A few turns of the armature assembly inter-turn impulse withstand test tool

Abstract

The application belongs to the technical field of motor testing, and particularly relates to a few-turn armature assembly inter-turn impulse withstand test tool. The impulse withstand test tool comprises a base (1) with a mandrel (2) vertically arranged on the bottom surface of the base (1); a cushion block (3) made of non-magnetic material, which is sleeved on the mandrel (2) and located above the base (1); and an iron core (4) made of magnetic material, which is sleeved on the mandrel (2) and located above the cushion block (3), wherein the cushion block (3) has an exposed annular step surface (31) towards the top; the bottom end surface of the winding iron core (51) of the measured armature assembly is crimped on the annular step surface (31), and part of the winding (52) extends downwards to the periphery of the cushion block (3); and the axial length of the iron core (4) is less than the axial length of the winding iron core (51). The application avoids the false judgment of the winding inter-turn quality problem and quality hidden danger caused by the line passing and line outlet difference.

Description

Technical Field

[0001] This application belongs to the field of motor testing technology, specifically relating to a tooling for inter-turn impact withstand voltage test of a few-turn armature assembly. Background Technology

[0002] During motor manufacturing, when the armature is wound to form the armature assembly, a high-voltage pulse generated by an inter-turn impulse withstand voltage tester is applied to both ends of the coil. By collecting the waveform response of the coil, it is determined whether there are any quality problems or potential quality hazards in the inter-turn insulation of the motor windings. Under normal circumstances, due to differences in assembly and manufacturing, if the waveform area difference of the multi-phase windings of the same armature assembly does not exceed 10%, the armature assembly is considered qualified.

[0003] The main factor affecting the coil waveform response is the armature winding inductance, which is determined by the length of the lead wires, the effective series conductors in the winding, and the magnetic reluctance of the magnetic circuit containing the magnetic flux generated by the winding current. Before the motor is fully assembled, it consists of either a stator or a rotor. The magnetic flux path generated by the effective series conductors in the winding is similar to that generated by the current in the lead wires and output wires. The majority of the material in the magnetic circuit is air, and the inductance generated by the effective series turns of the armature winding is much smaller than when the motor is fully assembled.

[0004] When the number of series turns in its winding is large, the inductance of the through wires and outgoing wires is very small. Therefore, the through wires and outgoing wires have little effect on the coil waveform response. This can be considered as a difference in assembly and manufacturing. Under normal circumstances, the waveform area difference of the multiphase windings of the same armature assembly can meet the requirement of not more than 10%.

[0005] However, when the number of turns in series per phase of the winding is small, the length of the through-wire and out-wire of the multi-phase winding accounts for a relatively high proportion of the total winding length. The magnetic reluctance on the magnetic flux path generated by the current in the through-wire and out-wire is close to the magnetic reluctance on the magnetic flux path generated by the current in the effective series conductor. Therefore, even when there are no inter-turn insulation quality problems or inter-turn insulation hazards in the winding, the waveform area difference of the multi-phase windings of the same armature assembly exceeds the requirement of 10%. This makes it impossible to determine whether the motor actually has inter-turn quality problems or quality hazards. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a few-turn armature assembly inter-turn impulse withstand voltage test fixture, primarily applicable to armature assemblies with fewer than 8 turns.

[0007] The inter-turn impulse withstand voltage test fixture for a few-turn armature assembly provided in this application mainly includes:

[0008] The base has a spindle in the middle that is perpendicular to the bottom surface of the base;

[0009] A pad, made of non-magnetic material, is fitted onto the mandrel and located above the base, and the pad has a first outer diameter;

[0010] The iron core, made of magnetically conductive material, is sleeved on the mandrel and located above the pad. The iron core has a second outer diameter smaller than the first outer diameter, so that the pad has an exposed annular stepped surface facing upward.

[0011] Wherein, the first outer diameter is larger than the inner diameter d1 of the winding core of the armature assembly under test and smaller than the inner diameter d2 of the winding of the armature assembly under test, and the second outer diameter is smaller than the inner diameter d1 of the armature assembly under test, so that the winding core of the armature assembly under test can be sleeved on the outside of the core, and the bottom end face of the winding core of the armature assembly under test is pressed against the annular step surface, and a portion of the winding extends downward to the periphery of the pad block;

[0012] The axial length of the iron core is less than the axial length of the winding iron core.

[0013] Preferably, the base and the mandrel are an integral structure.

[0014] Preferably, the base has a central through hole, and one end of the mandrel is inserted into the through hole of the base through an interference fit to achieve a tight connection.

[0015] Preferably, a flange is provided at the bottom end of the mandrel, and the base is connected to the flange of the mandrel by screws.

[0016] Preferably, the pad is made of rubber, plastic or wood.

[0017] Preferably, the pad and the mandrel are fitted with a small clearance.

[0018] Preferably, the iron core is made of DT4 electrical pure iron or No. 10 steel.

[0019] Preferably, the iron core and the mandrel are fitted with a small clearance.

[0020] This application significantly improves the inductance parameters of the effective conductor of the winding in the inter-turn impulse withstand voltage test, thereby greatly reducing the impact of unevenness between the lead wire and the output wire on the test results. This avoids misjudgment of inter-turn quality problems and potential quality hazards caused by differences in lead wire and output wire. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a preferred embodiment of the inter-turn impulse withstand voltage test fixture for a few-turn armature assembly according to this application.

[0022] Figure 2 For this application Figure 1A schematic diagram of the tooling used in the embodiment shown.

[0023] Among them, 1-base, 2-mandrel, 3-pad, 31-annular stepped surface, 4-iron core, 5-armature assembly under test, 51-winding iron core, 52-winding, 53-lead wire. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0025] The purpose of this application is to provide a fixture for inter-turn impulse withstand voltage testing of armature assemblies with a small number of effective turns, which significantly increases the effective conductor inductance of the armature winding without increasing the inductance of the lead wires and outlet wires. This reduces the differences in coil waveform response caused by differences in lead wires and outlet wires, and avoids misjudgments of inter-turn quality problems and potential quality issues due to these differences. Therefore, this application provides an inter-turn impulse withstand voltage testing fixture for armature assemblies with a small number of turns, such as… Figure 1 As shown, it mainly includes:

[0026] A base 1, with a spindle 2 perpendicular to the bottom surface of the base 1 in the middle;

[0027] The pad 3 is made of non-magnetic material, and it is sleeved on the spindle 2 and located above the base 1. The pad 3 has a first outer diameter.

[0028] The iron core 4 is made of magnetic material and is sleeved on the mandrel 2 and located above the pad 3. The iron core 4 has a second outer diameter smaller than the first outer diameter, so that the pad 3 has an exposed annular stepped surface 31 facing upward.

[0029] Wherein, the first outer diameter is larger than the inner diameter d1 of the winding core 51 of the armature assembly 5 under test and smaller than the inner diameter d2 of the winding 52 of the armature assembly 5 under test, and the second outer diameter is smaller than the inner diameter d1 of the armature assembly 5 under test, so that the winding core 51 of the armature assembly under test can be sleeved on the core 4, and the bottom end face of the winding core 51 of the armature assembly under test is pressed on the annular step surface 31, and a portion of the winding 52 extends downward to the periphery of the pad block 3;

[0030] The axial length of the iron core 4 is less than the axial length of the winding iron core 51.

[0031] refer to Figure 2 This application is mainly applied to armature assemblies with fewer than 8 turns. For example, in one specific embodiment, it is applied to the inter-turn impulse withstand voltage test of a 28V, 12kW, 36-slot armature assembly with 6 turns per phase in series. The armature assembly under test 5 is inserted into the iron core 4, with its bottom surface in contact with the upper bottom surface of the pad 3. That is, the winding iron core 51 is pressed on the annular stepped surface 31, and the end of the downward-extending winding 52 is fitted outside the pad 3. Because the iron core is a magnetically conductive material, the magnetic reluctance of the magnetic flux path generated by the current in the effective conductor of the armature assembly is greatly reduced, thereby greatly increasing the inductance of the effective conductor of the winding. Since the area near the through-wire and outlet wires is still air, its inductance is the same as when no iron core is inserted. Ultimately, the proportion of the inductance of the through-wire and outlet wires is greatly reduced. Then, in accordance with the operating procedures of the inter-turn impact withstand voltage tester, high voltage pulses are applied to both ends of the winding through multiple sets of winding leads 53 for testing. The multi-phase winding waveform is obtained by the test equipment holding the leads 53. If the area difference of the obtained multi-phase winding waveform does not exceed 10%, the armature assembly is considered to be qualified.

[0032] In some alternative embodiments, the base 1 and the mandrel 2 are an integral structure. In an alternative embodiment, the base 1 and the mandrel 2 are fixedly connected; for example, the base 1 has a central through hole, and one end of the mandrel 2 is inserted into the through hole of the base 1 via an interference fit to achieve a tight connection. Another example is that the bottom end of the mandrel 2 is provided with a flange, and the base 1 and the flange of the mandrel 2 are connected by screws.

[0033] In some alternative embodiments, the pad 3 is made of rubber, plastic, or wood. (See reference) Figure 2 The pad 3 is mainly used to support the winding core 51 and is covered with part of the winding 52. Therefore, it can be made of non-magnetic materials such as rubber, plastic, and wood blocks that are not likely to cause mechanical damage to the armature winding.

[0034] In some alternative embodiments, the pad 3 is fitted with the mandrel 2 with a small clearance.

[0035] In some alternative embodiments, the core 4 is made of DT4 electrical pure iron or No. 10 steel.

[0036] In some alternative embodiments, the iron core 4 is fitted with the mandrel 2 with a small clearance.

[0037] By adopting the above technical solution, the inductance parameter of the effective conductor of the winding is greatly improved in the inter-turn impulse withstand voltage test, which greatly reduces the impact of unevenness between the lead wire and the output wire on the test results, thereby avoiding misjudgment of inter-turn quality problems and potential quality hazards caused by differences in lead wire and output wire.

[0038] Although this application has been described in detail above with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, such modifications or improvements made without departing from the spirit of this application are all within the scope of protection claimed in this application.

Claims

1. A fixture for inter-turn impulse withstand voltage testing of a few-turn armature assembly, wherein the armature assembly has fewer than 8 turns, characterized in that, The impact resistance test fixture includes: The base (1) has a spindle (2) in the middle that is perpendicular to the bottom surface of the base (1); The pad (3) is made of non-magnetic material, and is sleeved on the spindle (2) and located above the base (1). The pad (3) has a first outer diameter. The iron core (4) is made of magnetic material and is sleeved on the mandrel (2) and located above the pad (3). The iron core (4) has a second outer diameter smaller than the first outer diameter, so that the pad (3) has an exposed annular step surface (31) facing upward. Wherein, the first outer diameter is larger than the inner diameter d1 of the winding core (51) of the armature assembly under test (5), the first outer diameter is smaller than the inner diameter d2 of the winding (52) of the armature assembly under test (5), and the second outer diameter is smaller than the inner diameter d1 of the armature assembly under test (5), so that the winding core (51) of the armature assembly under test can be sleeved outside the core (4), and the bottom end face of the winding core (51) of the armature assembly under test is pressed against the annular step surface (31), and a portion of the winding (52) extends downward to the periphery of the pad (3); The axial length of the iron core (4) is less than the axial length of the winding iron core (51).

2. The inter-turn impulse withstand voltage test fixture for a few-turn armature assembly as described in claim 1, characterized in that, The base (1) and the spindle (2) are an integral structure.

3. The inter-turn impulse withstand voltage test fixture for a few-turn armature assembly as described in claim 1, characterized in that, The base (1) has a central through hole, and one end of the spindle (2) is inserted into the through hole of the base (1) through an interference fit to achieve a tight connection.

4. The inter-turn impulse withstand voltage test fixture for a few-turn armature assembly as described in claim 1, characterized in that, The bottom end of the mandrel (2) is provided with a flange, and the base (1) is connected to the flange of the mandrel (2) by screws.

5. The inter-turn impulse withstand voltage test fixture for a few-turn armature assembly as described in claim 1, characterized in that, The pad (3) is made of rubber, plastic or wood.

6. The inter-turn impulse withstand voltage test fixture for a few-turn armature assembly as described in claim 1, characterized in that, The pad (3) is fitted with the spindle (2) with a small clearance.

7. The inter-turn impulse withstand voltage test fixture for a few-turn armature assembly as described in claim 1, characterized in that, The iron core (4) is made of DT4 electrical pure iron or No. 10 steel.

8. The inter-turn impulse withstand voltage test fixture for a few-turn armature assembly as described in claim 1, characterized in that, The iron core (4) is fitted with the mandrel (2) with a small clearance.

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