A high-precision single-axis turntable with an ultra-wide speed range

Abstract

The invention discloses a high-precision single-axis turntable with an ultra-wide speed range, comprising a protective cover, a work surface, a spindle, a high-precision angular contact ball bearing, a bearing locking device, a lifting ring, a base, an AC servo motor, a high-precision angular contact ball bearing, a reading head (1), an angle sensor (1), an adjustment pad, an angle sensor (2), a reading head (2), a slip ring and a user connection socket 16. The invention is characterized in that: the invention adopts a modular design, and is designed with two sets of angle measurement systems. The two systems share a mechanical platform body. The system adopts an AC servo motor for direct drive and a high-precision bearing as a supporting structural member. The connection is convenient and efficient. Considering safety, the turntable mechanical platform body is designed with a protective cover. The overall design is scientific and reasonable, and the operation is simple, convenient, flexible and fast, which overcomes the shortcomings of the prior art.

Description

Technical Field

[0001] The present invention relates to the field of inertial testing equipment turntables, and in particular to a high-precision single-axis turntable that can simultaneously ensure high-precision positioning of the turntable in a low-speed state and high-speed accuracy and speed stability in a high-speed state. Background Art

[0002] The single-axis turntable is a single-axis platform multifunctional test equipment with position, speed and other functions, which can meet the functional test and experiment of inertial system and inertial components. The turntable is controlled by industrial control computer and has high-precision positioning capability, stable speed, small operation distortion and good dynamic performance.

[0003] High-precision positioning capability in low-speed environment, high-speed accuracy and stability in high-speed environment. If the conventional design method is used, it is necessary to design two single-axis tables, and use different angle sensors to respond to the above technical indicators. That is, a small-diameter angle sensor is used to respond to the high-speed accuracy and stability requirements of the single-axis turntable, and a large-diameter high-precision angle sensor system is used to respond to the high-precision positioning capability requirements of the single-axis turntable.

[0004] The mechanical body of the turntable provides a platform for the installation and movement of the load, and is generally composed of a servo motor, an angle measuring element, a load mounting table, a precision mechanical shaft system, a base, etc. The single-axis turntable is equipped with:

[0005] Work surface - used for positioning and mounting of loads;

[0006] Spindle - provides a mounting carrier for the slewing support and motor;

[0007] High-precision angular contact ball bearings - as the main support of the turntable shaft system;

[0008] Servo motor - driving element of the rotary table shaft system;

[0009] High-precision angular contact ball bearings - used as auxiliary support for the turntable shaft system;

[0010] Angle sensor - used for angle measurement and angular position feedback;

[0011] Leveling foot assembly - used to level and secure the turntable.

[0012] Except for the angle sensor, the bearings, motors and the entire mechanical structure are very expensive, so the cost of making two high-precision single-axis turntables is very high.

[0013] Based on this background, the present invention provides a high-precision single-axis turntable with an ultra-wide speed range, which can not only meet the high-precision positioning capability in a low-speed environment but also meet the high-speed accuracy and stability requirements in a high-speed environment.

[0014] The present invention adopts the same set of mechanical structures of the high-speed single-axis turntable and utilizes two sets of angle sensor combination structures with different functions, thereby achieving high-precision positioning capability in a low-speed environment and high-speed accuracy and stability in a high-speed environment. In addition, the two angle sensors can be automatically switched according to actual usage and the speed can be adjusted according to test needs, thereby reducing the development cost of the equipment and overcoming the shortcomings of the prior art. Summary of the invention

[0015] The purpose of the present invention is to provide a high-precision single-axis turntable with an ultra-wide speed range, which reasonably and effectively solves the shortcomings of the prior art such as complex structure and high cost. The prior art generally requires two sets of single-axis turntables to be developed separately for turntables that meet high-precision angle positioning at low speed and high-speed requirements for high-speed accuracy and rate stability, because the same angle sensor cannot meet the design requirements at the same time. The present invention solves the problem that the same mechanical platform of such single-axis turntables has both high-precision angle positioning and high-speed accuracy and stability.

[0016] Working principle of the present invention:

[0017] 1. The table provides a platform for the installation and movement of the load. The mechanical table consists of a load work surface, a spindle, a high-precision angular contact ball bearing, a servo motor, a high-precision angular contact ball bearing, an angle sensor and a base. The control cabinet is a 19-inch standard cabinet, which is equipped with an angle calculation circuit, a turntable control circuit, a motor driver, a power supply and an industrial computer system. The turntable system has the functions of automatic state control and data acquisition, processing and display by a computer. The turntable also has protection functions such as overspeed, overload, emergency power off, and misoperation.

[0018] 2. The mechanical body of the turntable includes two sets of angle sensors. The turntable angle sensor uses Renishaw grating scale, grating reading head with analog output, and digital quantity output by the reading head subdivision card as the shaft angle position loop feedback signal. The grating scale models are RESM20USA100 and RESM20USA52. The two grating scales correspond to high-precision positioning at low speed and high-speed accuracy and high-speed stability at high speed.

[0019] The present invention adopts the following technical solution:

[0020] A high-precision single-axis turntable with an ultra-wide speed range has not only good angular position accuracy, but also high rate accuracy and rate stability. This function is achieved by integrating two sets of angle sensors in the mechanical table. The turntable includes a work surface, a spindle, a high-precision angular contact ball bearing, an AC servo motor and an angle sensor; a high-precision single-axis turntable with an ultra-wide speed range is characterized by:

[0021] The high-precision single-axis turntable with an ultra-wide speed range described above has a table top designed as a Φ300mm round table top structure. The table top material is made of stainless steel (grade 12Cr18Ni9), and corresponding reinforcing ribs are set. The surface is precision machined, with a surface roughness of 1.6, a flatness better than 0.015mm, a table top runout better than 0.02mm, and a table top magnetic leakage: ≤1Gs (2cm above the table top). There are 3 circles of 8 radially distributed M6 threaded holes on the table top for installing user loads. Two sets of electrical connectors are also symmetrically installed on the table top for signal and power transmission of user test pieces.

[0022] The bearing is one of the key components of the high-precision single-axis turntable with an ultra-wide speed range described above. The bearing's accuracy, support stiffness, and friction torque will directly affect the dynamic and static characteristics of the turntable shaft system. The turntable shaft system is supported by precision mechanical bearings, with two pairs of upper and lower bearings as the support. The upper bearing is the main support, using P4-grade high-precision angular contact bearings, the bearing model is 7216AC / P4.DB.A, installed in pairs back to back, mainly providing axial and radial support for the shaft system.

[0023] The lower bearing is an auxiliary support. The bearing model is 7212AC / P4.DF.A. It is installed face to face and mainly provides radial support for the shaft system. The advantage of this design is that it can make the shaft system have the highest possible rotation accuracy and support stiffness.

[0024] The high-precision single-axis turntable with an ultra-wide speed range described above is directly driven by a rare earth permanent magnet brushless servo motor to improve the reliability of the turntable, taking into account the high rotation speed of the turntable.

[0025] The high-precision single-axis turntable with an ultra-wide speed range described above, the spindle is the mounting carrier of the turntable work surface, high-precision angular contact ball bearings, AC servo motors and angle sensors. The spindle is made of 40Cr material, and the spindle is subjected to static analysis, modal analysis and other dynamic analysis using ANSYS mechanical analysis. The spindle meets the strength, stiffness and natural frequency requirements.

[0026] The high-precision single-axis turntable with an ultra-wide speed range described above has two sets of angle sensors installed on the turntable shaft end, namely: RESM20USA100 and RESM20USA52. Depending on the usage function, the angle sensor angle measurement data can be automatically switched according to the speed of the turntable. When the spindle speed is low and high angular position accuracy is required, the turntable switches to RESM20USA100 angle measurement data; when the spindle speed is high and high rate accuracy and high rate smoothness are required, the turntable switches to RESM20USA52 angle measurement data. The turntable can automatically switch according to the speed.

[0027] The beneficial technical effects of the present invention are:

[0028] The present invention discloses a high-precision single-axis turntable with an ultra-wide speed range, which reasonably and effectively solves the shortcomings of the turntable in the prior art, such as high cost and single function of the turntable system; for the single-axis turntable in the prior art, when the speed accuracy meets the use requirements at high speed, the angular position accuracy cannot meet the use requirements at low speed; when the angular position accuracy meets the use requirements at low speed, the speed accuracy and speed stability cannot meet the use requirements at high speed, and the function is relatively single. When two functional requirements are to be met, two turntable systems must be designed, which increases the equipment development cost, causes serious waste, and is also very inconvenient to use.

[0029] The present invention adopts the modular design principle. Two systems share a mechanical platform. The functions and uses of each system are independent, which is convenient for maintenance and fault detection, and ensures good ergonomics and interchangeability of the system.

[0030] The overall design of a high-precision single-axis turntable with an ultra-wide speed range is scientific and reasonable, and the operation is simple, convenient, flexible and fast, which effectively reduces the development cost of the turntable. The invention overcomes the shortcomings of the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0032] As shown in the figure: 1-protective cover, 2-work table, 3-spindle, 4-high-precision angular contact ball bearing, 5-bearing locking device, 6-lifting ring, 7-base, 8-AC servo motor, 9-high-precision angular contact ball bearing, 10-reading head 1, 11-angle sensor 1, 12-adjusting shim, 13-angle sensor 2, 14-reading head 2, 15-slip ring, 16-user socket. DETAILED DESCRIPTION

[0033] The following description of the embodiments will help the public better understand the present invention, but the specific embodiments given by the applicant cannot and should not be regarded as limitations on the technical solutions of the present invention. Any changes to the definitions of components or technical features and / or formal but not substantial changes to the overall structure should be regarded as the scope of protection defined by the technical solutions of the present invention.

[0034] Example: Figure 1 The high-precision single-axis turntable with an ultra-wide speed range shown in the figure includes a protective cover 1, a work table 2, a spindle 3, a high-precision angular contact ball bearing 4, a bearing locking device 5, a lifting ring 6, a base 7, an AC servo motor 8, a high-precision angular contact ball bearing 9, a reading head 110, an angle sensor 111, an adjusting shim 12, an angle sensor 213, a reading head 214, a slip ring 15 and a user socket 16.

[0035] First, install the mechanical table body. The main structural parts in the mechanical table body are processed to the precision requirements, including the work table 2, the main shaft 3, the bearing locking device 5 and other key structural parts. The high-precision angular contact ball bearing 4 is installed on the main shaft 3, and the high-precision angular contact ball bearing 4 is pre-tightened with the bearing locking device 5. Then, the installed shaft system is inserted into the base 7, and the servo motor 8, the auxiliary support high-precision angular contact ball bearing 9 and the reading head 110, the angle sensor 111, the reading head 214 and the angle sensor 213 are installed in sequence. Finally, the slip ring 15, the user socket 16, the work table 2 and the hanging ring 6 in the mechanical table body are installed to complete the installation of a high-precision single-axis turntable with an ultra-wide speed range.

[0036] Wiring of the table body. After the table body is installed, connect the signal line of the slip ring 15 to the user socket 16 on the work surface 2, and the other end of the slip ring 15 to the user socket on the base 7. Connect the power line of the servo motor 8 to the user socket on the base 7, and connect the signal line on the reading head 1 and the signal line on the reading head 2 to the signal socket on the base 7 separately. Connect the socket on the mechanical table body to a high-precision single-axis turntable control cabinet with an ultra-wide speed range through a cable to complete the wiring of a high-precision single-axis turntable system with an ultra-wide speed range.

[0037] Achieve high-precision positioning requirements. After completing the installation, wiring and debugging of the high-speed single-axis turntable, switch to the positioning working mode through the program. At this time, the data collected by the angle sensor 213 and the reading head 214 are sent to the control system. When the turntable is in a closed-loop control state, the keyboard controls the computer to send a position command to the turntable. The position command contains two parameters: the target position and the speed used to reach the target position. The acceleration default (generally 10° / s 2 ), when the turntable is in position control state, it can only receive a stop command. A high-precision single-axis turntable drive element with an ultra-wide speed range is an AC servo motor 8.

[0038] Achieve high speed accuracy requirements. After completing the installation, wiring and debugging of the high-speed single-axis turntable, switch to the speed working mode through the program. At this time, the angle sensor 111 and the reading head 110 enter the working state. When the turntable is in a closed-loop control state, the computer can be controlled by the keyboard to send a speed command to the turntable. The speed command contains two parameters: the target speed and the acceleration used to reach the target speed. The acceleration defaults to 10° / s. 2 , the turntable can receive a stop command when it is in a speed control state. A high-precision single-axis turntable drive element with an ultra-wide speed range is an AC servo motor 8.

[0039] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A high-precision single-axis turntable with an ultra-wide speed range, comprising a protective cover, a work surface, a spindle, a high-precision angular contact ball bearing, a bearing locking nut, a lifting ring, a base, an AC servo motor, a high-precision angular contact ball bearing, a reading head 1, an angle sensor 1, an adjustment shim, an angle sensor 2, a reading head 2, a slip ring and a user connection socket, characterized in that: It is directly driven by an AC servo motor and uses two sets of angle sensors. The two systems with different functions adopt a modular design and share a common mechanical table. The two sets of angle sensors are installed at the end of the spindle. The two sets of angle sensors are connected separately, and the signals of the two sets of angle sensors are collected simultaneously, calculated separately, and switched automatically. The angle data of angle sensor 1 and reading head 1 collected at high speed are sent to the data processing module, and the angle data of angle sensor 2 and reading head 2 collected at low speed are sent to the data processing module. The turntable mechanical table uses the angle sensor to feed back the turntable position signal to the control program through the angle measurement module and the data acquisition module. The control system then uses the PID algorithm to control the turntable. The high-speed acquisition and real-time control schemes are adopted to enable the entire turntable to have the characteristics of high-precision positioning capability, high-precision rate, and high-precision rate stability.

2. According to claim 1, a high-precision single-axis turntable with an ultra-wide speed range, characterized in that Two sets of angle sensors are installed on the spindle end, the two sets of angle sensors are wired separately, and the signals of the two sets of angle sensors are collected simultaneously, calculated separately, and switched automatically.

3. A high-precision single-axis turntable with an ultra-wide speed range according to claim 2, characterized in that The angle data of angle sensor 1 and reading head 1 collected at high speed are sent to the data processing module, and the angle data of angle sensor 2 and reading head 2 collected at low speed are sent to the data processing module. The turntable mechanical body uses the angle sensor to feed back the turntable position signal to the control program through the angle measurement module and the data acquisition module. The control system then uses the PID algorithm to control the turntable, adopting a high-speed acquisition and real-time control solution.

Images