JP2001238403A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor for reducing the temperature rise of a speed sensor of a bearing. SOLUTION: A cooling air suction port for introducing cooling air into the motor is provided at an peripheral side or a side of a stator, corresponding to a power transmission unit side. A cooling air exhaust port for exhausting the air after cooling in the motor is provided at the outer peripheral side of a stator, corresponding to an opposite side of the transmission unit. A cooling centrifugal fan disposed rotatably at an inside of an end bracket at the opposite side of the transmission unit and is disposed so that the outer peripheral side is opposed to the inside of the exhaust port, is supported to a rotary shaft. A speed sensor for detecting the rotary speed of a rotor is provided at the end bracket at the opposite side of the transmission unit. A cooling air suction hole for the sensor for sucking the cooling air to the fan is provided at the bracket equipped with the sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor mainly used for driving wheels for vehicles.

[0002]

2. Description of the Related Art An electric motor of this type is disclosed in
A description will be given with reference to the application specification and drawings of US Pat.

That is, a cooling air intake port for sucking cooling air and a cooling air exhaust port for discharging cooling air are provided at both ends of the outer periphery of the stator, and a cooling centrifugal fan provided on a rotating shaft of a rotor is provided with a cooling air exhaust port. The power transmission unit provided on one end side of the rotating shaft is located on the same side as the cooling centrifugal fan, and the cooling air intake hole is provided on the end bracket on the side adjacent to the cooling centrifugal fan. The cooling centrifugal fan has a main plate provided with a cooling air introduction hole. Then, the inside of the electric motor is cooled by the cooling air sucked from the cooling air suction port, and the end bracket and the bearing on the side adjacent to the cooling centrifugal fan are cooled by the cooling air taken from the cooling air intake hole.

[0004]

However, the following problem arises when an electric motor configured to dispose the cooling centrifugal fan on the opposite side away from the power transmission unit is provided with a speed sensor.

[0005] Motors used for vehicles have a relatively large capacity and the exhaust temperature of the cooling air exceeds 100 ° C.

On the other hand, when the speed sensor is used in a high temperature environment, there is a possibility that the detection accuracy is reduced and the speed control of the motor is impaired. In addition, the speed sensor must be provided with a rotating disk for the sensor and the like, so that a space for an attachment point is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an apparatus which can solve the problems of temperature and space.

[0008]

SUMMARY OF THE INVENTION The present invention comprises a stator and a rotor rotatably provided inside the stator, wherein the stator is provided with an outer frame and inside the outer frame. A stator core, and a stator coil provided in the stator core,
An end bracket provided on both sides of the outer frame, wherein the rotor is rotated by a rotor core provided inside the stator core and a bearing that supports the rotor and is provided with the both end brackets. A motor having a rotating shaft freely supported, and a power transmitting portion provided at a portion located on one end side of the rotating shaft and outside the end bracket; A cooling air inlet for introducing cooling air into the motor on the outer peripheral side or side portion, and cooling air exhaust for discharging air after cooling the electric motor on the outer peripheral side of the stator opposite to the power transmission section. A cooling port that is rotatably placed inside the end bracket opposite to the power transmission section, and that is arranged so that the outer peripheral side faces the inside of the cooling air exhaust port. A centrifugal fan is supported on the rotating shaft, and a speed sensor for detecting a rotation speed of the rotor is provided on the end bracket on the opposite side of the power transmission unit, and the end bracket provided with the speed sensor is provided on the end bracket. Is characterized in that a cooling air intake hole for a sensor to be sucked into the cooling centrifugal fan is provided.

[0009]

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIGS.

The motor shown here is a relatively large induction motor having a capacity for driving the driving wheels of a vehicle of about 150 KW. This motor has a rotatable rotor inside a stator. The stator includes an outer frame 1 surrounding the outer periphery, a stator core 2 provided inside the outer frame section 1, a stator coil 3 provided in the stator core 2, and end brackets 4 and 5 provided on both sides of the outer frame 1. Have.

The cylindrical stator core 2 fitted to the outer frame 1 is provided with a plurality of slots communicating with each other in the axial direction at predetermined intervals in the circumferential direction. The stator coil 3 is accommodated in the slot.

The rotor has a rotor core 6, a rotor coil 7 provided on the rotor core 6, and a rotating shaft 8 for supporting the rotor core 6. Both sides of the rotating shaft 8 are rotatably supported by bearings 9 and 10 provided on the end brackets 4 and 5.

The rotor core 6 fitted to the rotating shaft 8
Has a plurality of slots communicating in the axial direction arranged at predetermined intervals in the circumferential direction. The rotor coil 7 is housed in the plurality of slots in a driving bar system.

The rotor core 6 has a plurality of cooling air ventilation holes 20 penetrating in the axial direction. This cooling air ventilation hole 20
Are arranged at predetermined intervals in the circumferential direction. The cooling air flows through the cooling air ventilation holes 20. Since there is a gap between the outer periphery of the rotor core 6 and the inner periphery of the stator core 2, the cooling air also flows through this gap.

A power transmission unit 21 for transmitting power to the driving wheels of the vehicle is provided at one end of the rotating shaft 8. This power transmission unit 21 is arranged on the bearing 9 side. A cooling air intake port 22 and a cooling air exhaust port 23 are provided on the outer peripheral side of the stator.

The cooling air intake port 22 is disposed on the bearing 9 side, and the cooling air exhaust port 23 is disposed on the bearing 10. The cooling centrifugal fan 60 provided in the stator is
And fixed to the rotating shaft 7 by mounting it on the side. The cooling centrifugal fan 60 is fixed to the rotor core 6 with the fan bolts 24 so as not to rotate with respect to the rotating shaft 7.

The cooling centrifugal fan 60 includes a main plate 25,
It has a number of fan blades 26 and side plates 27. Main plate 2
5 has a disk shape and a conical shape at the center. The side plates 27 are arranged so as to face the main plate 25 with an interval, and the fan blades 26 are arranged at equal intervals and radially between the side plate 27 and the main plate 25. The main plate 25 is provided with a plurality of cooling air introduction holes 28 for guiding cooling air into the cooling centrifugal fan 60 at equal pitches. The end bracket 5 is provided with a plurality of sensor cooling air intake holes 29 at equal pitches for sucking cooling air flowing through the cooling air introduction holes 28 from the outside.

The cooling air inlet hole 28 and the sensor cooling air inlet hole 29 are desirably provided close to each other. When separated, it is desirable to arrange the cooling air introduction hole 28 on the outer peripheral side rather than the cooling air intake hole 29 for the sensor. In this case, the flow of the cooling air to the cooling air introduction hole 28 is improved as compared with the case where the cooling air is disposed in reverse. Cooling air introduction hole 2
By setting the position of the fan blade 8 on the inner peripheral side with respect to the outer peripheral end of the fan blade 26, the suction of the cooling air becomes better than the arrangement of the fan blade 26 on the contrary. Further, the provision of the sensor cooling air inlet hole 29 eliminates the pressure difference between the inside and the outside of the end bracket 5, so that the lubricating oil (grease) filled in the bearing 10 is sucked out and is not significantly consumed. .

A filter 14 is provided on the side of the cooling air inlet 22 to prevent dust from entering the interior 13 of the electric motor. The cooling air passing through the filter 14 and cooling the inside of the electric motor is discharged outside by the cooling centrifugal fan 60. Such an electric motor of this embodiment is of an open type adopting a self-ventilation system of a suction fan type.

A speed sensor 40 is provided outside the end bracket 5, and a sensor rotating disk 41 is provided at an end of the rotating shaft 7 on the end bracket 5 side. The sensor rotating disk 41 is fixed to the rotating shaft 7 with bolts 42. The bolt 42 is locked by the detent plate.

The rotating disk for sensor 41 has a large number of teeth on a circular outer periphery. The teeth are formed at equal pitches with high precision intervals. The speed sensor 40 is arranged so that the tip of the speed sensor 40 faces the outer periphery of the tooth portion. The distance between the tooth portion and the tip of the speed sensor 40 is about 0.1 to 1 mm. The speed sensor 40 includes a magnet and a coil, and a rotation signal is generated in the coil as the peaks and valleys of the teeth pass. By measuring this rotation signal,
You can know the rotation speed. By using a two-phase speed sensor, the direction of rotation can also be known.

The sensor rotating disk 41 and the speed sensor 40 are covered with a dust-proof cover 43. The cover 43 is attached to the end bracket 5 with bolts 44. The sensor cooling air inlet hole 29 is provided with a dustproof cover 43.
It is provided outside the outer periphery of.

The speed sensor 40 includes a sensor support 45.
, And the adjustment screw 46 is tightened or loosened to adjust the (0.
(1 to 1 mm). The sensor support 45 closes a side opening of the cover 43 on the sensor support side to prevent dust from entering the cover.

Next, the operation will be described.

The outside air flows into the motor through the filter 14 by the suction action of the cooling centrifugal fan 60 accompanying the operation of the motor. The flowing cooling air flows through the cooling air ventilation holes 20 and is drawn into the cooling centrifugal fan 60. The divided cooling air flows through a gap formed between the outer periphery of the rotor core 6 and the inner periphery of the stator core 2 and is sucked into the cooling centrifugal fan 60. The cooling intake air discharged from the cooling centrifugal fan 60 is exhausted from the cooling air exhaust port 23 to the outside. In this flowing process, the cooling air cools the inside of the motor.

In addition to the cooling air, outside air is drawn into the cooling centrifugal fan 60 through the cooling air intake hole 29 for the sensor and the cooling air introduction hole 28, and is exhausted from the cooling air exhaust port 23 to the outside. Cooling air intake hole 2 for this sensor
The speed sensor 40, the end bracket 5 and the bearing 10 are cooled by the cooling air sucked into the cooling centrifugal fan 60 through the cooling fan 9.

The upper limit operating temperature of the speed sensor 40 is lower than the temperature of the cooling air on the exhaust side that cools the inside of the motor.
If used in an environment above this temperature, the function of the sensor will be impaired and accurate speed information will not be obtained. The temperature of the cooling air on the exhaust side that has cooled the inside of the motor is about 100 ° C., and the speed sensor 40 cannot be cooled by this high-temperature exhaust gas. By providing the sensor cooling air intake hole 29 in the end bracket 5 and the cooling air introduction hole 28 in the cooling centrifugal fan 60, the speed sensor 40 is directly cooled by cold cooling air that has been drawn in from the outside and has not yet been heated. , It can be kept below the upper limit temperature of use.

Since the speed sensor 40 is cooled to a temperature equal to or lower than the upper-limit temperature for use, the function of the sensor is not impaired, and high-precision speed control can be performed based on accurate speed information. Since the bearing 10 is also cooled as the end bracket 5 is cooled, consumption of lubricating oil and the like are suppressed.

In the electric motor having such a configuration (in which the power transmitting portion 21 of the rotating shaft 8 is provided on the cooling air intake port 22 side), a speed sensor is provided on the end bracket 4 on the power transmitting portion 21 side. Although measures to cope with the temperature rise can be considered, it is impossible in practice. That is, the presence of the power transmission unit 21 makes it difficult to mount the sensor rotating disk. Since a coupling mechanically coupled to the power transmission unit 21 is located near the outer surface of the end bracket 4, a space for disposing a cover that covers the speed sensor and the rotation for the sensor and the disk speed sensor is provided. It is difficult to secure and it is not feasible.

Due to such circumstances, the speed sensor 40
Has to be provided on the end bracket 5 opposite to the power transmission unit 21 side, and in order to solve the problem of the temperature rise newly generated here, the cooling air intake hole 29 for the sensor is provided on the end bracket 5. The cooling air introduction hole 28 is provided in the cooling centrifugal fan 60 to achieve cooling. In this way, the temperature rise of the speed sensor was suppressed, and the problem of space for mounting the speed sensor and the sensor rotating disk was also solved.

Another embodiment of the present invention shown in FIG. 4 will be described.

In the description of this embodiment, the points different from those described above are mainly described, and the common portions are denoted by the same reference numerals as in the previous embodiment, and the description is omitted.

That is, the electric motor shown in FIG.
, A cooling centrifugal fan 60 is disposed in the power transmission unit 21, a cooling air inlet hole 50 is provided in the end bracket 4, and a cooling air exhaust port 23 is provided on the outer periphery of the stator on the outer peripheral side of the end bracket 4. Have. Although not shown,
The end bracket provided on the opposite side of the end bracket 4 is provided with a speed sensor. A cooling air inlet and a filter are also provided on the outer periphery of the stator having the speed sensor.

According to this configuration, since the end bracket provided with the speed sensor is cooled well by the outside air sucked into the cooling air suction port, the temperature of the speed sensor does not rise. The temperature of the bearing provided on the end bracket side does not rise.

The end bracket 4 is cooled well by the cooling air of the outside air sucked through the cooling air intake hole 50 and the cooling air introduction hole 28 by the cooling centrifugal fan 60. Accordingly, the bearing 9 provided on the end bracket 4 is cooled, and the temperature rise is suppressed.

[0036]

According to the present invention, the temperature rise of the speed sensor can be suppressed. At the same time, the problem of space at the mounting point has been solved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an essential part of an electric motor according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a bearing unit and a speed sensor according to an embodiment of the present invention.

FIG. 3 is an enlarged plan view of a bearing unit and a speed sensor according to an embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a main part of an electric motor according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Outer frame, 2 ... Stator core, 3 ... Stator coil, 6 ... Rotor core, 4, 5 ... End bracket, 7 ... Rotating shaft,
9, 10 ... bearing, 21 ... power transmission part, 22 ... cooling air intake, 23 ... cooling air exhaust, 29 ... cooling air intake hole for sensor, 40 ... speed sensor, 60 ... centrifugal fan for cooling.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hayato Imai 3-1-1, Sachimachi, Hitachi-shi, Ibaraki F-term in Hitachi Works, Ltd. F-term (reference) 5H609 BB02 BB12 BB18 PP02 PP06 PP07 PP08 PP17 QQ12 QQ13 QQ14 RR03 RR07 RR10 RR16 RR20 RR27 RR32 RR36 RR38 RR42 RR69 RR73 SS03

Claims (3)

[Claims] 1. A stator comprising: a stator; and a rotor rotatably provided inside the stator, wherein the stator includes an outer frame,
A stator core provided inside the outer frame, a stator coil provided in the stator core, and end brackets provided on both sides of the outer frame, wherein the rotor is provided inside the stator core. A rotor core provided, and a rotating shaft that supports the rotor and is rotatably supported by bearings provided on the both end brackets, and is located at one end of the rotating shaft and outside the end bracket. In a motor provided with a power transmission unit in a portion to be provided, a cooling air suction port for introducing cooling air into the motor is provided on an outer peripheral side or a side portion of the stator corresponding to the power transmission unit side, A cooling air exhaust port for discharging air after cooling the inside of the motor is provided on the outer peripheral side of the stator on the opposite side. And a cooling centrifugal fan arranged on the rotating shaft and arranged so that the outer peripheral side faces the inside of the cooling air exhaust port, and the end bracket which is on the opposite side of the power transmission unit has the rotating shaft. An electric motor, comprising: a speed sensor for detecting a rotation speed of a child; and a cooling air intake hole for a sensor to be sucked into the cooling centrifugal fan is provided on the end bracket provided with the speed sensor. 2. The cooling centrifugal fan according to claim 1, wherein the cooling centrifugal fan has a disk-shaped main plate and a plurality of fan blades provided on the main plate, and the cooling centrifugal fan is configured such that the main plate is formed of the main plate. An electric motor, wherein the main plate is provided with a cooling air introduction hole which is arranged adjacent to and opposed to an end bracket and guides outside air sucked from the sensor cooling air intake hole into the cooling centrifugal fan. 3. The sensor according to claim 1, wherein a rotating disk for a sensor is provided on an end side of the rotating shaft opposite to the power transmission unit, and the speed sensor is provided on an outer periphery of the rotating disk for the sensor. An electric motor characterized in that a speed sensor is disposed so as to face a detection side end of the motor.