JPH0242065Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention uses cooling air supplied by a blowing means driven by an independent motor among motors such as induction motors, synchronous motors, and DC motors. This invention relates to an externally ventilated cooling type motor that is cooled by cooling.

[Conventional technology]

For motors whose rotation speed and rotation angle are controlled during use, such as feed control motors and spindle drive motors used in machine tools,
Sensors that detect rotation speed, rotation angle, etc. are often incorporated.

Since this type of motor is required to be small and produce a large output, it generates a lot of heat, and it is difficult to achieve sufficient cooling using a method of cooling the motor using air blowers attached to the motor itself. Particularly, in the case of a motor that is driven to rotate intermittently, such as a servo motor, sufficient cooling cannot be achieved by a method of cooling the motor using a blower blade attached to the motor itself. Therefore, in these cases, an external ventilation cooling system is often adopted in which a blowing means driven by an independent motor is attached and the motor is cooled by cooling air sent by the blowing means.

FIG. 3 is a half longitudinal sectional view showing an example of a conventional external force ventilation cooling type motor, and the lower half of this motor is symmetrical to the upper half. In the figure, 1 is a motor case consisting of a cylindrical case body 1a and end caps 1b and 1c attached to both ends of the case body, and 2 is an electric motor connected to an annular iron core 2a fitted inside the case body 1a. A stator having a child winding 2b wound thereon; 3 a rotary shaft rotatably supported by end caps 1b, 1c via bearings 4; 5;
is a rotor attached to a rotating shaft 3, and these motor case 1, stator 2, rotating shaft 3, and rotor 5 constitute a motor main body M.

A cup-shaped cooling fan mounting cover 6 is attached to the end cap 1b constituting the non-output side end of the motor case 1, and a sensor 7 that provides information indicating the state of the motor is housed inside this cover 6. has been done.

This sensor 7 is, for example, a photo encoder, a magnetic encoder, a brushless co-radiator, a resolver, etc., but these sensors are often equipped with a semiconductor element for generating a detection signal and an electronic circuit for signal processing. , have a low tolerance to temperature rises and require special consideration for their cooling. The illustrated sensor 7 works together with a rotating element 7a attached to the end of the rotating shaft 3 to obtain predetermined information (rotational speed, rotational position, etc.)
The fixed element 7b is attached to the inside of a cup-shaped sensor cover 7c. In the case of a photo encoder, the rotating element 7a consists of, for example, a code disk, and the fixed element 7b consists of, for example, a light emitting element such as a light emitting diode, a light receiving element such as a phototransistor, and a signal processing circuit that processes the output signal of the light receiving element. .

A cooling fan 8 driven by an independent motor is attached to the end face of the cover 6, and an outer cover 9 is attached to surround the motor cover 1 of the motor body M and the cooling fan 8 from the outside. A motor cooling ventilation passage 10 is formed inside the outer cover 9 and extends from the end cap 1c side through the outer periphery of the motor case 1 to the cooling fan 8 side. The motor is cooled by flowing through the cooling ventilation passage 10.

[Problem that the invention attempts to solve]

In the above-mentioned external ventilation cooling type motor, the cooling air A passes through the motor body and then reaches the sensor 7, so the cooling air heated by the heat generated by the motor body hits the sensor 7. 7
There was a problem that the cooling was not sufficient.
As a result, the temperature of the sensor 7 rises, making it difficult to cause the sensor to operate with high precision and stability. In this case, in order to guarantee the accuracy of the sensor, it is necessary to limit the motor load to less than the rated value to suppress the temperature rise, making it impossible to meet the demand for smaller motors and increased output. There was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide an externally ventilated cooling type motor that allows both the motor body and the sensor to be cooled well and allows the sensor to operate with high precision while the motor is running at its rated value.

[Means for solving problems]

As seen in the embodiment shown in the drawings, the present invention has a stator 2 and a rotor 5 in a motor case 1.
The sensor comprises a motor main body M in which is housed, sensor elements 7a and 7b, and a sensor cover 7c that covers the sensor elements, and the sensor cover 7c is attached to the non-output side end 1b of the motor case 1. 7 and sensor cover 7 of sensor 7
A motor that allows outside air to be supplied by the cooling fan 8 to flow between the cooling fan 8 arranged away from the motor cover 1 and the outer peripheral surface of the motor case 1 while being in contact with the motor cover 1. The cooling fan 8 is provided with an outer cover 9 forming a cooling ventilation passage 10, and the cooling fan 8 is connected to the sensor 7 from the motor body M side.
The present invention is directed to an externally ventilated cooling type motor in which outside air is fed into the motor cooling ventilation passage 10 toward the side.

In the present invention, a sensor cooling ventilation passage forming cover 11 is disposed between the sensor cover 7c and the cooling fan 8. This cover 11 is fixed to the non-output side end 1b of the motor case 1 so as to cover the sensor cover 7c and form a sensor cooling ventilation path 12 on the outside of the sensor cover 7c. The sensor cooling ventilation path forming cover 11 is provided with an outside air introduction duct 11b that directly introduces outside air from the outside of the outer cover 9, and an exhaust port 11c that opens on the side of the blower blade 8a of the cooling fan 8.

[Effect of invention]

When the cooling fan 8 rotates, outside air flows through the motor cooling ventilation path 10 to cool the motor body M, and the sensor cooling ventilation path forming cover 11
The exhaust port 11c side becomes negative pressure, and outside air is directly introduced into the sensor cooling ventilation path 12 from the outside air introduction duct 11b, and the sensor cover 7c of the sensor 7 is directly cooled by the outside air outside the outer cover 9. . Therefore, according to the present invention, the sensor 7 can be directly cooled by the outside air at the same time as the motor body M is cooled by the outside air, so that the sensor can be cooled well. In this case, since the cooling air whose temperature has increased by cooling the motor body M does not directly touch the sensor 7, the sensor 7 can be cooled well regardless of the temperature of the motor body M, and the motor can be cooled. The sensor temperature can be kept low even if the sensor is operated at its rated capacity with a considerable temperature rise. Therefore, it is possible to operate the motor at its rated value and to operate the sensor stably with high precision, thereby making it possible to obtain a small, large-output motor.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show an embodiment of the present invention, in which FIG. 1 is a half longitudinal sectional view, and FIG. 2 is a sectional view taken along the line -- in FIG. 1. In this embodiment, 1 is a cylindrical case body 1a and an end cap 1b, 1
A motor case consisting of c and 2 is a motor case 1.
5 is a stator attached to the inside of the motor case 1, and 5 is a rotor attached to a rotating shaft 3 supported via bearings 4, 4 on the end caps 1b, 1c of the motor case 1. A motor main body M is constructed. Further, 7 is a sensor attached to the end cap 1b, and this sensor is
a rotating element 7a attached to the rotating shaft 3;
It consists of a fixed element 7b that cooperates with the rotating element 7a to generate a signal containing predetermined information such as the rotation speed and rotation angle of the motor, and the fixed element 7b is a cup-shaped sensor cover fixed to the end cap 1b. It is attached to 7c. The sensor cover 7c has a sealed structure, and the rotating element 7a and the fixed element 7b (sensor element) are completely covered by the sensor cover.

An outer cover 9 having an octagonal cross section is attached to cover the outer peripheral surface of the motor cover 1, and an annular motor cooling ventilation that surrounds the motor body M from the outside is provided between the outer cover 9 and the motor cover 1. A channel 10 is formed.

In this embodiment, a cover 11 for forming a cooling ventilation path that covers the sensor 7 is attached to the end cap 1b, and a cooling fan 8 as an air blowing means is attached to the end face of this cover 11. cover 1
1 has a structure in which four outside air introduction ducts 11b protrude radially from the outer periphery of a cup-shaped or dish-shaped cover body 11a at angular intervals of 90 degrees. An exhaust port 11c that opens toward the blower blade 8a of the cooling fan 8 is provided at a corresponding position. cover 11
The tips of the outside air introduction ducts 11b pass through holes provided in the outer cover 9 and are led out to the outside, and an independent sensor cooling ventilation path 12 is formed between the cover 11 and the sensor cover 7c. ing.

In the above embodiment, when the cooling fan 8 is rotated, outside air A is introduced into the motor cooling ventilation passage 10 between the outer cover 9 and the motor body M, and the motor body M is cooled, as in the case of a conventional motor. At the same time, the outside air is introduced into the sensor cooling ventilation path 12 from the outside air introduction duct 11b of the cover 11, and is introduced into the exhaust port 11c.
The sensor 7 is directly cooled by the outside air B exhausted from the sensor. In this way, in the present invention, since the sensor 7 is directly cooled by the outside air whose temperature has not risen due to the heat generated by the motor body, the sensor can be cooled well and the temperature of the sensor can be prevented from rising. The sensor can be operated stably with high precision. Additionally, since the sensor can be cooled regardless of the temperature rise of the motor, the motor can be operated at its rated rating, making it possible to generate higher output while being smaller than conventional motors that were used at reduced ratings. .

In the above embodiment, if a heat radiation fin is attached to the outer surface of the sensor cover 7c of the sensor 7, the sensor can be cooled more efficiently. Further, in the above embodiment, the cover 11 is directly fixed to the end cap 1b, but by fixing the cover 11 to the sensor cover 7, the cover 11 is fixed directly to the end cap 1b.
1 may be fixed to the end cap 1b.

[Effect of idea]

As described above, according to the present invention, the motor body can be cooled by outside air, and at the same time, the sensor can be directly cooled by outside air without being affected by the temperature of the motor body, and the sensor can be cooled well. Can be done. Therefore, it is possible to operate the motor at the rated value and also to operate the sensor stably with high precision, and there is an advantage that a small-sized motor with a large output can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a half longitudinal sectional view showing an embodiment of the present invention;
FIG. 2 is a sectional view taken along the line -- in FIG. 1, and FIG. 3 is a half longitudinal sectional view showing a conventional motor. 1...Motor case, 2...Stator, 3...
Rotating shaft, 5...rotor, 7...sensor, 7c...
Sensor cover, 8...Cooling fan (air blowing means),
9... Outer cover, 10... Motor cooling ventilation path, 11... Sensor cooling ventilation path formation cover,
12...Sensor cooling ventilation path.

Claims (1)

[Claims for Utility Model Registration] A motor body M in which a stator 2 and a rotor 5 are housed in a motor case 1, sensor elements 7a and 7b, and the sensor elements 7a and 7b.
A sensor 7 is provided with a sensor cover 7c that covers the element and the sensor cover 7c is attached to the non-output side end 1b of the motor case 1; A motor cooling ventilation passage 10 is provided between the fan 8 and the outer circumferential surface of the motor case 1 so as to surround the outer circumferential surface of the motor case 1, and allows outside air supplied by the cooling fan 8 to flow while being in contact with the motor cover 1. an external cover 9 forming an outer cover 9, the cooling fan 8 supplies outside air into the motor cooling ventilation passage 10 from the motor main body M side toward the sensor 7 side. , a sensor cooling ventilation passage 1 disposed between the sensor cover 7c and the cooling fan 8 to cover the sensor cover 7c and outside the sensor cover 7c;
Cover 1 for forming a ventilation path for sensor cooling forming 2
1 is the non-output side end 1 of the motor case 1;
b, and the sensor cooling ventilation path forming cover 11 has an outside air introduction duct 11b that directly introduces outside air from the outside of the outer cover 9, and an exhaust port that opens on the side of the blower blade 8a of the cooling fan 8. 11c.