Measuring device for positioning torque of motor

Abstract

The utility model relates to a motor positioning torque measuring device, which comprises a base, a protective cover, a force measuring module, a rotation positioning module, a driving rotation module and a fixing seat and coupling module, and a force measuring shaft is arranged on the fixing seat and coupling module. The force measuring module, the rotation positioning module and the driving rotation module are respectively installed on the base and covered by the protective cover, the product to be tested is installed on the fixing base and the coupling module, and an output shaft of the product to be tested is connected with the force measuring shaft; and the driving rotation module drives the fixed seat and the coupling module to rotate, so that the to-be-tested product rotates as a whole. Compared with the prior art, the utility model has the advantages of high precision, high stability, low cost and the like.

Description

Measurement device for motor positioning torque Technical Field

[0001] This utility model relates to motor positioning torque measurement technology, and in particular to a motor positioning torque measuring device. Background Technology

[0002] Motor positioning torque, also known as reluctance torque or cogging torque, refers to the electromagnetic torque generated by the interaction between the permanent magnet and the cogging teeth of the iron core when the motor is not energized. It is an inherent physical phenomenon of motors.

[0003] The existing methods for measuring motor positioning torque typically include the following:

[0004] 1. Dynamic torque sensor measurement: Connect the dynamic torque sensor to the motor output shaft, fix the motor body, and then set up a power source and transmission mechanism to rotate the motor output shaft. Use the dynamic torque sensor to measure the torque of the rotating motor output shaft. This measurement method is limited by the structure of the mechanism, the accuracy of the sensor, and the manufacturing difficulty. The smaller the positioning torque of the motor being measured, the higher the requirements for the structure of the mechanism and the accuracy of the sensor.

[0005] 2. Back EMF waveform analysis method: The positioning torque is indirectly evaluated by measuring the decay time of the back EMF or the degree of waveform distortion after the motor is powered off. This measurement method is easily affected by environmental interference, and it cannot capture high-frequency torque pulsation, only reflecting the average torque characteristics.

[0006] 3. Dynamic inertia measurement method: The load is simulated by an inertia disk, and the dynamic torque is calculated by combining an accelerometer and an encoder. This measurement method requires a high-precision inertia disk, and the calculation of rotational inertia depends on the accuracy of mechanical parameters. Errors will amplify the deviation of the torque result.

[0007] A search of Chinese Patent Publication No. CN201476914U reveals a motor torque testing device, specifically comprising a base plate with a tension gauge mounted on it. An axle is positioned at a certain distance from the tension gauge on the base plate, rotatably supported by the axle. A wheel is fixed to the axle, and several columns surround it. A motor positioning plate is fixed to the upper end of each column, and the motor positioning plate has a through hole through which the motor shaft passes. The upper end of the axle corresponds to the area below the through hole in the motor positioning plate. A rope is wound around the wheel, and the free end of the rope is hooked to the tension gauge. However, this existing patent suffers from problems such as low measurement accuracy.

[0008] Therefore, how to further reduce measurement costs and improve measurement efficiency while ensuring measurement accuracy has become a technical problem that needs to be solved. Summary of the Invention

[0009] The purpose of this invention is to overcome the defects of the existing technology and provide a measuring device for motor positioning torque.

[0010] The objective of this utility model can be achieved through the following technical solutions:

[0011] According to one aspect of the present invention, a measuring device for measuring the positioning torque of a motor is provided for measuring the positioning torque of a product under test. The measuring device includes a base and a protective cover. The measuring device also includes a force measuring module, a rotary positioning module, a drive rotary module, and a fixed base and coupling module. The fixed base and coupling module is provided with a force measuring shaft.

[0012] The force measuring module, rotary positioning module, and drive rotary module are respectively mounted on the base and covered by a protective cover. The product under test is mounted on the fixed base and coupling module. The output shaft of the product under test is connected to the force measuring shaft.

[0013] The drive rotation module drives the fixed base and coupling module to rotate, causing the product under test to rotate as a whole.

[0014] As a preferred technical solution, the force measuring module includes a force sensor, a tension rope, and a tension adjustment mechanism. The tension rope is wound around the force measuring shaft and connected to the force sensor at both ends. The tension adjustment mechanism is connected to the tension rope and is used to adjust the tension of the tension rope.

[0015] As a preferred technical solution, the tension adjustment mechanism is provided in two sets, each set of tension adjustment mechanism includes an adjustment slide and an adjustment screw, the force sensor is fixed on the adjustment slide, and the adjustment screw drives the adjustment slide to realize the adjustment of the tension of the tension rope.

[0016] As a preferred technical solution, the force sensor is a force sensor or a static torque sensor.

[0017] As a preferred technical solution, the rotary positioning module includes a positioning seat, a worm gear, an adapter sleeve, a first bearing, and a second bearing. The force measuring shaft is connected to the positioning seat through the second bearing, the worm gear is connected to the positioning seat through the first bearing, and the adapter sleeve is fixed on the worm gear.

[0018] As a preferred technical solution, the drive rotation module includes a drive motor, a first synchronous pulley, a synchronous toothed belt, a second synchronous pulley, and a worm gear. The drive motor is connected to the first synchronous pulley, the first synchronous pulley is connected to the second synchronous pulley via the synchronous toothed belt, the synchronous toothed belt is connected to the worm gear, and the worm gear is connected to the worm wheel.

[0019] As a preferred technical solution, the drive rotation module further includes a worm gear mounting base, a third bearing, and a fourth bearing. The worm gear is mounted on the worm gear mounting base, and its two ends are fixed by the third bearing and the fourth bearing.

[0020] As a preferred technical solution, the fixed base and coupling module further includes a rotary base, a fixed base and a connecting component. The rotary base is fixed to the adapter sleeve, the rotary base is fixed to the fixed base, the product to be tested is fixed on the fixed base, and one end of the connecting component is connected to the output shaft of the product to be tested, and the other end is connected to the force measuring shaft.

[0021] As a preferred technical solution, the connecting component is a coupling.

[0022] As a preferred technical solution, the base is equipped with a start button.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1) This utility model enables relative rotational motion between the stationary and rotating parts of the motor. Based on the relationship that the action torque and reaction torque are equal, the torque measuring unit is placed and connected to the stationary side.

[0025] That is, the torque measuring unit of this utility model can be a static torque sensor with high precision and low price; or it can be a force measuring device acting on the lever arm, from which the positioning torque or torque of the motor can be calculated.

[0026] Compared with existing technologies, it has advantages such as high precision, high stability and low cost.

[0027] 2) Existing testing methods generally use dynamic torque sensors that are difficult to manufacture and expensive. However, this invention achieves the same measurement accuracy using force sensors that are easy to manufacture and inexpensive, namely push-pull force sensors or static torque sensors.

[0028] 3) Existing dynamic torque sensors in testing methods directly and actively measure and read torque values, while this invention utilizes the principle that action and reaction forces are equal to achieve passive measurement. Attached Figure Description

[0029] Figure 1 is a schematic diagram of the force measuring model of this utility model;

[0030] Figure 2 is a schematic diagram of the appearance result of this utility model;

[0031] Figure 3 is a schematic diagram of the structure of this utility model after the protective cover is opened;

[0032] Figure 4(a) is a schematic diagram of the structure of the drive rotary module of this utility model;

[0033] Figure 4(b) is a cross-sectional view of the drive rotation module of this utility model;

[0034] Figure 5 is a structural schematic diagram of the force measuring module of this utility model;

[0035] Figure 6 is a structural schematic diagram of the rotary positioning module of this utility model;

[0036] Figure 7 is a schematic diagram of the tension rope connection between the force measuring module and the force measuring shaft of this utility model;

[0037] Figure 8 is a schematic diagram of the connection between the fixed base assembly of this utility model and the product under test.

[0038] Where F1 and F2 are the forces at both ends of the tension rope;

[0039] 1 is the force measuring module, 2 is the rotary positioning module, 3 is the drive rotary module, 4 is the fixed base and coupling module, 5 is the protective cover, 6 is the product to be tested, 7 is the base, and 71 is the start button;

[0040] 11 is a force sensor, 12 is a tension rope, 13 is an adjusting slide, and 14 is an adjusting screw;

[0041] 21 is the positioning seat, 22 is the worm gear, 23 is the adapter sleeve, 24 is the first bearing, 25 is the second bearing, and 26 is the bearing lock nut;

[0042] 31 is the drive motor, 32 is the first synchronous pulley, 33 is the synchronous toothed belt, 34 is the second synchronous pulley, 35 is the connecting shaft, 36 is the worm gear mounting seat, 37 is the third bearing, 38 is the worm gear, and 39 is the fourth bearing.

[0043] 41 is the force measuring shaft, 42 is the rotary seat, 43 is the fixed seat, and 44 is the connecting assembly. Detailed Implementation

[0044] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present utility model.

[0045] As shown in Figures 2 and 3, a motor positioning torque measuring device is used to measure the motor positioning torque of the product 6 to be tested. The measuring device includes a base 7 and a protective cover 5. The measuring device also includes a force measuring module 1, a rotary positioning module 2, a drive rotary module 3, and a fixed seat and coupling module 4. The fixed seat and coupling module 4 is provided with a force measuring shaft 41.

[0046] The force measuring module 1, the rotary positioning module 2, and the drive rotary module 3 are respectively mounted on the base 7 and covered by the protective cover 5. The product under test 6 is mounted on the fixed base and the coupling module 4. The output shaft of the product under test 6 is connected to the force measuring shaft 41. The drive rotary module 3 drives the fixed base and the coupling module 4 to rotate, causing the product under test 6 to rotate as a whole. The output shaft is subjected to the positioning torque, generating a torque T. The force measuring module 1 collects the torque T and calculates the motor positioning torque.

[0047] As shown in Figure 2, the force measuring module 1, the rotary positioning module 2, and the drive rotary module 3 are all mounted on the base 7 and protected by the protective cover 5. The product to be tested 6 is visible from the outside and is placed on the fixed seat and coupling module 4. The fixed seat and coupling module 4 are used to drive the product to rotate and limit the position of the product to be tested.

[0048] As shown in Figures 4(a) and 4(b), the drive rotation module 3 includes a drive motor 31, a first synchronous pulley 32, a synchronous toothed belt 33, a second synchronous pulley 34, and a worm gear 38, which are used to provide rotation drive.

[0049] The drive motor 31 is connected to the first synchronous pulley 32, which is connected to the second synchronous pulley 34 via a synchronous toothed belt 33. The synchronous toothed belt 33 is connected to the worm gear 38, which is connected to the worm wheel 22. The drive rotation module 3 also includes a worm gear mounting base 36, a third bearing 37, and a fourth bearing 39. The worm gear 38 is mounted on the worm gear mounting base 36, and its two ends are fixed by the third bearing 37 and the fourth bearing 39.

[0050] The drive motor 31 provides power for the rotation of the mechanism. Through the first synchronous pulley 32 and the second synchronous pulley 34, the synchronous toothed belt 33 transmits the rotational power to the worm 38. The worm 38 drives the worm wheel in the above-mentioned rotational positioning module to rotate together. The worm 38 is installed in the worm mounting seat 36, and the rotational center of the worm is maintained by the third bearing 37 and the fourth bearing 39.

[0051] As shown in Figure 5, the force measuring module 1 includes a force sensor 11, a tension rope 12, and a tension adjustment mechanism. The tension rope 12 is wound around the force measuring shaft 41 and connected to the force sensor 11 at both ends. The tension adjustment mechanism is connected to the tension rope 12 and is used to adjust the tension of the tension rope 12.

[0052] The tension adjustment mechanism is provided in two sets, one on the left and one on the right. Each set of tension adjustment mechanism includes an adjustment slide 13 and an adjustment screw 14. The force sensor 11 is fixed on the adjustment slide 13. The adjustment screw 14 drives the adjustment slide 13 to adjust the tension of the tension rope 12.

[0053] As shown in Figure 6, the rotary positioning module 2 includes a positioning seat 21, a worm gear 22, an adapter sleeve 23, a first bearing 24 and a second bearing 25. The force measuring shaft 41 is connected to the positioning seat 21 through the second bearing 25. The force measuring shaft 41 is connected to the positioning seat 21 through the upper and lower second bearings 25, and the second bearings 25 only constrain the axial position of the force measuring shaft 41.

[0054] The worm gear 22 is connected to the positioning seat 21 via the first bearing 24, allowing it to rotate around the axis of the positioning seat 21. The adapter sleeve 23 is fixed on the worm gear 22 and can rotate with the worm gear.

[0055] The force measuring shaft 41 is confined within the positioning seat 21 by the second bearing 25, which allows for a small range of axial movement but does not allow for complete disengagement. The bearing can be a rolling bearing, a sliding bearing with a sufficiently low coefficient of friction, or other types of components that can maintain the center position of the force measuring shaft 41, ensuring that the force measuring shaft can generate a rotational tendency when subjected to external torque.

[0056] Figure 7 shows a schematic diagram of the tension rope connection, specifically the connection between the force measuring module 1 and the force measuring shaft 41 via the tension rope 12. The tension rope 12 is wound around the force measuring shaft 41, with both ends of the rope fixed to two force sensors on the force measuring device assembly. The initial tension of the tension rope is adjusted by the adjusting screw of the adjusting slide of the force measuring module 1, so that static friction is formed at the contact point between the tension rope and the force measuring shaft, achieving force balance. The static friction needs to be greater than the tangential force generated by the external torque (test range) on the force measuring shaft.

[0057] As shown in Figure 8, the fixed base and coupling module 4 also includes a rotary base 42, a fixed base 43, and a connecting assembly 44. The rotary base 42 is fixed to the adapter sleeve 23, and the rotary base 42 is fixed to the fixed base 43. The product to be tested 6 is fixed on the fixed base 43. One end of the connecting assembly 44 is connected to the output shaft of the product to be tested 6, and the other end is connected to the force measuring shaft 41.

[0058] The rotary seat 42 is fixed to the adapter sleeve and can rotate together with it. The fixed seat 43 is fixedly connected to the rotary seat 42 and can rotate together with it. The fixed seat 43 provides limit positioning for the product under test and can drive the product to rotate together. The connecting component 44 connects the stationary side of the product under test to the force measuring shaft and transmits the external torque to the force measuring shaft. It can be connected by a coupling or other means. When the motor under test is driven to rotate, due to the existence of the motor positioning torque, its stationary end (motor shaft) is connected to the force measuring shaft through the connecting component 44 (the connecting component can be designed according to the product structure). The motor positioning torque during the rotation process will cause the force measuring shaft to have a rotational tendency. As shown in Figure 7, the torque transmitted to the force measuring shaft will cause the force at both ends of the tension rope to change. The actual positioning torque can be calculated from the change value of the force at both ends of the tension rope and the radius of the force measuring shaft.

[0059] As shown in Figure 1, the measurement actions of the measuring device of this utility model are broken down as follows:

[0060] Place the motor under test on the fixed base, start the device, and the measuring mechanism will begin working, thus commencing the measurement:

[0061] The drive motor (power source) drives the worm gear transmission assembly to rotate the fixed base assembly, causing the entire motor under test to rotate. The stationary part (output shaft) of the motor under test is subjected to the positioning torque, generating a torque T. This torque is transmitted to the force measuring shaft through the connector, causing the force measuring shaft to rotate. This causes a change in the tension at both ends of the tension rope wrapped around the force measuring shaft. The measured torque is calculated by using the change in tension and the radius of the force measuring shaft.

[0062] The tension rope of this device is wound around the force measuring shaft and a preload F0 is applied to ensure that the two ends of the rope are initially balanced. The purpose of applying the preload is to ensure that the static friction force generated by the rope on the force measuring shaft is greater than the force exerted on the force measuring shaft by the external torque, thus preventing slippage during testing and causing test failure.

[0063] Since the forces are balanced, the forces at both ends of the rope are F1 and F2 respectively. Therefore: F1 = F2 = F0

[0064] When an external torque T is transmitted to the force-measuring shaft, it causes a change in the forces (F1 and F2) at both ends of the rope, with one end increasing and the other decreasing (assuming F2 > F1). The change is ΔF. Therefore, F2 = F0 + ΔF; F1 = F0 - ΔF

[0065] When subjected to the aforementioned external torque, the net force exerted by the rope on the axis is F = F2 - F1;

[0066] The force acts on the radius r of the shaft. Since the action and reaction forces are the same, the calculated value is T = (F2 - F1) × r.

[0067] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A measuring device for motor positioning torque, used for measuring the motor positioning torque of a product (6) under test, the measuring device comprising a base (7) and a protective cover (5), characterized in that, The measuring device further includes a force measuring module (1), a rotary positioning module (2), a drive rotary module (3), and a fixed base and coupling module (4). The fixed base and coupling module (4) is provided with a force measuring shaft (41). The force measuring module (1), the rotary positioning module (2), and the drive rotary module (3) are respectively mounted on the base (7) and covered by a protective cover (5). The product to be tested (6) is mounted on the fixed base and coupling module (4). The output shaft of the product to be tested (6) is connected to the force measuring shaft (41). The drive rotary module (3) drives the fixed base and coupling module (4) to rotate, so that the product to be tested (6) rotates as a whole.

2. The measuring device for motor positioning torque according to claim 1, characterized in that, The force measuring module (1) includes a force sensor (11), a tension rope (12) and a tension adjustment mechanism. The tension rope (12) is wound around the force measuring shaft (41) and connected to the force sensor (11) at both ends. The tension adjustment mechanism is connected to the tension rope (12) and is used to adjust the tension of the tension rope (12).

3. The measuring device for motor positioning torque according to claim 2, characterized in that, The tension adjustment mechanism is provided in two sets. Each set of tension adjustment mechanism includes an adjustment slide (13) and an adjustment screw (14). The force sensor (11) is fixed on the adjustment slide (13). The adjustment screw (14) drives the adjustment slide (13) to adjust the tension of the tension rope (12).

4. The measuring device for motor positioning torque according to claim 2, characterized in that, The force sensor (11) is a force sensor or a static torque sensor.

5. The measuring device for motor positioning torque according to claim 1, characterized in that, The rotary positioning module (2) includes a positioning seat (21), a worm gear (22), an adapter sleeve (23), a first bearing (24), and a second bearing (25). The force measuring shaft (41) is connected to the positioning seat (21) through the second bearing (25), the worm gear (22) is connected to the positioning seat (21) through the first bearing (24), and the adapter sleeve (23) is fixed on the worm gear (22).

6. The measuring device for motor positioning torque according to claim 5, characterized in that, The drive rotation module (3) includes a drive motor (31), a first synchronous pulley (32), a synchronous toothed belt (33), a second synchronous pulley (34), and a worm (38). The drive motor (31) is connected to the first synchronous pulley (32), the first synchronous pulley (32) is connected to the second synchronous pulley (34) through the synchronous toothed belt (33), the synchronous toothed belt (33) is connected to the worm (38) through a transmission, and the worm (38) is connected to the worm wheel (22) through a transmission.

7. The measuring device for motor positioning torque according to claim 6, characterized in that, The drive rotation module (3) also includes a worm gear mounting base (36), a third bearing (37) and a fourth bearing (39). The worm gear (38) is mounted on the worm gear mounting base (36) and its two ends are fixed by the third bearing (37) and the fourth bearing (39).

8. The measuring device for motor positioning torque according to claim 5, characterized in that, The fixed seat and coupling module (4) also includes a rotary seat (42), a fixed seat (43) and a connecting component (44). The rotary seat (42) is fixed to the adapter sleeve (23), and the rotary seat (42) is fixed to the fixed seat (43). The product to be tested (6) is fixed on the fixed seat (43). One end of the connecting component (44) is connected to the output shaft of the product to be tested (6), and the other end is connected to the force measuring shaft (41).

9. The measuring device for motor positioning torque according to claim 8, characterized in that, The connecting component (44) is a coupling.

10. The measuring device for motor positioning torque according to claim 1, characterized in that, The base (7) is equipped with a start button (71).

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