Shaft braking device and method and servo motor

Abstract

The invention discloses a shaft braking device and method and a servo motor, the device comprises a power supply mechanism, an execution mechanism and a braking mechanism, the power supply mechanism is electrically connected with the execution mechanism and used for supplying power to the execution mechanism; the executing mechanism comprises piezoelectric ceramics, and the piezoelectric ceramics extend in the radial direction when the power supply voltage rises and retract when the power supply voltage drops. The actuating mechanism is mechanically connected with the brake mechanism, and transmits pressure to the brake mechanism when the piezoelectric ceramics extend; the brake mechanism comprises a brake pad, and the brake pad is used for applying friction force to the shaft when the brake mechanism is pressed. According to the invention, the shaft is braked by using the deformation of the piezoelectric ceramic after the power supply voltage is increased, the response time is greatly prolonged, and the braking force and the braking frequency can be accurately controlled by controlling the voltage and the current applied to the piezoelectric ceramic, so that the braking effect is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of precision control technology, and in particular to a shaft braking device, method and servo motor. Background Art

[0002] A servo motor is a motor that can precisely control position, speed, and torque. It is widely used in automation equipment, robotics, CNC machine tools, aerospace, and other fields. Its core feature is that it achieves high-precision control through a closed-loop feedback system and can adjust its operating status in real time according to external commands.

[0003] Existing servo motors use an electromagnet + armature method to achieve shaft braking. Limited by the charge and discharge time of the electromagnet, the response time is between 20-50ms, which cannot meet the high requirements for motor control precision. Summary of the Invention

[0004] An object of the present invention is to provide a shaft braking device, method and servo motor to at least partially solve the above-mentioned problems in the prior art.

[0005] To achieve the above-mentioned objectives, the present invention provides, on one hand, a shaft braking device, comprising: a power supply mechanism, an actuator and a brake mechanism, wherein the power supply mechanism is electrically connected to the actuator for supplying power to the actuator; the actuator comprises piezoelectric ceramics, which extend radially when the power supply voltage increases and retract when the power supply voltage decreases; the actuator is mechanically connected to the brake mechanism, and transmits pressure to the brake mechanism when the piezoelectric ceramics extend; the brake mechanism comprises brake pads, which are used to apply friction to the shaft when the brake mechanism is under pressure.

[0006] Preferably, the actuator is connected to the brake mechanism at one or both radial ends via a lever mechanism; the lever mechanism converts the radial extension force of the piezoelectric ceramic into pressure on the brake mechanism.

[0007] Preferably, the actuator and the brake mechanism are arranged side by side, and the lever mechanism converts the radial extension force of the piezoelectric ceramic into a compressive force on the brake mechanism.

[0008] Preferably, the lever mechanism is used to amplify the stroke of the piezoelectric ceramic.

[0009] Preferably, the lever mechanism includes a lever and a fulcrum, a recess is provided on the lever, the recess is used to match the fulcrum, and the fulcrum is provided on a device for mounting the shaft braking device.

[0010] Preferably, the shaft braking device further includes a base, the actuator and the brake mechanism are both arranged in the base, and the fulcrum is arranged on the base.

[0011] Preferably, the lever mechanism includes a lever and a fulcrum, and the fulcrum is a protrusion on the lever.

[0012] Preferably, the lever includes a first protrusion in contact with the actuator and a second protrusion in contact with the brake mechanism.

[0013] Preferably, the brake mechanism comprises an elastic metal, the brake pad is mounted on the elastic metal, and a plurality of cutouts are provided on the elastic metal.

[0014] Preferably, the elastic metal includes Mn steel, spring steel, or elastic alloy.

[0015] Preferably, a plurality of the actuators are evenly arranged around the shaft, and the brake mechanism is provided at one end of each of the actuators.

[0016] Preferably, the two actuators are symmetrically arranged on both sides of the shaft.

[0017] Preferably, the four actuators are equidistantly arranged around the shaft.

[0018] Preferably, the piezoelectric ceramic includes a stacked piezoelectric ceramic.

[0019] Preferably, the power supply mechanism is used to provide voltages of different magnitudes and / or different frequencies.

[0020] Another aspect of the present invention provides a servo motor, comprising the above-mentioned shaft braking device and any preferred embodiment thereof, wherein the shaft braking device is used to brake the shaft of the servo motor.

[0021] Another aspect of the present invention provides a shaft braking method, which is applied to the shaft braking device provided by the above-mentioned shaft braking device and any preferred embodiment thereof, comprising:

[0022] Increasing the supply voltage of the piezoelectric ceramic causes the piezoelectric ceramic to extend radially, transmitting pressure to the brake mechanism, causing the brake pad to apply friction to the shaft;

[0023] When the power supply voltage of the piezoelectric ceramic is reduced, the piezoelectric ceramic retracts radially, and the brake mechanism automatically recovers under the action of elasticity.

[0024] Compared with the prior art, the present invention has at least the following advantages:

[0025] The present invention utilizes the deformation of piezoelectric ceramics after the supply voltage is increased to achieve braking of the shaft, which greatly improves the response time. Moreover, by controlling the voltage and current applied to the piezoelectric ceramics, the braking force and braking frequency can be precisely controlled, thereby greatly improving the braking effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic structural diagram of a shaft braking device provided in an embodiment of the present invention.

[0027] Figure 2 A schematic diagram of a shaft braking device according to an embodiment of the present invention.

[0028] Figure 3 A schematic structural diagram of a shaft braking device provided in another embodiment of the present invention.

[0029] Figure 4 A schematic structural diagram of a shaft braking device provided in another embodiment of the present invention.

[0030] Figure 5 A schematic flow chart of a shaft braking method provided in an embodiment of the present invention.

[0031] Wherein, each reference numeral and its meaning is as follows:

[0032] 101 brake mechanism; 102 brake pad; 201 actuator; 301, 302 lever mechanism; 3011 lever; 3012 fulcrum; 3013 first protrusion; 3014 second protrusion; 401 shaft; 501 power supply mechanism; base 601. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate to facilitate understanding of the embodiments of the present invention described herein. In addition, the terms "including," "comprising," and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a product or device comprising a series of elements is not necessarily limited to those elements explicitly listed, but may include other elements not explicitly listed or inherent to the product or device.

[0035] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not intended to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0036] In addition, in addition to indicating the orientation or positional relationship, the above-mentioned partial terms can also be used to indicate other meanings, for example, the term "upper" can also be used to indicate a certain dependent relationship or connection relationship in some cases. For those skilled in the art, the specific meaning of these terms in the present application can be understood according to the specific circumstances.

[0037] In addition, the terms "mounting", "setting", "provided with", "connected", "connected", "sleeved" should be broadly understood. For example, it can be fixedly connected, detachably connected, or integrally constructed; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be internal communication between two devices, elements or components. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0039] Embodiment 1

[0040] The embodiment 1 of the present application provides a shaft brake device, referring to Figure 1 The drawings show that it comprises a power supply mechanism 501, an execution mechanism 201 and a brake mechanism 101, wherein the power supply mechanism is electrically connected with the execution mechanism 201, and is used for supplying power to the execution mechanism 201; the execution mechanism 201 comprises a piezoelectric ceramic, which is elongated in the radial direction when the power supply voltage is raised, and is retracted when the power supply voltage is lowered; the execution mechanism 201 is mechanically connected with the brake mechanism 101, and transmits pressure to the brake mechanism 101 when the piezoelectric ceramic is elongated; the brake mechanism 101 comprises a brake pad 102, which is used to apply friction force to the shaft 401 when the brake mechanism is pressed.

[0041] The brake mechanism 101 includes an elastic material, and the brake pad 102 is mounted on the elastic material. When the elastic material is compressed, the brake pad applies friction to the shaft. The elastic material is, for example, an elastic metal, including Mn steel, spring steel, or an elastic alloy, which is a metal capable of elastic deformation. In one embodiment, in order to increase the deformation of the elastic metal, multiple cuts can be provided on the elastic metal to facilitate deformation at designated locations. Figure 1 As shown, the positions of the cutouts are preferably set to generate an elastic force that is beneficial to braking, and the number of the cutouts is preferably 3-5.

[0042] Mechanical connections include direct and indirect connections. Indirect connections include transmission connections, such as a lever mechanism connecting the actuator and brake mechanism. For example, one or both ends of the actuator are connected to the brake mechanism via a lever mechanism, which converts the radial expansion force of the piezoelectric ceramic into pressure on the brake mechanism.

[0043] The piezoelectric ceramic is preferably a stacked piezoelectric ceramic.

[0044] The overall shape of the piezoelectric ceramic is a bar or a cylinder.

[0045] The actuator may include a piezoelectric ceramic and a metal component. For example, the actuator contacts other components via the metal component, and the piezoelectric ceramic is disposed at a position that does not contact other components.

[0046] The power supply mechanism is connected to an external power source and is used for providing voltages of different magnitudes and / or different frequencies.

[0047] The present invention utilizes the deformation of piezoelectric ceramics after the supply voltage is increased to achieve braking of the shaft, which greatly improves the response time. Moreover, by controlling the voltage and current applied to the piezoelectric ceramics, the braking force and braking frequency can be precisely controlled, thereby greatly improving the braking effect.

[0048] The shaft braking device provided by the present invention can achieve a response time of 0.5-1ms and realize a complete parking and release of the shaft within 1ms.

[0049] By controlling the power supply voltage, high-precision control of the stationary spindle in motion can be achieved. The required force can be applied to the moving spindle as required, with a force resolution of 1N. The specified stroke change in μm can be applied to the moving spindle.

[0050] Example 2

[0051] Embodiment 2 of the present invention provides a shaft braking device, referring to Figure 1As shown, it includes: a power supply mechanism 501, an actuator 201 and a brake mechanism 101, wherein the power supply mechanism 501 is electrically connected to the actuator 201 and is used to supply power to the actuator 201; the actuator 201 includes piezoelectric ceramics, which extend radially when the power supply voltage increases and retract when the power supply voltage decreases; the actuator 201 is mechanically connected to the brake mechanism 101, and transmits pressure to the brake mechanism when the piezoelectric ceramics extend; the brake mechanism 101 includes brake pads, which are used to apply friction to the shaft when the brake mechanism is under pressure.

[0052] One end or both ends of the actuator 201 are connected to the brake mechanism 101 via a lever mechanism 301 . The lever mechanism 301 converts the radial extension force of the piezoelectric ceramic into pressure on the brake mechanism. Figure 1 and Figure 2 The figure shows a situation where both ends of the actuator are connected to the brake mechanism via a lever mechanism, but does not exclude a situation where only one end is connected to the brake mechanism via a lever mechanism.

[0053] The actuator 201 and the brake mechanism 101 are arranged side by side, and the lever mechanism 301 converts the radial extension force of the piezoelectric ceramic into a compressive force on the brake mechanism.

[0054] In this embodiment, the lever mechanism 301 is used to amplify the stroke of the piezoelectric ceramic. In a preferred embodiment, the lever amplifies the stroke by 10 to 20 times, which can be flexibly adjusted according to actual needs.

[0055] The lever mechanism 301 includes a lever and a fulcrum, Figure 1 and Figure 2 As shown, a recess is provided on the lever, and the recess is used to match the fulcrum, and the fulcrum is provided on the equipment for installing the shaft brake device.

[0056] In one embodiment, the shaft braking device further includes a base 601 , the actuator and the brake mechanism are both disposed in the base, and the fulcrum 3012 is disposed on the base.

[0057] In one embodiment, the lever mechanism includes a lever and a fulcrum, with the fulcrum being a protrusion on the lever. In this case, the surface of the device on which the shaft brake device is mounted may be flat or may include a recessed portion to limit the position of the fulcrum. In this case, the recessed portion may be smaller than the protrusion on the fulcrum to facilitate the fulcrum in performing its function.

[0058] The lever is preferably an integrally formed structure and is made of a hard material, preferably a rigid metal material.

[0059] refer to Figure 1As shown, the lever also includes a first protrusion 3013 in contact with the actuator and a second protrusion 3014 in contact with the brake mechanism. The protrusion is spherical or triangular in shape to facilitate the lever to play its role.

[0060] exist Figure 1 In the example shown, the two ends of the actuator 201 are connected to lever mechanisms 301 and 302 respectively. The lever mechanisms 301 and 302 convert the radial extension force of the piezoelectric ceramic into pressure on the brake mechanism. The brake mechanism is an elastic body that contracts when subjected to pressure, driving the two brake pads in the center of the brake mechanism to apply friction to the shaft. Figure 1 The brake mechanism is a single unit, with a central hollow portion housing the rotating shaft and spaces for mounting upper and lower brake pads. The brake pads can be glued to the brake mechanism or secured by other means. The brake mechanism is symmetrically arranged about the axis, and notches can be provided on the left and right sides of the brake mechanism to enhance flexibility. The number of notches is preferably an odd number, such as 3, 5, or 7.

[0061] Among them, the shape of the brake mechanism can be flexibly set according to actual needs. As an example, in the cross-sectional view of the brake mechanism in this embodiment, the width of the part of the brake mechanism in contact with the lever is equal to or approximately equal to the sum of the widths of the brake mechanism on the left and right sides of the brake pad.

[0062] Figure 2 FIG. 1 shows a schematic diagram of a shaft brake device according to an embodiment of the present invention. Figure 2 As shown, the device comprises a base 601, a power supply mechanism 501, an actuator 201, and a brake mechanism 101. The power supply mechanism 701 is electrically connected to the actuator 201 for supplying power to the actuator 201. The actuator 201 comprises piezoelectric ceramics, which radially extend when the supply voltage increases and retract when the supply voltage decreases. The actuator 201 is mechanically connected to the brake mechanism 101, transmitting pressure to the brake mechanism 101 when the piezoelectric ceramics extend. The brake mechanism 101 comprises a brake pad 102, which is used to apply friction to the shaft when the brake mechanism is under pressure. When the device is installed on a device, the shaft 401 is located in the center of the brake mechanism 101 and is surrounded by the brake pad 102. In one embodiment, a positioning device may also be included to adjust the position of the shaft to better achieve the braking effect of the brake pad.

[0063] Example 3

[0064] Embodiment 3 of the present invention provides a shaft braking device, referring to Figure 3As shown, it includes: a power supply mechanism (not shown), an actuator 201 and a brake mechanism 101, wherein the power supply mechanism is electrically connected to the actuator 201 for supplying power to the actuator 201; the actuator 201 includes piezoelectric ceramics, which extend radially when the power supply voltage increases and retract when the power supply voltage decreases; the actuator 201 is mechanically connected to the brake mechanism 101, and transmits pressure to the brake mechanism 101 when the piezoelectric ceramics extend; the brake mechanism includes a brake pad 102, which is used to apply friction to the shaft 401 when the brake mechanism is under pressure.

[0065] The two actuators are symmetrically arranged on either side of the shaft. When the voltage supplied to the actuators increases, the end connected to the brake mechanism extends, pushing the brake pads against the shaft 401 to apply friction, thus braking. When the voltage supplied to the actuators decreases, the end connected to the brake mechanism contracts, releasing the brake.

[0066] The brake mechanism 101 may include an elastic brake structure and a brake pad, or may only include a brake pad. In this case, the brake pad is directly connected to the actuator 201 and expands and contracts under the action of the actuator 201.

[0067] The ends of the two actuators away from the shaft can be fixed, for example, in contact with a device for installing a brake device on the shaft, so that the ends cannot be deformed.

[0068] The device may include a base for securing the actuator and brake mechanism. The base houses the actuator 201 and brake mechanism 101, and may also house a power supply. The power supply is electrically connected to a power source external to the base to power the piezoelectric ceramics in the actuator 201.

[0069] Compared with the shaft braking device provided in Example 2, the shaft braking device provided in this embodiment is simple to set up and has lower cost. At the same time, it can still greatly improve the response time of braking of the shaft. Moreover, by controlling the voltage and current applied to the piezoelectric ceramic, the braking force and braking frequency can be precisely controlled, thereby greatly improving the braking effect.

[0070] Example 4

[0071] Embodiment 4 of the present invention provides a shaft braking device, referring to Figure 4 As shown, it includes: a power supply mechanism (not shown), an actuator 201 and a brake mechanism 101, wherein the power supply mechanism is electrically connected to the actuator 201 for supplying power to the actuator 201; the actuator 201 includes piezoelectric ceramics, which extend radially when the power supply voltage increases and retract when the power supply voltage decreases; the actuator 201 is mechanically connected to the brake mechanism 101, and transmits pressure to the brake mechanism 101 when the piezoelectric ceramics extend; the brake mechanism includes a brake pad 102, which is used to apply friction to the shaft 401 when the brake mechanism is under pressure.

[0072] The four actuators are equidistantly arranged around the shaft. When the supply voltage increases, the end of the actuator connected to the brake mechanism extends, pushing the brake pads against the shaft 401 to apply friction, thereby braking. When the supply voltage decreases, the end of the actuator connected to the brake mechanism contracts, releasing the brake.

[0073] The ends of the four actuators away from the shaft can be fixed, for example, in mechanical contact with the mounting portion, so that they cannot be deformed, and when the supply voltage increases, only the end connected to the brake mechanism extends.

[0074] The brake mechanism 101 may include an elastic brake structure and a brake pad, or may only include a brake pad. In this case, the brake pad is directly connected to the actuator 201 and expands and contracts under the action of the actuator 201.

[0075] The device may include a base for fixing the positions of the actuator and the brake mechanism.

[0076] Compared with the shaft braking devices provided in Examples 2 and 3, the solution provided in this embodiment is not only simple in structure, easy to implement, and low in cost, but also achieves greater braking force and better braking effect through four brake pads.

[0077] It is easy to understand that in addition to the solutions provided in Example 3 and Example 2, there may be other numbers of multiple actuators evenly arranged around the shaft, with a brake mechanism provided at one end of each actuator. The present invention cannot enumerate all possible implementation solutions.

[0078] Example 5

[0079] Embodiment 5 of the present invention provides a servo motor, comprising a shaft braking device provided according to any one of embodiments 1-4 and any implementation manner thereof, wherein the shaft braking device is used to brake the shaft of the servo motor.

[0080] It is easy to understand that the servo motor is only one application scenario of the shaft braking device provided in the embodiment of the present invention. The shaft braking device can also be applied to other fields, such as precision pressing equipment, robotics, and especially precision control of machine joints.

[0081] Example 6

[0082] Embodiment 6 of the present invention provides a shaft braking method, which is applied to the shaft braking device provided by any one of embodiments 1-4 and any of its implementation methods, such as Figure 5 As shown, the method includes:

[0083] Step 51 , increasing the supply voltage of the piezoelectric ceramic, causing the piezoelectric ceramic to extend radially, transmitting pressure to the brake mechanism, causing the brake pad to apply friction to the shaft;

[0084] Step 52: Reduce the power supply voltage of the piezoelectric ceramic, so that the piezoelectric ceramic retracts radially, and the brake mechanism automatically recovers under the action of elasticity.

[0085] The specific implementation of this method can refer to the introduction of the above device embodiment, which will not be repeated here.

[0086] In an embodiment of the present invention, the deformation of the piezoelectric ceramic after the power supply voltage is increased is used to achieve braking of the shaft, which greatly improves the response time. Moreover, by controlling the voltage and current applied to the piezoelectric ceramic, the braking force and braking frequency can be precisely controlled, thereby greatly improving the braking effect.

[0087] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit them. Those skilled in the art will appreciate that the technical solutions described in the aforementioned embodiments may be modified, or some of the technical features thereof may be replaced with equivalents; such modifications or replacements do not deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A shaft braking device, characterized in that: include: A power supply mechanism, an actuator and a brake mechanism, wherein the power supply mechanism is electrically connected to the actuator for supplying power to the actuator; the actuator includes piezoelectric ceramics, which extend radially when the power supply voltage increases and retract when the power supply voltage decreases; the actuator is mechanically connected to the brake mechanism, and transmits pressure to the brake mechanism when the piezoelectric ceramics extend; the brake mechanism includes brake pads, which are used to apply friction to the shaft when the brake mechanism is under pressure.

2. The shaft braking device according to claim 1, characterized in that The actuator is connected to the brake mechanism at one or both radial ends via a lever mechanism; the lever mechanism converts the radial extension force of the piezoelectric ceramic into pressure on the brake mechanism.

3. The shaft braking device according to claim 2, characterized in that The actuator and the brake mechanism are arranged side by side, and the lever mechanism converts the radial extension force of the piezoelectric ceramic into a compressive force on the brake mechanism.

4. The shaft braking device according to claim 2, characterized in that The lever mechanism is used to amplify the stroke of the piezoelectric ceramic.

5. The shaft braking device according to claim 4, characterized in that The lever mechanism includes a lever and a fulcrum. A recess is provided on the lever, and the recess is used to match the fulcrum. The fulcrum is provided on a device for installing the shaft braking device.

6. The shaft braking device according to claim 5, characterized in that The shaft braking device further comprises a base, the actuator and the brake mechanism are both arranged in the base, and the fulcrum is arranged on the base.

7. The shaft braking device according to claim 4, characterized in that: The lever mechanism includes a lever and a fulcrum, and the fulcrum is a protrusion on the lever.

8. The shaft braking device according to any one of claims 5 to 7, characterized in that: The lever includes a first protrusion in contact with the actuator and a second protrusion in contact with the brake mechanism.

9. The shaft braking device according to claim 2 or 3, characterized in that: The brake mechanism comprises an elastic metal, the brake pad is mounted on the elastic metal, and a plurality of cutouts are provided on the elastic metal.

10. The shaft braking device according to claim 9, characterized in that The elastic metal includes Mn steel, spring steel, or elastic alloy.

11. The shaft braking device according to claim 1, characterized in that The plurality of actuators are evenly arranged around the shaft, and the brake mechanism is arranged at one end of each of the actuators.

12. The shaft braking device according to claim 11, characterized in that The two actuators are symmetrically arranged on both sides of the shaft.

13. The shaft braking device according to claim 11, characterized in that The four actuators are equidistantly arranged around the shaft.

14. The shaft braking device according to claim 1, wherein The piezoelectric ceramic includes a stacked piezoelectric ceramic.

15. The shaft braking device according to claim 1, wherein The power supply mechanism is used to provide voltages of different magnitudes and / or different frequencies.

16. A servo motor, characterized in that: The invention comprises a shaft braking device according to any one of claims 1 to 15, wherein the shaft braking device is used to brake the shaft of the servo motor.

17. A shaft braking method, applied to the shaft braking device according to any one of claims 1 to 15, characterized in that: include: Increasing the supply voltage of the piezoelectric ceramic causes the piezoelectric ceramic to extend radially, transmitting pressure to the brake mechanism, causing the brake pad to apply friction to the shaft; When the power supply voltage of the piezoelectric ceramic is reduced, the piezoelectric ceramic retracts radially, and the brake mechanism automatically recovers under the action of elasticity.

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