An experimental device for testing the ventilation of a motor rotor

Abstract

The present invention discloses a motor rotor ventilation test experimental device, which includes a rotor die holder. The rotor die holder is installed between a rectangular duct I and a rectangular duct II. The front end of the rectangular duct I is connected to a front pressure measuring pipe through a rotary adapter I. A Pitot tube I is installed on the front pressure measuring pipe. The front end of the front pressure measuring pipe is connected to the rear end of a buffer pipe, and the front end of the buffer pipe is connected to a bell mouth. The rear end of the rectangular duct II is connected to a rear pressure measuring pipe. A Pitot tube II is installed on the rear pressure measuring pipe. The rear pressure measuring pipe is connected to a fan through a rotary adapter II. A rotor is fitted in the rotor die holder in a matching manner. Both ends of the rotating shaft of the rotor are respectively supported on two bearing seats on both sides through bearings. One end of the rotating shaft of the rotor is connected to the output shaft of a driving machine through a coupling. The bearing seat on the air inlet side is located in the rectangular duct I, and the bearing seat and the driving machine on the air outlet side are located in the rectangular duct II. The design of the present invention is reasonable and has good practical application value.

Description

Technical Field

[0001] The present invention relates to the technical field of motor rotor testing, and particularly to a ventilation testing experimental device for a motor rotor. Background Art

[0002] During the operation of a motor, losses occur, causing the temperature rise of the motor to increase, seriously affecting the heat dissipation of the motor. Ventilation cooling is widely used in the heat dissipation design of various motors due to its advantages of low cost and high efficiency. Forced ventilation can take away the heat inside the motor to achieve motor cooling. When there is forced ventilation inside the motor, air usually flows through the rotor ventilation holes, air gaps, and stator ventilation holes. The air volume at these three ventilation holes cannot be estimated, and the design of the size and quantity of the ventilation holes has no basis. Usually, the air volume at each ventilation position can be obtained through simulation means during design, but the accuracy of the simulation results needs to be verified, and related experimental measurements have the disadvantages of high difficulty and high cost. Summary of the Invention

[0003] Aiming at the above technical problems, the purpose of the present invention is to provide a new type of ventilation testing experimental device for a motor rotor, aiming to measure the air volume of the air gap and rotor ventilation holes of the motor rotor during forced ventilation, and at the same time measure the pressure difference on both sides of the rotor die card to calculate the resistance of the air flowing through the rotor.

[0004] The present invention is implemented by the following technical solutions:

[0005] A ventilation testing experimental device for a motor rotor includes a rotor die card, which is installed between a rectangular pipe Ⅰ and a rectangular pipe Ⅱ. The front end of the rectangular pipe Ⅰ is connected to a front pressure measuring pipe through a connecting pipe Ⅰ. A Pitot tube Ⅰ is installed on the front pressure measuring pipe. The front end of the front pressure measuring pipe is connected to the rear end of a buffer pipe, and the front end of the buffer pipe is connected to a bell mouth. The rear end of the rectangular pipe Ⅱ is connected to a rear pressure measuring pipe. A Pitot tube Ⅱ is installed on the rear pressure measuring pipe. The rear pressure measuring pipe is connected to a fan through a connecting pipe Ⅱ. A rotor is fitted in the rotor die card. The two ends of the rotating shaft of the rotor are respectively supported by bearings on both sides of the bearing seats. One end of the rotating shaft of the rotor is connected to the output shaft of a driving machine through a coupling. The bearing seat on the air inlet side is located in the rectangular pipe Ⅰ, and the bearing seat and the driving machine on the air outlet side are located in the rectangular pipe Ⅱ.

[0006] Further preferably, both the driving machine and the fan are powered by a power supply. The driving machine and the fan are both controlled in terms of speed by a frequency converter. A buffer section support is provided at the bottom of the buffer pipe. The connections between the pipes of the entire experimental device are sealed with high-elastic sealing gaskets to ensure sealing, and other small air leakage positions are locally sealed with hot melt adhesive to ensure the overall sealing of the device.

[0007] Further preferably, the rectangular duct I and the rectangular duct II are respectively located on the support table. The bearing seats on both sides are respectively located on their respective bearing seat brackets. The bearing seat bracket on the air outlet side and the driving machine are jointly located on the driving machine support, and the driving machine support is installed on the inner bottom surface of the rectangular duct II. The bearing seat bracket on the air inlet side is located on the base, and the base is installed on the inner bottom surface of the rectangular duct I. The two ends of the rotor shaft are connected to the bearings, and the bearings are nested in the bearing seats to support the rotor. The shaft is connected to the driving machine through a coupling, and the driving machine drives the rotor to rotate.

[0008] Further preferably, the rotor die card is a detachable device, and rotor die cards with different size parameters can be designed for different motors. The rotor is an aluminum hollow structure, and the two ends of its slot openings and ventilation holes are both welded structures, simulating the real air gap and rotor ventilation holes of the motor. The rotor die card is composed of an upper flange box and a lower flange box spliced together, and the upper flange box and the lower flange box are fixedly connected by bolts. The diameters of the inner cylinders of the upper flange box and the lower flange box are the same as the actual stator core, and the inner cylinders of the upper flange box and the lower flange box and the rotor with ventilation holes jointly simulate the air gap and rotor ventilation structure of the motor. A bottom plate is provided between the two side flanges of the lower flange box, and a rotor support is provided on the bottom plate. The bottom of the lower flange box is connected to the rotor support by bolts.

[0009] Further preferably, the base is connected to the air inlet side of the lower flange box, and the driving machine support is connected to the air outlet side of the lower flange box.

[0010] During the experiment, the principle of single variable control is adopted. The controllable variables include rotor speed, fan speed, and ventilation position of the rotor die card. The fan speed is fixed at five variable values, and each variable value corresponds to six rotor speeds. The influence of rotor rotation on the air pressure and air volume before and after the rotor die card during forced ventilation is measured under 30 working conditions. The air volume and air pressure in the above experimental process are measured by Pitot tube I and Pitot tube II. To ensure the measurement accuracy, the Pitot tube measures pressure and flow using the static pressure traverse method. After the above 30 working conditions are measured, in order to confirm the resistance caused by the air gap and rotor ventilation holes, the ventilation holes of the rotor can be blocked so that the fluid only flows through the air gap, and 30 working conditions are measured again to verify the relationship between the flow rate and pressure at the air gap. Thus, the air volume measurement of the air gap and rotor ventilation holes of the motor rotor during forced ventilation can be realized, and at the same time, the pressure difference on both sides of the rotor die card is measured, and the resistance of the air flowing through the rotor is calculated.

[0011] The design of the present invention is reasonable. The motor rotor ventilation test experimental device can measure the air volume in the air gap and rotor ventilation holes of the motor rotor during forced ventilation, measure the pressure difference on both sides of the rotor mold card at the same time, calculate the resistance of the air flowing through the rotor, combine simulation with experiment, clarify the flow state of the air flowing through the air gap and rotor ventilation holes during forced ventilation, provide a basis for the efficient heat dissipation design of the motor, and has good practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The front view showing the whole of the present invention.

[0013] Figure 2 The front view showing the rotor mold card in the present invention.

[0014] Figure 3 The right view showing the rotor mold card in the present invention.

[0015] Figure 4 The schematic diagram showing the relationship between the rotational speed of the rotor mold card and the pressure difference.

[0016] In the figure: 1 - bell mouth, 2 - buffer pipe, 3 - front pressure measuring pipe, 4 - Pitot tube Ⅰ, 5 - adapter pipe Ⅰ, 6 - rectangular pipe Ⅰ, 7 - rotor mold card, 8 - rectangular pipe Ⅱ, 9 - power supply, 10 - Pitot tube Ⅱ, 11 - rear pressure measuring pipe, 12 - fan, 13 - support table, 14 - buffer section support, 15 - driving machine support, 16 - driving machine, 17 - coupling, 18 - bearing seat, 19 - upper flange box, 20 - rotating shaft, 21 - bearing seat support, 22 - lower flange box, 23 - rotor support, 24 - bearing, 25 - rotor, 26 - adapter pipe Ⅱ, 27 - base, 28 - bottom plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The following will describe the specific embodiments of the present invention in detail with reference to the drawings.

[0018] A motor rotor ventilation test experimental device mainly includes a rotor mold card 7, a buffer pipe 2, a front pressure measuring pipe 3, a Pitot tube Ⅰ 4, an adapter pipe Ⅰ 5, a rectangular pipe Ⅰ 6, a rectangular pipe Ⅱ 8, a power supply 9, a Pitot tube Ⅱ 10, a rear pressure measuring pipe 11, a fan 12, etc.

[0019] As Figure 1As shown, the rotor die holder 7 is installed between the rectangular duct Ⅰ6 and the rectangular duct Ⅱ8, and the rectangular duct Ⅰ6 and the rectangular duct Ⅱ8 are respectively located on the support table 13. The front end of the rectangular duct Ⅰ6 is connected to the front pressure measuring tube 3 through the round-to-square adapter Ⅰ5. The Pitot tube Ⅰ4 is installed on the front pressure measuring tube 3 for measuring the pressure on the air inlet side. The front end of the front pressure measuring tube 3 is connected to the rear end of the buffer tube 2. The front end of the buffer tube 2 is connected to the bell mouth 1. A buffer section support 14 is provided at the bottom of the buffer tube 2. The rear end of the rectangular duct Ⅱ8 is connected to the rear pressure measuring tube 11. The Pitot tube Ⅱ10 is installed on the rear pressure measuring tube 11 for measuring the pressure on the air outlet side. The rear pressure measuring tube 11 is connected to the fan 12 through the round-to-square adapter Ⅱ26.

[0020] As Figure 3 shown, a rotor 25 is fitted inside the rotor die holder 7. As Figure 2 shown, the rotor die holder 7 is composed of an upper flange box 19 and a lower flange box 22 which are joined together, and are respectively sealed and connected to the rectangular duct Ⅰ6 and the rectangular duct Ⅱ8 through the flange structures at both ends. Both ends of the rotating shaft 20 of the rotor 25 are respectively supported on the bearing seats 18 on both sides through bearings 20. The bearing seats 18 on both sides are respectively located on their own bearing seat brackets 21. The bearing seat bracket 21 on the air inlet side is located on the base 27, and the base 27 is installed on the inner bottom surface of the rectangular duct Ⅰ6 (that is, the bearing seat 18 on the air inlet side is located inside the rectangular duct Ⅰ6). One end of the rotating shaft 20 of the rotor 25 (on the air outlet side) is connected to the output shaft of the driving machine 16 through a coupling 17. The bearing seat bracket 21 on the air outlet side and the driving machine 16 are both located on the driving machine support 15, and the driving machine support 15 is installed on the inner bottom surface of the rectangular duct Ⅱ8 (that is, the bearing seat 18 on the air outlet side and the driving machine 16 are located inside the rectangular duct Ⅱ8). The base 27 is connected to the air inlet side of the lower flange box 22, and the driving machine support 15 is connected to the air outlet side of the lower flange box 22. A bottom plate 28 is provided between the two side flanges of the lower flange box 22, and a rotor support 23 is provided on the bottom plate 28 for supporting the rotor die holder. The driving machine 16 and the fan 12 are both powered by the power supply 9.

[0021] During the experiment, first check the airtightness of the experimental device, turn on the power supply 9 and the fan 12. Air enters from the duct bell mouth 1, passes through the buffer tube 2, the front pressure measuring tube 3, the round-to-square adapter Ⅰ5 and the rectangular duct Ⅰ6, then flows through the air gap and the rotor ventilation holes of the rotor die holder 7, and finally discharges from the air outlet of the fan 12. Check whether the working states of the Pitot tube Ⅰ4 and the Pitot tube Ⅱ10 are normal, and measure the dynamic pressure on the front pressure measuring tube 3 and the rear pressure measuring tube 11 respectively to verify the airtightness of the device. After verification, turn on the power supply of the driving machine 16, and adjust the rotational speed of the rotor 25 through the speed control frequency converter to verify the safety and reliability of the rotor die holder 7.

[0022] Figure 4For the relationship between the rotational speed and pressure difference of the rotor die card, it can be found that the rotational speed of the rotor die card has no effect on the pressure difference before and after the rotor die card. When the air volume of the fan is larger, the pressure difference on both sides of the rotor die card is larger, which means the resistance of the rotor die card is larger.

[0023] During the experiment, the principle of single-variable control is adopted. The controllable variables include the rotor speed, the fan speed, and the ventilation position of the rotor die card. The speed of fan 12 is fixed at five variable values, and each variable value corresponds to five rotor speeds. The influence of the rotation of rotor 25 on the air pressure and air volume before and after the rotor die card 7 during forced ventilation is measured under 30 working conditions. The air volume and air pressure in the above experimental process are measured by Pitot tube I 4 and Pitot tube II 10. To ensure the measurement accuracy, the Pitot tube measures the pressure and flow rate by the static pressure traverse method. After the above 30 working conditions are measured, in order to confirm the resistance caused by the air gap and the rotor ventilation holes, the ventilation holes of the rotor can be blocked so that the fluid only flows through the air gap, and 30 working conditions are measured again to verify the relationship between the flow rate and pressure at the air gap. Thus, the air volume measurement of the air gap and the rotor ventilation holes of the motor rotor during forced ventilation can be realized, and at the same time, the pressure difference on both sides of the rotor die card 7 is measured, and the resistance of the air flowing through the rotor 25 is calculated.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the protection scope of the claims of the present invention.

Claims

1. A motor rotor ventilation test experimental device, characterized in that: It includes a rotor die card (7), which is installed between a rectangular duct I (6) and a rectangular duct II (8). The front end of the rectangular duct I (6) is connected to a front pressure measuring tube (3) through a rotary joint I (5). A Pitot tube I (4) is installed on the front pressure measuring tube (3). The front end of the front pressure measuring tube (3) is connected to the rear end of a buffer tube (2), and the front end of the buffer tube (2) is connected to a bell mouth (1). The rear end of the rectangular duct II (8) is connected to a rear pressure measuring tube (11). A Pitot tube II (10) is installed on the rear pressure measuring tube (11). The rear pressure measuring tube (11) is connected to a fan (12) through a rotary joint II (26). A rotor (25) is fitted inside the rotor die card (7). Both ends of the rotating shaft (20) of the rotor (25) are supported by bearings on the bearing seats (18) on both sides. One end of the rotating shaft (20) of the rotor (25) is connected to the output shaft of a driving machine (16) through a coupling (17). The bearing seat (18) on the air inlet side is located inside the rectangular duct I (6), and the bearing seat (18) and the driving machine (16) on the air outlet side are located inside the rectangular duct II (8).

2. The motor rotor ventilation test experimental device according to claim 1, characterized in that: Both the driving machine (16) and the fan (12) are powered by a power supply (9).

3. The motor rotor ventilation test experimental device according to claim 1 or 2, characterized in that: A buffer section support (14) is provided at the bottom of the buffer tube (2).

4. An electric motor rotor ventilation test experimental device according to claim 1 or 2, characterized in that: The rectangular duct I (6) and the rectangular duct II (8) are respectively located on a support table (13).

5. The motor rotor ventilation test experimental device according to claim 4, characterized in that: The bearing seats (18) on both sides are respectively located on their own bearing seat supports (21).

6. The motor rotor ventilation test experimental device according to claim 5, characterized in that: The bearing seat support (21) and the driving machine (16) on the air outlet side are jointly located on a driving machine support (15), and the driving machine support (15) is installed on the inner bottom surface of the rectangular duct II (8).

7. An electric motor rotor ventilation test experimental device according to claim 6, characterized in that: The bearing seat support (21) on the air inlet side is located on a base (27), and the base (27) is installed on the inner bottom surface of the rectangular duct I (6).

8. The motor rotor ventilation test experimental device according to claim 7, characterized in that: The rotor die card (7) is composed of an upper flange box (19) and a lower flange box (22) assembled together.

9. An electric motor rotor ventilation test experimental device according to claim 8, characterized in that: The base (27) is connected to the air inlet side of the lower flange box (22), and the driving machine support (15) is connected to the air outlet side of the lower flange box (22).

10. The motor rotor ventilation test experimental device according to claim 9, characterized in that: A bottom plate (28) is provided between the two side flanges of the lower flange box (22), and a rotor support (23) is provided on the bottom plate (28).

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