Micro-displacement driving device

Abstract

The invention provides an infinitesimal displacement driving device which can convert rotation of each step angle of a motor into submicron displacement driving, and belongs to the related technical field of precision machinery, optical instruments and the like. In order to realize the function of the device, two stages of flexible structures connected in series are arranged on the driving structure, each stage of flexible structure can respectively realize amplification and reduction of driving force and driving displacement, and a motor converts rotation into linear motion through a ball screw and a nut and drives the first stage of flexible structure; after the motor rotates and passes through the ball screw nut and the two-stage flexible structure, rotation of each step angle can be converted into submicron-level displacement driving, and the driving force of the motor is amplified. The invention has the advantages of simple and reliable principle and compact structure, and can realize low-cost high-precision driving.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of micro displacement driving device, belongs to precision machinery and optical instrument and other related technical fields. BACKGROUND

[0002] In the field of precision machinery and optical instrument, micro displacement driving device is one of the key technologies to realize high-precision positioning and attitude control, but in the existing technology, traditional micro displacement driving device usually adopts piezoelectric ceramic, electromagnetic drive and other ways, although it is excellent in precision and response speed, but the manufacturing cost is higher, which limits its widespread use in some fields, the present application aims to provide a kind of low-cost micro displacement driving device, which realizes the balance of low cost and high precision by simplifying structure, general transmission structure and using ordinary materials. SUMMARY

[0003] In order to achieve the above purpose, a kind of micro displacement driving device is invented. In order to realize the method, two-stage flexible structure is arranged on the driving structure, each stage of flexible structure can realize the amplification and reduction of driving force and driving displacement respectively, the motor converts rotation into linear motion through ball screw and nut, and drives the first stage flexible structure, and the motor rotation converts each step angle rotation into sub-micron displacement driving after ball screw nut and two-stage flexible structure, and amplifies the motor driving force. The number of flexible structure in series arranged on the driving structure is not limited to two stages, the more the number of stages, the higher the driving precision, but the driving stroke will be smaller, the structure volume will increase, depending on the use demand.

[0004] The specific technical scheme is: a kind of micro displacement driving device, comprising: driving structure, bearing cover, bearing, screw nut, ball screw, bearing seat, shaft coupling, driving motor;Driving structure includes base and U-shaped frame and micro displacement output surface, two first stage flexible structures are symmetrically arranged in the upper part of U-shaped frame, two first stage flexible structures are connected with micro displacement output surface, two second stage flexible structures are extended into the frame from the middle part of U-shaped frame, driving motor is installed on base, the output shaft of driving motor is connected with ball screw through shaft coupling, bearing seat is cylindrical structure, bearing seat is installed on base and surrounds driving motor periphery, the upper end of bearing seat is provided with annular groove for installing bearing, the bearing is used to install ball screw, the top end of ball screw is installed bearing, the bearing is installed on bearing cover, bearing cover is installed on bearing seat, screw nut is arranged between the upper and lower bearings of ball screw, the outer side of screw nut is connected with one end of second stage flexible structure, the other end of second stage flexible structure is connected with the lower end of first stage flexible structure, the upper end of first stage flexible structure is connected through the upper frame edge of U-shaped frame, micro displacement output surface is used to install load, output displacement.

[0005] Further, the screw nut and the second-stage flexible structure are in interference fit, and low-temperature assembly technology is adopted, the screw nut is cooled in liquid nitrogen before assembly, and the size is reduced, and then the screw nut is installed with the second-stage flexible structure.

[0006] Further, two-stage serial flexible structures are arranged on the driving structure, each stage of the flexible structure realizes amplification and reduction of driving force and driving displacement, the driving motor converts rotation into linear motion through the ball screw and the screw nut, and drives the first-stage flexible structure, and the driving motor converts the rotation of each step angle into sub-micron displacement driving after the ball screw, the screw nut and the two-stage flexible structures, and amplifies the driving force of the motor.

[0007] Further, the number of the serial flexible structures arranged on the driving structure 1 is not limited to two stages.

[0008] Further, the ball screw without gap is matched with the screw nut.

[0009] Further, the driving stroke of the device is limited by the stress generated by the deformation of the first-stage flexible structure of the driving structure, and the stress of the first-stage flexible structure at the limit position of the driving stroke does not exceed the yield strength limit of the material.

[0010] Further, the driving precision Delta of the device, i.e. the driving amount of the driving motor per step angle, is related to the length D of the first-stage flexible structure, the length L of the second-stage flexible structure, the angle alpha of the first-stage flexible structure with the horizontal plane, the angle beta of the second-stage flexible structure with the vertical plane, the lead S of the ball screw, the motor step angle delta and the rotation angle theta of the motor relative to the initial position, and the relationship is as follows:

[0011] .

[0012] Further, the driving structure is preferably made of titanium alloy.

[0013] Further, the processing technology of the driving structure is preferably wire cutting slow wire cutting.

[0014] Further, the rotation angle theta of the driving motor 8 relative to the initial position is zero, i.e. the driving precision Delta of the device is as follows when the device is in the initial position:

[0015] .

[0016] Advantages of the present application:

[0017] The application adopts the ball screw without gap matched with the nut to avoid the empty return and gap in the whole mechanism, and further improve the driving precision. The driving stroke of the device is limited by the stress generated by the deformation of the first flexible structure of the driving structure. The stress of the first flexible structure at the limit position of the driving stroke should not exceed the yield strength limit of the material, and the safety margin and fatigue factors should also be fully considered. The application has simple and reliable principle, compact structure, strong universality of each part, easy-to-get material and low cost. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a three-dimensional partial sectional view of the application;

[0019] Figure 2 It is a three-dimensional schematic view of the application;

[0020] Figure 3 It is a plane schematic view of the application.

[0021] In the figure: 1 is a driving structure; 2 is a bearing cover; 3 is a bearing; 4 is a screw nut; 5 is a ball screw; 6 is a bearing seat; 7 is a shaft coupling; 8 is a driving motor.

[0022] Base 1-1; U-shaped frame 1-2; micro displacement output surface 1-3. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the application more clear and obvious, the application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the application and not to limit the application. In addition, the technical features involved in each embodiment of the application described below can be combined with each other as long as there is no conflict. In order to achieve the above purpose, the application adopts the following technical scheme.

[0024] As Figure 1 , Figure 2As shown, the present application provides a micro-displacement driving device, comprising: a driving structure 1, a bearing cover 2, a bearing 3, a screw nut 4, a ball screw 5, a bearing seat 6, a shaft coupling 7, a driving motor 8; the driving structure 1 comprises a base 1-1, a U-shaped frame 1-2 integrally formed on the base 1-1, and a micro-displacement output surface 1-3, the upper part of the U-shaped frame 1-2 is symmetrically provided with two first-level flexible structures, the two first-level flexible structures are connected with the micro-displacement output surface 1-3, the middle part of the U-shaped frame 1-2 extends two second-level flexible structures into the frame, the driving motor 8 is installed on the base 1-1, the output shaft of the driving motor 8 is connected with the ball screw 5 through the shaft coupling 7, the bearing seat 6 is a cylindrical structure, the bearing seat 6 is also installed on the base 1-1 and surrounds the periphery of the driving motor 8, the upper end of the bearing seat 6 is provided with an annular groove for installing a bearing, the bearing is used for installing the ball screw 5, the top end of the ball screw 5 is installed with a bearing, the bearing is installed on the bearing cover 2, the bearing cover 2 is installed on the bearing seat 6, the screw nut 4 is arranged between the upper and lower bearings of the ball screw 5, one end of the screw nut 4 is connected with the second-level flexible structure, the screw nut 4 and the second-level flexible structure are connected by interference fit, low-temperature assembly technology is adopted, the screw nut 4 is cooled in liquid nitrogen before assembly, and the size is reduced before being installed with the second-level flexible structure. The other end of the second-level flexible structure is connected to the lower end of the first-level flexible structure, and the upper end of the first-level flexible structure is connected through the upper frame edge of the U-shaped frame 1-2. The micro-displacement output surface 1-3 is used for installing a load and outputting displacement.

[0025] The two-level flexible structures in series are arranged on the driving structure 1, each level of the flexible structure can respectively realize amplification and reduction of driving force and driving displacement, the driving motor 8 converts rotation into linear motion through the ball screw 5 and the screw nut 4, and drives the first-level flexible structure, and the driving motor 8 can convert the rotation of each step angle into sub-micron displacement driving and amplify the motor driving force after rotating through the ball screw 5, the screw nut 4 and the two-level flexible structures. The number of flexible structures arranged in series on the driving structure 1 is not limited to two levels, the more the number of levels, the higher the driving precision, but the driving stroke will be smaller, the structure volume will increase, and it is determined according to the use requirement. The ball screw 5 and the screw nut 4 are matched without gap, avoiding the existence of empty return and gap in the whole mechanism, and further improving the driving precision. The driving stroke of the device is limited by the stress generated by the deformation of the first-level flexible structure of the driving structure 1, the stress of the first-level flexible structure at the limit position of the driving stroke should not exceed the yield strength limit of the material, and sufficient consideration should also be given to the safety margin and fatigue factors.

[0026] The driving structure 1 is preferably made of titanium alloy (such as TC4), which has high yield strength and can improve the fatigue strength of the structure. Avoiding failure caused by long-term reciprocating deformation. The processing technology is preferably wire cutting slow wire cutting, avoiding the stress residue generated by mechanical processing, and controlling the surface defects, ensuring the symmetry of the two sides processing. Figure 3As shown, the driving precision Δ of the device, i.e. the driving amount of the driving motor 8 per step angle, is related to the first-stage flexible structure length D, the second-stage flexible structure length L, the first-stage flexible structure and horizontal plane angle α, the second-stage flexible structure and vertical plane angle β, the lead S of the ball screw 5, the motor step angle δ and the motor relative initial position rotation angle θ as follows:

[0027] ;

[0028] When the first-stage flexible structure and horizontal plane angle α is 6°, the second-stage flexible structure and vertical plane angle β is 3°, the motor step angle δ is 1.8°, and the ball screw lead S is 1.5 mm, the initial driving precision Δ of the device is 0.04 μm, and the driving precision can be further improved by subdividing the step angle of the driving motor 8.

[0029] ;

[0030] When the first-stage flexible structure and horizontal plane angle α is 6°, the second-stage flexible structure and vertical plane angle β is 3°, the motor step angle δ is 1.8°, and the ball screw lead S is 1.5 mm, the initial driving precision Δ of the device is 0.04 μm, and the driving precision can be further improved by subdividing the step angle of the driving motor 8.

[0031] The parts of the present application not described in detail are known in the art.

Claims

1. A micro-displacement driving device, characterized by comprising: The device comprises a driving structure, a bearing cover, a bearing, a screw nut, a ball screw, a bearing seat, a shaft coupling, and a driving motor. The driving structure comprises a base and a U-shaped frame, and a micro displacement output surface. Two first-stage flexible structures are symmetrically arranged on the upper part of the U-shaped frame, and the two first-stage flexible structures are connected with the micro displacement output surface. Two second-stage flexible structures extend inward from the middle part of the U-shaped frame. The driving motor is installed on the base. The output shaft of the driving motor is connected with the ball screw through the shaft coupling. The bearing seat is in a cylindrical structure, and is installed on the base and surrounds the periphery of the driving motor. An annular groove is arranged on the upper end of the bearing seat for installing the bearing. The bearing is used for installing the ball screw. The top end of the ball screw is installed with a bearing, and the bearing is installed on the bearing cover. The bearing cover is installed on the bearing seat. The screw nut is arranged between the upper and lower bearings of the ball screw. The outer side of the screw nut is connected with one end of the second-stage flexible structure. The other end of the second-stage flexible structure is connected with the lower end of the first-stage flexible structure. The upper end of the first-stage flexible structure is connected through the upper frame edge of the U-shaped frame. The micro displacement output surface is used for installing a load and output displacement. The screw nut and the second-stage flexible structure are connected through interference fit, and low-temperature assembly technology is adopted. Before assembly, the screw nut is cooled in liquid nitrogen, and then the size is reduced for installation with the second-stage flexible structure.

2. The microminiature displacement drive device according to claim 1, wherein: Two-stage serial flexible structures are arranged on the driving structure. Each stage of the flexible structure realizes amplification and reduction of driving force and driving displacement. The driving motor converts rotation into linear motion through the ball screw and the screw nut, and drives the first-stage flexible structure. The driving motor converts the rotation of each step angle into sub-micron displacement driving, and amplifies the motor driving force after rotation through the ball screw, the screw nut and the two-stage flexible structures.

3. The micromovement driving device according to claim 1, wherein: The number of the serial flexible structures arranged on the driving structure is not limited to two stages.

4. A micro-displacement driving device according to claim 3, characterized in that: The ball screw and the screw nut are connected without gap.

5. The micromovement driving device according to claim 1, wherein: The driving stroke of the device is limited by the stress generated by the deformation of the first-stage flexible structure of the driving structure. The stress of the first-stage flexible structure at the limit position of the driving stroke does not exceed the yield strength limit of the material.

6. The micromovement driving device according to claim 1, wherein: The driving precision Δ of the device, i.e. the driving amount of the driving motor per step angle, is related to the length D of the first-stage flexible structure, the length L of the second-stage flexible structure, the angle α of the first-stage flexible structure with the horizontal plane, the angle β of the second-stage flexible structure with the vertical plane, the lead S of the ball screw, the motor step angle δ, and the rotation angle θ of the motor relative to the initial position.

7. The micromovement driving device according to claim 1, wherein: The driving structure is preferably made of titanium alloy. 。 8. The micromovement driving device according to claim 1, wherein: The processing technology of the driving structure is preferably wire cutting slow wire cutting.

9. The micromovement driving device according to claim 1, wherein: ​ 10. The micromovement driving device according to claim 7, wherein: The driving motor rotates an angle θ relative to the initial position, and the driving precision Δ of the device is zero when the device is in the initial position. .

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