JPH0736467Y2 - Motor with encoder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a motor with an encoder, and particularly to a heat insulating structure for an encoder portion.

(Prior Art) In a motor with an encoder, when the heat generated in the motor part is transferred to the encoder part and the ambient temperature of the encoder rises, the detection accuracy of the encoder decreases, so there is a gap between the motor part and the encoder part. Some have a heat insulating plate. FIG. 3 shows a conventional example of such a motor with an encoder.

In FIG. 3, a bearing 28 is fitted to one end of a motor body 21 having a cup-shaped motor case 33, and a bearing (not shown) fitted to the bearing 28 and the other end of the motor body 21. The output shaft 27 of the motor is rotatably supported by. The motor case 33 is made of aluminum or iron. A heat insulating plate 31 made of resin or the like is attached to one end of the motor body 21, and an encoder case 38 is attached via the heat insulating plate 31. A bearing retainer 25 made of aluminum or iron is interposed between one end of the motor case 33 and the heat insulating plate 31. The bearing retainer 25 positions the bearing 28 by pushing the end surface of the outer ring of the bearing 28 toward the receiving portion side of the motor case 33. An encoder 30 for detecting the rotation angle of the output shaft 27 is attached to one end of the output shaft 27 protruding from the heat insulating plate 31. The encoder case 38 is made of aluminum or iron and seals the encoder 30 part.

When the drive coil of the motor is energized to drive the motor, as is well known, the drive coil, the stator core, and the like generate heat, and the heat tends to be conducted to the encoder 30 side through the motor case 33. However, the motor body 21 and the encoder 30
Since a heat insulating plate 31 is installed between
The conduction of heat to 30 is blocked, and an increase in the ambient temperature of encoder 30 is suppressed.

(Problems to be Solved by the Invention) As described above, in the conventional motor with an encoder, some heat insulating measures are taken. However, the conventional heat insulation structure is
The heat insulating plate 31 is merely interposed between the motor body 21 and the encoder 30, and the heat insulating effect is not always sufficient.
Therefore, it is necessary to suppress heat generation on the side of the motor main body 21, and for that purpose, measures such as enlarging the physique of the motor main body 21 are taken, resulting in high cost.

The present invention has been made in order to solve the problems of the prior art, and provides a motor with an encoder in which the effect of shutting off heat conduction from the motor body to the encoder is improved by devising the structure of the heat insulating portion. The purpose is to do.

(Means for Solving the Problem) The present invention supports a motor output shaft with a bearing attached to the end of the motor main body, and arranges an encoder for detecting the rotation angle of the output shaft at one end of the motor main body. In a motor with an encoder in which a heat insulating plate is interposed between the encoder and the motor main body, the bearing is sandwiched between one end of the motor main body and the heat insulating plate to form a space between the motor main body and the heat insulating plate. It is characterized by

(Function) The heat from the motor body to the encoder is blocked by the heat insulating plate and also by the space between the motor body and the heat insulating plate. The heat insulating plate also serves as a bearing holding member.

(Embodiment) An embodiment of a motor with an encoder according to the present invention will be described below.

In FIG. 1, cup-shaped motor cases 3 and 4 are arranged with the stator core 2 sandwiched therebetween, and both ends of a positioning pin 6 penetrating the stator core 2 are respectively formed into motor cases 3 and 4.
The stator core 2 and the motor case 3, 4 by fitting
The relative positional relationship with is determined. A tightening screw 5 penetrates the motor case 4 and the stator core 2, and the screw 5 is screwed into the motor case 3 so that the stator core 2 and the motor cases 3 and 4 are integrally coupled to each other. A body 1 is formed. A bearing 9 is fitted inside the side wall of the motor case 3, and a bearing 8 is fitted outside the side wall 4a of the motor case 4. These bearings
The output shaft 7 is rotatably supported by a motor by 9,8. The output shaft 7 is integrally assembled with a rotor having a rotor magnet and the like. The outer peripheral surface of the rotor opposes the inner peripheral surface of the stator core 2 at a constant interval. The stator core 2 has an appropriate number of salient poles, and a drive coil 19 is wound around each salient pole. Motor case 3,
4 is made of a metal material with good heat dissipation, such as aluminum or iron.

As shown also in FIG. 2, an annular rubber sheet 12, a heat insulating plate 11 and a shield plate 14 are arranged in this order on the outer side of the side wall portion 4a of the motor case 4 constituting the motor body 1, and the shield plate The shield plate 14, the heat insulating plate 11, and the rubber sheet 12 are screwed into the side wall portion 4a of the motor case 4 by tightening a tightening screw 16 penetrating the heat insulating plate 11, the heat insulating plate 11, and the rubber sheet 12.
Are fixed to the motor case 4. The outer diameter of the rubber sheet 12 is smaller than the inner diameter of the outer peripheral portion of the motor case 4. Therefore, a space 15 is formed between the motor case 4 and the heat insulating plate 11, and the space 15 extends further inward than the thickness of the outer peripheral portion of the motor case 4.
Further, the space 15 communicates with the outside air. The outer ring of the bearing 8 is sandwiched by the heat insulating plate 11 mounted as described above and the side wall 4a of the motor case 4. Insulation board
11 is made of PBT resin or the like. The shield plate 14 is made of a material having a high magnetic shield effect and good thermal conductivity, such as iron.

An encoder 10 is attached to one end of the output shaft 7 protruding from the shield plate 14. The form of the encoder 10 is not particularly limited, and may be a magnetic encoder or an optical encoder. An encoder case 18 is fixed to the heat insulating plate 11, and the encoder case 18 closes the encoder 10. Encoder case 18
Is made of aluminum or iron in consideration of heat dissipation.

According to the embodiment described above, not only the heat insulating plate 11 is interposed between the motor body 1 and the encoder 10,
Since the space 15 is formed between the motor body 1 and the heat insulating plate 11 to perform heat insulation by utilizing the heat insulation effect of air, the conductivity of the heat generated on the motor body 1 side to the encoder 10 side is extremely low. Therefore, the heat insulating effect between the motor body 1 and the encoder 10 is dramatically improved. Moreover, since the space 15 communicates with the outside air, the heat radiation effect of the portion facing the space 15 is great, the temperature rise of the motor body 1 itself is suppressed, and the heat insulation effect with the encoder 10 is further improved. In this way, the heat insulating effect is improved and the temperature rise of the motor body 1 itself is suppressed, and as a result, the ambient temperature rise of the encoder 10 is suppressed more effectively.

Further, since the heat insulating plate 11 also serves as a bearing retainer by sandwiching the bearing 8 with the motor case 4 constituting the motor body 1, it is not necessary to prepare the bearing retainer as a separate member.

The shield plate 14 is not only effective in the case of a magnetic encoder, but also functions as a reinforcing member for the heat insulating plate 11 because it is fixed by pressing the heat insulating plate 11.
On the other hand, since the heat insulating plate 11 also serves as a bearing retainer as described above, it is necessary to have some strength, but the heat insulating plate 11 is reinforced by the shield plate 14 to ensure necessary and sufficient strength. You can

It should be noted that the rubber butt 12 is provided inside the motor body 1 and the encoder 10.
It not only plays a role of preventing water and the like from entering the inside, but also functions as a heat insulating material.

Further, as described above, the space 15 can be secured in a wider area by configuring the space 15 so as to extend inward from the thickness of the outer peripheral portion of the motor case 4, whereby the heat dissipation effect can be secured. Can be further increased.

In the illustrated embodiment, the motor body 1 is divided into three parts, that is, the stator core 2 and the two motor cases 3 and 4, and these are integrally connected. The present invention is not limited to this, and for example, the motor main body may be configured by one bottomed cylindrical motor case and the end plate fitted to the open end of the motor case.

According to the present invention, not only the heat insulating plate is interposed between the motor body and the encoder, but a space is formed between the motor body and the heat insulating plate to utilize the heat insulating effect of air. As a result of this heat insulation, the conductivity of the heat generated on the motor body side to the encoder side is extremely low, the heat insulation effect between the motor body and the encoder is dramatically improved, and the temperature rise of the motor body itself Suppressed. In this way, the heat insulating effect is improved and the temperature rise of the motor body itself is suppressed, and as a result, the ambient temperature rise of the encoder is more effectively suppressed.

The heat insulating plate also serves as a bearing retainer by sandwiching the bearing with the motor case that constitutes the motor main body, so there is no need to prepare the bearing retainer as a separate member, and the cost is reduced. In addition, the space for arranging the bearing retainer can be omitted.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a motor with an encoder according to the present invention, FIG. 2 is a right side view of a motor main body portion in the same embodiment, and FIG. 3 is an example of a conventional motor with an encoder. It is a partial cross section front view. 1 ... Motor body, 7 ... Motor output shaft, 8 ... Bearing, 10 ... Encoder, 11 ... Insulation plate, 15 ... Space.

Claims (1)

[Scope of utility model registration request] 1. A bearing attached to an end of a motor body supports an output shaft of the motor, and an encoder for detecting a rotation angle of the output shaft is arranged at one end of the motor body. In a motor with an encoder having a heat insulating plate interposed therebetween, the bearing is sandwiched between one end of the motor body and the heat insulating plate, and a space is formed between the motor body and the heat insulating plate. A motor with an encoder.