Friction type inertia motor

Abstract

The utility model provides a friction type inertia motor, and relates to the technical field of driving. The utility model relates to a friction type inertia motor. The motor comprises a base; the sliding part is in sliding fit with the base and can slide in the first direction; the sliding piece is provided with a bearing face used for bearing loads and a first friction face perpendicular to the bearing face. The driving module comprises a piezoelectric driving part, a transmission part and a second friction surface; the second friction surface is in friction contact with the first friction surface, and the deformation of the piezoelectric driving part can be transmitted to the second friction surface through the transmission part; and the second friction surface is driven to move along the first direction, so that the sliding piece is driven to slide along the first direction through the friction contact between the second friction surface and the first friction surface.

Description

Technical Field

[0001] This specification relates to the field of drive technology, and particularly to a frictional inertial motor. Background Art

[0002] In high-precision manufacturing and assembly in fields such as optical engineering, microelectronics, aerospace technology, ultra-precision machinery, and biomedicine, ultra-high-precision position control technology is a prerequisite for achieving high-precision work. A high-precision servo drive is the core equipment for realizing ultra-high-precision position control technology. It can achieve multi-degree-of-freedom motion of precision workpieces, thereby realizing high-precision position control. Frictional inertial drives have the characteristics of small size, high smoothness, and good self-locking property, and are widely used in the process of ultra-high-precision position control.

[0003] Generally speaking, the forces on the load surface and the friction surface of existing frictional inertial motors are interrelated. For example, if the load surface and the friction surface are parallel to each other, the load force will affect the force on the friction surface, thereby affecting the overall performance stability of the motor. Summary of the Utility Model

[0004] Some embodiments of this specification provide an improved frictional inertial motor, aiming to decouple the forces on the motor load surface and the friction surface to a large extent and improve the stability of the motor performance.

[0005] One or more embodiments of this specification provide a frictional inertial motor, including: a base; a sliding member, slidably engaged with the base and capable of sliding along a first direction; the sliding member is provided with a load-bearing surface for carrying a load and a first friction surface perpendicular to the load-bearing surface; a driving module, including a piezoelectric driving part, a transmission part, and a second friction surface; the second friction surface is in frictional contact with the first friction surface, and the deformation of the piezoelectric driving part can be transmitted to the second friction surface through the transmission part to drive the second friction surface to move along the first direction, and then drive the sliding member to slide along the first direction through frictional contact with the first friction surface.

[0006] According to the motor described in some embodiments of this specification, it further includes a guiding member fixed on the base; a first guiding surface of the guiding member is slidably connected to a second guiding surface of the sliding member through a track extending along the first direction.

[0007] According to the motor described in some embodiments of this specification, the number of the guiding members is 2; the two guiding members are arranged on the base at intervals in a second direction perpendicular to the first direction, and the first guiding surfaces of the two guiding members are arranged oppositely; the sliding member is located between the two guiding members, and second guiding surfaces are respectively arranged on the two sides of the sliding member opposite to the two guiding members; the two second guiding surfaces of the sliding member are respectively slidably connected to the first guiding surfaces of the two guiding members through tracks.

[0008] According to the motor described in some embodiments of this specification, the driving module includes a first wall; the first wall has an inclined surface forming an angle less than 90° with respect to the second friction surface; the inclined surface of the first wall is used to decompose the force acting thereon into a first component force parallel to the second friction surface and a second component force perpendicular to the second friction surface, wherein the first component force can provide a pre-tightening force for the deformation of the piezoelectric driving part, and the second component force can provide a normal pressure for the frictional contact between the second friction surface and the first friction surface.

[0009] According to the motor described in some embodiments of this specification, the driving module is located on the base and on one side of the first friction surface, so that the second friction surface can be opposite to and in frictional contact with the first friction surface; the motor further includes a ball screw threadedly engaged with the base; the ball end of the ball screw abuts against the inclined surface to provide a force acting on the inclined surface.

[0010] According to the motor described in some embodiments of this specification, the transmission part includes a first wall, a connecting rod, an elastic retaining piece and a second wall arranged in sequence along the first direction; the elastic retaining piece is arranged opposite to the second wall to at least cooperate with the second wall to form a driving part accommodating area for accommodating the piezoelectric driving part; one end of the connecting rod is fixedly connected to the elastic retaining piece, and the other end is connected to the first wall through at least a first elastic structure; the first elastic structure can elastically deform along the first direction; the second friction surface is arranged on the connecting rod; when the piezoelectric driving part in the driving part accommodating area deforms, one end of the piezoelectric driving part close to the elastic retaining piece can push the elastic retaining piece and the connecting rod to move, thereby driving the second friction surface to move along the first direction.

[0011] According to the motor described in some embodiments of this specification, the side of the sliding member opposite to the bearing surface has a rib extending along the first direction; the first friction surface is arranged on one side of the rib; the driving module is located on the base and on one side of the first friction surface, so that the second friction surface can be opposite to and in frictional contact with the first friction surface.

[0012] The motor according to some embodiments of the present specification, wherein a first groove for accommodating the rib and a second groove for accommodating the driving module are provided on the base; a communication gap is provided between the first groove and the second groove, so that the second friction surface is in frictional contact with the first friction surface through the communication gap.

[0013] The motor according to some embodiments of the present specification, wherein the piezoelectric driving part includes a piezoelectric stack formed by arranging one or more piezoelectric sheets along the first direction; the first wall has an inclined surface forming an angle less than 90° with respect to the second friction surface; a threaded hole is provided in the base, and the threaded hole penetrates along the first direction between the outer side surface of the base and the first side wall of the second groove; a ball head screw threadedly engaged with the threaded hole is provided in the threaded hole, and the ball head end of the ball head screw abuts against the inclined surface of the first wall, thereby abutting the second wall against the second side wall of the second groove; the second side wall is opposite to the first side wall.

[0014] The motor according to some embodiments of the present specification, wherein the transmission part is positioned in the second groove by means of hole-shaft fit.

[0015] The motor according to some embodiments of the present specification, wherein the other end of the connecting rod is further connected to the first wall through a second elastic structure; the second elastic structure can elastically deform along a second direction perpendicular to the first direction.

[0016] The motor according to some embodiments of the present specification, wherein the first elastic structure and / or the second elastic structure includes a flexible hinge.

[0017] The beneficial effects that may be brought by the embodiments of the present specification include but are not limited to: (1) The load-bearing surface of the motor mover is perpendicular to the friction surface, decoupling the load force and the frictional force to a large extent and ensuring the stability of the motor performance. (2) The driving module and the friction surface for realizing friction drive are arranged below the sliding part bearing surface, making the overall structure of the motor more compact and small. (3) The inclined surface structure on the driving module can decompose the force acting thereon to simultaneously provide the pre-tightening force required by the piezoelectric driving part and the normal pressure required for friction, further streamlining the structure of the driving module. (4) The second elastic structure provides a yielding space for the particles between the friction surfaces, effectively reducing the wear of the particles on the friction surfaces, improving the service life of the motor and the smoothness of the motor drive. (5) By processing the first wall to form a flexible hinge, the addition of extra elastic structure parts in the driving module is avoided, further streamlining the structure of the driving module. It should be noted that the beneficial effects that may be produced by different embodiments are different. In different embodiments, the beneficial effects that may be produced may be any one or several combinations of the above, or any other beneficial effects that may be obtained. Description of the Drawings

[0018] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote the same structures or steps.

[0019] Figure 1 is a schematic diagram of the overall structure of a friction inertial motor according to some embodiments of this specification.

[0020] Figure 2 is a schematic diagram of the structure of a sliding member according to some embodiments of this specification.

[0021] Figure 3 is a schematic diagram of the structure of a base according to some embodiments of this specification.

[0022] Figure 4 is a schematic diagram of the structure of a drive module according to some embodiments of this specification.

[0023] Figure 5 is a schematic diagram of the drive module and its force analysis according to some embodiments of this specification.

[0024] Figure 6 is a schematic diagram of the assembly of the base and the drive module according to some embodiments of this specification.

[0025] Figure 7 is a schematic diagram of the assembly of the base, the rib and the drive module according to some embodiments of this specification.

[0026] Figure 8 is an enlarged schematic diagram of the first elastic structure and the second elastic structure according to some embodiments of this specification.

[0027] Figure 9 is a schematic diagram of the control waveform of a friction inertial motor according to some embodiments of this specification.

[0028] Reference numerals in the drawings: 1 base; 11 first groove; 12 second groove; 121 positioning rod; 2 sliding member; 21 bearing surface; 22 second guiding surface; 23 rib; 24 first friction surface; 3 drive module; 301 first flexible hinge; 302 second flexible hinge; 31 piezoelectric driving part; 32 transmission part; 321 first wall; 322 connecting rod; 323 elastic retaining piece; 324 second wall; 325 through hole; 326 connecting part; 33 second friction surface; 4 guiding member; 41 first guiding surface; 5 threaded hole; 6 ball head screw. Detailed Description of the Invention

[0029] To more clearly illustrate the technical solutions of the embodiments of this specification, the embodiments will be introduced in detail below with reference to the accompanying drawings. Obviously, the content described below is some examples or embodiments of this specification. For those of ordinary skill in the art, without creative efforts, the technical solutions or means disclosed in this specification can also be applied to other scenarios based on this technical content.

[0030] It should be understood that the "system", "device", "unit" and / or "module" used in this specification is a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the said words can be replaced by other expressions.

[0031] Unless otherwise specified, the technical terms describing components, elements, etc. in this specification do not specifically refer to the singular number and may also include the plural. Generally speaking, terms such as "including" and "comprising" only indicate the inclusion of the clearly identified steps, elements or components, and these steps, elements and components do not constitute an exclusive list. For example, the method or device described may also include other steps or components.

[0032] The frictional inertial motor relies on the action of friction to drive the movement of the mover. It generally includes a first friction surface located on the mover and a second friction surface located on the drive module. The drive module drives the second friction surface to move at a certain frequency and speed, and drives the mover to move in a preset direction through inertial action and frictional contact between the second friction surface and the first friction surface. In the field of frictional inertial motors, the inverse piezoelectric effect of piezoelectric materials is often used to convert electrical energy into mechanical energy, so as to provide the driving force for driving the second friction surface to move. Such frictional inertial motors have the characteristics of small volume, stable movement, good self-locking performance, etc., and are widely used in high-precision manufacturing and assembly in the fields of optical engineering, microelectronics, aerospace technology, ultra-precision machinery, biomedicine, etc., as the core equipment for ultra-high-precision position control. On the other hand, the frictional piezoelectric inertial motor does not require a magnetic field during operation and generates less heat, which is also favored for precision manufacturing in a vacuum environment.

[0033] However, the forces on the load surface and the friction surface of the existing frictional inertial motor are interrelated. For example, when the load surface and the friction surface of the motor are parallel to each other, when the load force (such as the gravity of the load) acts on the load surface, it will also act on the friction surface parallel to the load surface, thereby affecting the normal pressure and frictional force of the friction surface. This means that when the load of the motor changes, the frictional force as the driving force will also change, so the overall performance of the motor will be affected by the load and the stability is not good. More extremely, when the load force is too large, the frictional force also increases, even causing the motor to stop running.

[0034] To this end, some embodiments of this specification provide an improved frictional inertial motor, with the expectation of decoupling the forces on the motor load surface and the friction surface to a large extent and improving the stability of the motor performance.

[0035] Figure 1 It is a schematic diagram of the overall structure of the frictional inertial motor shown in some embodiments of this specification. A frictional inertial motor provided by some embodiments of this specification includes: a base 1, a sliding member 2, and a driving module 3. Among them, the sliding member 2 is slidably engaged with the base 1 and can slide along a first direction. The base 1 can be regarded as the stator of the motor, and the sliding member 2 can be regarded as the rotor of the motor. The first direction can be any arbitrarily specified direction. As an example, the first direction can be the x direction shown in the figure or its reverse direction (hereinafter, the first direction is mainly taken as the x direction for illustration). The sliding member 2 is provided with a load-bearing surface 21 for carrying a load. As Figure 1 shown, the load-bearing surface 21 can be provided with screw holes, and the load can be fixedly arranged on the load-bearing surface 21 through screws. The sliding member 2 is further provided with a first friction surface, and the first friction surface is perpendicular to the load-bearing surface 21. The driving module 3 can include a piezoelectric driving part, a transmission part, and a second friction surface. The second friction surface is in frictional contact with the first friction surface. The piezoelectric driving part deforms under the action of an electrical signal, and this deformation can be transmitted to the second friction surface through the transmission part to drive the second friction surface to move along the first direction, and then drive the sliding member 2 to slide along the first direction through frictional contact with the first friction surface.

[0036] Since the first friction surface of the motor is perpendicular to the load-bearing surface, the load force acting on the load-bearing surface will not provide the normal pressure required for the friction surface to generate frictional force, thereby decoupling the forces on the load-bearing surface and the friction surface (such as the force on the load-bearing surface will not affect or interfere with the force on the friction surface, and vice versa), and avoiding the influence of the change in the load force on the working performance of the motor.

[0037] In some embodiments, in order to enable the sliding member to slide stably along a preset trajectory (such as along a direction parallel to the x direction), the frictional inertial motor may further include a guiding member. The guiding member is fixed to the base, and the first guiding surface of the guiding member is slidably connected to the second guiding surface of the sliding member through a track extending along the first direction. In some embodiments, the guiding member can be single or two. Continuing to refer to Figure 1 , Figure 1 the shown motor has two guiding members 4, and the two guiding members 4 are along a second direction perpendicular to the first direction (such as Figure 1They are arranged on the base 1 at intervals in the y direction (as shown), and the first guiding surfaces 41 of the two guiding members 4 are arranged opposite to each other. The sliding member 2 is located between the two guiding members 4, and second guiding surfaces 22 are respectively arranged on the two sides of the sliding member 2 opposite to the two guiding members 4. The two second guiding surfaces 22 of the sliding member 2 are respectively slidably connected to the first guiding surfaces 41 of the two guiding members 4 through tracks, so as to restrict the movement direction of the sliding member 2. Specifically, as Figure 1 shown, the guiding member 4 can be a block with a cuboid shape, and its material can be metal, plastic, wood, etc. The guiding member 4 can be fixed to the base 1 by means of screw connection, bonding, welding, etc. The side of the guiding member 4 facing the sliding member 2 is the first guiding surface 41, and a first track can be fixedly arranged thereon. In some embodiments, the first track can be made of a metal material, or can be replaced with other non-metal materials according to the use environment, including but not limited to alumina, zirconia, etc. In some embodiments, the sides of the sliding member 2 facing the two guiding members 4 are the second guiding surfaces 22, and second tracks can be respectively fixedly arranged on the two second guiding surfaces 22 so as to be slidably connected to the first tracks on the guiding members 4. Similar to the first track, the material of the second track can be metal or non-metal. Continuing to refer to Figure 1 , the first track and the second track can be linear tracks extending in the x direction, thereby restricting the sliding member 2 to move in the x direction. In some embodiments, the two second guiding surfaces 22 of the sliding member 2 and the first guiding surfaces 41 of the two guiding members 4 can be slidably mated through crossed roller guides respectively.

[0038] Figure 2 is a schematic structural diagram of the sliding member shown in some embodiments of the present specification, which shows the side of the sliding member opposite to the bearing surface from a bottom view perspective. As Figure 2 shown, the sliding member 2 is located between the two guiding members 4. The side of the sliding member 2 opposite to the bearing surface 21 has a rib 23 extending in the first direction, and a first friction surface 24 is arranged on one side of the rib 23. In some embodiments, the cross-section of the rib 23 can be rectangular, trapezoidal, etc., so that the rib 23 has relatively flat sides, and then the first friction surface 24 can be arranged. The rib 23 can be fixed to the sliding member 2 by means of bonding, welding, screw connection, integral molding, etc. Correspondingly, the driving module 3 can be arranged on the base 1 and on one side of the first friction surface 24, so that the second friction surface 33 of the driving module 3 can be opposite to and in frictional contact with the first friction surface 24.

[0039] In some embodiments, the first friction surface 24 can be made of friction materials such as ceramic bodies, glass fibers, and semi-metals. The first friction surface 24 can be fixed on the side of the rib 23 by means of plating or integral molding, etc. The surface of the first friction surface 24 can be flat, or can be a non-flat surface provided with pits, mesh patterns, etc.

[0040] In some embodiments of the present specification, a rib is provided on the slider to install the first friction surface, which can create more space for the layout of the second slide rail. At the same time, the driving module and the friction surface for realizing friction drive can be arranged below the bearing surface of the slider, making the overall structure of the motor more compact and small. Specifically, refer to Figure 1 and Figure 2 . When the first friction surface 24 is arranged on the rib 23, both sides of the slider 2 can be used as the second guiding surface 22 to install the second rail, making the cooperation between the slider 2 and the guiding member 4 more stable. The specific setting methods of the driving module and the friction surface can be found in the relevant descriptions of Figure 3 and will not be elaborated here.

[0041] Figure 3 is a schematic structural diagram of the base shown in some embodiments of the present specification. As Figure 3 shown, a first groove 11 and a second groove 12 are provided on the base 1. Among them, the shape of the first groove 11 is adapted to the rib 23 to accommodate the rib 23. The second groove 12 can be rectangular, trapezoidal, etc. to accommodate the driving module 3. In some embodiments, the second groove 12 can have sufficient depth so that when the driving module 3 is placed in the second groove 12, the upper side of the driving module 3 does not protrude from the upper surface of the base 1. The depth of the first groove 11 can be the same as or different from that of the second groove 12. In some embodiments, the depth of the first groove 11 can be consistent with the height of the rib 23. Such a setting can make the rib 23 basically located in the first groove 11, effectively reducing the size of the motor in the vertical direction and making the motor structure more compact and small. Continuing to refer to Figure 3 , the first groove 11 and the second groove 12 are connected to each other, that is, there is a communication gap between them. When the rib 23 is located in the first groove 11 and the driving module 3 is placed in the second groove 12, the second friction surface 33 of the driving module 3 can be in frictional contact with the first friction surface 24 on the rib 23 through this communication gap.

[0042] Figure 4 is a schematic structural diagram of the driving module shown in some embodiments of the present specification, Figure 5 is a schematic diagram of the driving module and its force analysis shown in some embodiments of the present specification. As Figure 4 and Figure 5As shown, the driving module 3 may include a piezoelectric driving part 31, a transmission part 32, and a second friction surface 33. The second friction surface 33 is located on the transmission part 32. The deformation of the piezoelectric driving part 31 can be transmitted to the second friction surface 33 through the transmission part 32 to drive the second friction surface 33 to move in the first direction. In some embodiments, similar to the first friction surface 24, the second friction surface 33 can be made of friction materials such as ceramic bodies, glass fibers, and semi-metals. The second friction surface 33 can be fixed to the transmission part 32 by techniques such as plating or integral molding. The surface of the second friction surface 33 can be flat or an uneven surface provided with pits, mesh patterns, etc.

[0043] Continue to refer to Figure 4 and Figure 5 , the driving module 3 includes a first wall 321, and the first wall 321 has an inclined surface with an angle less than 90° relative to the second friction surface 33. When a force F acts on the inclined surface of the first wall 321, the inclined surface can decompose the force F into a first component force F1 parallel to the second friction surface 33 and a second component force F2 perpendicular to the second friction surface 33. Among them, the first component force F1 can provide a pre-tightening force for the deformation of the piezoelectric driving part 31, and the second component force F2 can provide a normal pressure for the frictional contact between the second friction surface 33 and the first friction surface 24. It can be seen that the inclined surface design of the first wall can decompose a single force into the pre-tightening force and the normal pressure required for the deformation of the piezoelectric material and frictional driving respectively, so that the frictional force no longer depends on the load force, while simplifying the motor structure, the performance stability of the motor is improved. In some embodiments, the angle α between the inclined surface and the second friction surface 33 α can be adjusted according to the magnitude of the required component force. Specifically, this angle α can be taken from the numerical range [30, 90), or taken from the numerical range [60, 85]. Exemplarily, the angle α can be 80°, 75°, 72°, etc.

[0044] In some embodiments, the force acting on the inclined surface of the first wall 321 can be provided by a structure that abuts against it. Continue to refer to Figure 5 , the ball head end of the ball screw 6 can be abutted against this inclined surface to provide the force F. The ball screw 6 is connected to the base 1 in a threaded fit manner. By rotating the ball screw 6, its tightening degree on the inclined surface can be adjusted, thereby changing the magnitude of the force F. For more descriptions of the connection relationship between the ball screw 6 and the base 1 and the driving module 3, reference can be made to the following content and will not be elaborated here. By abutting the ball head end of the ball screw 6 against the inclined surface, the generated force F can be perpendicular to the inclined surface, so that the component forces of the force F can all be used by the driving module 3, and no other component forces that affect the performance stability of the motor will be generated.

[0045] Such as Figure 5As shown, in some embodiments, the transmission part 32 in the driving module 3 may further include a first wall 321, a connecting rod 322, an elastic retaining piece 323, and a second wall 324 arranged in sequence along the first direction.

[0046] In some embodiments, the first wall 321 and the second wall 324 may be made of materials with a certain rigidity such as metal and plastic. The bottoms of the first wall 321 and the second wall 324 may be connected to each other or integrally formed through a connecting part 326. The elastic retaining piece 323 is disposed opposite to the second wall 324 to at least cooperate with the second wall 324 to form a driving part accommodating area for accommodating the piezoelectric driving part 31. The elastic retaining piece 323 may be a thin sheet having both a certain stiffness and flexibility. For example, the elastic retaining piece 323 may be a metal thin sheet, and its thickness may be 1.5 mm, 1 mm, 0.5 mm, etc. The bottom edge of the elastic retaining piece 323 may be fixed to the connecting part 326 between the first wall 321 and the second wall 324. In some embodiments, the piezoelectric driving part 31 may be placed between the elastic retaining piece 323 and the second wall 324. When the piezoelectric driving part 31 deforms along the first direction, one side thereof abuts against the second wall 324, and the other side can push the elastic retaining piece 323. In other embodiments, one side of the piezoelectric driving part 31 may be fixed to the second wall 324, and the other side is placed opposite to the elastic retaining piece 323. When the piezoelectric driving part 31 deforms along the first direction, the side thereof placed opposite to the elastic retaining piece 323 can push the elastic retaining piece 323. In still other embodiments, both sides of the piezoelectric driving part 31 may be fixedly connected to the second wall 324 and the elastic retaining piece 323 respectively. Since the second wall 324 has a greater stiffness relative to the elastic retaining piece 323, when the piezoelectric driving part 31 deforms, the elastic retaining piece 323 can be pushed.

[0047] One end of the connecting rod 322 is fixedly connected to the elastic retaining piece 323, and the other end is connected to the first wall 321 at least through a first elastic structure that can elastically deform along the first direction. The second friction surface 33 is disposed on the connecting rod 322. The fixing manner of the second friction surface 33 can be found in the foregoing text and will not be elaborated herein. In some embodiments, the material of the connecting rod 322 may be the same as that of the elastic retaining piece 323, and the two are integrally formed. In other embodiments, the connecting rod 322 may be plastic, ceramic, wood, etc., and it may be fixedly connected to the elastic retaining piece 323 by bonding, welding, etc. In some embodiments, the first elastic structure may be a structure such as a spring or a spring piece, or may be a flexible hinge.

[0048] When the elastic retaining piece 323 is pushed along the first direction, since the connecting rod 322 is fixedly connected to the elastic retaining piece 323 and elastically connected to the first wall 321, the connecting rod 322 will be pushed along the first direction at the same time. Thus, the second friction surface 33 disposed on the connecting rod 322 will also move along the first direction.

[0049] In some embodiments, the piezoelectric driving part 31 includes a piezoelectric stack formed by arranging more than one piezoelectric sheet in the first direction. The piezoelectric sheet can be a thin sheet made of piezoelectric ceramic or piezoelectric thin film. When an electric signal excitation in different directions is applied, the piezoelectric sheet can bulge towards different sides of itself. In some embodiments, the front and back sides of each piezoelectric sheet can be adjusted so that the front and back sides of more than one piezoelectric sheet in the piezoelectric stack face the same direction. When the piezoelectric stack is excited by an electric signal, each piezoelectric sheet can simultaneously bulge along the first direction or the reverse direction of the first direction. Macroscopically, the piezoelectric driving part 31 deforms along the first direction. In some embodiments, each piezoelectric sheet can be bonded together by an adhesive or bonded together in a molten state to form a piezoelectric stack. In some embodiments, there are gaps with a certain width between the piezoelectric sheets to varying degrees. When the piezoelectric sheets deform, these gaps will consume part of the deformation. That is to say, the deformation of the piezoelectric sheets will first fill these gaps, and then the piezoelectric stack will show deformation along the first direction. Therefore, in some embodiments, it is necessary to provide a certain pre-tightening force (such as the aforementioned first component force F1) for the piezoelectric driving part 31, and this pre-tightening force can significantly reduce the gaps between the piezoelectric sheets and improve the deformation efficiency of the piezoelectric driving part 31.

[0050] Figure 6 is an assembly schematic diagram of the base and the driving module shown in some embodiments of this specification. The driving module 3 can be placed in the second groove 12 of the base 1. In some embodiments, the transmission part 32 can be positioned in the second groove 12 by means of hole-shaft fit. Refer to Figure 3 , a positioning rod 121 is provided in the second groove 12, and the positioning rod 121 can be fixed to the bottom surface of the second groove 12 by bonding, welding or integral molding. Refer to Figure 5 , a through hole 325 is formed in the connecting part 326 of the transmission part 32, and the through hole 325 can be sleeved on the positioning rod 121, thereby preventing the driving module 3 from shifting in the second groove 12. In some embodiments, the lateral distance from the through hole 325 to the second wall 324 and the distance from the positioning rod 121 to the second side wall of the second groove 12 can be adjusted so that when the through hole 325 is sleeved on the positioning rod 121, the second wall 324 just contacts or substantially contacts the second side wall. As Figure 6 shown, the ball head end of the ball screw 6 can be screwed out from the first side wall of the second groove 12 to abut against the first wall 321. Among them, the first side wall and the second side wall are the relatively arranged side walls in the second groove 12.

[0051] Figure 7 is an assembly schematic diagram of the base, the rib and the driving module shown in some embodiments of this specification. As Figure 7As shown, after the base, the sliding member and the driving module are assembled, the rib 23 of the sliding member 2 is located in the first groove 11, the driving module 3 is located in the second groove 12, and the second friction surface 33 of the driving module 3 can face the first friction surface 24 on the rib 23 through the communication notch. As Figure 7 As shown, a threaded hole 5 is formed in the base 1. The threaded hole 5 penetrates through the outer side surface of the base 1 and the first side wall of the second groove 12 in the first direction. The inner wall of the threaded hole 5 has threads. The ball head screw 6 can be screwed into the threaded hole 5 from the outer side surface of the base 1. By rotating and pushing the ball head screw 6, its ball head end can be further screwed out of the threaded hole 5 and abutted against the inclined surface of the first wall 321 of the driving module 3, thereby pushing the driving module 3 towards the second side wall of the second groove 12 so that its second wall 324 abuts against the second side wall of the second groove 12. Such a setting can further prevent the driving module 3 from slipping in the first direction. When the piezoelectric driving part 31 deforms, the second friction surface 33 can be stably driven. On the other hand, when the ball head end of the ball head screw 6 is screwed out of the threaded hole 5 and abuts against the inclined surface of the first wall 321 of the driving module 3, the second friction surface 33 of the driving module 3 can also be pushed towards the first friction surface 24 to make the two friction surfaces in frictional contact.

[0052] In some embodiments, one end of the connecting rod 322 can also be connected to the first wall 321 through a second elastic structure, and the second elastic structure can elastically deform in a second direction perpendicular to the first direction (such as Figure 5 the y direction shown). On the one hand, the force generated by the ball head screw 6 abutting against the first wall 321 can press the second friction surface 33 tightly against the first friction surface 24. On the other hand, when particles are generated due to frictional wear between the two friction surfaces, the deformation space of the second elastic structure can make the particles between the friction surfaces adaptively roll into the potholes or groove channels on the friction surfaces, which can reduce the wear of the friction surfaces to a certain extent, improve the service life of the motor, and ensure the high smoothness of the motor drive. In some embodiments, the second elastic structure can be a spring or a spring sheet, or it can be a flexible hinge.

[0053] Figure 8 is an enlarged schematic view of the first elastic structure and the second elastic structure shown in some embodiments of this specification. As Figure 8As shown, the first elastic structure may be the first flexible hinge 301. The first flexible hinge 301 can be obtained by opening a through-hole in the first wall 321. "Through" may mean drilling through in a direction perpendicular to the plane of the figure. The cross-section of the through-hole (parallel to the plane of the figure) extends in the second direction (such as the y direction). As an example, the cross-section of the through-hole may be rectangular, and the long side of the rectangle is consistent with the y direction. When the connecting rod 322 is pushed in the x direction by the elastic flap 323, the through-hole is compressed, thereby providing space for the first flexible hinge 301 to deform in the x direction. When the elastic flap 323 resets, the through-hole also resets, and the connecting rod 322 also resets. The second elastic structure may be the second flexible hinge 302. As an example, a number of through-grooves may be opened on the first wall 321. Each through-groove extends in the x direction and is arranged in sequence in the y direction. A single through-groove only opens on one side of the first wall 321, and the opening directions of the number of through-grooves alternate in sequence, thereby forming the second flexible hinge 302. When particles appear between the first friction surface 24 and the second friction surface 33, due to the elastic deformation space of the second flexible hinge 302, the particles can push the second friction surface 33 to move away from the first friction surface 24 to a certain extent. At this time, the particles are likely to adaptively roll into the potholes or groove channels on the friction surface. After that, the second friction surface 33 rebounds under the action of the second flexible hinge 302 and re-abuts against the first friction surface 24.

[0054] In some embodiments of this specification, the first elastic structure and the second elastic structure can be directly formed by machining on the first wall, eliminating additional structural components and further streamlining the structure of the drive module.

[0055] Figure 9 is a schematic diagram of the control waveform of the friction inertial motor shown in some embodiments of this specification. As Figure 9 shown, the piezoelectric drive part of the friction inertial motor provided in some embodiments of this specification can be driven by a sawtooth wave or a triangular wave. The abscissa in the figure is time, and the ordinate is the voltage value of the control signal. The left side of the dashed line is the control waveform for driving the sliding part to move forward, and the right side of the dashed line is the control waveform for driving the sliding part to move backward. It should be understood that forward and backward are relative. In some embodiments, both forward and backward are parallel to the first direction (such as the x direction). The x direction can be taken as the forward direction, and the direction opposite to the x direction can be taken as the backward direction, and vice versa.

[0056] Combined with Figure 1, when the control signal applied to the piezoelectric driving part of the friction inertial motor is like the control waveform in the first cycle on the left side of the dashed line, the voltage of the control signal rises slowly. At this time, the piezoelectric driving part deforms slowly in the x direction, pushing the second friction surface to move slowly. Under the action of static friction, the first friction surface is driven to move in the x direction, and then the sliding part 2 moves in the x direction. When the voltage of the control signal reaches the maximum value, it drops rapidly. At this time, the piezoelectric driving part deforms rapidly in the reverse direction of the x direction, driving the second friction surface to move rapidly in the reverse direction of the x direction. The sliding part 2 remains stationary due to inertia, and the friction between the two friction surfaces becomes sliding friction. By analogy, under the drive of the control waveforms in several cycles on the left side of the dashed line, the sliding part can move smoothly in the x direction.

[0057] When the control signal applied to the piezoelectric driving part of the friction inertial motor is like the control waveform in the first cycle on the right side of the dashed line, the voltage of the control signal rises rapidly. At this time, the piezoelectric driving part moves rapidly in the first direction, driving the second friction surface to move rapidly in the first direction. The sliding part 2 remains stationary due to inertia, and the friction between the two friction surfaces is sliding friction. When the voltage of the control signal reaches the maximum value, it begins to drop slowly. At this time, the piezoelectric driving part deforms slowly in the reverse direction of the x direction, pushing the second friction surface to move slowly. Under the action of static friction, the first friction surface is driven to move in the reverse direction of the x direction, and then the sliding part 2 moves in the reverse direction of the x direction. By analogy, under the drive of the control waveforms in several cycles on the right side of the dashed line, the sliding part can move smoothly in the reverse direction of the x direction.

[0058] Thus, by changing the slope of the rise or fall of the control waveform, the forward and reverse driving of the friction inertial motor can be achieved.

[0059] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only an example and does not constitute a limitation to this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this specification. Such modifications, improvements, and corrections are taught in this specification, so such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of this specification.

Claims

1. A friction inertia motor, characterized in that: include: Base (1); A sliding member (2) is slidably matched with the base (1) and is capable of sliding along a first direction; the sliding member (2) is provided with a bearing surface (21) for bearing a load and a first friction surface (24) perpendicular to the bearing surface (21); The driving module (3) comprises a piezoelectric driving part (31), a transmission part (32) and a second friction surface (33); the second friction surface (33) is in frictional contact with the first friction surface (24); the deformation of the piezoelectric driving part (31) can be transmitted to the second friction surface (33) through the transmission part (32), so as to drive the second friction surface (33) to move along the first direction and then drive the sliding member (2) to slide along the first direction through frictional contact with the first friction surface (24).

2. The motor according to claim 1, characterized in that It also includes a guide member (4) fixed on the base (1); The first guide surface (41) of the guide member (4) is slidably connected to the second guide surface (22) of the sliding member (2) via a track extending along the first direction.

3. The motor according to claim 2, characterized in that The number of the guide members (4) is 2; the two guide members (4) are arranged on the base (1) at intervals along a second direction perpendicular to the first direction, and the first guide surfaces (41) of the two guide members (4) are arranged opposite to each other; The sliding member (2) is located between the two guide members (4), and the second guide surfaces (22) are respectively provided on the two sides thereof opposite to the two guide members (4); the two second guide surfaces (22) of the sliding member (2) are respectively slidably connected to the first guide surfaces (41) of the two guide members (4) via rails.

4. The motor according to claim 1, characterized in that The driving module (3) comprises a first wall (321); the first wall (321) has an inclined surface which is at an angle less than 90° relative to the second friction surface (33); the inclined surface of the first wall (321) is used to decompose the force acting thereon into a first component force parallel to the second friction surface (33) and a second component force perpendicular to the second friction surface (33), wherein the first component force can provide a preload force for the deformation of the piezoelectric driving part (31), and the second component force can provide a positive pressure for the friction contact between the second friction surface (33) and the first friction surface (24).

5. The motor according to claim 4, characterized in that The driving module (3) is located on the base (1) and on one side of the first friction surface (24), so that the second friction surface (33) can be opposite to and in frictional contact with the first friction surface (24); The motor further comprises a ball screw (6) threadably connected to the base (1); the ball end of the ball screw (6) abuts against the inclined surface so as to provide a force acting on the inclined surface.

6. The motor according to claim 1, characterized in that The transmission part (32) comprises a first wall (321), a connecting rod (322), an elastic blocking sheet (323), and a second wall (324) which are sequentially arranged along the first direction; The elastic baffle (323) is arranged opposite to the second wall (324) to at least cooperate with the second wall (324) to form a drive unit accommodating area for accommodating the piezoelectric drive unit (31); one end of the connecting rod (322) is fixedly connected to the elastic baffle (323), and the other end is connected to the first wall (321) at least via a first elastic structure; the first elastic structure is capable of elastic deformation along the first direction; The second friction surface (33) is arranged on the connecting rod (322); when the piezoelectric driving part (31) located in the driving part accommodating area is deformed, the end of the piezoelectric driving part (31) close to the elastic baffle (323) can push the elastic baffle (323) and the connecting rod (322) to move, thereby driving the second friction surface (33) to move along the first direction.

7. The motor according to claim 6, characterized in that The sliding member (2) has a convex strip (23) extending along the first direction on a side opposite to the bearing surface (21), and the first friction surface (24) is provided on one side of the convex strip (23); The driving module (3) is located on the base (1) and on one side of the first friction surface (24), so that the second friction surface (33) can be opposite to and in frictional contact with the first friction surface (24).

8. The motor according to claim 7, characterized in that The base (1) is provided with a first groove (11) for accommodating the convex strip (23) and a second groove (12) for accommodating the drive module (3); a connecting gap is provided between the first groove (11) and the second groove (12), so that the second friction surface (33) is in frictional contact with the first friction surface (24) through the connecting gap.

9. The motor according to claim 8, characterized in that The piezoelectric driving unit (31) comprises a piezoelectric stack formed by one or more piezoelectric sheets arranged along the first direction; The first wall (321) has an inclined surface with an angle less than 90° relative to the second friction surface (33); A threaded hole (5) is provided in the base (1), and the threaded hole (5) penetrates between the outer side surface of the base (1) and the first side wall of the second groove (12) along the first direction; The threaded hole (5) has a ball screw (6) threadedly connected thereto, the ball end of the ball screw (6) abuts against the inclined surface of the first wall (321), thereby abutting the second wall (324) against the second side wall of the second groove (12); the second side wall is opposite to the first side wall.

10. The motor according to claim 8, characterized in that The transmission part (32) is positioned in the second groove (12) by means of hole-shaft matching.

11. The motor according to claim 6, characterized in that The other end of the connecting rod (322) is also connected to the first wall (321) via a second elastic structure; the second elastic structure is capable of elastically deforming along a second direction perpendicular to the first direction.

12. The motor according to claim 11, characterized in that The first elastic structure and / or the second elastic structure comprises a flexible hinge.

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