A device for testing and compensating the axial deformation of circular grating

Abstract

A circular grating axial deformation test and compensation device comprises a bearing seat to be tested installed in a base, a shaft to be tested is installed in the bearing seat to be tested, a bearing to be tested is fixedly installed between the bearing seat to be tested and the shaft to be tested via a bearing cap of the shaft to be tested and a nut of the shaft to be tested, a handle is connected to one end of the shaft to be tested, a transition shaft is connected to the other end of the shaft to be tested, the transition shaft is connected to one end of a grating shaft via an elastic shaft, a grating bearing seat is mounted on the grating shaft, a grating bearing is fixedly mounted between the grating shaft and the grating bearing seat via a grating shaft bearing cap and a grating shaft nut, a grating seat is connected to the other end of the grating shaft, a circular grating is mounted on the grating seat, a reading head seat and a reading head mounted on the end face of the grating bearing seat are arranged outside the circular grating, and 6 gaskets are evenly distributed between the base and the bearing seat to be tested. When testing the output accuracy of the circular grating, the gasket is installed between the bearing seat to be tested and the base to simulate the change in the axial direction of the shaft system to be tested due to the influence of temperature.

Description

Technical Field

[0001] The invention relates to a circular grating axial deformation testing and compensation device. Background Art

[0002] Commonly used angle sensors include circular gratings, circular induction synchronizers, time gratings and rotary transformers. Circular gratings, as a precision measurement tool, have been widely used in precision instruments, coordinate measurement, precise positioning and high-precision precision machining. Due to manufacturing and installation errors, there is a deviation between the actual output accuracy of the circular grating and its own system accuracy. At present, the measures to correct the output error of the circular grating are mainly in two aspects: (1) When the measured axis system is constant, try to use a micrometer to reduce the eccentricity error of the circular grating; (2) Use an autocollimator and a polyhedron to measure the reading of the circular grating when the measured axis rotates one circle, and use the measured data to correct the system error of the axis system. However, this method is only applicable when the ambient temperature of the measured axis system is constant and the system error output of the measured axis system is stable. For example, in the development process of inertial navigation test equipment, the temperature chamber is often fixed to the inner frame, and the work table where the inertial navigation is installed is inside the temperature chamber. Therefore, the rise and fall of the temperature of the temperature chamber will cause the frame fixed with it to deform, and then drive the measured shaft to deform axially, and finally cause the circular grating to move in both axial and radial directions. Therefore, the output accuracy of the circular grating under this working condition is unstable and inaccurate. Summary of the invention

[0003] The purpose of the present invention is to provide a circular grating axial deformation testing and compensation device to solve the problems in the above-mentioned background technology.

[0004] The technical solution adopted to achieve the above-mentioned purpose is a circular grating axial deformation testing and compensation device, comprising a measured bearing seat installed in a base, a measured shaft installed in the measured bearing seat, a measured bearing is fixedly installed between the measured bearing seat and the measured shaft via a measured shaft bearing cover and a measured shaft nut, one end of the measured shaft is connected to a handle, the other end of the measured shaft is connected to a transition shaft, the transition shaft is connected to one end of a grating shaft via an elastic shaft, a grating bearing seat fixed on the base is mounted on the grating shaft, a grating bearing is fixedly installed between the grating shaft and the grating bearing seat via a grating shaft bearing cover and a grating shaft nut, the other end of the grating shaft is connected to a grating seat, a circular grating is mounted on the grating seat, a reading head seat and a reading head installed on the end face of the grating bearing seat are provided on the outside of the circular grating; 6 gaskets are evenly distributed between the base and the measured bearing seat.

[0005] In the present invention, the elastic shaft comprises a grating shaft connecting end, and groove structures are symmetrically connected on both sides of the grating shaft connecting end, and the groove structures are connected to transition shaft connecting ears; the elastic shaft is an axially deformable coupling that can transmit the rotation angle of the measured shaft in the circumferential tangent.

[0006] In the present invention, the six gaskets are six gaskets of equal height installed between the measured bearing seat and the base, and are used to simulate the change in the axial lengthening or shortening of the measured shaft.

[0007] Beneficial Effects

[0008] Compared with the prior art, the present invention has the following advantages.

[0009] 1. The present invention can simulate the axial deformation of the measured shaft before the circular grating is formally installed on the equipment, and can truly output the interference factors to the parts connected to the measured shaft, so as to timely verify the output accuracy of the circular grating component;

[0010] 2. The present invention adds a transition axis and an elastic axis between the measured axis and the grating axis, and utilizes the characteristics of the elastic axis itself to filter out the axial interference from the measured axis;

[0011] 3. The present invention adds an independent precision axis system to the circular grating, further isolating the interference factors from the measured axis. At this time, the output accuracy of the circular grating can be guaranteed by simply improving the rotation accuracy of the circular grating axis system and the installation accuracy of the circular grating. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the three-dimensional cross-sectional structure of the front end of the present invention;

[0013] Figure 2 It is a schematic diagram of the three-dimensional cross-sectional structure of the rear end of the present invention;

[0014] Figure 3 It is a front-end three-dimensional diagram of the present invention;

[0015] Figure 4 It is a three-dimensional diagram of the back end of the present invention;

[0016] Figure 5 is a three-dimensional diagram of the elastic axis in the present invention;

[0017] Figure 6 is a three-dimensional diagram of the base in the present invention;

[0018] As shown in the figure: 1. gasket, 2. base, 3. handle, 4. measured shaft, 5. measured shaft bearing cover, 6. measured bearing seat, 7. measured bearing, 8. measured shaft nut, 9. transition shaft, 10. elastic shaft, 11. grating shaft, 12. grating bearing, 13. grating bearing seat, 14. reading head seat, 15. reading head, 16. circular grating, 17. grating seat, 18. grating shaft nut, 19. grating shaft bearing cover, 101. grating shaft connecting end, 102. groove structure, 103. transition shaft connecting ear. DETAILED DESCRIPTION

[0019] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0020] A device for testing and compensating the axial deformation of a circular grating, such as Figure 1-Figure 6 As shown, it includes a measured bearing seat 6 installed in the base 2, a measured shaft 4 is installed in the measured bearing seat 6, a measured bearing 7 is fixedly installed between the measured bearing seat 6 and the measured shaft 4 via a measured shaft bearing cover 5 and a measured shaft nut 8, one end of the measured shaft 4 is connected to a handle 3, the other end of the measured shaft 4 is connected to a transition shaft 9, the transition shaft 9 is connected to one end of a grating shaft 11 via an elastic shaft 10, a grating bearing seat 13 is mounted on the grating shaft 11, a grating bearing 12 is fixedly installed between the grating shaft 11 and the grating bearing seat 13 via a grating shaft bearing cover 19 and a grating shaft nut 18, the other end of the grating shaft 11 is connected to a grating seat 17, a circular grating 16 is mounted on the grating seat 17, a reading head seat 14 is installed on the circular grating 16, and a reading head 15 is provided on one side of the reading head seat 14; 6 gaskets 1 are evenly distributed between the base 2 and the measured bearing seat 6.

[0021] The elastic shaft 10 comprises a grating shaft connection end 101, and groove structures 102 are symmetrically connected on both sides of the grating shaft connection end 101, and the groove structure 102 is connected to the transition shaft connection ear 103; the elastic shaft 10 is an axially deformable coupling that can transmit the rotation angle of the measured shaft in the circumferential tangent.

[0022] The six gaskets 1 are six gaskets of equal height installed between the measured bearing seat 6 and the base 2, and are used to simulate the change in the axial lengthening or shortening of the measured shaft.

[0023] In the simulation of actual working conditions, the present invention causes the measured shaft to have an axial deformation of 0.05mm to 0.2mm due to temperature changes, and the deformation is transferred to the transition shaft; an elastic shaft is installed between the transition shaft and the grating shaft to isolate the deformation of the measured shaft along the axial direction to prevent such deformation from affecting the accuracy of the circular grating. In addition, an independent precision circular grating axis system is added to the circular grating assembly to improve the rotation accuracy of the circular grating axis system and the installation accuracy of the circular grating, which can improve and stabilize the output accuracy of the circular grating.

[0024] In the present invention, when the gasket 1 is specifically manufactured, 4 groups of gaskets 1 are first manufactured, each group of gaskets 1 is composed of 6 gaskets of equal height and thickness, and the thicknesses of the 4 groups of gaskets 1 are 0.05mm, 0.1mm, 0.15mm and 0.2mm respectively; when testing the output accuracy of the circular grating, the 4 groups of gaskets 1 are sequentially installed between the measured bearing seat 6 and the base 2 to simulate the change in the axial direction of the measured shaft system due to the influence of temperature; a pair of precision measured bearings 7 are installed in the measured bearing seat 6, and the measured shaft 4 is installed in the measured bearing 7. The measured bearing 7 is axially fixed by the measured shaft bearing cover 5 and the measured shaft nut 8 respectively, a handle 3 is installed at the left end of the measured shaft 4 to facilitate the rotation of the measured shaft 4, and a transition shaft 9 is installed at the right end of the measured shaft 4 to transmit all information of the measured shaft 4 to the grating shaft 11 In order to filter the axial movement of the measured shaft 4, an elastic shaft 10 is installed between the transition shaft 9 and the grating shaft 11, so as to protect the grating shaft 11 from external interference factors to the maximum extent; specifically, the grating bearing seat 13 is installed at the right end of the base 2, and the grating bearing 12 is installed inside the grating bearing seat 13. The grating bearing 12 and the grating shaft 11 are locked with a grating shaft nut 18. The grating shaft bearing cover 19 is used to fix the grating bearing 12 to prevent the grating bearing 12 from axial movement; then the grating seat 17 and the circular grating 16 are calibrated in turn by the micrometer, the grating seat 17 is installed at the right end of the grating shaft 11, and the circular grating 16 is fixed on the outer circle of the grating seat 17. The reading head 15 optimizes the output signal of the circular grating 16 by adjusting the height and radial position of the reading head seat 14.

[0025] In specific use of the present invention, the base 2 is fixed on the ground, a group of gaskets 1 and a measured bearing seat 6 are sequentially installed at the left end of the base 2, a pair of measured bearings 7 are installed inside the measured bearing seat 6, the inner ring of the measured bearing 7 is inserted into the measured shaft 4 and the inner ring of the measured bearing 7 is axially locked with two measured shaft nuts 8, the measured shaft bearing cover 5 is fixed to the measured bearing seat 6 and presses the outer ring of the measured bearing 7, in order to facilitate manual rotation of the measured shaft 4, a handle 3 is installed at the left end of the measured shaft 4, and a transition shaft 9 is installed at the right end of the measured shaft 4 to transmit the rotational motion of the measured shaft 4 to the right.

[0026] A grating bearing seat 13 is fixed at the right end of the base 2, and a pair of precision grating bearings 12 are installed in the inner hole of the grating bearing seat 13. The inner hole of the grating bearing 12 is inserted into the grating shaft 11, and the grating shaft nut 18 is used to axially lock the grating shaft 11 so that the ring of the grating bearing 12 is fixed on the grating shaft 11. Then the grating shaft bearing cover 19 is fixed to the grating bearing seat 13 and the outer ring of the grating bearing 12 is pressed to prevent the grating bearing 12 from axial movement.

[0027] Fix the grating seat 17 at the axial end of the grating shaft 11, and fix the circular grating 16 on the outer circle of the grating seat 17. During the installation process, the radial runout of the grating seat 17 should be continuously calibrated to within ±0.001mm using a micrometer. Based on this, calibrate the radial runout and end runout of the circular grating 16, and adjust the runout of the circular grating 16 to the minimum according to the use requirements.

[0028] The reading head seat 14 and the reading head 15 are installed on the end face of the grating bearing seat 13. During the installation process, the height of the reading head seat 14 should be processed as required, and then the reading head 15 and the reading head seat 14 should be fixed and the position of the reading head seat 14 should be continuously adjusted in the radial and tangential directions of the circular grating 16, so that the relative position of the reading head 15 and the circular grating 16 is optimal, and the output signal of the reading head 15 is also optimal.

[0029] An elastic shaft 10 is installed between the transition shaft 9 and the grating shaft 11 to connect the two independent shaft systems. Relying on the characteristics of the elastic shaft 10 itself, the axial variation of the measured shaft 4 can be filtered out while transmitting the angle information of the measured shaft 4.

[0030] Due to limited conditions, only four axial variation test states can be discretely simulated. In actual use, this axial variation is continuous, not four independent states. It can be foreseen that even with continuous axial variation, the circular grating component equipped with an elastic shaft and an independent axis system can filter out the axial variation within ±0.2mm and complete the stable output of the circular grating signal.

[0031] The grating bearing 12 used in the present invention is a standard bearing, and is also applicable to replacing the standard bearing with a ball bearing.

[0032] The angle sensor device in the present invention is a circular grating, and a circular induction synchronizer is also suitable for this application.

[0033] The present invention simulates the axial deformation of the measured shaft 4 in actual working conditions by adjusting the thickness of each group of gaskets 1, so that the deformation is transmitted in the axial direction. In order to stabilize the output accuracy of the circular grating 16, an independent set of precision axis system is added to the circular grating 16, and the circular grating 16 is installed on the grating axis 11 through the grating seat 17; in addition, the deformation of the measured shaft 4 transmitted in the axial direction is isolated by the elastic shaft 10, the grating axis 11 only receives the angle information from the measured shaft 4, and the output accuracy of the grating is stabilized by the accuracy of the grating axis system.

Claims

1. A circular grating axial deformation test and compensation device, comprising a bearing seat (6) to be tested installed in a base (2), characterized in that: A measured shaft (4) is installed in the measured bearing seat (6); a measured bearing (7) is fixedly installed between the measured bearing seat (6) and the measured shaft (4) via a measured shaft bearing cover (5) and a measured shaft nut (8); one end of the measured shaft (4) is connected to a handle (3); the other end of the measured shaft (4) is connected to a transition shaft (9); the transition shaft (9) is connected to one end of a grating shaft (11) via an elastic shaft (10); a grating bearing seat (13) fixed on the base (2) is sleeved on the grating shaft (11); a grating bearing (12) is fixedly installed between the grating shaft (11) and the grating bearing seat (13) via a grating shaft bearing cover (19) and a grating shaft nut (18); the other end of the grating shaft (11) is connected to a grating seat (17); The invention is provided with a circular grating (16), and a reading head seat (14) and a reading head (15) are arranged on the outer side of the circular grating (16) and are mounted on the end surface of the grating bearing seat (13); six gaskets (1) are evenly distributed between the base (2) and the measured bearing seat (6); the elastic shaft (10) comprises a grating shaft connecting end (101), and groove structures (102) are symmetrically connected on both sides of the grating shaft connecting end (101), and the groove structures (102) are connected to transition shaft connecting ears (103); the elastic shaft (10) is an axially deformable coupling that can transmit the rotation angle of the measured shaft in the circumferential tangent direction; the six gaskets (1) are six equal-height gaskets installed between the measured bearing seat (6) and the base (2), and are used to simulate the change in the axial extension or shortening of the measured shaft.

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