A new dynamometer and its dynamometer method

Abstract

The application discloses a novel dynamometer and a dynamometer method thereof, which comprises a rack and a motor mounting seat, a bearing support, a transmission shaft, a slide rail, a torsion sensor mounting plate, a torsion sensor servo motor and a data tester which are sequentially mounted on the rack from left to right. A motor mounting groove is arranged on the top of the motor mounting seat. The left end of the transmission shaft is connected with the motor shaft of a measured motor through a shaft coupling. The right end of the transmission shaft is connected with a magnetic steel rotor. The magnetic steel rotor rotates at the same speed with the measured motor through the transmission shaft. A rotating speed sensor is further arranged below the transmission shaft and fixed on the bearing support to measure the rotating speed of the transmission shaft. A metal cylinder is arranged on the adjacent end of the magnetic steel rotor, so that the metal cylinder can be sleeved on the magnetic steel rotor, and the torsion on the metal cylinder is measured by the torsion sensor. The torsion is indirectly transmitted to a static torsion sensor without loss to collect torsion data. Since the static torsion sensor has higher precision and lower cost, the application has the advantages of high precision, low cost and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to a novel dynamometer and a dynamometer testing method. BACKGROUND

[0002] High-speed electric machines have great advantages in power density and operating efficiency. Currently, high-speed electric machines above 2Wrpm and ultra-high-speed electric machines above 10Wrpm are increasingly popular in various industries, such as new energy vehicle electric machines, small vacuum cleaner blower machines, and other household appliances, as well as military, aerospace, and medical fields. However, to measure and evaluate the characteristics of electric machines, actual data testing using a dynamometer is required. Currently, the mainstream dynamometers, such as hysteresis dynamometers and eddy current dynamometers, use dynamic torque sensors (dynamic torque sensors refer to the shaft of the torque sensor rotating at the same speed as the electric machine) to collect torque data. Due to the limitations of the dynamic torque sensor itself, such as moment of inertia and mechanical structure, it cannot meet the measurement requirements at high speeds. SUMMARY

[0003] The main purpose of the present application is to design a dynamometer for high-speed electric machines to meet the requirement of accurately measuring the power of electric machines at high speeds.

[0004] A novel dynamometer includes a rack and, from left to right, a motor mounting seat, a bearing support, a transmission shaft, a slide rail, a torque sensor mounting plate, a torque sensor servo motor, and a data tester mounted on the rack. The motor mounting seat is fixed on the rack, with a motor mounting groove at the top for mounting and fixing the measured electric machine. The bearing support is fixed on the rack and located at the right end of the motor mounting seat. The transmission shaft is installed on the bearing support through a bearing at the top of the bearing support. The left end of the transmission shaft is connected to the motor shaft of the measured electric machine through a coupling, and the right end of the transmission shaft is connected to a magnetic steel rotor. The magnetic steel rotor rotates at the same speed as the measured electric machine through the transmission shaft. A speed sensor is also installed below the transmission shaft and fixed on the bearing support to measure the speed of the transmission shaft. The slide rail is installed at the right end of the bearing support, with a slidable slider on the slide rail. The bottom of the torque sensor mounting plate is fixed with the slider, and the torque sensor mounting plate can slide along the slide rail together with the slider. A horizontal screw rod is also fixedly connected to the torque sensor mounting plate. A torque sensor is fixed on the top of the torque sensor mounting plate. The torque sensor is installed with a metal cylinder adjacent to the end of the magnetic steel rotor, so that the metal cylinder can be inserted into the cylinder. The torque sensor measures the torque on the metal cylinder generated by the electromagnetic eddy current resistance when the magnetic steel rotor rotates. The front end of the screw rod is connected to the servo motor, which converts the rotary motion of the servo motor into the horizontal linear motion of the screw rod. The screw rod, torque sensor mounting plate, torque sensor, slider, and metal cylinder form an integral motion assembly A. Under the connection of the screw rod and the servo motor, the integral motion assembly A is controlled to move horizontally on the slide rail. The servo motor is fixed to the rack through a servo motor mounting plate.

[0005] The motor mounting seat top is further provided with a motor pressing plate, after the measured motor is fixed and installed, the measured motor is buckled.

[0006] The sensor data line of the torsion sensor and the sensor data line of the rotating speed sensor are electrically connected with an external data tester. The data tester calculates the corresponding test results through the data collected by the sensors and the CPU of the data tester.

[0007] During the test, the measured motor is installed on the motor mounting seat, the magnetic steel rotor is rotated by the measured motor, and the rotating speed n of the measured motor is measured by the rotating speed sensor; the servo motor drives the whole motion assembly A to slide horizontally, so that the metal cylinder on the whole motion assembly A is gradually sleeved into the magnetic steel rotor, the torsion T on the metal cylinder formed by the electromagnetic eddy current resistance of the magnetic steel rotor when rotating and the metal cylinder is measured by the torsion sensor, at each test point, the depth L of the magnetic steel rotor sleeved into the metal cylinder is recorded, the depth L of the magnetic steel rotor sleeved into the metal cylinder is different, the magnetic hysteresis eddy current resistance is different, the value of the torsion sensor is recorded, the voltage value U of the measured motor end is recorded, and the current value I of the measured motor end is recorded, then the motor output power, motor efficiency and other data are calculated according to the formula:

[0008] Pinput=U*I, Poutput=T*n / 9.55.

[0009] The present application generates electromagnetic eddy current resistance by a rotor magnetic steel rotating at the same speed as the motor and a metal sleeve, indirectly transmits the torsion to a static torsion sensor without loss for torsion data collection, so that the static torsion sensor has higher precision, lower cost and is not affected by the rotating speed of the motor, so that the test motor rotating speed is not limited, and the present application has great application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the new dynamometer; Figure 2 It is an electrical structure diagram of the data tester;

[0011] Figure 3 It is a structural schematic diagram of the new dynamometer in a test starting state; Figure 4 It is a structural schematic diagram of the new dynamometer in a test state;

[0012] Among them, the signs are as follows: 1 measured motor, 2 motor shaft, 3 shaft coupling, 4 bearing support, 5 bearing, 6 transmission shaft, 7 magnetic steel rotor, 8 metal cylinder, 9 screw, 10 torsion sensor, 11 torsion sensor mounting plate, 12 sensor data line, 13 screw rod, 14 servo motor mounting plate, 15 servo motor, 16 sliding block, 17 sliding rail, 18 rack, 19 rotating speed sensor, 20 motor mounting seat, 21 motor pressing plate, 22 data tester. DETAILED DESCRIPTION

[0013] The present invention will be further described below with reference to specific embodiments and the accompanying drawings. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0014] Example: A novel dynamometer, such as Figure 1 As shown, the system comprises a test bench 18, a motor mounting base 20 mounted on the test bench, a drive shaft assembly, a torque sensor assembly, a servo motor 15, and a data tester 22. The motor mounting base 20 is fixed to the test bench at the bottom and has a motor mounting slot at the top for mounting the motor under test 1. A motor mounting plate 21 is also provided to press and fix the motor under test 1. The motor mounting plate 21 can be fixed to the motor mounting base 20 with screws. The transmission assembly includes a coupling 3, a bearing bracket 4, and a drive shaft 6. The bearing bracket 4 is fixed to the test bench 18 at the bottom and has a bearing 5 at the top, which fixes the drive shaft 6 to the bearing bracket 4. The drive shaft 6 is connected to the motor shaft 2 of the motor under test 1 via the coupling 3. The other end of the drive shaft 6 is connected to a magnetic rotor 7, forming a coaxial, same-speed rotational connection between the motor under test 1 and the magnetic rotor 7. A speed sensor 19 is also provided at the lower end of the drive shaft 6, fixed to the bearing bracket, to measure the speed of the drive shaft 6, i.e., the speed of the motor under test 1. At the other end of the magnet rotor 7, a torque sensor assembly is installed. The torque sensor assembly is a translational component, including a metal cylinder 8, a torque sensor mounting plate 11, a torque sensor 10, a slider 16, a slide rail 17, and a lead screw 13. The slide rail 17 and slider 16 are a pair of slide rail assemblies. The slide rail 17 is fixed to the frame 18, and the slider 16 is mounted on the slide rail and can move along it. The torque sensor mounting plate 11 is fixed to the slider 16. The torque sensor 10 is mounted on the top of the torque sensor mounting plate 11 and secured with mounting screws 9. A horizontally arranged lead screw 13 is connected to the middle of the torque sensor mounting plate 11. The metal cylinder 8 is mounted at the front end of the torque sensor 10, adjacent to the magnet rotor 7, with its height precisely fitting into the magnet rotor 7. A servo motor 15 is connected to the tail end of the lead screw 13, controlling its movement. The servo motor 15 is fixed to the frame 18 via a servo motor mounting plate 14, and its power cable is connected to an external power source. The torque sensor assembly can move left and right along the slide rail 17. The depth at which the metal cylinder 8 fits into the magnetic rotor 7 is controlled by the translation. The translation distance is completed by the servo motor 15 driving the lead screw 13. The servo motor 15 converts the rotational motion into the lateral linear motion of the lead screw 13, which drives the entire torque sensor assembly to translate.

[0015] The data cable 12 of the torque sensor 10 and the data cable of the speed sensor are both electrically connected to the external data tester 22. For example... Figure 2As shown, the data tester connects the power supply of the measured motor 1 and the servo motor 15 through the switch control circuit, plays a switch control function, measures the input current of the measured motor 1 through the current sensor, and calculates the corresponding test results by the internal CPU according to the data collected by the input speed sensor 19 and the torque sensor 10. The data tester uses low-cost 8-bit or 16-bit single-chip microcomputer, matches corresponding power module, A / D module, switch circuit control module and software programming, so as to realize the required data testing and calculation functions, and control the switch of the measured motor and the servo motor.

[0016] The power test method of the dynamometer is as follows: the measured motor 1 is installed on the motor mounting seat 20, the magnetic steel rotor 7 is driven to rotate by the measured motor 1, and the motor speed n is measured by the speed sensor 19. The torque sensor assembly is driven by the servo motor 15, so that the metal cylinder 8 on it gradually sleeves into the magnetic steel rotor 7 as shown in the state. Figures 3-4 The torque T on the metal cylinder 8 generated by the electromagnetic eddy current resistance of the magnetic steel rotor 7 rotating with the metal cylinder 8 is measured by the torque sensor 10. At each test point, that is, at different depths L of the metal cylinder 8 sleeving into the magnetic steel rotor 7, the hysteresis eddy current resistance generated is different, the value of the torque sensor 10 is recorded, the voltage value U of the measured motor end is recorded, and the current value I of the measured motor end is recorded. Then, according to the formula:

[0017] Pinput=U*I, Poutput=T*n / 9.55, the motor output power, motor efficiency and other data are calculated.

[0018] The novel dynamometer indirectly transmits the torque without loss to a static torque sensor by sleeving the metal cylinder around the magnetic steel rotor rotating at the same speed as the measured motor to generate electromagnetic eddy current resistance, collecting torque data, realizing static collection of torque value, and realizing high-precision data collection at high speed of the motor. It has simple structure, low production cost, is suitable for promotion, and has market prospect.

Claims

1. A new dynamometer characterized in that, The utility model relates to a motor test device, including stand (18) and install in order on stand motor mounting seat (20), bearing support (4), transmission shaft (6), slide rail (17), torsion sensor mounting plate (11), torsion sensor (10), servo motor (15) and data tester (22), motor mounting seat (20) is fixed on stand (18), top sets up motor mounting groove, is used for fixing the motor (1) of measured, bearing support (4) is fixed on stand (18), is located motor mounting seat (20) right -hand member, transmission shaft (6) is installed through bearing (5) on bearing support (4), transmission shaft (6) left -hand member is connected with the motor shaft (2) of measured motor (1) through coupling (3), transmission shaft (6) right -hand member connects magnetic steel rotor (7), magnetic steel rotor (7) is rotated through transmission shaft (6) with measured motor (1) coaxial same speed, transmission shaft (6) below installs rotating speed sensor (19), slide rail (17) is installed in bearing support (4) right -hand member, sets up the sliding block (16) of sliding on slide rail, torsion sensor mounting plate (11) bottom with sliding block (16) are fixed, can along slide rail (17) sliding, torsion sensor mounting plate (11) top fixed torsion sensor (10), torsion sensor (10) with magnetic steel rotor (7) adjacent end installs metal cylinder (8), makes metal cylinder (8) can with magnetic steel rotor (7) sleeve into cylinder, servo motor (15) is fixed with stand (18) through servo motor mounting plate (14), servo motor (15) installs screw rod (13) on, and the front end of screw rod (13) is fixedly connected with torsion sensor mounting plate (11), can push torsion sensor mounting plate (11) and slide, motor mounting seat (20) top still sets up motor pressure plate (21), fixes measured motor, and the sensor data line (12) of torsion sensor (10), the data line of rotating speed sensor (19) all are electrically connected with external data tester (22).

2. A novel method of measuring the power of a dynamometer according to claim 1, characterized in that, Magnetic steel rotor (7) is rotated by measured motor (1), and rotating speed sensor (19) measures measured motor rotating speed n, through servo motor (15) drive torsion sensor mounting plate (11) and slide, make on its metal cylinder (8) gradually sleeve into magnetic steel rotor (7), and the torsion T on metal cylinder (8) that the electromagnetic eddy current resistance that torsion sensor (10) measures when magnetic steel rotor (7) rotates with metal cylinder (8) forms, in each test point, record the depth L of magnetic steel rotor (7) sleeve into metal cylinder (8), and the depth L of metal cylinder sleeve into magnetic steel rotor is different, and the value of torsion sensor (10) is recorded, and the voltage value U of measured motor end is recorded, and the current value I of measured motor end is recorded, then according to formula: Pinput=U*I, Poutput=T*n / 9.55, calculates motor output power, motor efficiency data.

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