JPH07245917A - Servo motor with rotational position detector - Google Patents

Abstract

PURPOSE:To shorten the axial length of a motor by eliminating the components, e.g. a cover, for a rotational position detector while facilitating the fixing work of fixing part and the work for leading out the lead wires. CONSTITUTION:The casing 11 comprises brackets 2a, 12b and a frame 13. A rotor 5 comprising a permanent magnet 5a and a yoke 5b is disposed on the inside of a stator 4 through an air gap. A shaft 16 for securing the rotor 5 is born by bearings 7a, 7b fixed to the brackets 2a, 12a. An opening 21 extending in the radial direction of the motor is made through the bracket 12a. An optical encoder 18 is inserted, at the fixing part 18a thereof, into the opening 21 and coupled with the rotary part 18b fixed to the shaft 16. A lead wire 18c for external connection and a flange 18d abutting on the end face of the opening 21 are provided on the outside at the fixing part 18a and the flange 18d is secured to the end face of the opening 21. The fixing part 18a is preferably located on the radial outside of the bearing box of the bracket 12b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servomotor characterized by a rotational position detector mounting structure. Here, the rotational position detector is an optical encoder, a magnetic encoder, an induction encoder, or the like, and the servo motor is a permanent magnet synchronous motor, an induction motor driven by an inverter, or the like.

[0002]

2. Description of the Related Art FIG. 8 is a half sectional view of a conventional example. In the figure, the jacket 1 is formed from brackets 2 a and 2 b and a frame 3. Inside the stator 4 fixed to the frame 3 and having the winding wire 4a, a permanent magnet 5a and a yoke 5 are provided through a gap.
A rotor 5 composed of b and b is arranged. The shaft 6 for fixing the rotor 5 is a bearing 7a, 7 mounted on the bracket 2a, 2b.
It is supported by b. The lead wire 4b of the winding wire 4a is the frame 3
Is pulled out from the packing 3a.

The fixing portion 8a of the optical encoder 8 is attached to the outer end surface of the bracket 2a on the non-driving side, and the rotating portion 8b of the optical encoder 8 is attached to the end portion of the shaft 6 penetrating the bracket 2a. The fixed portion 8a having a light emitting portion and a light receiving portion (not shown) and the rotating portion 8b having a slit (not shown) are coupled to each other through an appropriate gap. The cover 9 surrounding the optical encoder 8 is attached to the bracket 2a with screws or the like, and the lead wire 8c of the optical encoder 8 is pulled out from the packing 9a of the cover 9.

[0004]

In the above-mentioned conventional example, the cover 9 and the packing 9a are required as parts for the optical encoder 8 which is the rotational position detector, and the fixed portion 8a is required.
Installation work, lead wire 8c drawing work, cover 9
Installation work is required. Then, the motor needs to have an axial space for the optical encoder 8 outside the bracket 2a on the non-driving side, and the motor is long in the axial direction. Leave B.

An object of the present invention is to eliminate the need for parts such as a cover for a rotational position detector, simplify the work of attaching a fixed portion, pulling out lead wires, etc., and shorten the axial length of the motor. It is an object of the present invention to provide a servomotor having a rotational position detector that can be used.

[0006]

According to another aspect of the present invention, there is provided a servomotor having a rotational position detector, wherein a fixed portion of the rotational position detector is inserted into an opening provided in an outer cover to be coupled to the rotary portion, and the fixed portion is provided outside the fixed portion. Provide a lead wire or electrical connection for external connection,
A fixing means for fixing the fixing portion from the outside to the opening is provided.

At this time, the second aspect of the invention is that the fixing means is a flange or a plurality of ears that abut against the end surface of the opening.
A third aspect of the invention is to set the axial center of the opening in the radial direction or the axial direction of the motor, and a fourth aspect is to set the position of the fixed portion of the rotational position detector to the outside in the radial direction of the bearing box. A servomotor including a rotational position detector according to a fifth aspect of the present invention has a pair of bearings mounted on a bearing box forming an inner cylindrical portion of a jacket having a U-shaped cross section on one side, and a shaft supported by the bearing has a Γ-shaped cross section on one side. The hub is attached to surround the bearing box, and the stator, which is placed outside the rotor on the outer circumference of the hub with a gap, is fixed to the inner circumference of the outer cylindrical part of the jacket, and the rotating part of the rotation position detector is set to the hub. The outer cylindrical portion of the jacket is closed by the flange of the fixed portion of the rotary position detector, the fixed portion is connected to the rotary portion, and a lead wire or an electrical connector for external connection is provided outside the fixed portion. Is provided.

A sixth aspect of the present invention is the same as the first aspect of the present invention, in which the stator and the bracket of the outer cover on the side opposite to the rotational position detector are integrally molded with synthetic resin, and the seventh aspect is that the stator is integrally molded with synthetic resin. According to the eighth aspect of the present invention, the outer cover is composed of a pair of brackets.
Both ends of the outer circumference of the stator are joined to the cylindrical portion of the bracket.

A ninth aspect of the present invention is the same as the fifth aspect of the present invention, in which the stator and the outer cover are integrally molded with a synthetic resin. A pair of bearings are attached to the bearing box that forms the inner cylindrical part of the outer casing with an L-shaped cross section, and a hub with a Γ-shaped one side cross section is attached to the shaft supported by these bearings to enclose the bearing box and the stator is the hub. Is placed outside the rotor on the outer periphery of the rotor with a gap, the rotary part of the rotary position detector is fixed to the hub, the flange of the fixed part of the rotary position detector is arranged on the counter drive side of the stator, and the fixed part Is connected to the rotating part, a lead wire or an electrical connecting tool for external connection is provided outside the fixed part, and the stator is integrally molded with synthetic resin to be connected between the outer cover and the flange.

The eleventh aspect of the present invention is to mount a pair of bearings on a bearing box forming an inner cylindrical portion of an outer cover having a U-shaped cross section on one side, and to attach a hub having a Γ-shaped cross section on one side to a shaft supported by the bearings. The rotor is located on the outer circumference of the hub, and the stator is arranged on the outer side of the rotor through a gap. Both ends of the outer circumference of the stator are connected to the outer cylindrical portion of the jacket and the cylindrical portion provided on the flange, and the rotational position detector The rotary part is fixed to the hub, the fixed part of the rotary position detector is integrated with the flange, and the rotary part is connected to the rotary part, and a lead wire or an electrical connector for external connection is provided outside the fixed part.

[0011]

According to the invention, since the fixed portion of the rotary position detector is inserted into the opening of the outer cover and fixed by the fixing means, the outside of the fixed portion closes the opening of the outer cover and the inside of the fixed portion is opened outside. It will be located inside the cover. At the same time, the lead wire or the electrical connector for external connection is pulled out to the outside of the fixed portion, that is, the outside of the jacket.

At this time, according to the second aspect of the invention, the fixing means is embodied by a flange or a plurality of ears. Naturally, from the viewpoint of dust prevention, the gap between the outside of the fixed portion and the opening is free in the case of the flange and is made as small as possible in the case of the ear. According to the third aspect of the invention, the position or directionality of the opening, that is, the fixed portion of the rotational position detector is free. According to the fourth aspect of the invention, as the position of the fixed portion of the rotational position detector, the radial outside of the bearing box, which was conventionally a wasted space, is utilized to shorten the axial length of the motor.

According to the fifth aspect of the invention, in this servomotor, the bearing group, the rotor, and the stator are arranged in the radial direction and are short in the axial direction. Since the fixed part of the rotary position detector is inserted into the opening of the outer cover and fixed with the flange, the outside of the fixed part closes the opening of the outer cover and the inside of the fixed part is located inside the outer cover. Become. At the same time, the lead wire or the electrical connector for external connection is pulled out to the outside of the fixed portion, that is, the outside of the jacket.

According to the sixth aspect of the present invention, since the stator and the bracket on the side opposite to the rotational position detector of the outer cover are molded, the stator core and the winding are in close contact with the synthetic resin for good cooling, and the stator and the bracket. The structure becomes simple by integrating and. Invention 7
According to the method, since the stator and the outer cover are molded, the stator core and the winding are in close contact with the synthetic resin and the cooling is good. According to the eighth aspect of the invention, since the outer cover is only the bracket and the frame is not provided, the structure is simplified.

According to the ninth aspect of the present invention, since the stator and the outer cover are molded, the stator core and the winding are in close contact with the synthetic resin for good cooling, and the stator and the outer cover are integrated into a structure. It will be easy. According to the tenth aspect, in this servomotor, the bearing group, the rotor, and the stator are arranged in the radial direction and are short in the axial direction. The molded stator is joined between the outer cover and the flange so that the stator core and the winding are in close contact with the synthetic resin for good cooling. At the same time, a lead wire or an electrical connector for external connection is pulled out to the outside of the fixing portion.

According to invention 11, this servomotor is
The bearing group, the rotor, and the stator are arranged in the radial direction and are short in the axial direction. Both ends of the outer circumference of the stator are joined between the outer cover and the flange and do not require a frame. At the same time, a lead wire or an electrical connection portion for external connection is drawn out of the fixed portion.

[0017]

EXAMPLE FIG. 1 is a half sectional view of Example 1, and FIG. 2 is P of FIG.
FIG. 3 is a half sectional view of the second embodiment, FIG. 4 is a half sectional view of the third embodiment, FIG. 5 is a half sectional view of the fourth embodiment, and FIG.
7 is a half sectional view of the sixth embodiment, FIG. 9 is a half sectional view of the seventh embodiment, FIG. 10 is a half sectional view of the eighth embodiment, and FIG. 11 is a half sectional view of the ninth embodiment. 12 is a half sectional view of the tenth embodiment. In the conventional example and in each drawing, those denoted by the same reference numerals have approximately the same function, and duplicate explanation may be omitted.

In the first embodiment shown in FIGS. 1 and 2, the outer cover 11 is formed of the brackets 2a and 12b and the frame 13. Inside the stator 4 fixed to the frame 13 and having the winding 4a, a permanent magnet 5a and a yoke 5 are provided with a gap.
A rotor 5 composed of b and b is arranged. The shaft 16 for fixing the rotor 5 is a bearing 7 attached to the brackets 2a and 12b.
It is supported by a and 7b. The lead wire 4b of the winding 4a is pulled out from the packing 3a of the frame 13.

The bracket 12b is provided with an opening 21 whose axial center is in the radial direction of the motor. The optical encoder 1 is provided in this opening 21.
The fixed portion 18a of No. 8 is inserted and coupled with the rotating portion 18b attached to the shaft 16. A flange 1 that abuts the end surface of the opening 21 and a lead wire 18c for external connection outside the fixed portion 18a.
8d is provided, and the flange 18d is fixed to the end surface of the opening 21 with a screw or the like not shown. Instead of the flange 18d, a plurality of ears that contact the end surface of the opening 21 may be used. Lead wire 1
An electrical connector such as a connector may be used instead of 8c. The position of the fixed portion 18a of the optical encoder 18 is determined by the bracket 1
It is preferable to use the outer side in the radial direction of the bearing box 2b.

According to the first embodiment, the fixed portion 18a of the optical encoder 18, which is a rotational position detector, is provided in the opening 21 of the jacket 11.
Since it is inserted and fixed by the flange 18d or a plurality of ears which are fixing means, the outside of the fixing portion 18a closes the opening 21 of the jacket 11 and is located inside the jacket 11. At the same time, the lead wire 18c for external connection or the electrical connector is pulled out to the outside of the fixed portion 18a, that is, to the outside of the jacket 11. From the viewpoint of dust prevention, the gap between the outside of the fixed portion 18a and the opening 21 is free in the case of the flange and is made as small as possible in the case of the ear.
The position and directionality of the fixed portion 18a of the optical encoder 18 are free. In addition, the position of the fixed portion 18a of the optical encoder 18 is utilized as the outside in the radial direction of the bearing box, which has conventionally been a wasted space, and the axial length of the motor is shortened.

In the second embodiment shown in FIG. 3, in the opening 21
Differs from the first embodiment in that the shaft center is provided on the bracket 32a of the outer cover 31 so as to face the axial direction of the motor, and the degree of freedom in the directionality of the optical encoder 38 increases accordingly. This opening 2
1. The fixed portion 38a of the optical encoder 38 is inserted into 1 to be coupled with the rotating portion 38b, and the lead wire 38c for external connection and the flange 3 for contacting the end face of the opening 21 outside the fixed portion 38a.
8d is the same as that of the first embodiment, and the effect is the same.

Example 3 shown in FIG. 4 relates to Invention 5.
In the figure, the servomotor is a jacket 4 having a U-shaped cross section on one side.
A pair of bearings 7a in the bearing box forming the inner cylindrical portion 41a of
7b, and a hub 45b having a Γ-shaped cross section on one side is attached to a shaft 46 supported by this bearing to enclose the bearing box.
The stator 4 arranged outside the permanent magnet 5a on the outer periphery of b with a gap is fixed to the inner periphery of the outer cylindrical portion 41b of the outer cover 41. The rotating portion 48b of the optical encoder 48 is fixed to the hub 4b. The opening 51 of the outer cylindrical portion 41b of the jacket 41 is closed by the flange 48d of the fixed portion 48a of the optical encoder 48, which is a rotational position detector, and the fixed portion 48a is coupled to the rotary portion 48b, and is externally connected to the outside of the fixed portion 48a. A lead wire 48c or an electrical connection tool is provided. The structure of this permanent magnet type synchronous motor can also be applied to an induction motor or the like.

According to the third embodiment, this servomotor is
The bearing group, the permanent magnet 5a, and the stator 4 are arranged in the radial direction and are short in the axial direction. Then, the fixing portion 48a of the optical encoder 48 is inserted into the opening 50 of the outer cover 41 and the flange 48d is formed.
Therefore, the outside of the fixed portion 48a closes the opening 51 of the jacket 41 and is located inside the jacket 41. At the same time, the lead wire 48c for external connection or the electrical connector is pulled out to the outside of the fixed portion 48a, that is, to the outside of the jacket 41.

Example 4 shown in FIG. 5 relates to Invention 6.
In the figure, the servomotor is configured as a so-called molded motor. 1 and 2 in that the stator 4 and the bracket 2a of the jacket 11 on the side opposite to the optical encoder 18 are integrally molded with a synthetic resin 50. The optical encoder 18 and the bracket 12b for mounting the same are the same. As an application example of FIG. 5, only the stator 4 is made of synthetic resin 5
There is one that is integrally molded with 0 and is joined to the brackets 2a and 12b of the outer cover. Also, a so-called frameless motor can be simply constructed. In the first embodiment shown in FIGS. 1 and 2, the outer cover is composed only of the pair of brackets 2a and 12b, and both ends of the outer periphery of the stator 4 are brackets 2a and 12b. It is to be connected to the cylindrical part of.

Example 5 shown in FIG. 6 relates to Invention 6.
3, the servo motor of FIG. 3 is configured as a mold motor, and the stator 4 and the bracket 2b of the outer cover 31 on the side opposite to the optical encoder 38 are integrally molded with a synthetic resin 60. Different from The optical encoder 38 and the bracket 32a for mounting the same are the same.

Example 7 of FIG. 9 relates to Invention 7. In the figure, as in the first aspect of the invention, the fixed portion 18a of the rotational position detector 18 is inserted into the opening 21 provided in the bracket 12b to be coupled with the rotating portion 18b. A lead wire 18c or an electrical connecting tool for external connection is provided outside the fixing portion 18a, and fixing means such as a flange 18d for fixing the fixing wire 18c from the outside of the fixing portion 18a to the opening 21 is provided. Then, the stator 4 is made of synthetic resin 9
It is integrally molded with 0 and joined with the brackets 2a and 12b of the outer cover. According to the seventh embodiment, in addition to the effect of the first aspect, the stator core and the winding are closely attached to the synthetic resin for cooling.

Embodiment 8 of FIG. 10 relates to Invention 8. In the figure, as in the first aspect of the invention, the fixed portion 18a of the rotational position detector 18 is inserted into the opening 21 provided in the bracket 102b to be coupled with the rotating portion 18b. A lead wire 18c for external connection or an electrical connection tool is provided outside the fixed portion 18a,
Flange 18 for fixing to the opening 21 from the outside of the fixing portion 18a
A fixing means such as d is provided. The outer cover is composed of a pair of brackets 102a and 102b, and both ends of the outer circumference of the stator 4 are connected to the cylindrical portions of the brackets 102a and 102b. The lead wire 4b of the winding wire 4a is pulled out from the packing 103a of the bracket 102a. According to the eighth embodiment, in addition to the operation of the first aspect, the outer cover is the bracket 102a,
Since only 102b does not have a frame, the structure is simple.

In the sixth embodiment shown in FIG. 7, the servomotor of FIG. 4 is constructed as a mold motor, and the stator 4 and the outer cover 41 are integrally molded with a synthetic resin 70 in the embodiment of FIG. Different from 3. The optical encoder 48 and the flange 48d for mounting the same are the same. Example 9 of FIG.
Relates to Invention 10. In the figure, a pair of bearings 7a and 7b are attached to a bearing box 41a which forms an inner cylindrical portion of an outer cover 112b having an L-shaped cross section on one side. A hub 45b having a Γ-shaped cross section on one side is attached to a shaft 46 supported by the bearings 7a and 7b to surround the bearing box 41a. The stator 4 is arranged outside the rotor 5 on the outer periphery of the hub 45b with a gap. Transposition detector 4
The rotating part 48b of No. 8 is fixed to the hub 45b. The flange 48d of the fixed portion 48a of the rotational position detector 48 is arranged on the opposite side of the outer jacket 112b in the axial direction with respect to the stator 4. Fixed part 4
8a is connected to the rotating portion 48b. A lead wire 48c for external connection or an electrical connecting tool is provided outside the fixing portion 48a. The molding 4 is integrally molded with the synthetic resin 110 to form the outer cover 1.
It connects between 12b and the flange 48d. According to the ninth embodiment, in this servomotor, the bearing groups 7a and 7b, the rotor 5 and the stator 4 are arranged in the radial direction and are short in the axial direction.
The molded stator 4 is coupled between the outer cover 112b and the flange so that the stator core and the winding are in close contact with the synthetic resin 110 for good cooling. At the same time, lead wire 4 for external connection
8c or the electrical connector is pulled out to the outside of the fixed portion 48a.

Example 10 of FIG. 12 relates to Invention 11. In the figure, a pair of bearings 7a and 7b are attached to a bearing box 41a which forms an inner cylindrical portion of an outer cover 122b having a U-shaped cross section on one side. A hub 45b having a Γ-shaped cross section on one side is attached to a shaft 46 supported by the bearings 7a and 7b to surround the bearing box 41a. The stator 4 is arranged outside the rotor 5 on the outer circumference of the hub 45b with a gap, and both ends of the outer circumference of the stator 4 are covered with the jacket 122.
It is connected to the outer cylindrical portion 122f of b and the cylindrical portion 122e provided on the flange 122a. The rotating portion 48b of the rotational position detector 48 is fixed to the hub 45b. The fixed portion 48a of the rotational position detector 48 is integrated with the flange 122a and is joined to the rotating portion 48b. A lead wire 48c for external connection or an electrical connecting tool is provided outside the fixing portion 48a. Example 10
According to this, the servomotor is short in the axial direction because the bearings 7a and 7b group, the rotor 5 and the stator 4 are arranged in the radial direction. At the same time, the lead wire 48c for external connection or the electrical connection tool is pulled out to the outside of the fixed portion. Further, since the stator 4 is coupled between the outer cover 122b and the flange 122a and does not require a frame, the structure is simple.

[0030]

According to the servomotor having the rotational position detector of the first aspect of the present invention, when the fixed portion of the rotational position detector is inserted into the opening of the outer cover and fixed, the outside of the fixed portion closes the opening of the outer cover. Is located inside the outer cover, and the lead wire or electrical connector for external connection is pulled out to the outside of the fixed part, that is, the outside of the outer cover, and parts such as a cover for the rotational position detector are unnecessary. Therefore, there is an effect that it is possible to simplify the work of attaching the fixed portion and the work of pulling out the lead wire, and shortening the axial length of the motor.

At this time, according to the second aspect of the invention, the fixing means is embodied, and according to the third aspect of the invention, there is an effect that the position and directionality of the rotational position detector can be freely set, and according to the fourth aspect of the invention.
The outer side of the bearing box in the radial direction is utilized to further reduce the axial length of the motor. According to the fifth aspect of the invention, the bearing group, the permanent magnets, and the stator are arranged in the radial direction and are short in the axial direction, and the rotary position detector is fixed to the opening of the jacket with the flange. The fixed position of the rotary position detector is closed and located inside the outer cover, and the lead wire or electrical connector for external connection is pulled out to the outside of the fixed part, that is, the outer side of the outer cover. Since there is no need for a component such as a cover for the above, there is an effect that the attachment of the fixing portion and the work of pulling out the lead wire can be simplified and the axial length of the motor can be shortened.

According to the sixth or ninth aspect of the invention, the stator core and the winding are in close contact with the synthetic resin for good cooling, and the stator and the bracket or the jacket are integrated with each other to simplify the structure. There is. According to invention 7 or invention 10, there is an effect that the stator core and the winding are closely attached to the synthetic resin and the cooling is good. According to the eighth or eleventh aspect, there is an effect that a so-called frameless motor is configured and the structure is simplified.

[Brief description of drawings]

FIG. 1 is a half sectional view of a first embodiment.

FIG. 2 is a view on arrow P of FIG.

FIG. 3 is a half sectional view of the second embodiment.

FIG. 4 is a half sectional view of a third embodiment.

FIG. 5 is a half sectional view of the fourth embodiment.

FIG. 6 is a half sectional view of the fifth embodiment.

FIG. 7 is a half sectional view of a sixth embodiment.

FIG. 8 is a half sectional view of a conventional example.

FIG. 9 is a half sectional view of the seventh embodiment.

FIG. 10 is a half sectional view of the eighth embodiment.

FIG. 11 is a half sectional view of the ninth embodiment.

FIG. 12 is a half sectional view of the tenth embodiment.

[Explanation of symbols]

1 outer cover 2a bracket 2b bracket 3 frame 4 stator 5 rotor 5a permanent magnet 6 shaft 7a bearing 7b bearing 11 outer cover 12b bracket 13 frame 16 shaft 18 optical encoder 18a fixed part 18b rotating part 18c lead wire 18d flange 21 opening 31 Outer cover 32a Bracket 38 Optical encoder 38a Fixed part 38b Rotating part 38c Lead wire 38d Flange 41 Outer cover 41a Inner cylindrical part 41b Outer cylindrical part 48 Optical encoder 48a Fixed part 48b Rotating part 48c Lead wire 48d Flange 50 Synthetic resin 51 Opening 60 Composite Resin 70 Synthetic resin 90 Synthetic resin 102a Bracket 102b Bracket 103a Packing 110 Synthetic resin 112b Outer cover 122a Flange 122b Outer cover 122e Cylindrical part 122f Outer cylinder Department

Claims (11)

[Claims] 1. A fixed part of a rotary position detector is inserted into an opening provided in an outer cover to be coupled with a rotary part, and a lead wire or an electrical connecting tool for external connection is provided outside the fixed part, and the fixed part is provided. A servo motor provided with a rotational position detector, which is provided with fixing means for fixing the opening to the opening. 2. A servomotor having a rotational position detector according to claim 1, wherein the fixing means is a flange or a plurality of ears that abut against an end face of the opening. 3. A servomotor provided with the rotational position detector according to claim 1 or 2, wherein the axial center of the opening is in the radial direction or axial direction of the motor. 4. A servo motor comprising a rotational position detector according to claim 1, 2 or 3, wherein the position of the fixed portion of the rotational position detector is located outside the bearing box in the radial direction. Servo motor equipped with a container. 5. A pair of bearings are attached to a bearing box forming an inner cylindrical portion of a jacket having a U-shaped cross section on one side, and a hub having a Γ-shaped cross section on one side is attached to a shaft supported by the bearings to surround the bearing box. , The outer circumference of the hub is fixed to the outer circumference of the rotor with a gap on the inner circumference of the outer cylindrical part of the jacket, and the rotating part of the rotary position detector is fixed to the hub, A rotation characterized in that the opening of the cylindrical portion is closed by the flange of the fixed portion of the rotary position detector, the fixed portion is connected to the rotary portion, and a lead wire or an electrical connector for external connection is provided outside the fixed portion. Servo motor with position detector. 6. A servomotor having a rotational position detector according to claim 1, wherein the stator and the bracket on the side opposite to the rotational position detector of the outer cover are integrally molded with synthetic resin. Servo motor equipped with a container. 7. A servomotor having a rotary position detector according to claim 1, wherein the stator is integrally molded with synthetic resin and is joined to a bracket of an outer cover. . 8. A servomotor having a rotary position detector according to claim 1, wherein the outer cover is composed of a pair of brackets, and both ends of the outer circumference of the stator are connected to the cylindrical portion of the bracket. Servo motor with position detector. 9. A servomotor having a rotary position detector according to claim 5, wherein the stator and the outer cover are integrally molded with a synthetic resin. 10. A pair of bearings are attached to a bearing box that forms an inner cylindrical portion of an outer cover having an L-shaped cross section on one side, and a hub having a Γ-shaped cross section on one side is attached to a shaft supported by the bearings to enclose the bearing box. , The stator is arranged on the outer circumference of the hub outside the rotor through a gap, the rotating part of the rotational position detector is fixed to the hub, and is arranged on the non-driving side of the flange of the fixed part of the rotational position detector, The fixed part is connected with the rotating part, the lead wire or the electrical connection tool for external connection is provided outside the fixed part, and the stator is integrally molded with synthetic resin so that it is connected between the outer cover and the flange. A servo motor equipped with a characteristic rotational position detector. 11. A pair of bearings are attached to a bearing box that forms an inner cylindrical portion of a jacket having a U-shaped cross section on one side, and a hub having a Γ-shaped cross section on one side is attached to a shaft supported by the bearings to enclose the bearing box. , The stator is arranged outside the rotor on the outer periphery of the hub with a gap, and both ends of the outer periphery of the stator are connected to the outer cylindrical portion of the jacket and the cylindrical portion provided on the flange, and the rotary position detector is mounted on the flange. A servo motor having a rotary position detector, characterized in that the fixed part of the above is integrated and coupled with the rotating part, and a lead wire or an electrical connecting tool for external connection is provided outside the fixed part.