Dynamometer rack shaft current suppression device, coupler and dynamometer rack

Abstract

The utility model relates to the technical field of motor EMC testing, and particularly discloses a dynamometer rack shaft current suppression device, a coupler and a dynamometer rack. The shaft current suppression device comprises an insulating spacer, and the insulating spacer comprises a central sheet and four same petal sheets. The coupling comprises a shaft current suppression device, and further comprises two metal blocks and an eight-petal plastic part which are used for connecting two shafts. Each metal block is provided with a circular end face and four convex teeth. The eight-petal plastic part is provided with eight inter-petal grooves. And the eight convex teeth of the two metal blocks penetrate through the eight inter-petal grooves. And an insulating spacer is arranged between the eight-petal plastic part and each end face. And each convex tooth passes through the space between the adjacent petals of one insulating spacer and points to one petal of the other insulating spacer. The coupler is installed on a dynamometer rack, and the current transmission effect of two shafts can be basically isolated. The insulating spacer is additionally arranged between the two metal blocks, so that the cost is low, the spacer is not easy to break, and an effective insulating effect is kept in the testing process.

Description

Technical Field

[0001] The present application relates to the technical field of motor EMC testing, and in particular to a dynamometer bench shaft current suppression device, a coupling and a dynamometer bench. Background Art

[0002] When the new energy vehicle drive motor is tested under load for EMC (electromagnetic compatibility), a dynamometer bench is required to load torque and speed. Load testing is one of the important means to evaluate the EMC performance of the drive motor. It aims to simulate the electromagnetic radiation of the drive motor under the actual working load. During the load test, the dynamometer bench connecting shaft and the drive motor output shaft are connected by a coupling. Since the coupling is made of metal, shaft current will be generated between the dynamometer bench connecting shaft and the drive motor output shaft, thereby affecting the noise floor of the entire EMC test. In order to reduce the shaft current, a plum blossom coupling lined with polyurethane elastic plum blossom pieces is generally used to connect the two shafts. Although the plum blossom piece separates the metal at both ends of the coupling in the horizontal direction, the metal at both ends is close in the axial direction, and it will still break through the conduction and generate shaft current. In this regard, the traditional solution is mostly to install a carbon fiber insulation shaft between the dynamometer bench connecting shaft and the drive motor output shaft. This solution is costly and the carbon fiber insulation shaft is easy to break. After breaking, it is also easy to cause the phenomenon of flying (out of control and rapid rotation). Utility Model Content

[0003] In order to solve the problem of high cost and easy breakage of the traditional solution of installing a carbon fiber insulating shaft between the dynamometer bench connecting shaft and the drive motor output shaft to reduce the shaft current, the present application proposes a solution of installing an insulating gasket between the dynamometer bench output shaft and the drive motor shaft to solve this problem.

[0004] In a first aspect, the present application proposes a dynamometer bench shaft current suppression device and adopts the following technical solution.

[0005] A dynamometer stand shaft current suppression device comprises an insulating gasket, wherein the insulating gasket comprises a center piece and four identical petals. The four petals are equidistantly formed integrally on the peripheral side of the center piece. The four petals and the center piece are on the same plane. The outer periphery of each petal is divided into an outer arc and two opposite side convex arcs, and the outer arc connects the two side convex arcs. The four outer arcs of the four petals are on the same circle.

[0006] By adopting the above technical solution, the insulating gasket is installed between the two metal blocks of the coupling, and the four petals are filled on the end face of the metal block, giving way to the splicing teeth on the end face, which can play the role of insulating the end face. The insulating gasket is used to suppress the shaft current of the dynamometer bench, which is low in cost and the insulating gasket is durable and not easy to break.

[0007] A preferred solution of the dynamometer bench shaft current suppression device is that the insulating gasket is made of silicone rubber.

[0008] By adopting the above technical solution, the silicone rubber has high insulation performance, strong flexibility, is not easy to break, and is suitable for installation in the coupling for effective insulation.

[0009] A preferred solution of the dynamometer bench shaft current suppression device is that the thickness of the insulating gasket is 2.5-3.5 mm.

[0010] By adopting the above technical solution, the thickness has good insulation properties. At the same time, installing the gasket in the coupling will not occupy too much installation space of adjacent components.

[0011] A preferred solution of the shaft current suppression device of the dynamometer bench is that the shaft current suppression device includes two identical insulating gaskets.

[0012] By adopting the above technical solution, two gaskets can be installed on the opposite end faces of the two metal blocks of the coupling, which can better play the role of insulating the end face of any metal block and the convex teeth of the other end metal block.

[0013] In the second aspect, the present application proposes a coupling and adopts the following technical solution.

[0014] A coupling includes the above-mentioned shaft current suppression device, and also includes two metal blocks and an eight-petal plastic part for connecting two shafts. Each of the metal blocks has a circular end face and four protruding teeth. The four protruding teeth are equidistantly and vertically connected to the end face. The eight-petal plastic part has eight expansion petals and forms eight inter-petal grooves. The four protruding teeth of one metal block pass through four of the spaced inter-petal grooves, and the four protruding teeth of the other metal block pass through the other four spaced inter-petal grooves. An insulating gasket is installed between the eight-petal plastic part and each of the end faces. Each protruding tooth passes through the space between adjacent petals of one insulating gasket and points to a petal of another insulating gasket.

[0015] By adopting the above technical solution, the coupling can basically isolate the current transmission effect of the two shafts to be connected. An insulating gasket is installed between the two metal blocks, which is low in cost and not easy to break, and maintains effective insulation during the test process.

[0016] A preferred solution of the coupling is that the four outer arcs of the four petals of each of the insulating gaskets are flush with the outer periphery of each of the end faces.

[0017] By adopting the above technical solution, the insulation isolation is sufficient and the coupling has good integrity.

[0018] A preferred solution of the coupling is that every two adjacent flaps are adapted to half-enclose one of the protruding teeth.

[0019] By adopting the above technical solution, the gasket with the petal has higher insulation coverage.

[0020] In a third aspect, the present application proposes a dynamometer stand and adopts the following technical solution.

[0021] A dynamometer bench comprises the above coupling, a dynamometer, a connector, a torque sensor and an intermediate shaft. One end of the connector is connected to the output shaft of the dynamometer, and the other end is connected to the intermediate shaft. The torque sensor is sleeved outside the intermediate shaft, and the intermediate shaft is connected to the coupling.

[0022] By adopting the above technical solution, when the dynamometer bench is used to test the EMC function of the drive motor, the shaft current between the dynamometer bench connecting shaft and the output shaft of the drive motor is extremely small, and the noise generated is small.

[0023] In summary, the dynamometer stand shaft current suppression device, coupling and dynamometer stand of the present application have the following beneficial effects:

[0024] The insulating gasket isolates the electrical connection between the dynamometer bench output shaft and the drive motor shaft, effectively isolating the shaft current transmission path, reducing the background noise of the entire EMC test environment, and ensuring that the drive motor under-load EMC test meets the standard requirements.

[0025] This suppression device has a simple structure, low cost, and is easy to implement. It is installed in the coupling and can effectively reduce the shaft current between the dynamometer bench connecting shaft and the drive motor output shaft, so that when the new energy vehicle drive motor is subjected to EMC testing under load, the test environment noise floor is within the standard range. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a structural diagram of the shaft current suppression device of the dynamometer bench.

[0027] Figure 2 For installation Figure 1 Exploded view of a coupling with a shaft current suppression device.

[0028] Figure 3 For the general Figure 1 Combination diagram of the shaft current suppression device installed in one of the metal blocks of the coupling.

[0029] Figure 4 for Figure 2 Another perspective view of the coupling after closing.

[0030] Figure 5 for Figure 2Structural diagram of one of the metal blocks of the coupling.

[0031] Figure 6 for Figure 2 Structural diagram of the eight-petal plastic part in the coupling.

[0032] Figure 7 for Figure 2 The combined installation diagram of a metal block, an insulating gasket and eight-petal plastic parts in the coupling.

[0033] Figure 8 This is a structural diagram of a dynamometer stand.

[0034] Fig. 9 This is a noise floor curve diagram of the EMC test of the motor on the dynamometer bench without insulating gasket installed.

[0035] Fig.10 The bottom noise curve diagram of the EMC test of the motor performed by the dynamometer bench equipped with the insulating gasket of the present application.

[0036] Figure numerals: insulating gasket 1; center piece 11; petal piece 12; outer arc 121; side convex arc 122; coupling 2; metal block 21; eight-petal plastic part 22; end face 211; convex tooth 212; expansion petal 221; inter-petal groove 222; dynamometer 3; connector 4; torque sensor 5; intermediate shaft 6; motor to be tested 7. DETAILED DESCRIPTION

[0037] The dynamometer bench shaft current suppression device, coupling and dynamometer bench of the present application are described in detail below with reference to the accompanying drawings.

[0038] Please refer to Figure 1 , a dynamometer bench shaft current suppression device, includes an insulating gasket 1, and the insulating gasket 1 includes a center piece 11 and four identical petals 12. The four petals 12 are equidistantly integrally formed on the circumferential side of the center piece 11. The four petals 12 and the center piece 11 are on the same plane. The outer periphery of each of the petals 12 is divided into an outer arc 121 and two opposite side convex arcs 122, and the outer arc 121 connects the two side convex arcs 122. The four outer arcs 121 of the four petals 12 are on the same circle, and the center of the circle coincides with the center of the center piece 11.

[0039] Please refer to Figure 2 The purpose of the insulating gasket 1 is that it can be installed between two metal blocks 21 of the coupling 2. Please refer to Figure 3, four petals 12 are filled on the end face 211 of the metal block 21, giving way to the convex teeth 212 on the end face 211, which can play the role of insulating the two metal blocks 21. Among them, a cylindrical hole is opened in the center of the two metal blocks 21 of the coupling 2, and a keyway is also opened on the edge of the cylindrical hole, which is used to connect two shafts with key sheaths, such as connecting the output shaft of the dynamometer bench and the drive motor shaft, so as to play a synchronous transmission role. This suppression device has a simple structure and low cost, and the insulating gasket 1 is durable and not easy to break. It is installed in the coupling 2, which can effectively reduce the shaft current between the dynamometer bench connecting shaft and the drive motor output shaft, so that when the new energy vehicle drive motor is loaded for EMC testing, the test environment background noise is within the standard range.

[0040] The insulating gasket 1 is preferably made of silicone rubber, which has high insulation performance, strong flexibility, and is not easy to break, and is suitable for being installed in the coupling 2 for effective insulation.

[0041] A preferred solution of the dynamometer stand shaft current suppression device is that the thickness of the insulating gasket 1 is 2.5-3.5 mm, for example, 3 mm. The insulating gasket 1 of this thickness is not easy to break and has good insulation. The insulating gasket 1 of this thickness is installed in the coupling 2 without occupying too much installation space of adjacent components.

[0042] See also Figure 3 In order to better suppress the shaft current when performing EMC testing on the motor under load, the shaft current suppression device preferably includes two identical insulating gaskets 1. Figure 4 The two gaskets can be installed on the opposite end faces 211 of the two metal blocks 21 of the coupling 2, so as to better insulate the end face 211 of any metal block 21 and the convex teeth 212 of the other end metal block 21, and effectively block the axial current.

[0043] See also Figure 2 and Figure 4 Based on the above shaft current suppression device, the present application also discloses a coupling 2, which includes the above shaft current suppression device, and also includes two metal blocks 21 and an eight-petal plastic part 22 for connecting two shafts. Figure 5 Each of the metal blocks 21 has a circular end surface 211 and four protruding teeth 212. The four protruding teeth 212 are equidistantly and vertically formed integrally on the end surface 211. Figure 6 The eight-petal plastic part 22 has eight expansion petals 221 and forms eight inter-petal grooves 222. Figure 7, the four protruding teeth 212 of one metal block 21 pass through four of the spaced inter-petal grooves 222, and the four protruding teeth 212 of another metal block 21 pass through the other four spaced inter-petal grooves 222. After installation, the expansion petal 221 is clamped and squeezed by the protruding teeth 212 of one metal block 21 and the protruding teeth 212 of another adjacent metal block 21, thereby playing an expansion and fixing role. The material of the eight-petal plastic part 22 can be polyurethane. An insulating gasket 1 is installed between the eight-petal plastic part 22 and each of the end faces 211, and each of the protruding teeth 212 passes through the space between the adjacent petals 12 of one of the insulating gaskets 1 and points to a petal 12 of another of the insulating gaskets 1, forming the coupling 2 structure. Compared with the general coupling 2, the coupling 2 of this structure is equipped with two insulating gaskets 1, which can basically isolate the current transmission effect of the two shafts to be connected. For example, when the motor is subjected to the EMC test under load, the insulating gasket 1 isolates the electrical connection between the output shaft of the dynamometer bench and the drive motor shaft, effectively isolates the shaft current transmission path, reduces the background noise of the entire EMC test environment, and enables the drive motor to meet the standard requirements for the EMC test under load. The coupling 2 is equipped with an insulating gasket 1 between the two metal blocks 21, which is low in cost, the gasket is not easy to break, and can maintain an effective insulation effect during the test process.

[0044] See also Figure 3 In order to strengthen the suppression of the peripheral shaft current, the four outer arcs 121 of the four petals 12 of each insulating gasket 1 are arranged to be flush with the outer periphery of each end surface 211. This design can fully isolate the peripheral shaft current, and the design also better maintains the integrity of the coupling 2.

[0045] See also Figure 3 In order to strengthen the suppression of internal shaft current, it is designed that every two adjacent petals 12 are adapted to half surround one convex tooth 212, so that the gasket with the petals 12 has a higher internal insulation coverage. The side convex arcs 122 of every two adjacent petals 12 are symmetrical and can be adapted to fit the edge of the convex tooth 212 to strengthen the insulation coverage.

[0046] See also Figure 8Based on the above coupling 2, the present application also designs a dynamometer bench, which includes the above coupling 2, and also includes a dynamometer 3, a connector 4, a torque sensor 5 and an intermediate shaft 6. The connector 4 can be another larger coupling, and an insulating gasket can also be installed inside it. One end of the connector 4 is connected to the output shaft of the dynamometer 3, and the other end is connected to the intermediate shaft 6. The torque sensor 5 is sleeved outside the intermediate shaft 6 to measure the torque of the rotating intermediate shaft 6. The intermediate shaft 6 is connected to one end of the coupling 2 (referring to one of the metal blocks 21), and the other end of the coupling 2 (referring to the other metal block 21) is used to connect the motor 7 to be tested, such as a new energy vehicle drive motor. When the dynamometer bench is used to test the EMC function of the drive motor, the shaft current between the dynamometer bench connecting shaft and the output shaft of the drive motor is extremely small, and the noise generated is small.

[0047] The following experiment compares the dynamometer bench without and with the insulation gasket 1 installed to conduct the EMC test on the new energy vehicle drive motor. The noise floor curve of the dynamometer bench without the insulation gasket 1 is as follows: Fig. 9 As shown in the figure, the noise floor is large and exceeds the horizontal line above. The noise floor curve of the dynamometer bench test with the insulation gasket 1 installed is as follows Fig.10 As shown, the background noise is small and does not exceed the horizontal line above, meeting the test requirements. By comparing the two experiments, it can be concluded that the dynamometer bench equipped with the insulating gasket 1 can effectively reduce the shaft current between the dynamometer bench connecting shaft and the output shaft of the drive motor, so that when the new energy vehicle drive motor is loaded for EMC testing, the background noise of the test environment is within the standard range.

[0048] The above are only some embodiments of the present application, and the protection scope of the present application is not limited to the above embodiments. For ordinary technicians in this technical field, some improvements and modifications without departing from the creative design of the present application should also fall within the protection scope of the present application.

Claims

1. A dynamometer stand shaft current suppression device, characterized in that: The insulating gasket (1) comprises a central piece (11) and four identical petals (12); the four petals (12) are integrally formed at equal intervals on the peripheral side of the central piece (11); the four petals (12) and the central piece (11) are on the same plane; the outer periphery of each petal (12) is divided into an outer arc (121) and two opposite side convex arcs (122), the outer arc (121) connecting the two side convex arcs (122); and the four outer arcs (121) of the four petals (12) are on the same circle.

2. The dynamometer stand shaft current suppression device according to claim 1, characterized in that: The insulating gasket (1) is made of silicone rubber.

3. The dynamometer stand shaft current suppression device according to claim 1, characterized in that: The thickness of the insulating gasket (1) is 2.5-3.5 mm.

4. The dynamometer stand shaft current suppression device according to any one of claims 1 to 3, characterized in that: The shaft current suppression device comprises two identical insulating spacers (1).

5. A coupling, characterized in that: The shaft current suppression device according to claim 4 further comprises two metal blocks (21) and an eight-petal plastic part (22) for connecting two shafts; each of the metal blocks (21) has a circular end face (211) and four protruding teeth (212); the four protruding teeth (212) are connected to the end face (211) at equal intervals and vertically; the eight-petal plastic part (22) has eight expansion petals (221) and forms eight inter-petal grooves (222); the four protruding teeth (212) of one metal block (21) pass through four of the spaced inter-petal grooves (222), and the four protruding teeth (212) of the other metal block (21) pass through the other four spaced inter-petal grooves (222); One insulating gasket (1) is installed between each of the eight-petal plastic parts (22) and each of the end faces (211); each of the protruding teeth (212) passes through the space between adjacent petals (12) of one insulating gasket (1) and points to a petal (12) of another insulating gasket (1).

6. The coupling according to claim 5, characterized in that: The four outer arcs (121) of the four petals (12) of each insulating gasket (1) are flush with the outer periphery of each end surface (211).

7. The coupling according to claim 5, characterized in that: Every two adjacent petals (12) are adapted to half-enclose one of the convex teeth (212).

8. A dynamometer stand, characterized in that: A coupling (2) comprising any one of claims 5 to 7, further comprising a dynamometer (3), a connector (4), a torque sensor (5) and an intermediate shaft (6); One end of the connector (4) is connected to the output shaft of the dynamometer (3), and the other end is connected to the intermediate shaft (6); the torque sensor (5) is sleeved outside the intermediate shaft (6); and the intermediate shaft (6) is connected to the coupling (2).

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