Vibration control structure, method and ball screw drive for a ball screw drive
By introducing a friction plate assembly and actuator into the ball screw drive, and using a control unit to actively control the contact and separation of the friction plates, the vibration problem caused by the gap is solved, achieving precise vibration reduction and accurate positioning of the output shaft.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING MECHANICAL EQUIP INST
- Filing Date
- 2022-10-31
- Publication Date
- 2026-08-04
AI Technical Summary
Vibration occurs in ball screw drives during transmission due to gaps between the shift fork and the drive pin, as well as between the screw bearing and the housing. Existing technologies struggle to effectively address this issue, particularly the gap between the shift fork and the drive pin. Furthermore, traditional methods are complex and inefficient.
A friction plate assembly and an actuator are used. The control unit receives signals and controls the actuator to move, causing the friction plates to contact and generate frictional resistance, thereby actively eliminating vibration. Specifically, the friction plate assembly consists of first and second friction plates, and the actuator, such as a piezoelectric ceramic actuator, is used. The control unit receives signals and commands the actuator to move to achieve contact and separation of the friction plates, using frictional resistance to eliminate vibration.
It achieves precise and reliable vibration reduction for ball screw drives, reduces the difficulty of parts processing and assembly inspection, has strong adaptability, can actively control and provide feedback on the vibration reduction effect, and ensures accurate positioning of the output shaft.
Smart Images
Figure CN115823201B_ABST
Abstract
Description
Technical Field
[0001] This application relates to a vibration control structure, method, and ball screw drive device for ball screw transmission, and particularly to a non-shim-compensated vibration control structure, method, and ball screw drive device for ball screw transmission. Background Technology
[0002] Ball screw drives, also known as threaded screw drives, are widely used due to their advantages such as small size, light weight, high efficiency, and high transmission and positioning accuracy. For example... Figure 1 As shown, in the ball screw drive, the screw shaft rotates, the screw nut moves axially along the screw shaft, and the transmission pin on the screw nut acts on the shift fork of the output shaft assembly, causing the output shaft to rotate.
[0003] Ball screw drives often vibrate during transmission, which is mostly caused by the following reasons:
[0004] (1) Due to the tolerances in manufacturing and assembly, there is a certain gap between the shift fork and the transmission pin.
[0005] (2) The lead screw bearings at both ends of the lead screw are installed in the housing. Due to the tolerances in manufacturing and assembly, there is also a gap (axial) between the lead screw bearing and the housing.
[0006] During operation, the ball screw assembly drives the output shaft to rotate to a certain angle according to the control angle command. Because there is a gap between the shift fork and the transmission pin, and a gap between the screw bearing and the housing, the output shaft will generate continuous vibration at the commanded angle (a certain angle amplitude and a certain vibration frequency). This continuous vibration has a great adverse effect on the positioning accuracy of the output shaft.
[0007] Therefore, a commonly used method to eliminate vibration is to place shims between the lead screw bearing and the housing to eliminate the gap between them and reduce vibration. However, this method only eliminates the gap between the lead screw bearing and the housing; there is no good solution for the gap between the shift fork and the drive pin. Furthermore, although this method can reduce the vibration of the transmission device to a certain extent, it is difficult to operate and test, and troubleshooting is complex and inefficient. Summary of the Invention
[0008] The purpose of this application is to provide a vibration control structure, method, and ball screw transmission device for ball screw transmission devices. The vibration control structure of this application can effectively control and reduce the vibration phenomenon of ball screw transmission devices.
[0009] The first solution provided in this application is: a vibration control structure for a ball screw transmission device, comprising:
[0010] The friction plate assembly includes a first friction plate and a second friction plate, wherein the first friction plate is connected to the output shaft assembly of the ball screw drive device;
[0011] An actuator is connected to and controls the movement of the second friction plate; the first friction plate is located on the movement path of the second friction plate.
[0012] The control unit receives signals from the ball screw drive and issues commands to the actuators.
[0013] Optionally, the control unit includes a sensor and a controller, wherein the sensor receives signals from the ball screw drive and issues commands to the actuator through the controller.
[0014] Optionally, the second friction plate can move up and down.
[0015] Optionally, the second friction plate is connected to the lower end of the actuator.
[0016] Optionally, the actuator is a piezoelectric ceramic actuator.
[0017] Optionally, the total friction contact area of the first friction plate is greater than the total friction contact area of the second friction plate.
[0018] Optionally, the first friction plate is arc-shaped to match the curvature of the output shaft assembly.
[0019] Optionally, the instantaneous friction contact area of the first friction plate is not less than 50% of the instantaneous friction contact area of the second friction plate.
[0020] This application also provides a second solution, namely a vibration control method for a ball screw drive device, including any of the aforementioned vibration control structures, and the following steps:
[0021] S1: The control unit receives the vibration signal transmitted from the ball screw drive and sends a movement command to the actuator.
[0022] S2: After receiving the movement command, the actuator moves until the second friction plate and the first friction plate are in contact.
[0023] S3: The vibration signal is reduced to disappear under the frictional resistance generated by the friction plate assembly; after the control unit does not receive the vibration signal, it sends a stop command to the actuator, and the actuator moves to the point where the second friction plate separates from the first friction plate.
[0024] This application also provides a third solution, namely a ball screw transmission device, including a housing, and a guide rail, a ball screw assembly, an output shaft assembly, and any of the aforementioned vibration control structures disposed within the housing;
[0025] The ball screw assembly includes a screw shaft, a screw nut sleeved on the outer periphery of the screw shaft, and a drive pin connected to the screw nut; the guide rail is connected to the screw nut and is located on both sides of the screw nut, respectively, along with the drive pin.
[0026] The output shaft assembly includes an output shaft, an output shaft bearing sleeved on the outer periphery of the output shaft, and a shift fork connected to the output shaft bearing;
[0027] The drive pin is located inside the shift fork;
[0028] The first friction plate and the shift fork are located on both sides of the output shaft bearing, respectively.
[0029] The vibration control structure for ball screw transmission devices provided in this application mainly adopts the following... Figure 3 The structure shown receives signals from the ball screw drive via a control unit to determine whether vibration occurs. If vibration occurs, a command is sent to the actuator, which moves to contact the first and second friction plates of the friction plate assembly. The frictional resistance of the friction plates is used to eliminate the vibration of the ball screw drive.
[0030] The above work process mainly adopts, for example Figure 2 The vibration active control method shown assumes that the sensor in the control unit detects the system vibration signal, and uses a suitable control algorithm (e.g., the strength of the vibration signal is positively correlated with the moving speed and moving distance of the actuator) to implement appropriate control on the intelligent actuator (e.g., a piezoelectric ceramic actuator) acting on the output shaft, thereby achieving vibration reduction. The vibration control structure and method used in this application are both active controls, forming a closed-loop vibration control scheme with vibration reduction feedback. When the system no longer generates vibration signals, the controller in the control unit can also issue timely commands to the actuator, causing the friction plate assembly to separate. This scheme can more accurately and reliably reduce system vibration, is highly adaptable, and reduces the stringent requirements on transmission clearance, thereby reducing the difficulty of processing, assembling, and inspecting related components of the ball screw transmission device. Attached Figure Description
[0031] Figure 1 This is a schematic structural diagram of an existing ball screw drive device;
[0032] Figure 2 This is a schematic diagram of a specific embodiment of the vibration control method of this application;
[0033] Figure 3 This is an axonometric view (box not shown) of a specific embodiment of the ball screw drive device of this application;
[0034] Figure 4This is a top view of a specific embodiment of the ball screw transmission device of this application (the housing is not shown);
[0035] Figure 5 This is a front view of a specific embodiment of the ball screw transmission device of this application (the housing is not shown);
[0036] Figure 6 This is a schematic diagram of a specific embodiment of the ball screw transmission device of this application (the housing is not shown, and the guide rail is hidden).
[0037] Among them, 01-guide rail, 02-ball screw assembly, 03-output shaft assembly, 04-piezoelectric ceramic actuator, 05-upper friction plate, 06-lower friction plate. 02-ball screw assembly includes: 0201-screw bearing, 0202-screw shaft, 0203-screw nut, 0204-drive pin; 03-output shaft assembly includes: 0301-output shaft, 0302-output shaft bearing, 0303-shift fork. Detailed Implementation
[0038] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown herein can generally be arranged and designed in various different configurations.
[0039] The following is a detailed example illustrating the proposed solution:
[0040] refer to Figures 3-5 As shown, it is a structural schematic diagram of the ball screw transmission device in an embodiment, as follows. Figure 3 As shown, it includes a guide rail 01, a ball screw assembly 02, an output shaft assembly 03, a piezoelectric ceramic actuator 04, an upper friction plate 05, and a lower friction plate 06.
[0041] exist Figure 3 The sensor is not shown in the diagram. The sensor can be placed at any position in the housing of the ball screw drive that can obtain vibration signals, or it can be connected to the housing. The sensor used can be a conventional vibration sensor, and the vibration signal it receives can be the vibration signal conventionally collected by the existing vibration sensor.
[0042] exist Figure 3In the structure shown, the friction plate assembly uses an upper friction plate and a lower friction plate; that is, the second friction plate connected to the actuator is the upper friction plate, and the first friction plate connected to the output shaft assembly is the lower friction plate. In more embodiments, a friction plate assembly consisting of a left friction plate and a right friction plate can also be used; the former generates frictional resistance through contact between the bottom and top surfaces, while the latter generates frictional resistance through contact between the two sides. However, from the perspective of practical application, a combination with a larger mutual contact area of the friction plate assemblies is preferred. This can be specifically selected based on the structure and size of the ball screw drive device and the installation method of the friction plates. As a preferred embodiment, the total frictional contact area of the first friction plate is greater than the total frictional contact area of the second friction plate; in a preferred embodiment, the total frictional contact area of the lower friction plate is greater than the total frictional contact area of the upper friction plate. This preferred solution ensures that the second friction plate is always in contact with the first friction plate during operation, thereby ensuring that the second friction plate will not detach from the first friction plate due to excessive vibration distance.
[0043] More preferably, in the present application, the first friction plate is arc-shaped, matching the curvature of the output shaft assembly, and particularly matching the circular curvature of the output shaft bearing. Furthermore, a more preferred embodiment is that the instantaneous friction contact area of the first friction plate is not less than 50% of the instantaneous friction contact area of the second friction plate. Under this configuration, the vibration distance can be determined in advance based on the monitored vibration signal, allowing for the matching of friction plate assemblies of appropriate size. This ensures that, at any vibration control moment, the friction contact area of the first friction plate is not less than 50% of the friction contact area of the second friction plate, thereby ensuring sufficient frictional resistance to a certain extent.
[0044] exist Figure 3 In the structure shown, the actuator is a piezoelectric ceramic actuator; in other embodiments, other actuators with the same function may also be used.
[0045] Additionally, refer to Figure 4 As shown, the ball screw assembly 02 includes: a screw bearing 0201, a screw shaft 0202, a screw nut 0203, and a transmission pin 0204;
[0046] Additionally, refer to Figure 5 As shown, the output shaft assembly 03 includes: an output shaft 0301, an output shaft bearing 0302, and a shift fork 0303. Figure 5 As shown, the first friction plate can be connected to the output shaft bearing.
[0047] like Figures 3-5 As shown, the transmission pin 0204 is mounted on the lead screw nut 0203, the lead screw bearing 0201 is mounted on both ends of the lead screw shaft 0202, and the ball screw assembly 02 is mounted on the housing via the lead screw bearing 0201. Figure 5As shown, output shaft bearings 0302 are mounted at both ends of output shaft 0301, shift fork 0303 is mounted on one side of output shaft 0301, shift fork 0303 cooperates with drive pin 0204, and lower friction plate 06 is mounted on the other side of output shaft 0301. Output shaft assembly 03 is mounted in the housing via output shaft bearings 0302. The upper end of piezoelectric ceramic actuator 04 is mounted on the housing, and the upper friction plate 05 is mounted on the lower end of piezoelectric ceramic actuator 04. When piezoelectric ceramic actuator 04 is not working, the upper friction plate 05 and lower friction plate 06 are not in contact. When piezoelectric ceramic actuator 04 is working, the upper friction plate 05 moves downwards and contacts the lower friction plate 06, generating frictional torque. This frictional torque eliminates the vibration of output shaft assembly 03 caused by external load (system clearance), achieving accurate positioning of output shaft assembly 03. Figure 4 As shown, the guide rail 01 is installed on the housing, on one side of the lead screw nut 0203, restricting the rotation of the lead screw nut 0203 so that the lead screw nut 0203 can only translate along the lead screw axis 0202.
[0048] Figures 3-5 In the illustrated embodiment, during practical application, the lead screw shaft rotates, the lead screw nut moves linearly, and the lead screw shaft is subjected to radial and axial loads. The transmission pin on the lead screw nut acts on the shift fork on the output shaft, driving the output shaft to rotate. The lead screw is supported at both ends by lead screw bearings; one bearing is fixed, while the other bearing has axial clearance (allowing for movement). The ball screw transmission device drives the output shaft to rotate to a specified angle according to the control angle command. The motor's output torque balances the external load torque, and the output shaft locks at the specified angle. Due to the clearance between the shift fork and the transmission pin, and the axial clearance of the ball screw transmission device, under the action of external loads, the output shaft will vibrate at a certain angle amplitude and frequency after rotating to the specified angle, causing inaccurate positioning of the output shaft. This invention installs a piezoelectric ceramic actuator on one side of the output shaft. Through intelligent feedback control, it controls the contact and disengagement of the friction plates and controls the contact positive pressure to control the friction torque, suppressing the output shaft vibration caused by the clearance of the ball screw transmission device under external loads, thus enabling accurate positioning of the output shaft.
[0049] Figures 3-5 The structure during operation is illustrated in the diagram below. Figure 6As shown (with guide rail 01 removed), the lead screw shaft 0202 rotates under the input torque of the motor. Driven by the lead screw shaft 0202, the lead screw nut 0203 moves horizontally up and down along the axial direction of the lead screw shaft 0202. The transmission pin 0204 on the lead screw nut 0203 transmits force to the shift fork 0303, converting the translational motion of the lead screw nut 0203 into the rotational motion of the output shaft assembly 03. The piezoelectric ceramic actuator 04 can drive the upper friction plate 05 to move vertically up and down along the axial direction of the output shaft 0301. When the piezoelectric ceramic actuator 04 is not working, the upper friction plate 05 and the lower friction plate 06 are not in contact. When the piezoelectric ceramic actuator 04 is working, the upper friction plate 05 moves downwards and contacts the lower friction plate 06, generating a frictional torque. When an external load causes angular vibration of the output shaft, the controller in the control unit will calculate the control voltage of the piezoelectric ceramic actuator in real time based on the vibration signal obtained by the sensor, thereby controlling the friction torque to eliminate the angular vibration of the output shaft 03 and achieve accurate positioning of the output shaft assembly 03.
[0050] In addition, the vibration control method for ball screw transmission devices provided in this application is roughly as follows: Figure 2 As shown, the vibration sensor detects the vibration signal of the system. Using a suitable control algorithm (e.g., the strength of the vibration signal is positively correlated with the actuator's moving speed and distance), the controller implements appropriate control over the intelligent actuator (piezoelectric ceramic actuator) acting on the output shaft, achieving vibration reduction. The vibration control structure and method used in this application are both active controls, forming a closed-loop vibration control scheme with feedback on vibration reduction effects. When the system no longer generates vibration signals, the controller can still issue timely commands to the actuator, causing the friction plate assembly to separate.
[0051] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A vibration control structure for a ball screw transmission device, characterized in that, include: The friction plate assembly includes a first friction plate and a second friction plate. The first friction plate is connected to the output shaft assembly of the ball screw drive device. The drive pin of the ball screw is mounted on the screw nut. The shift fork of the output shaft assembly is mounted on one side of the output shaft, and the shift fork cooperates with the drive pin. The first friction plate is mounted on the other side of the output shaft. An actuator is connected to and controls the movement of a second friction plate; a first friction plate is located on the movement path of the second friction plate; the upper end of the actuator is mounted on the housing, and the second friction plate is mounted on the lower end of the actuator; when the actuator is not working, the second friction plate and the first friction plate are not in contact; when the actuator is working, the friction torque is used to eliminate the vibration of the output shaft assembly caused by the system clearance under external load, thereby achieving accurate positioning of the output shaft assembly; The control unit receives signals from the ball screw drive and issues commands to the actuators.
2. The vibration control structure according to claim 1, characterized in that, The control unit includes sensors and a controller. The sensors receive signals from the ball screw drive and issue commands to the actuators through the controller.
3. The vibration control structure according to claim 1, characterized in that, The second friction plate moves up and down.
4. The vibration control structure according to claim 1, characterized in that, The actuator is a piezoelectric ceramic actuator.
5. The vibration control structure according to claim 1, characterized in that, The total friction contact area of the first friction plate is greater than the total friction contact area of the second friction plate.
6. The vibration control structure according to claim 1, characterized in that, The first friction plate is arc-shaped, matching the curvature of the output shaft assembly.
7. The vibration control structure according to claim 1, characterized in that, The instantaneous friction contact area of the first friction plate is not less than 50% of the instantaneous friction contact area of the second friction plate.
8. A vibration control method for a ball screw drive system, characterized in that, The device includes the vibration control structure described in any one of claims 1 to 7, and the following steps: S1: The control unit receives the vibration signal transmitted from the ball screw drive and sends a movement command to the actuator; S2: After receiving the movement command, the actuator moves until the second friction plate and the first friction plate are in contact; S3: The vibration signal is reduced to disappear under the action of the friction resistance generated by the friction plate assembly; After the control unit no longer receives the vibration signal, it sends a stop command to the actuator, and the actuator moves until the second friction plate separates from the first friction plate.
9. A ball screw transmission device, characterized in that, The device includes a housing, a guide rail, a ball screw assembly, an output shaft assembly, and the vibration control structure described in any one of claims 1 to 7, all housed within the housing. The ball screw assembly includes a screw shaft, a screw nut sleeved on the outer periphery of the screw shaft, and a drive pin connected to the screw nut. The guide rail is connected to the screw nut and is located on both sides of the screw nut, respectively, along with the drive pin. The output shaft assembly includes an output shaft, an output shaft bearing sleeved on the outer periphery of the output shaft, and a shift fork connected to the output shaft bearing. The drive pin is located inside the shift fork. The first friction plate and the shift fork are located on both sides of the output shaft bearing, respectively.