Real-time automatic testing device for small torque

Abstract

The present invention relates to a real-time automatic testing device for micro torque, comprising a frame, a bearing fixture, a torque sensor, a lifting assembly, and a clamping assembly. The lifting assembly and the clamping assembly are respectively fixedly connected to the frame through a backing plate, and the lifting assembly and the clamping assembly are respectively located at the upper and lower parts of the backing plate; the lifting assembly is fixedly connected to a servo motor and a reducer through a lifting bracket, the reducer and the torque sensor are connected in series with a flexible coupling, an upper pressure plate of the bearing fixture is installed on the clamping assembly, a lower pressure plate of the bearing fixture is fixed on the frame, and a load sensor is installed at the bottom of the lower pressure plate. Aiming at the complex requirements of the automatic test of the bearing no-load starting torque, the present invention introduces technologies such as high-precision torque sensors, load sensors, torque servo drivers, and bearing clamping fixtures, determines quantitative parameters in the test process, and establishes a test automation control system to meet quantitative control and automatic control in the test process.

Description

Technical Field

[0001] The invention relates to a micro torque testing technology, in particular to a real-time automatic testing device for no-load starting torque of a spherical bearing. Background Art

[0002] The starting torque value of the spherical plain bearing is relatively small, generally between 0.01Nm and 0.2Nm. At present, the commonly used methods for measuring the no-load starting friction torque of self-lubricating spherical plain bearings in actual production are mainly: the weight method and the measurement method based on the torque sensor.

[0003] The measurement principle of the weight method is as follows Figure 1 As shown in the figure, the weight method has a simple test device and low precision. When loading the weight, a radial load is applied to the bearing, changing the "no-load" state of the bearing. In addition, the order of loading the weight, the stability of the placement, and the last load have a great influence on the test results, and the random error is too large.

[0004] The schematic diagram of the tester based on the torque sensor is as follows Figure 2 As shown in the figure, the use of torque sensor measurement can eliminate the additional radial load introduced by the test and the operator's human influence factors. The outer ring of the tested bearing is fixed with a clamping device, and the inner ring of the bearing is connected to the motor through a torque sensor. The torque sensor can detect the torque during the motor starting process, thereby measuring the no-load starting torque of the tested bearing.

[0005] Since the outer ring of the bearing is thin and easy to deform, the preload state of the bearing will inevitably change when the outer ring is fixed, thereby changing the no-load starting torque of the bearing. The measuring device adopts a horizontal structure and introduces the influence of the bending moment of the torque sensor.

[0006] The "rolling bearing no-load starting torque measurement device" applied by Lin Jing and others adopts a vertical structure of torque sensor, which effectively avoids the above two disadvantages. The inner ring and the mandrel are fixed through the interference fit between the tapered mandrel and the inner ring, avoiding the problem of introducing axial force during the measurement process and avoiding damage to the inner ring of the bearing by tightening the nut. Unlike rolling bearings, the end face clamping of spherical bearings requires a relatively high axial clamping force, and the axial force cannot be quantitatively controlled, so "no-load starting" cannot be guaranteed. Summary of the invention

[0007] The purpose of the present invention is to provide a real-time automatic testing device for tiny torques. Aiming at the complex requirements of the automatic testing of the no-load starting torque of bearings, the present invention introduces technologies such as high-precision torque sensors, load sensors, torque servo drivers, and bearing clamping fixtures, determines the quantitative parameters in the test process, and establishes an automatic test control system to meet the quantitative control and automatic control requirements in the test process.

[0008] To achieve the above-mentioned purpose, the technical solution of the present invention is: a real-time automatic testing device for tiny torque, comprising a frame, a bearing fixture, a torque sensor, a lifting assembly, and a clamping assembly, wherein the lifting assembly and the clamping assembly are fixedly connected to the frame through a support plate, and the lifting assembly and the clamping assembly are respectively located at the upper and lower parts of the support plate; the lifting assembly is fixedly connected to a servo motor and a reducer through a lifting bracket, the reducer and the torque sensor are connected in series with a flexible coupling, an upper pressure plate of the bearing fixture is installed on the clamping assembly, a lower pressure plate of the bearing fixture is fixed on the frame, and a load sensor is installed at the bottom of the lower pressure plate.

[0009] Furthermore, the contact surfaces between the upper and lower pressing plates and the spherical bearing to be measured are arc contact surfaces, through which the center of the spherical bearing to be measured can be automatically aligned, thereby greatly reducing the influence of the coaxiality of the upper and lower pressing plates.

[0010] Furthermore, the lifting and lowering assembly and the clamping assembly are both composed of a drive motor, a ball screw, a screw nut, and a guide rail pair. The drive motor is connected to the screw nut through the ball screw, the screw nut is connected to the lifting bracket or the upper pressure plate, and the lifting bracket or the upper pressure plate is connected to the guide rail pair.

[0011] Furthermore, the clamping assembly uses a driving motor, a ball screw, and a screw nut to drive the upper pressure plate of the bearing fixture to move up and down, and axially clamps the spherical bearing to be tested through the upper and lower pressure plates with circular arc contact surfaces. A load sensor is also provided at the bottom of the lower pressure plate. The load sensor displays the size of the clamping force in real time, and the clamping force can be adjusted according to the type of the spherical bearing to be tested, ensuring that "no-load" starting is truly achieved.

[0012] Furthermore, the torque sensor is connected to the measured spherical bearing in a vertical connection manner, so that the connection direction of the torque sensor is the same as the direction of gravity, both of which are perpendicular to the horizontal plane, thereby not generating additional bending moment influence.

[0013] Furthermore, the bottom of the rack is fixed on a marble bottom plate, and a protective cover is provided on the rack to reduce the impact of the external environment on the test.

[0014] Furthermore, the servo motor and reducer drive angle control accuracy is ±0.01°, and the torque sensor accuracy is ±0.05% FS.

[0015] Furthermore, the micro-torque real-time automatic testing device is connected to a control system, which realizes automatic control and outputs a torque-time curve during the test in real time.

[0016] The beneficial effects of the present invention are:

[0017] 1. The real-time automatic testing device for micro torque of the present invention has a calibrated torque sensor, high testing accuracy, and is accurate and reliable;

[0018] 2. The real-time automatic testing device for micro torque of the present invention can be calibrated on site, is easy to use, is driven by a servo motor and a reducer, has an angle control accuracy of up to ±0.01°, has stable torque loading, and a torque sensor accuracy of ±0.05% FS;

[0019] 3. The real-time automatic testing device for micro torque of the present invention can axially clamp the outer ring and quantitatively control the clamping load. The control software can realize automatic control according to the specification, and the torque-time curve can be output in real time during the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the measurement principle diagram of the weight method;

[0021] Figure 2 It is a schematic diagram of a tester based on a torque sensor;

[0022] Figure 3 This is a structural schematic diagram of the micro torque real-time automatic testing device of the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0024] like Figure 3 As shown, the real-time automatic testing device for tiny torque of the present invention comprises a marble base plate 1, a frame 2, a servo motor 3, a reducer 4, a load sensor 5, a bearing fixture 6, a torque sensor 7, a flexible coupling 8, a lifting assembly 9, a clamping assembly 10, a protective cover 11 and the like.

[0025] The basic working principle of the test device is to connect the high-precision torque sensor in series with the spherical bearing, load it with a servo drive, and use the output data of the high-precision torque sensor as the starting torque of the spherical bearing. The device adopts a design method of vertically connecting the high-precision torque sensor and the spherical bearing to be tested, so that the connection direction of the torque sensor connection system is the same as the direction of gravity, both of which are perpendicular to the horizontal plane. This connection method will not produce additional bending moment influence.

[0026] The frame 2 is installed on the marble bottom plate 1, and the lifting assembly 9 and the clamping assembly 10 are fixed with a backing plate. The lifting assembly 9 and the clamping assembly 10 are respectively located at the upper and lower parts of the backing plate. The lifting assembly 9 is fixedly connected to the servo motor 3 and the reducer 4 through a lifting bracket. The reducer 4 and the torque sensor 5 are connected in series with a flexible coupling 8. The upper pressure plate 6-1 of the bearing fixture 6 is installed on the clamping assembly 10. The lower pressure plate 6-2 of the bearing fixture 6 is fixed on the frame 2. The load sensor 5 is installed at the bottom of the lower pressure plate 6-2. The upper and lower pressure plates 6-1 and 6-2 adopt rounded contact, which can automatically find the center and greatly reduce the influence of coaxiality. The lifting assembly 9 and the clamping assembly 10 are composed of a driving motor, a ball screw, a screw nut, and a guide pair. The driving motor is connected to the screw nut through a ball screw, and the screw nut is connected to the lifting bracket or the upper pressure plate 6-1. The lifting bracket or the upper pressure plate 6-1 is connected to the guide pair.

[0027] Before starting the test, start the driving motor of the lifting assembly 9 to lift the lifting bracket in the lifting assembly 9, and drive the servo motor 3, the reducer 4, and the flexible coupling 8 to lift together, place the spherical bearing between the upper and lower pressure plates 6-1, 6-2 of the bearing fixture 6, start the driving motor of the clamping assembly 10 to move the upper pressure plate 6-1 of the clamping assembly 10 downward to load the spherical bearing. After the installation is completed, clamp it according to the test requirements of the spherical bearing, then the lifting bracket of the lifting assembly 9 descends, connect the flexible coupling 8 with the torque sensor 5, and start the servo motor 3 to rotate.

[0028] The clamping assembly 10 of the present invention adopts a driving motor, a ball screw, and a screw nut to drive the upper pressure plate 6-1 of the bearing clamp 6 to move up and down, and axially clamps the spherical bearing to be tested through the upper and lower pressure plates 6-1 and 6-2 with R fillets. A load sensor is provided at the bottom of the lower pressure plate 6-2 to display the size of the clamping force in real time, and the clamping force can be adjusted according to the type of the spherical bearing to be tested, ensuring that "no-load" starting is truly achieved.

[0029] The present invention adopts a marble base plate fixed at the bottom, a frame fixed on the marble base plate, and a lifting assembly installed on the frame, which provides convenience for replacing different spherical bearings. The servo motor and the reducer realize torque loading, the torque sensor is connected by a flexible coupling, the clamping assembly applies an axial load to the spherical bearing to realize quantitative clamping, and the protective cover reduces the influence of the external environment on the test.

Claims

1. A real-time automatic testing device for micro torque, comprising a frame, a bearing fixture, a torque sensor, a lifting assembly, and a clamping assembly, characterized in that: The lifting assembly and the clamping assembly are respectively fixedly connected to the frame through a support plate, and the lifting assembly and the clamping assembly are respectively located at the upper and lower parts of the support plate; the lifting assembly is fixedly connected to a servo motor and a reducer through a lifting bracket, the reducer and the torque sensor are connected in series with a flexible coupling, the upper pressure plate of the bearing fixture is installed on the clamping assembly, the lower pressure plate of the bearing fixture is fixed on the frame, and a load sensor is installed at the bottom of the lower pressure plate; the clamping assembly uses a driving motor, a ball screw, and a screw nut to drive the upper pressure plate of the bearing fixture to move up and down, and axially clamps the measured joint bearing through the upper and lower pressure plates with circular arc contact surfaces, and a load sensor is also provided at the bottom of the lower pressure plate, which displays the size of the clamping force in real time through the load sensor, and the clamping force is adjusted according to the type of the measured joint bearing to ensure that "no-load" start-up is truly achieved; the torque sensor is connected to the measured joint bearing through a vertical connection, so that the connection direction of the torque sensor is the same as the gravity direction, both of which are perpendicular to the horizontal plane, so that no additional bending moment influence is generated.

2. The micro torque real-time automatic testing device according to claim 1 is characterized in that: The contact surfaces between the upper and lower pressing plates and the spherical bearing to be measured are arc contact surfaces, and the center of the spherical bearing to be measured is automatically aligned through the arc contact surfaces, thereby greatly reducing the influence of the coaxiality of the upper and lower pressing plates.

3. The micro torque real-time automatic testing device according to claim 1 is characterized in that: The lifting assembly and the clamping assembly are both composed of a driving motor, a ball screw, a screw nut, and a guide rail pair. The driving motor is connected to the screw nut through the ball screw, the screw nut is connected to the lifting bracket or the upper pressure plate, and the lifting bracket or the upper pressure plate is connected to the guide rail pair.

4. The micro torque real-time automatic testing device according to claim 1 is characterized in that: The bottom of the rack is fixed on a marble bottom plate, and a protective cover is arranged on the rack to reduce the influence of the external environment on the test.

5. The micro torque real-time automatic testing device according to claim 1 is characterized in that: The servo motor and reducer drive angle control accuracy is ±0.01°, and the torque sensor accuracy is ±0.05%FS.

6. The real-time automatic testing device for micro torque according to any one of claims 1 to 5, characterized in that: The micro-torque real-time automatic testing device is connected to a control system, which realizes automatic control and outputs a torque-time curve during the test in real time.

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