A micro-torque motor power testing system and testing method

Abstract

The present application belongs to the technical field of motor testing, and discloses a micro-torque motor power testing system and testing method, wherein the testing system comprises a support, an adjusting screw, a permanent magnet disc, a magnetic hysteresis disc, an output shaft, a torque calibration disc and a torque measuring device; the adjusting screw is erected on the support, one end of the adjusting screw is a handle, and the other end is the permanent magnet disc; the output shaft is erected on the support, one end of the output shaft extends out of the support and is detachably connected with the torque calibration disc, and the other end of the output shaft is the magnetic hysteresis disc; the disc surface of the permanent magnet disc is opposite to the disc surface of the magnetic hysteresis disc, the permanent magnet disc is provided with alternately distributed permanent magnets, and the magnetic hysteresis disc is made of magnetic damping material; and the torque measuring device is connected with and measures the rotating torque of the torque calibration disc. The present application solves the problem that the torque of a motor is difficult to balance the dynamic friction force generated by a rope when the testing torque is small, has high testing precision, and the overall investment is only 5% of the imported equipment, thereby greatly reducing the testing cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of motor testing, and relates to a motor power testing method and system, in particular to a micro-torque motor power testing system and method. BACKGROUND

[0002] The micro-torque motor power testing has always been a difficulty in the motor industry, one is how to stably and continuously provide a micro-load torque, and the other is how to calibrate the micro-load torque.

[0003] Currently, there are two methods for testing the micro-power motor:

[0004] One is the weight pulley method, which uses the measured motor to drive the pulley, and the rope with the lifting weight is wound on the pulley. When the driving torque of the measured motor and the dynamic friction force generated by the rope on the pulley are balanced, the weight will hover in the air. As long as the appropriate weight and rope are selected, they can be used as the rated load torque of the measured motor to determine whether the power of the measured motor is qualified. However, when the test torque is small, it is difficult for the motor torque to balance the dynamic friction force generated by the rope, and the test precision is poor.

[0005] The second method is the hysteresis dynamometer method, which uses the current in the control coil to control the magnetic field generated by the control coil to generate a hysteresis force on the metal disc to provide a load torque. When the test torque is small, a series of measures need to be taken to reduce the rotational loss of the system to improve the test precision. The disadvantage of this method is that the system is complex and expensive, and the hysteresis dynamometer below 10mN.m is monopolized by foreign manufacturers. SUMMARY

[0006] In order to solve the above problems, the present application provides a micro-torque motor power testing system and method, which not only does not need to balance the dynamic friction force, but also has low cost and high precision.

[0007] The technical scheme of the present application is as follows:

[0008] A micro-torque motor power testing system, comprising a support, an adjusting screw, a permanent magnet disc, a hysteresis disc, an output shaft, a torque calibration disc and a torque measuring device. The adjusting screw is erected on the support, one end of the adjusting screw is a handle, and the other end is the permanent magnet disc. The output shaft is erected on the support, one end of the output shaft extends out of the support and is detachably connected with the torque calibration disc, and the other end of the output shaft is the hysteresis disc. The disc surface of the permanent magnet disc is opposite to the disc surface of the hysteresis disc, the permanent magnet disc is provided with N and S alternately distributed permanent magnets, and the hysteresis disc is made of magnetic damping material. The torque measuring device is connected with and measures the rotational torque of the torque calibration disc.

[0009] Further, the permanent magnet disc is a disc structure with an inner circle and an outer circle, the center of the inner circle of the permanent magnet disc is fixedly connected with the end of the adjusting screw, and the outer circle of the permanent magnet disc is provided with permanent magnets alternately distributed with N and S, all the permanent magnets are consistent in size and uniformly distributed on the outer circle of the permanent magnet disc.

[0010] Further, the disc area of the magnetic hysteresis disc is within 10% of the disc area of the permanent magnet disc.

[0011] Further, the torque measuring device comprises a high-precision tension meter, a traction rope and a weight, the traction rope is wound on the annular surface of the torque calibration disc and moves with the rotation of the torque calibration disc, the high-precision tension meter is arranged on the same horizontal plane as the torque calibration disc and is connected with one end of the traction rope, and the weight is naturally hung and connected with the other end of the traction rope.

[0012] Further, the left side of the support is provided with a threaded hole, the adjusting screw is rotatably arranged through the threaded hole, and the rotation of the adjusting screw enables the permanent magnet disc to rotate and horizontally move on one side of the support.

[0013] Further, the right side of the support is provided with a through hole, and the output shaft is rotatably arranged through the through hole through a bearing.

[0014] Further, the torque measuring device comprises a high-precision tension meter, a traction rope and a weight, the traction rope is wound on the annular surface of the torque calibration disc and moves with the rotation of the torque calibration disc, the high-precision tension meter is arranged on the same horizontal plane as the torque calibration disc and is connected with one end of the traction rope, and the weight is naturally hung and connected with the other end of the traction rope.

[0015] A micro-torque motor power testing method using the micro-torque motor power testing system, comprising the following steps:

[0016] Step one, adjusting the air gap between the permanent magnet disc and the magnetic hysteresis disc by screwing in or out the adjusting screw;

[0017] Step two, controlling the rotation of the torque calibration disc by the torque measuring device to measure the magnetic damping torque;

[0018] Step three, repeating step one and step two according to the difference between the measured magnetic damping torque and the target torque until the measured magnetic damping torque is equal to the target torque;

[0019] Step four, disassembling the torque calibration disc, connecting the output shaft with the rotating shaft of the motor to be tested, and testing the power of the motor to be tested.

[0020] A micro-torque motor power testing method using the micro-torque motor power testing system, comprising the following steps:

[0021] Step one, adjusting the air gap between the permanent magnet disc and the magnetic hysteresis disc by screwing in or out the adjusting screw;

[0022] Step two, the value of the magnetic damping torque is calculated by the reading of the tension gauge, the weight of the weight, the radius of the calibration disc and the radius of the traction rope;

[0023] Step three, steps one and two are repeated according to the difference between the measured magnetic damping torque and the target torque until the measured magnetic damping torque is equal to the target torque;

[0024] Step four, disassemble the torque calibration disc, connect the rotating shaft of the measured motor with the output shaft, and test the power of the measured motor.

[0025] Further, the rotating torque generated by the interaction of the permanent magnet disc and the hysteresis disc = (the reading of the tension gauge - the weight of the weight) x (the radius of the calibration disc + the radius of the traction rope).

[0026] The beneficial effects of the present application are:

[0027] 1. The combination of the tension gauge and the weight in the present application is used to transform the auxiliary torque into the magnetic field load torque, which solves the problem that the torque of the motor is difficult to balance the dynamic friction force generated by the rope when the test torque is small, and the test precision is high, and the effect can meet the demand of the power test of the small torque motor.

[0028] 2. Compared with the 10mN.m below hysteresis dynamometer technology of foreign manufacturers, the cost is low, the overall investment is only 5% of the imported equipment, and the domestic process level cannot currently independently complete the manufacturing of 10mN.m below hysteresis dynamometer. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the patent implementation manner of the present application, the following will briefly introduce the drawings needed to be used in the implementation manner. It should be understood that the following drawings only show some embodiments of the present application, and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0030] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0031] Figure 2 It is a schematic diagram of the structure of the tested motor of the present application.

[0032] Figure 3 It is a schematic diagram of the structure of the permanent magnet disc.

[0033] Among them, 1 is a support, 2 is an adjusting screw, 3 is a locking screw, 4 is a permanent magnet disc, 5 is a hysteresis disc, 6 is an output shaft, 7 is a bearing, 8 is a torque calibration disc, 9 is a high-precision tension gauge, 10 is a traction rope, 11 is a weight, 12 is a connecting sleeve, and 13 is a measured motor. DETAILED DESCRIPTION

[0034] This part is the embodiment of the present application, used to explain and illustrate the technical solutions of the present application. The embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0035] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship as the orientation or position relationship given to the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or the case referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implying the number of the technical features indicated. Therefore, the features defined with "first", "second" and the like can explicitly or implicitly include more features. In the description of the present application, unless otherwise stated, "a plurality of" means two or more.

[0036] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be interpreted broadly, for example, it can be fixed connection, or detachable connection or integrated connection, it can be mechanical connection, or point connection, it can be direct connection, or indirect connection through intermediate medium, it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] A micro-torque motor power test system, comprising a support 1, an adjusting screw 2, a permanent magnet disc 4, a magnetic hysteresis disc 5, an output shaft 6, a torque calibration disc 8 and a torque measuring device, the adjusting screw 2 is erected on the support 1, one end of the adjusting screw 2 is a handle, and the other end is the permanent magnet disc 4; the output shaft 6 is erected on the support 1, one end of the output shaft 6 extends out of the support 1 and is detachably connected with the torque calibration disc 8, and the other end of the output shaft 6 is the magnetic hysteresis disc 5; the disc surface of the permanent magnet disc 4 is opposite to the disc surface of the magnetic hysteresis disc 5, the permanent magnet disc 4 is provided with N, S alternately distributed permanent magnets, and the magnetic hysteresis disc 5 is made of magnetic damping material; the torque measuring device is connected with and measures the rotating torque of the torque calibration disc 8.

[0038] The permanent magnet disc 4 is a disc structure with an inner circle and an outer ring, the center of the inner circle of the permanent magnet disc 4 is fixedly connected with the end of the adjusting screw 2, and the outer ring of the permanent magnet disc 4 is provided with N, S alternately distributed permanent magnets, all the permanent magnets are consistent in size and uniformly distributed on the outer ring of the permanent magnet disc 4.

[0039] The area of the magnetic hysteresis disc 5 is within 10% of the area of the permanent magnet disc 4.

[0040] The connecting sleeve 12 is detachably connected to the output shaft 6 at one end and to the rotating shaft of the motor 13 at the other end, so that the rotation of the rotating shaft of the motor 13 can drive the output shaft 6 to rotate.

[0041] The left side of the support 1 is provided with a threaded hole, and the adjusting screw 2 is rotatably arranged through the threaded hole.

[0042] The right side of the support 1 is provided with a through hole, and the output shaft 6 is rotatably arranged through the through hole via the bearing 7.

[0043] The torque measuring device includes a high-precision tension gauge 9, a traction rope 10 and a weight 11. The traction rope 10 is wound around the toric surface of the torque calibration disc 8 and moves with the rotation of the torque calibration disc 8. The high-precision tension gauge 9 is arranged on the same horizontal plane as the torque calibration disc 8 and is connected to one end of the traction rope 10. The weight 11 is naturally suspended and connected to the other end of the traction rope.

[0044] A micro-torque motor power testing method using the micro-torque motor power testing system described above, comprising the following steps:

[0045] Step one: adjust the air gap between the permanent magnet disc and the magnetic hysteresis disc by screwing in or out the adjusting screw;

[0046] Step two: measure the magnetic damping torque by controlling the rotation of the torque calibration disc through the torque measuring device;

[0047] Step three: repeat steps one and two according to the difference between the measured magnetic damping torque and the target torque until the measured magnetic damping torque is equal to the target torque;

[0048] Step four: detach the torque calibration disc, connect the rotating shaft of the motor to be tested to the output shaft, and test the power of the motor to be tested.

[0049] A micro-torque motor power testing method using the micro-torque motor power testing system described above, comprising the following steps:

[0050] Step one: adjust the air gap between the permanent magnet disc and the magnetic hysteresis disc by screwing in or out the adjusting screw;

[0051] Step two: calculate the value of the magnetic damping torque by the reading of the tension gauge, the weight of the weight, the radius of the calibration disc and the radius of the traction rope;

[0052] Step 3: Repeat steps 1 and 2 based on the difference between the measured magnetic damping torque and the target torque until the measured magnetic damping torque is equal to the target torque.

[0053] Step 4: Remove the torque calibration disc, rotate the shaft of the motor under test to connect it to the output shaft, and test the power of the motor under test.

[0054] The present invention will now be described in conjunction with the accompanying drawings as a practical example.

[0055] The micro-torque motor power testing system of the present invention has a main body of bracket 1, and a permanent magnet 4 with N and S poles of alternating permanent magnets embedded at its end. The position of the permanent magnet 4 relative to the hysteresis disk 5 can be adjusted by screwing in and out of the adjusting screw 2 on the bracket. The hysteresis disk 5 is mounted on a bearing 7 fixed on the bracket 1 via an output shaft 6, and can rotate freely in a free state. During torque calibration, the torque calibration disk 8 is installed at the end of the output shaft, and a high-precision tension gauge 9 pulls the traction rope. The traction rope 10 rubs against the torque calibration disk 8, causing the torque calibration disk 8 to rotate and the weight 11 to rise. During motor testing, the torque calibration disk and traction rope are removed, and the motor 13 under test is connected to the output shaft 6 by a connecting sleeve 12.

[0056] Adjust the air gap between the permanent magnet disk 4 and the hysteresis disk 5 by screwing in or out the adjusting screw 2. Pull the weight 11 with a force gauge. The torque calibration disk 8 drives the output shaft 6 to rotate, and the output shaft 6 drives the hysteresis disk 5 to rotate. The hysteresis disk 5 will generate a magnetic damping torque under the alternating magnetic field. The value of the magnetic damping torque can be calculated by using the reading of the high-precision force gauge 9, the weight 11, the radius of the torque calibration disk 8, and the radius of the traction rope 10. After adjusting to the required torque for the test, fix the adjusting screw 2 with the set screw 3, remove the torque calibration wheel 8, the high-precision force gauge 9, the traction rope 10, and the weight 11, and connect the motor 13 under test to the output shaft 6 to test the motor power.

[0057] like Figure 3 As shown, this invention utilizes the alternating N and S permanent magnets distributed on the permanent magnet disk 4 to form an alternating magnetic field. When the air gap between the permanent magnet disk 4 and the hysteresis disk 5 made of magnetic damping material changes, the hysteresis disk 5 will generate different rotational torques. Alternatively, the permanent magnet disk 4 and the hysteresis disk 5 can be made into rings or cups, nested together, and different rotational torques can be generated by changing the area of ​​their interaction. The generated rotational torque is used as the load torque during motor power testing.

[0058] The high-precision force gauge 9 pulls the traction rope 10, and the traction rope 10 generates sliding friction with the torque calibration disk 8, causing the torque calibration disk 8 to rotate and the weight 11 to rise. The rotational torque generated by the interaction between the permanent magnet disk 4 and the hysteresis disk 5 is equal to (force gauge reading - weight of the weight) × (calibration disk radius + traction rope radius).

[0059] Taking the testing of a 0.9mN.m motor as an example, the radius of the calibration disc is 16mm and the radius of the traction rope is 0.3mm.

[0060] 0.9mN.m=918.36g.mm=Fx(16+0.3)mm F=56.34g

[0061] Select 100g as weight 11, pull the high-precision force gauge 9, and rotate the adjusting screw 2 until the force gauge reading is 156.34g. At this time, the permanent magnet disk 4, passing through the alternating magnetic field, generates a hysteresis torque of 0.9mN.m on the hysteresis disk 5. Fix the adjusting screw 2 with the set screw 3, and the rotational torque of the output shaft 6 is now 0.9mN.m. Figure 1 As shown.

[0062] Remove the torque calibration disc 8, high-precision tension gauge 9, and traction rope 10. Connect the motor under test 13 to the output shaft 6 using the connecting sleeve 12. With the motor under test powered on, the actual speed can be easily measured using a tachometer, and the rated power of the motor under test can be calculated. For example... Figure 2 As shown.

Claims

1. A power testing system for a low-torque electric motor, characterized in that, The device includes a bracket (1), an adjusting screw (2), a permanent magnet disk (4), a hysteresis disk (5), an output shaft (6), a torque calibration disk (8), and a torque measuring device. The adjusting screw (2) is mounted on the bracket (1), with one end being a handle and the other end being the permanent magnet disk (4). The output shaft (6) is mounted on the bracket (1), with one end extending out of the bracket (1) and detachably connected to the torque calibration disk (8). The other end of the output shaft (6) is the hysteresis disk (5). The disk surface of the permanent magnet disk (4) is spaced opposite to the disk surface of the hysteresis disk (5). The permanent magnet disk (4) is provided with N and S permanent magnets that are alternately distributed. The hysteresis disk (5) is made of magnetic damping material. The torque measuring device is connected to and measures the rotational torque of the torque calibration disk (8). The left side of the bracket (1) is provided with a threaded hole, through which the adjusting screw (2) can rotatably pass. The rotation of the adjusting screw (2) causes the permanent magnet disk (4) to rotate while moving horizontally on the bracket (1).

2. The power testing system for a small torque motor according to claim 1, characterized in that, The permanent disk (4) is a disk structure with an inner circle and an outer ring. The center of the inner circle of the permanent disk (4) is fixedly connected to the end of the adjusting screw (2). The outer ring of the permanent disk (4) is equipped with permanent magnets with alternating N and S distributions. All permanent magnets are of the same size and are evenly distributed on the outer ring of the permanent disk (4).

3. The power testing system for a small torque motor according to claim 1, characterized in that, The disk area of ​​the hysteresis disk (5) is less than 10% different from that of the permanent disk (4).

4. The power testing system for a small torque motor according to claim 1, characterized in that, It also includes a connecting sleeve (12), one end of which is a detachable interface for connecting the output shaft (6) to one end of the bracket (1), and the other end of which is a detachable interface for connecting the shaft of the motor under test (13). The connecting sleeve (12) enables the shaft of the motor under test (13) to rotate so that the output shaft (6) can rotate.

5. The power testing system for a small torque motor according to claim 1, characterized in that, The bracket (1) has a through hole on the right side, through which the output shaft (6) rotatably passes via a bearing (7).

6. The power testing system for a small torque motor according to claim 1, characterized in that, The torque measuring device includes a high-precision tension gauge (9), a traction rope (10), and a weight (11). The traction rope (10) passes around the annular surface of the torque calibration disk (8) and moves with the rotation of the torque calibration disk (8). The high-precision tension gauge (9) is located on the same horizontal plane as the torque calibration disk (8) and is connected to one end of the traction rope (10). The weight (11) hangs down naturally and is connected to the other end of the traction rope.

7. A method for testing the power of a small torque motor, using a small torque motor power testing system as described in any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1: Adjust the air gap between the permanent magnet disk and the hysteresis disk by screwing the adjusting screw in or out. Step 2: The magnetic damping torque is measured by controlling the rotation of the torque calibration disk through a torque measuring device. Step 3: Repeat steps 1 and 2 based on the difference between the measured magnetic damping torque and the target torque until the measured magnetic damping torque is equal to the target torque. Step 4: Remove the torque calibration disc, rotate the shaft of the motor under test to connect it to the output shaft, and test the power of the motor under test.

8. A method for testing the power of a small torque motor, using a small torque motor power testing system as described in any one of claims 6, characterized in that, Includes the following steps: Step 1: Adjust the air gap between the permanent magnet disk and the hysteresis disk by screwing the adjusting screw in or out. Step two: Calculate the value of the magnetic damping torque using the readings of the dynamometer, the weight of the weights, the radius of the calibration pan, and the radius of the traction rope; Step 3: Repeat steps 1 and 2 based on the difference between the measured magnetic damping torque and the target torque until the measured magnetic damping torque is equal to the target torque. Step 4: Remove the torque calibration disc, rotate the shaft of the motor under test to connect it to the output shaft, and test the power of the motor under test.

9. The method for testing the power of a small torque motor according to claim 8, characterized in that, The rotational torque generated by the interaction between the permanent magnet disk and the hysteresis disk = (force gauge reading - weight of the weight) × (calibration disk radius + traction rope radius).

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