connector, and a slot is provided on the nut. The tenon is inserted into the slot so that one end of the nut and the other end of the connector are circumferentially fixed.
[0011] The working process of the utility model is as follows: when the motor is working, the rotor assembly in the motor rotates, and the rotor assembly drives the support bearing and the bearing to rotate, thereby rotating the first axial extension portion, and the first axial extension portion drives the connector to rotate. Since the tenon and the slot are circumferentially fixed, the connector drives the nut to rotate when it rotates. Since the nut is threadedly connected to the screw rod, and the screw rod is fixed to the output shaft, and the output shaft and the housing are splined, the screw rod is driven to move linearly when the nut rotates. Since the two ends of the preload spring are respectively pressed against the first axial extension portion and the annular portion, the gap between the internal thread of the nut and the external thread on the screw rod is eliminated.
[0012] In the utility model, the anti-backlash structure composed of the first axial extension part, the preload spring, the connector, the nut and the screw is arranged on the outside of the motor. This structure is conducive to simplifying the overall structure of the anti-backlash and is very convenient during installation, which is conducive to improving assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 An exploded view of the anti-backlash structure of a fixed-axis linear motor.
[0014] Figure 2 A cross-sectional view of the anti-backlash structure of a fixed-axis linear motor.
[0015] Figure 3 A cross-sectional view of the connector.
[0016] Figure 4 A cross-sectional view of a nut.
[0017] Figure 5 A cross-sectional view of the positioning sleeve.
[0018] Motor 1, housing 1a, stator assembly 1b, rotor assembly 1c, screw 1d, support bearing 1e, first bearing seat 1f, second bearing seat 1g, second support portion 1h, bearing 2, first axial extension portion 2a, first external thread 2b, first support portion 2c, output shaft 3, preload spring 4, connector 5, through hole 5a, first internal thread 5b, second external thread 5c, tenon 5d, nut 6, slot 6a, annular portion 6b, locating sleeve 7, second internal thread 7a. DETAILED DESCRIPTION
[0019] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0020] like Figures 1 to 5As shown, the anti-backlash structure of the fixed-axis linear motor includes a bearing 2, a connector 5, a preload spring 4, a nut 6, and a positioning sleeve 7. The various parts and the relationship between them are described in detail below.
[0021] The bearing 2 cooperates with the motor 1, and the motor 1 includes a housing 1a, a stator assembly 1b, a rotor assembly 1c, a screw 1d, a support bearing 1e, a first bearing seat 1f, and a second bearing seat 1g. The first bearing seat 1f is installed at one end of the housing 1a, and the second bearing seat 1g is installed at the other end of the housing 1a. The bearing 2 cooperates with the first bearing seat 1f, and the support bearing 1e cooperates with the second bearing seat 1g. The stator assembly 1b is located inside the housing 1a and is fixed to the housing 1a. The rotor assembly 1c passes through the stator assembly 1b, and the rotor assembly 1c and the stator assembly 1b are clearance-matched.
[0022] The rotor assembly 1 is fixed to an output shaft 3. Preferably, the output shaft 3 is provided with an external spline, and the housing 1a is provided with an internal spline. The external spline on the output shaft 3 cooperates with the internal spline on the housing 1a.
[0023] One end of the bearing 2 is provided with a first axial extension portion 2a for extending out of the motor 1, the other end of the bearing 2 is provided with a first support portion 2c for connecting to the rotor assembly 1c of the motor 1, and one end of the supporting bearing 1e is provided with a second support portion 1h. One end of the rotor assembly 1c is sleeved on the first support portion 2c and fixed to the first support portion 2c, and the other end of the rotor assembly 1c is sleeved on the second support portion 1h and fixed to the second support portion 1h. In this way, both ends of the rotor assembly 1c are supported, and when the rotor assembly 1c rotates, the rotor assembly 1c drives the supporting bearing 1e and the bearing 2 to rotate.
[0024] The connector 5 has an axial through hole 5a, and the connector 5 is sleeved on the first axial extension portion 2a and fixed to the first axial extension portion 2a. In the present utility model, a preferred mode is: a first external thread 2b is provided on the outer peripheral surface of the first axial extension portion 2a, and a first internal thread 5b is provided on the inner wall surface of the connector 5, and the first internal thread 5b on the connector 5 is connected to the first external thread 2b on the first axial extension portion 2a. Thus, the connector 5 and the first axial extension portion 2a are fixed as one body.
[0025] The preload spring 4 is located in the through hole 5a on the connector 5, one end of the preload spring 4 abuts against the end of the first axial extension portion 2a, one end of the nut 6 is circumferentially fixed to the other end of the connector 5, preferably, the other end of the connector 5 is provided with a tenon 5d, the nut 6 is provided with a slot 6a, the tenon 5d is inserted into the slot 6a so that one end of the nut 6 is circumferentially fixed to the other end of the connector 5.
[0026] The other end of the preload spring 4 abuts against the nut 6, and there is an annular portion 6b in the inner hole of the nut 6. The other end of the preload spring 4 abuts against the end surface of the annular portion 6b. The internal thread hole of the nut 6 is located on the inner wall of the annular portion 6b, and the nut 6 is threadedly connected to the screw rod 1d through the internal thread. The abutting force formed by the preload spring 4 on the nut 6 eliminates the gap between the internal thread of the nut 6 and the external thread on the screw rod 1d.
[0027] The positioning sleeve 7 is sleeved on the connector 5 and the nut 6, and one end of the positioning sleeve 7 is fixed to the connector 5. Preferably, a second external thread 5c is provided on the outer circumferential surface of the connector 5, and a second internal thread 7a is provided on the inner circumferential surface of the positioning sleeve 7. The second internal thread 7a is connected to the second external thread 5c to fix the positioning sleeve 7 to the connector 5.
[0028] The other end of the positioning sleeve 7 cooperates with the nut 6. Preferably, the other end of the positioning sleeve 7 has a clearance fit with the nut 6. Through the clearance fit relationship between the positioning sleeve 7 and the nut 6, the positioning sleeve 7 forms a radial restriction on the nut 6 to prevent the nut 6 from swinging.
[0029] The working process of the utility model is as follows: when the motor 1 is working, the rotor assembly 1c in the motor 1 rotates, and the rotor assembly 1c drives the support bearing 1e and the bearing 2 to rotate, thereby rotating the first axial extension portion 2a, and the first axial extension portion 2a drives the connector 5 to rotate. Since the tenon 5d and the slot 6a are circumferentially fixed, the connector 5 drives the nut 6 to rotate when it rotates. Since the nut 6 is threadedly connected to the screw rod 1d, and the screw rod 1d is fixed to the output shaft 3, and the output shaft 3 and the housing 1a are splined, the nut 6 drives the screw rod 1d to move linearly when it rotates. Since the two ends of the preload spring 4 are respectively against the first axial extension portion 2a and the annular portion 6b, the gap between the internal thread of the nut 6 and the external thread on the screw rod 1d is eliminated.
Claims
1. A backlash elimination structure for a fixed-axis linear motor, comprising a bearing (2) matched with a motor (1), characterized in that: It also includes a connector (5), a preload spring (4), a nut (6), and a positioning sleeve (7); one end of the bearing (2) is provided with a first axial extension portion (2a) for extending outside the motor (1); the connector (5) has an axial through hole (5a); the connector (5) is sleeved on the first axial extension portion (2a) and fixed to the first axial extension portion (2a); the preload spring (4) is located in the through hole (5a) on the connector (5); one end of the preload spring (4) abuts against the end of the first axial extension portion (2a); one end of the nut (6) is circumferentially fixed to the other end of the connector (5); the other end of the preload spring (4) abuts against the nut (6); the positioning sleeve (7) is sleeved on the connector (5) and the nut (6); one end of the positioning sleeve (7) is fixed to the connector (5); and the other end of the positioning sleeve (7) cooperates with the nut (6).
2. The anti-backlash structure of the fixed-axis linear motor according to claim 1, characterized in that: A first external thread (2b) is provided on the outer peripheral surface of the first axial extension portion (2a), a first internal thread (5b) is provided on the inner wall surface of the connector (5), and the first internal thread (5b) on the connector (5) is connected to the first external thread (2b) on the first axial extension portion (2a).
3. The anti-backlash structure of the fixed-axis linear motor according to claim 1, characterized in that: The other end of the bearing (2) is provided with a first support portion (2c) for connecting to the rotor assembly of the motor (1), and the other end of the positioning sleeve (7) is clearance-matched with the nut (6).
4. The anti-backlash structure of the fixed-axis linear motor according to claim 1, characterized in that: The outer circumferential surface of the connector (5) is provided with a second external thread (5c), and the inner circumferential surface of the positioning sleeve (7) is provided with a second internal thread (7a), and the second internal thread (7a) is connected to the second external thread (5c) to fix the positioning sleeve (7) and the connector (5).
5. The anti-backlash structure of the fixed-axis linear motor according to claim 1, characterized in that: The other end of the connector (5) is provided with a tenon (5d), and the nut (6) is provided with a slot (6a). The tenon (5d) is inserted into the slot (6a) so that one end of the nut (6) and the other end of the connector (5) are circumferentially fixed.