JPH0540692Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electric actuator that includes a brush type DC motor and a power transmission device that transmits the output of the motor to a load.

[Prior Art] In various control devices, electric actuators are used to operate operating sections. For example, in a speed control device for an internal combustion engine, an electric actuator is used to operate the injection amount adjusting section of a fuel injection pump, and a drive current is applied to the electric actuator to adjust the amount of fuel injected so as to reduce the speed deviation to zero. I'm trying to adjust it.

An electric actuator is comprised of an electric motor and a power transmission device that transmits the output of the electric motor to an output shaft via a power transmission mechanism that includes a speed reduction mechanism, various conversion mechanisms, and the like.

FIG. 3 shows a conventional electric actuator of this kind. In the figure, 1 is a power transmission device in which a power transmission mechanism 3 such as a speed reduction mechanism is housed in a casing 2, and 4 is a stator 6 in a cover 5. This is a brush type DC motor that accommodates a rotor 7 and a rotor 7.

A cover 5 of the electric motor 4 has an open end, and a brush 9 is fixed to a brush holding plate 8 which also serves as an end cover and is attached to close this opening. The rotation shaft 10 of the rotor 7 is located at the bottom 5a of the cover 5.
A commutator 13 is supported by a bearing 11 held by a bearing 11 held by a brush holding plate 8 and a bearing 12 held by a brush holding plate 8 , and is attached to a rotating shaft 10 .

The electric motor 4 is disposed with the end of the cover 5 on the bottom 5a side in contact with the side surface of the casing 2, and is connected by a screw 14 that is screwed into the bottom 5a of the cover 5 from inside the casing 2 through the casing. An electric motor 4 is fixed to the casing 2. Rotating axis 1
0 is inserted into the casing 2 and the power transmission mechanism 3
3A (a gear in this example). Although not shown, an output shaft is led out from the casing 2, and the output shaft is connected to the operated section.

[Problem to be solved by the invention] In the above conventional electric actuator, the electric motor 4
Since the structure was such that the electric motor 4 was assembled into the casing 2 after being assembled separately, when assembling the electric motor 4, the centering of the rotating shaft 10 was adjusted with respect to the brush holding plate 8 and the cover 5, and then When assembling the electric motor 4 to the casing 2, the power transmission mechanism 3
It is necessary to adjust the centering of the rotary shaft 10 with respect to the input section of the rotary shaft 10, which poses a problem that assembly becomes troublesome.

Further, in the conventional electric actuator, it was necessary to separately provide the brush holding plate 8, which caused a problem that the number of parts increased.

An object of the present invention is to provide an electric actuator equipped with an electric motor and a power transmission device that transmits the output of the motor to a load, in which centering work can be omitted when assembling the electric motor to the power transmission device. It is in.

[Means for Solving the Problems] An electric actuator according to the present invention includes an electric motor 101 and a power transmission device 100 that transmits the output of the electric motor 101 to a load.

The electric motor 101 is located at the bottom 115a of the cover 115.
It is a brush type DC motor with a rotating shaft 118 supported at one end and led out from the opening of the cover at the other end.

The power transmission device 100 includes a rotating shaft 118 of an electric motor.
It has a structure in which a power transmission mechanism 107 having an input section 108 coupled to the motor is housed in a casing 103, and a bearing 112 for supporting a rotating shaft 118 of an electric motor is fixed to the casing 103.

The casing 103 integrally has a brush holding part 111 that protrudes toward the electric motor 101 from one side of the side wall, and a center part of the brush holding part 111 has a
Bearing 11 for supporting the rotating shaft 118 of the electric motor
2 is fixed. The contour shape of the brush holding part 111 is such that when the opening of the cover 115 is fitted into the brush holding part 111, the central axis of the rotating shaft 118 and the central axis of the input part 108 of the power transmission mechanism 107 are aligned. It's summery.

In the electric motor 101, the opening of the cover 115 is fitted into the brush holding part 111 and the casing 1 is closed.
03, and the input section 10 of the power transmission mechanism 107 is fixed to
8 with their central axes aligned.

[Function] As described above, the brush holding part is integrally provided in the casing of the power transmission device, and the bearing for supporting the rotating shaft of the electric motor is fixed to the center of the brush holding part, and the contour shape of the brush holding part is fixed. is shaped so that when the opening of the cover of the electric motor is fitted into the brush holding part, the central axis of the rotating shaft of the electric motor coincides with the central axis of the input part of the power transmission mechanism. By connecting to the input part of the power transmission mechanism through the bearing and fitting the opening of the cover to the brush holding part, the central axis of the rotating shaft of the electric motor is automatically aligned with the central axis of the input part of the power transmission mechanism. be able to. Therefore, there is no need to perform centering work when assembling the electric motor to the power transmission device, and the actuator can be easily assembled.

Further, as described above, when the brush holding portion is integrally provided in the casing, the number of parts can be reduced, and therefore costs can be reduced.

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

1 and 2 show an embodiment of the present invention, and in these figures, 100 is a power transmission device, and 101 is a brush type DC motor.

The power transmission device 100 includes a casing 103 having a two-part structure that can be divided into two at a splitting surface 102, and the two halves 103A and 1 of this casing
03B is connected by a bolt 104 and a nut 105 (see FIG. 2).

An output shaft 106 is led out from a side surface near one end of the casing 103, and a power transmission mechanism 107 that transmits the output of the electric motor to the output shaft 106 is housed within the casing 103. The power transmission mechanism 107 decelerates the rotation of the electric motor as necessary or converts it into other motion such as linear motion, and may include a deceleration mechanism or a conversion mechanism that converts the rotation into linear motion or the like. can. In this embodiment, the power transmission mechanism 107 is simply a gear reduction mechanism, and the gear 108 constituting its input section is provided near the end of the casing 103 opposite to the output shaft 106. A hollow protrusion 109 is protruded from the side surface near the other end of the casing 103, and a position detector (for example, a potentiometer) 110 for detecting the rotational angular position of the output shaft 106 is housed within this protrusion. .

The casing 103 also integrally has a brush holding part 111 that protrudes from the side wall of the other end toward the electric motor 101, and a gear (input part) of the power transmission mechanism 107 is installed in the center of the brush holding part 111.
A bearing 112 is mounted that shares a central axis with 108. The bearing 112 is for supporting the rotating shaft of the electric motor 101, and the rotating shaft of the electric motor can be press-fitted into a hole in the shaft core of the gear 108 through the bearing 112.

The electric motor 101 includes a cylindrical cover 115,
A stator 116 and a rotor 117 are housed within this cover. One end of the rotating shaft 118 of the rotor 117 is supported by a bearing 119 held in a bearing holding portion 115 a1 formed at the center of the bottom 115 _a of the cover 115 , and the other end of this rotating shaft is supported by an opening in the cover 115 . It is derived from the side.

The brush holder 111 holds the brush 12 of the electric motor.
0 and 120 are fixed, and wiring 121 to these brushes passes through the brush holding part 111 and is introduced into the casing 103. The wiring 121 is connected to an electric wire 122, and the electric wire 122 is led out to the outside through a grommet 123 (see FIG. 2) attached to the side surface of the casing.

The rotating shaft 118 of the electric motor is press-fitted into a hole in the shaft core of the gear 108 in the casing 103 through the bearing part 112, and the opening of the cover 115 is fitted into the outer circumference of the brush holding part 111.

In this embodiment, the outer peripheral part of the brush holding part 111 constitutes a spigot part (a part to which other members are fitted for positioning) for positioning the cover 115, and the outline shape of the brush holding part 111 is , the opening of the cover 115 is connected to this brush holding part 1.
11, the central axis of the rotating shaft 118 and the input part of the power transmission mechanism 107 (gear 1
08) is shaped to match the central axis of 08). The illustrated brush holding portion 111 is formed to have a circular cross-sectional profile, and its center axis is aligned with the center axis of the input portion (gear 108) of the power transmission mechanism 107.

A commutator 124 is attached to the rotating shaft 118,
The commutator 124 is connected to the rotor 1 by a lead wire 123.
17 windings. This commutator is brought into contact with the brush 120.

The cover 115 has a plurality of (three in the illustrated example) protrusions 115a arranged at equal angular intervals around the opening end of the cover 115.
These protrusions are fastened to the casing 103 with screws 125.

A pair of ears 103a, 103a are provided in a protruding manner on the half portion 103A of the casing 103, and these ears are fixed to appropriate mounting locations with bolts (not shown).

In FIG. 1, reference numeral 126 is a breathing hole that communicates the inside of the casing 103 with the outside.

In this embodiment, as described above, one end of the rotating shaft 118 of the electric motor is supported by a bearing 119 positioned at the center of the bottom of the cover 115. Further, a bearing 112 for supporting the rotating shaft 118 of the electric motor is attached to the center of the brush holding part 111, and when the cover 115 of the electric motor is fitted to the brush holding part 111, the rotating shaft 118 of the electric motor
The contour shape of the brush holding part 111 is determined so that the central axis of the input part of the power transmission mechanism coincides with the central axis of the input part of the power transmission mechanism.

Therefore, the rotating shaft 118 of the electric motor is coupled to the input part of the power transmission mechanism 107 through the bearing 112,
When the opening of the cover 115 is fitted into the brush holding part 111, the rotating shaft 118 is connected to the power transmission mechanism 107.
At the same time, the cover 115 is positioned concentrically with respect to the input portion of the power transmission mechanism 107 . Therefore, when assembling the electric motor to the power transmission device, there is no need to particularly perform centering work, and the assembly work can be facilitated.

[Effects of the invention] As described above, according to the invention, the brush holding part is integrally provided in the casing of the power transmission device, a bearing is provided in the center of the brush holding part, and the rotating shaft of the electric motor is passed through the bearing. The electric motor There is no need to perform centering work when assembling the actuator to the power transmission device, and there is an advantage that assembly of the actuator can be facilitated.

Further, in the present invention, since there is no need to separately provide a brush holding plate, the number of parts can be reduced and costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a rear view of the same embodiment, and FIG. 3 is a sectional view showing essential parts of a conventional electric actuator. 100...Power transmission device, 101...Electric motor,
103...Casing, 106...Output shaft, 10
7... Power transmission mechanism, 108... Gear constituting the input part of the power transmission device, 111... Brush holding part, 112... Bearing, 115... Cover of electric motor, 116... Stator, 117... Rotation child, 11
8... Rotating shaft, 112... Bearing section, 120... Brush, 124... Commutator.

Claims (1)

[Claims for Utility Model Registration] An electric actuator comprising an electric motor 101 and a power transmission device 100 that transmits the output of the electric motor to a load, wherein the electric motor 101 is connected to a bottom portion 115a of a cover 115.
The power transmission device 100 is a brush-type DC motor equipped with a rotating shaft 118 that has one end supported by the motor and the other end guided outside through an opening in the cover.
The casing 103 has a structure in which a power transmission mechanism 107 having an input section 108 coupled to the motor is housed in a casing 103, and a bearing 112 for supporting a rotating shaft 118 of the electric motor is fixed to the casing 103. It has an integral brush holding part 111 that protrudes from one side of the side wall toward the electric motor 101, and a bearing 112 for supporting the rotating shaft 118 of the electric motor is fixed to the center of the brush holding part 111. Brush holding part 111
The outline shape of the cover 11 is attached to the brush holding part 111.
The electric motor 101 has a shape that, when the openings 5 and 5 are fitted, aligns the center axis of the rotating shaft 118 with the center axis of the input section 108 of the power transmission mechanism 107, and the cover 115 holds the brushes in the opening. The casing 103 is fitted into the portion 111.
An electric actuator that is fixed to an input section 108 of a power transmission mechanism 107 with a rotating shaft 118 passing through a bearing 112 and coupled to the input section 108 of the power transmission mechanism 107 with its central axis aligned.