A kind of speed reducer online testing device and method

Abstract

The present invention discloses an online testing device for a reducer, wherein a servo motor is connected to an input shaft via a coupling, the input shaft is connected to the input end of the reducer to be tested, the output end of the reducer to be tested is connected to an output shaft, the output shaft is connected to a brake via a coupling, a first offset detection unit is provided on both the input shaft and the output shaft, two of the first offset detection units are provided with two laser displacement sensors, the two laser sensors collect distance signals on the same side of the output shaft and the input shaft, the first offset detection unit is connected to an industrial control computer system via a signal line, and the acquired distance signal is sent to the industrial control computer system. The present invention has the advantages of high precision, good consistency, high reliability and life, etc.

Description

Technical Field

[0001] The invention relates to the technical field of reducers, and in particular to an online monitoring and testing device for the eccentric wear state of a harmonic reducer. Background Art

[0002] The popularization of industrial robots is an effective means to realize automated production, improve social production efficiency, and promote the development of enterprise and social productivity. At present, it is widely used in the fields of automobiles, aerospace, electronics, food, new energy, etc. As the development of industrial robots becomes more and more mature, its advantages are increasingly reflected, and it is becoming more and more an important means to realize industrial production automation, improve social production efficiency, and promote the development of enterprise and social productivity. Abroad, the various technologies of industrial robots have become increasingly mature, and have become a standard equipment that has been widely concerned by the industry. A number of international industrial robot companies with great influence have been formed, becoming the pillar industries in their regions. Among them, the leaders include Sweden's ABB Robotics, Germany's KUKA Roboter Gmbh, Italy's COMAU, and Japan's FANUC. In China, although the industrial robot industry is still in the stage of theoretical research and small-batch prototype trial production, it has a strong growth momentum and huge development space. Since the 1980s, various universities and scientific research institutions in my country have carried out comprehensive research in the field of industrial robots, and have achieved considerable scientific research results in the past 20 years. However, due to the lack of organic integration with enterprises, it has not yet formed an influential product and a large-scale industry. In particular, my country did not develop the corresponding parts industry in the early stage of developing robots, so that domestic enterprises can only rely on imported parts in the process of producing robots, which undoubtedly greatly weakened the market competitiveness of Chinese enterprises. Therefore, to form the industrialization of industrial robots, it is necessary to first form the industrialization of the production of related parts, and the joint reducer of industrial robots is one of the key items that need to be developed.

[0003] Harmonic reducer and RV reducer are the two most widely used reduction devices in industrial robot joints. Among them, the harmonic reducer has the advantages of large speed ratio, smooth movement, simple structure and high efficiency, and is a joint reduction device with superior performance. However, the harmonic reducer transmits power through the elastic deformation principle of the flexible wheel, which makes it accompanied by inherent defects such as low stiffness, large elastic backlash and significant decrease in transmission accuracy with the increase of service time. RV transmission is a new type of multi-stage, large speed ratio planetary transmission gradually developed on the basis of cycloid pinwheel transmission. Compared with the existing ordinary planetary transmission form, the reducer adopts a structure of shared crankshaft and center disc support to form a closed planetary transmission, which not only overcomes some shortcomings of the original cycloid pinwheel transmission, but also has much higher fatigue strength, stiffness and life than the harmonic reducer. In addition, the backlash and transmission accuracy are stable and will not be significantly reduced with the increase of service time. It has the advantages of large transmission ratio, large stiffness, high motion accuracy, high transmission efficiency, small backlash and stable load, so it is particularly suitable for industrial robots and other precision servo transmission systems. Compared with harmonic reducers, RV reducers have higher rigidity and rotation accuracy. Therefore, in articulated robots, RV reducers are generally placed in heavy load positions such as the base, upper arm, and shoulder, while harmonic reducers are placed in the forearm, wrist, or hand.

[0004] As an important transmission mechanism, reducers have excellent comprehensive transmission performance and are widely used in various transmission mechanisms. However, the dynamic service behavior of reducers under the comprehensive stress of complex working environments and their failure mechanisms have not been studied and analyzed in depth, and a set of scientific and reasonable performance and life test methods and performance and life reliability evaluation systems have not been established, which greatly restricts the application of reducers in aerospace, robotics, shipbuilding and other industries.

[0005] Focusing on the development needs of industrial robots for high-precision and high-efficiency reducers, accurate testing of performance parameters can be used to verify the reliability of theoretical analysis or modify theoretical formulas to make them more accurate and complete, thereby more reliably guiding the development of prototypes. Therefore, it is necessary to carry out experimental research on the performance parameter detection of industrial robot reducers. Systematic research on key reducer tests plays an important role in overcoming key technical issues in digital design, manufacturing process, precision and efficiency maintenance of the reducer, and has important engineering significance for promoting the development of my country's industrial robot industry. However, there is currently a lack of equipment that can test harmonic reducers online. Summary of the invention

[0006] The technical problem to be solved by the present invention is to realize a device capable of performing real-time online testing on the eccentric wear state of a reducer, which is particularly suitable for harmonic reducers to achieve the purpose of real-time detection of the eccentric wear state of a transmission shaft.

[0007] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a reducer online testing device, a servo motor is connected to an input shaft via a coupling, the input shaft is connected to the input end of the reducer under test, the output end of the reducer under test is connected to the output shaft, the output shaft is connected to the brake through a coupling, a first offset detection unit is provided on the input shaft and the output shaft, two of the first offset detection units are provided with two laser displacement sensors, the two laser sensors collect distance signals on the same side of the output shaft and the input shaft, the first offset detection unit is connected to the industrial control computer system via a signal line, and the acquired distance signal is sent to the industrial control computer system.

[0008] A second offset detection unit is also provided on the input shaft and the output shaft. Both of the second offset detection units are provided with two laser displacement sensors. The two laser sensors collect distance signals on the same side of the output shaft and the input shaft. The second offset detection unit is connected to the industrial control computer system via a signal line and sends the acquired distance signal to the industrial control computer system. The laser beams emitted by the laser displacement sensors of the first offset detection unit and the second offset detection unit are perpendicular to each other.

[0009] The first offset detection unit is located directly above or below the output shaft and the input shaft, and collects the offset status of the output shaft and the input shaft in the vertical direction. The second offset detection unit is located on the side of the output shaft and the input shaft, and collects the offset status of the output shaft and the input shaft in the horizontal direction.

[0010] The device is provided with two rotating platforms, which act on the output shaft and the input shaft respectively. The rotating platform is provided with a bearing fixed on the output shaft or the input shaft, the bearing is fixedly connected to the frame, the frame is fixedly connected to the motor power shaft, and the extension direction of the motor power shaft passes through the axis of the output shaft or the input shaft and is parallel to the laser beam emitted by the laser displacement sensor of the second offset detection unit.

[0011] A circular support plate is fixed on the frame, and the circular support plate is perpendicular to the power shaft of the motor. An electric cylinder is provided on each side of the circular support plate. The push rods of the two electric cylinders are coaxial and contact the side of the support plate. The electric cylinder and the motor are fixed next to the output shaft or the input shaft through a bracket.

[0012] The couplings connecting the input shaft and the output shaft are both provided with torque sensors. The two torque sensors are connected to the industrial control computer system via signal lines and transmit the two sets of torque signals obtained to the industrial control computer system.

[0013] The industrial control computer system includes an interface unit for acquiring signals, a host for processing signals, a display for displaying test data, and a printer for printing test data. The host is connected to a sensor and a torsion platform via the interface unit, the video interface of the host is connected to a display screen via a data cable, and the printing interface of the host is connected to a printer via a data cable.

[0014] Based on the testing method of the reducer online testing equipment, the industrial control computer system controls the servo motor and the brake to be coaxial according to the set program, and the first offset detection unit transmits the real-time acquired signal to the industrial control computer system. When the difference between the two distance signals of the two output shafts or the input shafts is greater than the set value, the two electric cylinders are driven to work and push the frame to deflect until the difference between the two distance signals is less than the set value.

[0015] The second offset detection unit transmits the real-time acquired signal to the industrial control computer system. When the difference between the two distance signals of the two output shafts or the input shafts is greater than the set value, the motor is driven to rotate the frame until the difference between the two distance signals is less than the set value.

[0016] After the equipment test is completed, the electric cylinder and the motor are driven back to their initial positions.

[0017] The present invention uses the feedback of the laser displacement sensor to understand the eccentric wear condition of the transmission shaft in real time, so as to timely correct it through the torsion platform with the motor loaded under the frame, improving the shortcomings of the traditional harmonic reducer due to the inability to know the eccentric wear state and the inability to correct the eccentric wear. It has the advantages of high precision, good consistency, high reliability and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following is a brief description of the contents expressed in each figure in the specification of the present invention and the marks in the figure:

[0019] Figure 1 This is the working principle diagram of the online test equipment for the reducer;

[0020] Figure 2 This is the structural schematic diagram of the reducer online testing equipment;

[0021] Figure 3 This is a schematic diagram of the normal state of the test;

[0022] Figure 4 This is a schematic diagram of the test eccentric wear state;

[0023] Figure 5 This is the schematic diagram of the torsion platform structure;

[0024] Figure 6 for Figure 2 Top view of the middle base;

[0025] The markings in the above figures are: 1. input shaft; 2. frame; 3. circular support plate; 4. bearing; 5. motor; 6. electric cylinder; 7. base; 8. limit plate. DETAILED DESCRIPTION

[0026] The following is a further detailed description of the specific implementation methods of the present invention, such as the shape, structure, relative position and connection relationship between the various components involved, the function and working principle of each part, the manufacturing process and operation method, etc., through the description of the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0027] like Figure 1 As shown, in the online test equipment for the reducer, the servo motor is connected to the input shaft 1 through a coupling, the input shaft 1 is connected to the input end of the reducer under test, the output end of the reducer under test is connected to the output shaft, the output shaft is connected to the brake through a coupling, the servo motor and the brake are powered by a frequency converter, and torque sensors can be provided on the couplings connecting the input shaft 1 and the output shaft to collect input and output torques respectively for data recording and detection, the two torque sensors are connected to the industrial control computer system through signal lines, and the two sets of torque signals obtained are transmitted to the industrial control computer system.

[0028] The input shaft 1 and the output shaft are both provided with a first offset detection unit. Preferably, the first offset detection unit collects the position deviation in the vertical direction. Each first offset detection unit is provided with two laser displacement sensors. The two laser sensors collect the distance signal on the same side of the output shaft and the input shaft 1, and are generally fixed at the same height position directly above the output shaft and the input shaft 1, such as Figure 3 As shown, the distance X between the output shaft and the input shaft 1 is collected. Since the position of the laser displacement sensor is fixed, X is a constant value, that is, under normal conditions, the distances measured by a group of laser displacement sensors are x1 and x2 respectively; if the output shaft and the input shaft 1 are offset up and down, the X value of one or two sensors will change, such as Figure 4 As shown in the figure, once the eccentric wear occurs, the distance measured by the laser displacement sensor is x3, x4. At this time, the formula To measure the slope k of the eccentric wear of the transmission shaft, the torsion platform is driven by the motor 5 to correct the eccentric wear.

[0029] In order to simultaneously measure whether there is a deviation in the horizontal direction, a second offset detection unit is provided on the input shaft 1 and the output shaft. The two second offset detection units are each provided with two laser displacement sensors. The two laser sensors collect distance signals on the same side of the output shaft and the input shaft 1. Generally speaking, they are fixed on the side of the output shaft and the input shaft 1. The distances from the side to the output shaft and the input shaft 1 of the two laser displacement sensors are also the same, and the distance Y collected from the output shaft and the input shaft 1 is also a constant, that is, under normal conditions, the distances measured by a group of laser displacement sensors are Y1 and Y2 respectively; if the output shaft and the input shaft 1 are offset in the horizontal direction, the Y value of one or both sensors will change, and the company testing the offset is the same as the first offset detection unit.

[0030] The first offset detection unit and the second offset detection unit are connected to the industrial control computer system through a signal line, and the acquired distance signal is sent to the industrial control computer system. The industrial control computer system includes an interface unit for acquiring signals, a host for processing signals, a display for displaying test data, and a printer for printing test data. The host is connected to the sensor and the torsion platform through the interface unit, the video interface of the host is connected to the display screen through a data line, and the printing interface of the host is connected to the printer through a data line.

[0031] The equipment is provided with two rotating platforms, which act on the output shaft and the input shaft 1 (transmission shaft) respectively. The rotating platform is provided with a bearing 4 fixed on the transmission shaft. A bracket is fixedly connected below the bearing 4, and the bracket is suspended on the bearing 4. The frame 2 is fixedly connected to the power shaft of the motor 5. The motor 5 is directly below the frame 2. The extension direction of the power shaft of the motor 5 passes through the axis of the output shaft or the input shaft 1. Through the rotation of the motor 5, the frame 2 can be driven to rotate, thereby correcting the deflection of the transmission shaft in the horizontal direction. In order to improve the output torque capacity of the motor 5, the motor 5 can be connected to the frame 2 through a gear box to improve the output torque.

[0032] At the same time, the two rotating platforms also have the ability to correct in the vertical direction. A limit plate 8 is fixed on the motor 5. A base 7 is provided below the motor 5. A slide groove is provided on the base 7. The extension direction of the slide groove is parallel to the axial direction of the transmission shaft. The limit plate 8 is inserted into the slide groove and can swing in the slide groove. Then the frame 2, the motor 5, and the limit plate 8 are all suspended on the transmission shaft by the bearing 4. In order to reduce the suspension weight, these devices are preferably made of aluminum alloy, or a gasket supporting the limit plate 8 is provided at the bottom of the slide groove. Since the limit plate 8 is a sheet structure and can only swing in the slide groove, the limit plate 8 and the slide groove can be used to provide reverse torque when the motor 5 rotates. A circular support plate 3 is fixed on the frame 2. The circular support plate 3 is perpendicular to the power shaft of the motor 5. An electric cylinder 6 is provided on each side of the circular support plate 3. The push rods of the two electric cylinders 6 are coaxial and contact the side of the support plate. Through the cooperation of the two electric cylinders 6, the circular support plate 3 can be pushed, and the entire frame 2 will swing along the slide groove direction, thereby realizing the vertical correction of the offset of the transmission axis. The motors 5 and electric cylinders 6 of the two rotating platforms are connected to the industrial control computer system, and are driven to work by the industrial control computer system according to the deflection of the transmission shaft.

[0033] The industrial control computer system controls the servo motor and the brake to be coaxial according to the set program. The first offset detection unit transmits the real-time acquired signal to the industrial control computer system. When the difference between the two distance signals of the two output shafts or the input shaft 1 is greater than the set value, an offset occurs in the vertical direction, driving the two electric cylinders 6 to work and push the frame 2 to deflect. The direction of the deflection is to reduce the difference. During the operation of the electric cylinder 6, the difference signal is fed back in real time until the difference between the two distance signals is less than the set value.

[0034] Similarly, the second offset detection unit transmits the real-time acquired signal to the industrial control computer system. When the difference between the two distance signals of the two output shafts or the input shaft 1 is greater than the set value, an offset occurs in the horizontal direction, and the motor 5 is driven to rotate the frame 2. The direction of rotation is aimed at reducing the difference. The motor 5 selects the difference signal in real time to feed back the difference signal until the difference between the two distance signals is less than the set value.

[0035] After the equipment test is completed, the electric cylinder 6 and the motor 5 are driven to return to the initial position.

[0036] Based on the above system and control method, once the transmission shaft has eccentric wear, the displacement difference measured by the laser displacement sensor will be transmitted to the industrial control computer system, and then the torsion platform will be driven by the motor 5 to correct the eccentric wear. As long as the loading angle of the loader is controlled, the load loaded on the test reducer can be adjusted. The towing equipment only supplements the power lost by the reducer and other parts of the test bench.

[0037] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A reducer online testing device, wherein the servo motor is connected to the input shaft via a coupling, the input shaft is connected to the input end of the reducer under test, the output end of the reducer under test is connected to the output shaft, and the output shaft is connected to the brake via a coupling, characterized in that: The input shaft and the output shaft are both provided with a first offset detection unit, and the two first offset detection units are both provided with two laser displacement sensors, and the two laser displacement sensors collect distance signals on the same side of the output shaft and the input shaft, and the first offset detection unit is connected to the industrial control computer system through a signal line, and sends the acquired distance signal to the industrial control computer system; The input shaft and the output shaft are also provided with a second offset detection unit, and the two second offset detection units are each provided with two laser displacement sensors, and the two laser displacement sensors collect distance signals on the same side of the output shaft and the input shaft, and the second offset detection unit is connected to the industrial control computer system through a signal line, and sends the acquired distance signal to the industrial control computer system, and the laser beams emitted by the laser displacement sensors of the first offset detection unit and the second offset detection unit are perpendicular to each other; The first offset detection unit is located directly above or directly below the output shaft and the input shaft, and collects the offset state of the output shaft and the input shaft in the vertical direction; the second offset detection unit is located on the side of the output shaft and the input shaft, and collects the offset state of the output shaft and the input shaft in the horizontal direction; The device is provided with two rotating platforms, acting on the output shaft and the input shaft respectively, the rotating platform is provided with a bearing fixed on the output shaft or the input shaft, the bearing is fixedly connected to the frame, the frame is fixedly connected to the motor power shaft, the extension direction of the motor power shaft passes through the axis of the output shaft or the input shaft, and is parallel to the laser beam emitted by the laser displacement sensor of the second offset detection unit; The industrial control computer system controls the servo motor and the brake to be coaxial according to the set program. The first offset detection unit transmits the real-time acquired signal to the industrial control computer system. When the difference between the two distance signals of the two output shafts or the input shafts is greater than the set value, the two electric cylinders are driven to work and push the frame to deflect until the difference between the two distance signals is less than the set value.

2. The reducer online testing device according to claim 1, characterized in that: A circular support plate is fixed on the frame, and the circular support plate is perpendicular to the power shaft of the motor. An electric cylinder is provided on each side of the circular support plate. The push rods of the two electric cylinders are coaxial and contact the side of the support plate. The electric cylinder and the motor are fixed next to the output shaft or the input shaft through a bracket.

3. The reducer online testing device according to claim 2, characterized in that: The couplings connecting the input shaft and the output shaft are both provided with torque sensors. The two torque sensors are connected to the industrial control computer system via signal lines and transmit the two sets of torque signals obtained to the industrial control computer system.

4. The reducer online testing device according to claim 3 is characterized in that: The industrial control computer system includes an interface unit for acquiring signals, a host for processing signals, a display for displaying test data, and a printer for printing test data. The host is connected to a sensor and a torsion platform via the interface unit, the video interface of the host is connected to a display screen via a data cable, and the printing interface of the host is connected to a printer via a data cable.

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