JP2521135Y2 - Motor type actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a motor type actuator. More specifically, the present invention relates to a motor type actuator that uses a motor as a drive source, decelerates and outputs the rotation of the motor, and gives a predetermined operation to a driven body.

(Prior Art) Conventionally, as an actuator of this type, for example, a valve drive actuator for a water heater comprises a DC motor, a reduction gear mechanism, and a control circuit for detecting the rotation and controlling the DC motor. Things are common. And
As the reduction gear mechanism, a reduction gear train generally composed of a combination of external spur gears is generally used. Therefore, in order to secure the strength of the gear train to some extent, it is necessary to increase the tooth width of each gear, increase the size of the module to make a gear with a large diameter, or use a material with mechanical strength. It was

(Problems to be solved by the invention) Therefore, in order to realize a small-sized actuator that generates a high torque, a gearbox having a large volume is required to withstand the high torque. If this is not allowed, the gear must be made of metal, which causes an increase in rotational noise, a deterioration in assembly workability, and an increase in cost. In addition, essentially only a combination of external gears leaves a dead space, which also limits the miniaturization of the actuator.

It is an object of the present invention to construct a motor-type actuator that is small in size, high in torque, and low in noise by reducing the dead space of a gear train as much as possible.

(Means for Solving the Problem) In order to achieve such an object, the motor type actuator of the present invention is provided with a rotation take-out portion and a shaft portion on the output shaft,
The shaft part and the output shaft of the motor are arranged parallel to each other, and the pinion of the motor and the rotation takeout part of the output shaft are arranged on one surface of the case. Forming a differential gear mechanism centered on the center of the differential gear mechanism, and further stacking the sensor unit for detecting the rotational position of the output shaft on the differential gear mechanism, and enclosing the sensor unit and providing a bottom portion on the differential gear mechanism side. Installed through the middle plate with a circular recess,
The sensor part and the terminal part of the motor are arranged so as to come to the other opposite surface of the case, the circuit board to which the sensor part is connected is extended to the terminal of the motor, and the terminal of the motor is connected to the circuit board. A case is provided in which all the components are directly connected and the circuit board is electrically connected to the outside, and all the components except the rotation take-out portion of the output shaft are housed.

(Operation) The circuit board on which the sensor part is mounted is extended to the motor terminal, and the motor terminal is directly connected to the same circuit board as the sensor part. Therefore, the sensor unit and the motor are directly arranged on the circuit board without the need for arranging lead wires and the like, and the space loss is eliminated. Moreover, only the rotational extraction portion of the output shaft and the electrical extraction portion of the circuit board that need to be extracted to the outside can be exposed, and the other components can be enclosed and sealed by the case. Further, since the sensor unit is installed via the center plate having the circular recess having the bottom portion on the differential gear mechanism side and including the sensor unit,
It is possible to protect the sensor part from dust or to provide a degree of freedom in setting the position of the sensor part.

(Embodiment) Hereinafter, the configuration of the present invention will be described in detail based on an embodiment shown in the drawings.

1 to 3 show an example of implementation of the present invention. This motor-type actuator decelerates the rotation of the drive motor 1 and transmits it to the output shaft 14 so that a driven body, such as a water heater valve (not shown), which is interlocked with the output shaft 14, is brought into a desired operating state. Therefore, a rotation transmission mechanism including a differential gear mechanism is provided between the motor 1 and the output shaft 14.

The pinion 2 press-fitted into the output shaft of the DC motor 1 is in mesh with the first gear 3. The first gear 3 has a gear portion 3a that meshes with the pinion 2 and a pinion portion 3b that meshes with the second gear 7, and is rotatably supported by a shaft 5 integrally formed with the main plate 4. The main plate 4 is for assembling the pinion 2, the first gear 3 and the second gear 7 in a partially assembled state at the time of assembly, and assembling them to the bottom of the case 8 as a whole. It is lightly pressed into and fixed. The pinion 2 has a flange 9
Is provided to prevent the gear 3 from being disengaged most from the shaft 5 and thus the second gear 7 from being disengaged in the assembled state. The second gear 7 is rotatably held in the case 8.

The second gear 7 has a gear portion 7a that meshes with the first gear 3 and a pinion portion 7b that meshes with the third gear 10. And
A third gear 10 is meshed with the second gear 7. The third gear 10 includes a gear portion 10a that meshes with the second gear 7 and a planetary gear 11
And a pinion portion 10b that meshes with. The third gear 10 is loosely fitted in the shaft portion 14a of the output shaft 14 and rotatably supported. Then, the planetary gear 1 is attached to the pinion 10b of the third gear 10.
1 is meshed. The planetary gear 11 has a shaft portion 14a of the output shaft 14.
It is rotatably supported by a holder 15 in a circular recess 22 centered at. The holder 15 corresponds to an arm that supports the planetary gear 11, is loosely fitted to the shaft portion 14a of the output shaft 14, and is rotatably provided with the shaft portion 14a as a bearing portion. A rotation take-out portion 14b formed of a square hole is formed on the same side of the output shaft 14 as the pinion 2 of the motor 1. The rotation take-out portion 14b is exposed to the outside of the case 8. The planet gear 11 has a tooth number difference of 3
The internal gear 12 and the internal gear 13 of the sheet are simultaneously meshed with each other. The internal gear 12 is fixed to the main body 8a side of the case 8, and the internal gear 13 is formed on the inner wall of the circular recess 22 of the output shaft 14. And
The pinion portion 10b of the third gear 10 is the sun gear, and the planetary gear 1
1, the fixed internal gear 12 and the movable internal gear 13 constitute an operating gear mechanism. Three planetary gears 11 are arranged at 120 ° intervals. The planetary gear 11 is supported by the shaft portion 15a of the holder 15 and is prevented from coming off by a spring-like holder cover 16 that holds the shaft end.

Further, a cam plate 18 carrying a plurality of, for example, four magnets 17 is fixed to the shaft portion 14a of the output shaft 14.
And a plurality of Hall elements 21 are installed around it,
A sensor that drives the plurality of Hall elements 21 by the movement of the magnet 17 and detects the rotation of the output shaft 14 is configured.
The cam plate 18 and the shaft portion 14a are fixed by making a part of the shaft portion 14a and the hole of the cam plate 18 into a D shape.

Further, the center plate 23 is arranged between the third gear 10 and the cam plate 18 so as to cover and enclose this sensor part by a circular recess having a bottom part on the differential gear mechanism side, and the difference from the sensor part. The dynamic gear mechanism is partitioned. In this case the middle plate
Since 23 functions as a backrest of the hall element 21, there are advantages that reliability is improved and that the sensor portion can be protected from dust and abrasion powder when the sensor is of a sliding contact type. Further, when the backrest is configured with the center plate 23 so as to form the circumscribed circle of the package of the hall element 21, the hall element
The positions of 21 can be set arbitrarily. That is, the center plate 23 plays a role of protecting the sensor unit from dust or providing flexibility to the position setting of the sensor unit. Further, the center plate 23 is provided with the shaft 33 of the second gear 7 and the output shaft 14
The shaft portion (14a) is rotatably supported, and the third gear (10) and the cam plate (18) are positioned via these. Also, this middle plate 23 also functions as a reinforcing material,
This contributes to maintaining the strength of the structure even when the case 8 is thin.

The wiring to the terminal 1a of the motor 1 and the hall element 21 is performed using one printed circuit board 19. As shown in the drawing, a connector terminal 20 for external connection is provided at one end and a hole is formed by one connector. All wirings of the element 21 and the motor 1 can be connected.

The case is composed of a case body 8a and a lid 8b, and the lid 8b is provided in a state where the motor 1 and the reduction gear train described above are accommodated on the body 8a side.
It is assembled by covering and covering with two snap-fit portions 24 symmetrically arranged. The snap-fit portion 24 is a resilient engagement portion with a protrusion 25 that protrudes in the vicinity of the divided surfaces of the abutting surfaces of the case body 8a and the lid 8b.
This is a method of elastically engaging the case main body 8a and the lid 8b with each other. Further, in order to secure the fixation of the case body 8a and the lid 8b more securely, the foot portion 28b protruding from the lid 8b side is ejected from the case body 8a by the mounting portion 27 for attaching the actuator to other parts or the like. It is configured so that when the actuator is placed on the foot portion 28a and the actuator is attached to the valve body or the like that is the driven body, the actuator is fastened together with the attachment screw. In this case, since screws are not required to tighten the case body 8a and the lid 8b, there is no problem that cutting chips or the like enter the sensor section and cause malfunction.

Further, a female connector 29 is formed by a part of the case body 8a, a terminal 20 corresponding to a wiring formed on one board 19 is provided in this part, and a male connector 30 corresponding to this is connected. By this, power supply to the motor 1 and Hall element 21
It is possible to supply power to and take out output signals.

Further, the feet 28a, 28b of both are positioned by a combination of the dowel 31 and the dowel hole 32 in order to prevent the mounting hole from being displaced.

In this embodiment, the motor 1 and the differential gear mechanism (output shaft 14) having substantially the same outer diameter as that of the motor 1 are arranged side by side in the case 8 to minimize the dead space. However, the size is not limited to this.

As configured above, the output of the motor 1 is the motor pinion 2 → first gear 3 → second gear 7 → third gear 10 → planetary gear 11 → movable internal gear 13 / fixed internal gear 12 → output Each time the planetary gear 11 revolves around the sun gear 10b once transmitted to the shaft 14, the movable internal gear 13 rotates by the difference in the number of teeth (3 pieces) from the fixed internal gear 12, and the movement is the output shaft. It is output as 14 rotations.

The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example,
The sensor section can be not only a combination of the Hall element 21 and the magnet 17 but also a potentiometer type actuator by fixing a sliding contact piece to the cam 18 and sliding a resistor printed on the substrate. Further, a position detection method by turning on / off the contact piece and the pattern on the substrate is also possible.

(Effects of the Invention) As is apparent from the above description, the motor type actuator of the present invention is provided with the rotation take-out portion and the shaft portion on the output shaft, and the shaft portion and the output shaft of the motor are arranged parallel to each other. The pinion and the rotation take-out portion of the output shaft are arranged so as to come to one surface of the case, and are overlapped with the rotation take-out portion of the output shaft to form a differential gear mechanism centered on the shaft portion,
Further, a sensor section for detecting the rotational position of the output shaft is placed on the differential gear mechanism via a central plate having a circular concave portion including the sensor section and having a bottom portion on the differential gear mechanism side. , The sensor section and the terminal section of the motor are located on the opposite side of the other side of the case, the circuit board to which the sensor section is connected is extended to the terminal of the motor, and the terminal of the motor is directly connected to the circuit board. Since a case for accommodating all the components except the portion for electrically connecting the circuit board to the outside and the rotation take-out portion of the output shaft is provided, the two shafts of the output shaft and the motor shaft are arranged side by side. This reduces the space in the axial direction and eliminates the need for laying out the sensor part and the lead wire of the motor. It is arranged directly on the circuit board to eliminate space loss, and the output shaft that needs to be taken out to the outside. Only the transfer part and the electrical part of the circuit board can be exposed and other components can be surrounded by a case and sealed, and the sensor part can be protected from dust or the position of the sensor part can be set freely. be able to. Therefore, the space in the axial direction can be shortened and the motor actuator as a whole can be made compact, and at the same time, the opening to the outside only needs to be provided in two places, that is, the circuit board and the electrical connection between the outside and the rotation takeout portion of the output shaft. When this type of actuator is used as a valve actuator for a water heater, it is compact and can prevent water from entering and dust from entering. Moreover, the dead space in the differential gear mechanism is extremely small, and when the meshing ratio of the internal gear is larger than that of the normal external gear, the size is small,
The gear train has a small torque. Therefore, the entire actuator can be downsized.

Particularly, in the motor actuator of the present invention, the output shaft is provided with a shaft portion serving as a center of rotation and a circular recess centered around the shaft portion, and the differential gear mechanism is disposed within the circular recess portion around the shaft portion. However, when an internal gear that is rotationally driven by the differential gear mechanism is provided on the inner wall of the circular recess, a dead space is extremely small, and a compact and high torque actuator can be realized.

In addition, in the motor actuator of the present invention, when one board serves all of the external connection connector, the hall element, and the motor wiring, it is possible to improve reliability and workability.

[Brief description of drawings]

FIG. 1 is a central longitudinal sectional view showing an embodiment of a motor type actuator of the present invention, and FIG. 2 is a view showing an arrangement relationship between a drive motor of the embodiment and a gear train up to a differential gear mechanism. II
-II line sectional view, FIG. 3 is a III-III line sectional view of FIG. 1 showing the differential gear mechanism in plan view. 1 ... Drive motor, 2 ... Pinion, 3 ... First gear,
7 ... Second gear, 8 ... Case, 10 ... Third gear, 11 ...
… Planetary gear, 12 …… Fixed internal gear, 13 …… Movable internal gear, 14
...... Output shaft, 14a …… Shaft part, 14b …… Rotary take-out part, 15
...... Holder, 17 ...... Magnet, 18 ...... Cam plate,
19: Printed circuit board, 20: Connector terminal, 21: Hall element, 22: Circular recess.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-88346 (JP, A) Actually open 60-77264 (JP, U) Actually open 56-39647 (JP, U) Actually open 62- 168795 (JP, U) Actually opened 58-49566 (JP, U)

Claims (3)

(57) [Scope of utility model registration request] Claim: What is claimed is: 1. A motor rotation is decelerated and transmitted to an output shaft,
In a motor-type actuator for rotating a drive shaft to bring a driven body into a desired operating state, a rotation take-out portion and a shaft portion are provided on the output shaft, and the shaft portion and the motor output shaft are arranged in parallel. And a pinion of the motor and a rotation take-out portion of the output shaft are arranged so as to come to one surface of the case, and are overlapped with the rotation take-out portion of the output shaft, and a differential gear having the shaft portion as a center. Forming a mechanism and further overlapping with the differential gear mechanism, a sensor portion for detecting the rotational position of the output shaft, and a circular recess having the sensor portion therein and having a bottom portion on the differential gear mechanism side. It is installed via a central plate, and the sensor part and the terminal part of the motor are arranged so as to come to the opposite surface of the other side of the case, and the circuit board to which the sensor part is connected is extended to the terminal of the motor. Of the motor Directly connected child to the circuit board,
A motor-type actuator comprising the above-mentioned case for accommodating all the components except a portion for electrically connecting the circuit board to the outside and a rotation take-out portion of the output shaft. 2. The output shaft is provided with a shaft portion serving as a center of rotation and a circular recess centered on the shaft portion, and the differential gear mechanism is disposed in the circular recess centering on the shaft portion. 2. The motor type actuator according to claim 1, wherein an inner gear that is rotationally driven by the differential gear mechanism is provided on the inner wall of the circular recess. 3. A sensor for detecting a rotational position of the output shaft is attached to a circuit board connected to a terminal of the motor, and a connector terminal for external connection is attached to the circuit board.
2. The motor type actuator according to claim 1, wherein power supply to the motor, power supply to the sensor, and output signal extraction are performed through the connector terminal.