JP2003156105A - Actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an actuator reducing material cost and processing cost. SOLUTION: This actuator comprises: a motor 25 for converting energy supplied from the outside into a rotational motion; an output member 26 for outputting the rotation of the motor to the outside; a gear train G intervened between the motor and the output member to decrease the rotational speed of the motor and increasing torque to transmit the torque to the output member; a housing 10; a mounting plate 20 fixed on the housing; and a main shaft 20d of which one end is tightened against the mounting plate. The output member is formed with teeth engaging with the gear train and is structured so as to be rotatably fitted onto the main shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator for rotating a valve shaft of a valve such as a ball valve via a reduction mechanism using an electric motor as a power source.

[0002]

2. Description of the Related Art An actuator that uses an electric motor or an air motor as a power source to rotate a valve shaft of a valve such as a ball valve through a speed reduction mechanism has been known. The deceleration mechanism of such an actuator comprises a gear train, the first stage gear is connected to the motor, and the final stage gear is fixed to the output shaft via the gear train. Then, in a normal use state of the actuator, the rotation of the motor is transmitted to the output shaft while being decelerated by the reduction mechanism.

By the way, Japanese Patent Application Laid-Open No. 11-63169 discloses a structure in which only one end of a shaft supporting a gear is fastened to a mounting plate. FIG. 1 of the publication describes a structure in which one ends of shafts 23 and 30 which support gears that reduce the rotation of a motor (gears forming a gear train of a reduction mechanism) are caulked and fixed to a mounting plate. . But in this figure,
The specific configuration of the output shaft that transmits torque to the outside is not described. In this regard, the gear train of the reduction mechanism transmits the torque by the gear itself, but the shaft supporting the gear itself does not transmit the torque itself. It is considered that it is described as adopting a different support structure.

On the other hand, FIG. 6 of the publication describes a structure in which the output shaft 9 is provided so as to rotate with respect to the mounting plate. More specifically, knurls (not numbered) are engraved on the circumferential surface of the output shaft 9 to fit and fix the output gear.
A bearing that supports the lower end of the output shaft 9 is fixed to the lower mounting plate, and a flange-shaped bearing that supports the outer periphery of the output gear (not numbered) is formed on the upper mounting plate 1D. ing.

[0005]

Since the output shaft is the part where the torque transmitted by the reduction gear is finally transmitted, a large torque is generated in the output shaft. Therefore, in order to obtain sufficient output to the outside of the housing while ensuring sufficient mechanical strength of the output shaft itself, it was necessary to use a long output shaft due to its large diameter and the provision of bearings. . Since a large bearing is used in accordance with this, the size of the actuator itself has increased.

Further, since the output gear and the output shaft are conventionally formed separately, a fastening mechanism such as a knurl or a key groove is formed on the output shaft in order to firmly fix the output gear to the output shaft. There was a need. Therefore, there has been a problem that the material cost and the processing cost of the shaft increase. Furthermore, because it is necessary to maintain the shaft center of the output shaft in order to maintain the shaft-to-shaft distance between the gears and to surely align the rotation center with the coupling partner (valve), the output shaft is conventionally arranged in the longitudinal direction of the shaft. It had a structure in which it was pivotally supported in at least two places. Since the bearing for the shaft support needs a certain length in the output shaft direction, merely forming a hole in the mounting plate does not serve as a bearing portion. Therefore, conventionally, the bearing formed as a separate member has to be fixed to the mounting plate, and the material cost and the processing cost cannot be reduced.

An object of the present invention is to provide an actuator which can reduce material cost and processing cost.

[0008]

In order to achieve the above-mentioned object, an actuator according to the present invention comprises a motor for converting energy supplied from the outside into rotary motion and an output member for outputting the rotation of the motor to the outside. And a gear train that is interposed between the motor and the output member to reduce the rotational speed of the motor and increase the torque to transmit the torque to the output member. The housing is fixed to the housing. The output plate includes a mounting plate and a main shaft having one end fastened to the mounting plate, and the output member has teeth that mesh with the gear train and is rotatably fitted to the main shaft.

Since one end of the main shaft is fastened to the mounting plate and the output member has teeth that mesh with the gear train, the output member is rotatably fitted to the main shaft. Can be simplified to reduce material cost and processing cost. Therefore, an inexpensive and downsized actuator can be obtained.

[0010]

DETAILED DESCRIPTION OF THE INVENTION An actuator according to an embodiment of the present invention will be described below with reference to the drawings. As shown in the exploded perspective view of FIG. 1, an actuator 1 according to an embodiment of the present invention includes a housing (housing) 10 and a base substrate that is housed in the housing 10 and to which a reduction mechanism and an output shaft described later are attached. A (mounting plate) 20, a printed circuit board 30 housed in the housing 10, a yoke 40 mounted on the bottom of the housing, and the like are provided.

The housing 10 has a rectangular box type case 11 having an open top surface and a cover 12 attached to the case 11.
And a gasket 13 sandwiched between the case 11 and the cover 12. Mounted on the printed circuit board 30 are electric parts 31 for motor drive control, terminals 32, etc., which will be described later.

The yoke 40 is for attaching the actuator 1 to the drive shaft (FIG. 3) of the valve, and a lock lever 41 for detaching the yoke 40 and the valve is rotatably provided in the yoke 40. It is housed. Also,
A joint 46 is interposed between the yoke 40 and the housing 10 to connect an output shaft described later and a valve drive shaft (shown only in FIG. 3).

The base substrate 20 is made of a metal plate,
The driving pulse motor 25 is mounted on one side surface (upper surface in the drawing), and the reduction mechanism G including a plurality of gear trains and an output shaft (output member) 26 are provided on the other side surface (lower surface in the drawing). . The reduction gear mechanism G includes a first reduction gear 21, a second reduction gear 22, and a third reduction gear 23, as shown in an enlarged view in FIG. In addition, the output shaft 26
Teeth 26g that mesh with the third reduction gear 23 are integrally formed (see FIGS. 1 and 3). In FIG. 2, the tooth portion of each gear is not shown.

These reduction gears 21-23 are
As shown from diagonally below in FIG. 2, the base substrate 20
It is rotatably supported by metal support shafts 20a to 20c that are erected upright. The output shaft 26 is also rotatably supported by a support shaft 20d provided upright on the base substrate 20. The first supporting shaft 20a to the third supporting shaft (main shaft) 20c are erected on the lower surface of the base substrate with one end thereof being crimped. The fourth support shaft 20d is also erected on the lower surface of the base substrate with one end thereof being crimped.

The first reduction gear 21 comprises a small gear portion 21a and a large gear portion 21b, and the second reduction gear 22 also comprises a small gear portion 22a (FIG. 3) and a large gear portion 22b. All are integrally formed of polyacetal. The second reduction gear 22 is located on one side of the second support shaft 20b (downward in the drawing) via the coil spring 27.
It is supported in a biased state. The coil spring 27 includes a second reduction gear 22 and a third reduction gear 23.
And a second release gear 22 is moved in the axial direction against the biasing force by pressing a release lever (not shown) to release torque transmission between the gears. There is.

The third reduction gear 23 also comprises a small gear portion 23a and a large gear portion 23b, but is integrally formed by using reinforced polyacetal. The output shaft 26 and the tooth portion 26g formed integrally with the output shaft 26 are made of reinforced polyacetal as in the third gear. The tooth portion 26g has a fan shape and is formed on a part of the output shaft in the circumferential direction. An annular output shaft end portion 26e (FIGS. 1 and 3) is formed on one end side of the output shaft, and a support shaft insertion hole 26h is formed on the other end side of the output shaft 26. Also, the output shaft end portion 26e
A female spline is formed on the inner peripheral wall of the joint 46
It engages with the male spline and rotates integrally.

The auxiliary plate 28 is attached to the support shaft 20c of the third reduction gear 23 and the support shaft 20b of the second reduction gear 22 and serves to temporarily fix each gear. As is apparent from the above configuration, the tooth portion 26g and the output shaft 26 do not have a configuration in which an output gear separate from the output shaft is fitted to the output shaft as in the conventional case, but are integrally formed and have a base. It is rotatably supported by a fourth support shaft 20d attached to the substrate 20 in a cantilever state.

A protrusion 26t for detecting a rotation angle is provided upright on the output shaft 26. The protrusion 26t protrudes upward from the through hole 20h of the base substrate 20 in the drawing and is attached to the printed circuit board 30 (FIG. 1).
The rotation angle of the output shaft 26 is detected via the. Next, the meshing state of each gear will be described in more detail.

The gear 25g attached to the output shaft 25s of the motor 25 meshes with the large gear portion 21b of the first reduction gear and the small gear portion 21a of the first reduction gear and the large gear portion of the second reduction gear. 22b meshes, the small gear portion 22a of the second reduction gear meshes with the large gear portion 23b of the third reduction gear, and the small gear portion 23a of the third reduction gear meshes with the tooth portion 26g of the output shaft. It is like this. As a result, the rotation speed of the motor 25 is gradually reduced and the torque is reliably transmitted to the output shaft 26.

An auxiliary switch gear 29g is further meshed with the output shaft 26, so that the auxiliary switch 29s can be selectively turned on / off via a cam 29c. Further, a potentiometer 29p is attached to detect the operating angular position of the output shaft 26. As described above, the actuator 1 according to the present invention has the tooth portion 26g that meshes with the final stage (third gear) 23 of the reduction gear.
And the output shaft 26 are integrated, and are rotatably supported by a support shaft 20d whose one end is caulked to the base substrate 20. Therefore, unlike the conventional case, it is not necessary to adopt a configuration in which the output shaft is supported by the substrate or the housing of the actuator at at least two places and the gear is fitted to the output shaft.
Therefore, the number of parts can be reduced, the cost can be reduced, and the actuator itself can be downsized.

Next, a state in which the actuator 1 configured as described above is attached to the ball valve 5 will be described. As shown in FIG. 3, the ball valve 5 is a housing 51, a ball valve 52 that is housed in the housing and that opens and closes a flow path, and is integrally attached to the ball valve 52 and rotates the output shaft 26 of the actuator 1. A drive shaft 56 for opening and closing the ball valve 52 is provided. As is clear from the structure, the drive shaft 56 only rotates about the axis of the drive shaft 56, and does not perform a bending operation with respect to the axis.

The end portion 56e of the drive shaft 56 is formed in a rectangular shape as viewed from the end, and is fitted with the joint 46 to transmit the torque of the output shaft 26 of the actuator 1. The lock lever 41 and the yoke 40 of the actuator 1
In each of these, a tapered portion (not shown) is formed at the contact portion in the circumferential direction, and when the lock lever 41 is rotated in a predetermined direction, the tapered portions are engaged with each other by a wedge action, and the yoke 40 and the flange portion of the ball valve 5 are engaged. The 51f is firmly abutted and fixed.

In this way, the output shaft 2 of the actuator 1
Although one end (lower end in the figure) of 6 is a free end when the actuator 1 is not attached to the ball valve 5,
When the actuator 1 is attached to the ball valve 5, this end is connected to the drive shaft 56 of the ball valve 5 via the joint 46. That is, one end of the output shaft 26 of the actuator 1 is restricted by the fourth support shaft 20d of the base substrate 20 to rotate only around the axis, and the other end of the output shaft 26 of the valve drive shaft 56 via the joint 46. The movement is restricted only by the rotation around the axis by the end portion.

Therefore, when the actuator 1 is attached to the ball valve 5, the output shaft 26 hardly bends the fourth support shaft 20d. Therefore, unlike the conventional example, even if the output shaft of the actuator is not previously supported at two points, the output shaft 26 applies a large torque through the joint 46 to the drive shaft 56 of the valve.
It is possible to communicate to.

In the above embodiment, the case where the actuator is attached to the ball valve has been described, but the present invention is not necessarily limited to this. That is, the actuator according to the present invention can be preferably used as long as the mating drive shaft to which the output shaft is connected does not accompany the bending operation in the axial direction and is limited only to the rotating operation.

Therefore, the actuator according to the present invention can be applied to a valve provided with an opening / closing mechanism such as a damper instead of the ball valve. In the actuator described above, the material of the output shaft partially including the first to third gears and the teeth is not limited to polyacetal.
Therefore, these components are made of polycarbonate, PB
It may be formed of engineering plastic such as T or PPE, or may be formed of sintered metal or die cast.

[0027]

As described above, in the actuator according to the present invention, one end of the main shaft of the actuator is fastened to the mounting plate, and the output member has the teeth meshing with the gear train, and the output member is rotated with respect to the main shaft. Since they are movably fitted to each other, the shape of the shaft for output can be simplified to reduce the material cost and the processing cost.

Therefore, an inexpensive and miniaturized actuator can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing an actuator according to an embodiment of the present invention in an exploded state from diagonally below.

FIG. 2 is a partial perspective view of FIG. 1, showing the base plate and the motor obliquely from below and the reduction gear from obliquely above.

3 is a cross-sectional view showing a state where the actuator of FIG. 1 is attached to a ball valve.

[Explanation of symbols]

1 actuator 5 ball valves 10 housing 20 Base board (mounting plate) 20a to 20d support shaft 21 First reduction gear 22 Second reduction gear 23 Third reduction gear 26 Output shaft 26g tooth 30 printed circuit boards 40 York 41 Lock lever 46 joint 51 housing 52 ball valve 56 drive shaft

Continued front page    F term (reference) 3H062 AA05 AA12 BB31 CC01 EE07                 3J009 DA18 EA04 EA11 EA21 EA32                       EB17 EB24 EC06 FA14                 3J063 AA31 AB02 AC01 BA04 BB46                       BB48 CA01 CB57 CD43 XA02                       XA04

Claims (2)

[Claims] 1. A motor for converting energy supplied from the outside into rotary motion, an output member for outputting the rotation of the motor to the outside, and a rotation of the motor interposed between the motor and the output member. In an actuator including a gear train that reduces the speed and increases the torque to transmit the torque to the output member, a housing, a mounting plate fixed to the housing, and one end fastened to the mounting plate. And a main shaft, the output member has teeth that mesh with the gear train, and is rotatably fitted to the main shaft. 2. The actuator according to claim 1, wherein all of the shafts supporting the gear train have one end fastened to the mounting plate.