JPH04364344A - Cooling method and unit for high speed motor - Google Patents

Abstract

PURPOSE:To provide a stabilized high speed motor by cooling the rotor through a cooling pipe opposing closely to the surface of a rotor thereby eliminating thermal imbalance. CONSTITUTION:A cooling pipe 81 having opposite ends jointed, respectively, to communication ring pipes 82, 83, extends axially at the opening of the slot 31 ire a stator core 3. The communication pipe 82 is communicated through a supply pipe 85 with the supply port 86 of the cooler 84 for a cooling liquid supply unit 8 whereas the communication pipe 83 is communicated through a collecting pipe 87 with the collection port 88 of the cooler 84. A temperature sensor 7 is fixed substantially in the center of the stator core 3 while being inserted to a position opposing to the surface of a rotor 4. The temperature sensor 7 detects the surface temperature of the rotor 4 and then temperature rise of the rotor is operated. Since the temperature of the cooling liquid is determined based on thus operated temperature rise and the rotor can be cooled quickly through thermal radiation, the rotor can be maintained at a predetermined temperature and thermal imbalance can be eliminated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the cooling of high-speed motors that drive spindles of machine tools, turbomolecular pumps, and the like.

0002

2. Description of the Related Art Conventionally, a high-speed motor 1 that drives a spindle of a machine tool, a turbo molecular pump, etc. has a spiral cooling jacket 12 provided in a cylindrical frame 11, as shown in FIG. 4, for example. It allows coolant to pass through it. A ring-shaped stator core 3 in which a plurality of slots 31 into which stator windings 2 are inserted are radially provided at equal intervals is fixed inside the frame 11. A rotor 4 is provided on the inner periphery of the stator core 3 to face each other with a gap therebetween, and a rotating shaft 41 that supports the rotor 4 is supported by a magnetic bearing 5 provided inside the frame 1.
is supported without contact. Brackets 6 are provided at both ends of the frame 1 to support the rotating shaft 41 via auxiliary bearings 61 when the rotor 4 is at rest. A temperature sensor 7 is provided approximately at the center of the stator core 3, and its output is input to the control device 9 of the cooling liquid supply device 8, which controls the amount of cooling liquid supplied to the cooling jacket 12 or the temperature of the cooling liquid. The stator core 3 is maintained at an appropriate temperature and the rotor 4 is indirectly cooled.

0003

[Problems to be Solved by the Invention] However, during high-speed rotation where the circumferential speed of the rotating shaft is 200 m/sec or more, the main body of heat generation is concentrated on the surface of the rotating shaft, rotor, and inner circumference of the stator core. This results in iron loss, copper loss, eddy current loss, etc. However, since the rotating shaft and rotor are cooled indirectly via the stator core, efficient cooling is not possible, and these electrical losses are unevenly distributed, resulting in a rise in temperature of the rotating shaft. This has the disadvantage that thermal imbalance occurs, which increases shaft vibration and makes it impossible to obtain the required rotational speed. SUMMARY OF THE INVENTION An object of the present invention is to provide a high-speed motor that is cooled so that no thermal imbalance occurs in the rotor or rotating shaft, and that does not cause trouble during high-speed rotation.

0004

[Means for Solving the Problems] The present invention provides a ring-shaped stator core with a plurality of opening slots for storing stator windings on the inner periphery, and a rotor facing the rotor with a gap therebetween. In the cooling device for a high-speed motor, the stator core is provided with a coolant passage for passing the coolant and a temperature sensor, wherein a cooling pipe extending in the axial direction is provided at the opening of the opening slot,
One end of the cooling pipe is communicated with a supply port of the coolant supply device, the other end of the cooling pipe is communicated with a recovery port of the coolant supply device, and the temperature sensor is opposed to the surface of the rotor, Outputting a temperature rise value deviation from the signal of the temperature sensor and an output of a memory in which an appropriate temperature rise value of the rotor is stored in advance, and outputting an amount of heat generated by the rotor from the deviation of the temperature rise value; In this cooling method, a temperature command value of the coolant is calculated from the calorific value, and the coolant is cooled by a cooler of the coolant supply device according to the temperature command value. In addition, a rotor is provided inside a ring-shaped stator core having a plurality of opening slots for storing stator windings on the inner periphery thereof, and is opposed to the stator core through a gap, and a cooling liquid is passed through the stator core. A cooling device for a high-speed motor including a passage and a temperature sensor, a cooling pipe extending in the axial direction to the opening of the opening slot, and a communication pipe communicating one end of the cooling pipe to a supply port of a cooling liquid supply device. , a communication pipe connecting the other end of the cooling pipe to a recovery port of the cooling liquid supply device, the temperature sensor facing the surface of the rotor, and storing an appropriate temperature rise value of the rotor in advance. a comparator that calculates the deviation of the temperature rise value of the rotor from the signal of the temperature sensor and the output of the memory; a function generator that outputs an output, an arithmetic unit that calculates the temperature of the coolant from the output of the function generator and outputs a temperature command value, and a coolant that cools the coolant with a cooler according to the temperature command value. A cooling device for a high-speed motor equipped with a supply device.

[0005]

[Operation] The deviation of the temperature rise value of the rotor is calculated from the output of the temperature sensor installed facing the rotor surface and the output from the memory in which the appropriate temperature rise value of the rotor is stored in advance. The temperature of the cooling fluid is determined by determining the temperature of the cooling fluid by commanding the cooling fluid supply device from the deviation of the temperature rise value, and changing the surface temperature of the cooling pipe according to the temperature rise of the rotor, causing rapid rotation. Since the rotor can be cooled by thermal radiation, the rotor can be maintained at a predetermined temperature and thermal imbalance can be eliminated.

[0006]

[Embodiment] The present invention will be described with reference to an embodiment shown in the drawings. Incidentally, elements common to the structure explained in FIG. 4 showing the conventional example are given the same names and the same reference numerals, and their explanations are omitted. FIG. 1 is a side sectional view showing an embodiment of the present invention, and FIG. 2 is a front sectional view, in which a spiral cooling jacket 12 is provided in a cylindrical frame 11 of a high-speed motor 1 to allow cooling fluid to pass through. be. A stator core 3 provided with a plurality of opening slots 31 into which stator windings 2 are inserted is fixed inside a frame 11, and a rotor 4 is provided on the inner periphery of the stator core 3 facing each other with a gap therebetween. A rotating shaft 41 supporting the rotor 4 is supported by a magnetic bearing 5 provided inside the frame 1 in a non-contact manner. Brackets 6 are provided at both ends of the frame 1 to support the rotating shaft 41 via auxiliary bearings 61 when the rotor 4 is at rest. The above configuration is almost the same as the conventional example, but the difference from the conventional example is that a cooling pipe 81 extending in the axial direction is provided at the opening of the open slot 31 of the stator core 3, and both ends of the cooling pipe 81 are ring-shaped. The connecting pipes 82 and 83 communicate with each other. As shown in FIG. 3, the communication pipe 82 communicates with a supply port 86 of the cooler 84 of the coolant supply device 8 through a supply pipe 85, and the communication pipe 83 communicates with a recovery port 88 of the cooler 84 through a recovery pipe 87. has been done. Temperature sensor 7 is connected to stator core 3
It is fixed in a substantially central part of the rotor 4 to a position facing the surface of the rotor 4, and its output is sent to a comparator 91 of the control device 9.
is input. A memory 92 provided in the control device 9 stores an appropriate temperature rise value of the rotor 4 in advance, and a comparator 91 compares the output of the temperature sensor 7 with the temperature rise value of the memory 92. , and input their deviation outputs to the function generator 93, respectively. The function generator 93 is capable of outputting the relationship between the amount of heat generated by the rotor 4 and the deviation of the temperature rise value in a functional form, and by inputting the deviation of the temperature rise value, it is output as the amount of cooling heat of the rotor 4. , is input to the arithmetic unit 94. The calculator 94 calculates the temperature of the coolant from the amount of cooling heat of the rotor 4, the specific gravity of the coolant, and the specific heat of the coolant, outputs a temperature command value, and sends the coolant temperature of the cooler 84 to the coolant supply device 8. command. In the coolant supply device 8, a coolant at a predetermined temperature is generated by a cooler 84 according to the temperature command value,
The cooling pipe 81 is cooled by being supplied to the communication pipe 82 . Therefore, the surface temperature of the rotor is detected by a temperature sensor, the temperature rise of the rotor is calculated, and the temperature of the coolant is determined by commanding the coolant supply device from the temperature rise value. The surface temperature of the cooling pipe changes according to the temperature rise of the rotor, and the rotor can be rapidly cooled by thermal radiation, so the rotor can be maintained at a predetermined temperature, eliminating thermal imbalance. be able to.

[0007]

As described above, according to the present invention, since the rotor is cooled by the cooling pipe facing near the surface of the rotor, the rotor can be rapidly cooled while rotating. This has the effect of eliminating thermal imbalance and providing a stable high-speed motor.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

FIG. 2 is a front sectional view of FIG. 1;

FIG. 3 is a block diagram showing an embodiment of the present invention.

FIG. 4 is a side sectional view showing a conventional example.

[Explanation of symbols]

1 High speed motor 11 Frame 2 Stator winding 3 Stator core 31 Opening slot 4 Rotor 7 Temperature sensor 8 Cooling liquid supply device 81 Cooling pipe 82, 83 Connecting pipe 84 Cooler 85 Supply pipe 86 Supply port 87 Recovery pipe 88 Collection port 9 Control device 91 Comparator 92 Memory 93 Function generator 94 Arithmetic unit

Claims (2)

[Claims] 1. A rotor is provided inside a ring-shaped stator core having a plurality of opening slots for storing stator windings on the inner periphery thereof, and is opposed to the stator core through a gap, and a cooling liquid is supplied to the stator core. In a cooling device for a high-speed motor, which is provided with a cooling fluid passage and a temperature sensor, a cooling pipe extending in the axial direction is provided at the opening of the opening slot, and one end of the cooling pipe is communicated with a supply port of a cooling fluid supply device. The other end of the cooling pipe is communicated with the recovery port of the cooling liquid supply device, the temperature sensor is made to face the surface of the rotor, and the signal of the temperature sensor and an appropriate temperature rise value of the rotor are determined in advance. outputs the deviation of the temperature rise value from the output of the memory that stores the temperature rise value, outputs the amount of heat generated by the rotor from the deviation of the temperature rise value, calculates the temperature command value of the coolant from the heat value, and calculates the temperature A method for cooling a high-speed motor, characterized in that a cooling liquid is cooled by a cooler of the cooling liquid supply device according to a command value. 2. A rotor is provided inside a ring-shaped stator core having a plurality of opening slots for storing stator windings on the inner periphery, and a rotor is provided facing the stator core with a gap therebetween, and a cooling liquid is supplied to the stator core. In the cooling device for a high-speed motor, which is provided with a cooling fluid passage and a temperature sensor, the cooling pipe extends in the axial direction through the opening of the opening slot, and one end of the cooling pipe is communicated with a supply port of the cooling fluid supply device. a communication pipe, a communication pipe that communicates the other end of the cooling pipe with the recovery port of the cooling liquid supply device, the temperature sensor that is opposed to the surface of the rotor, and a communication pipe that communicates the other end of the cooling pipe with the recovery port of the cooling liquid supply device; a comparator that calculates the deviation of the temperature rise value of the rotor from the signal of the temperature sensor and the output of the memory, and the relationship between the amount of heat generated by the rotor and the deviation of the temperature rise value. a function generator that outputs the temperature in a functional form; a calculator that calculates the temperature of the coolant from the output of the function generator and outputs a temperature command value; and a cooler that cools the coolant according to the temperature command value. 1. A cooling device for a high-speed motor, characterized in that a cooling liquid supply device is provided.