JP2008180238A - Rotary actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem on a conventional rotary actuator wherein piston members having a pair of rack gears is put in a casing serving as a cylinder for sliding with high pressure fluid in mutually opposite directions to rotate a pinion gear to which a rotating shaft is fitted, that the casing serving as the cylinder is a cast product to require highly precise work for cutting the inner diameter face, leading to very high cost. <P>SOLUTION: The rotary actuator comprises piston members having rack gears for reciprocating in a cylinder in mutually opposed linear directions, the rack gears of the piston members using one pinion gear in common for rotating a shaft fitted to the pinion gear. The piston members each have both ends formed as piston heads, and the cylinder uses an existing sanitary pipe. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotary actuator, and by rotating a rotary shaft such as valves that rotate and open a valve body by rotating a rotary shaft such as a butterfly valve and a ball valve, and dampers that rotate and open a valve lid by a rotary shaft. The present invention relates to an improvement of a rotary actuator for applying a rotational force to a rotating shaft of operated equipment.

  Conventionally, as a power source for applying a rotational force to this type of rotating shaft, in addition to those using a motor or human power, there are known types that use a fluid pressure to drive a pinion gear fitted to the central portion of the rotating shaft. This type of actuator has a basic structure in which a piston member that forms a rack gear that meshes with a pinion gear is reciprocated by fluid pressure in a cylinder.

  Conventionally, rotary actuators such as those shown in FIGS. 4 and 5 are known. FIG. 4 shows a first conventional example, and FIG. 5 shows a second conventional example. In FIG. 4, reference numeral 10 denotes a pinion gear that is inserted through and fitted to the central portion of the rotary shaft 12.

  In the figure, reference numeral 13 denotes a piston member. The piston member 13 includes piston heads 14 and 14 having the same diameter at both ends. The piston member 13 is hollow inside or has left and right walls penetrated, and a rack gear 15 that meshes with the pinion gear 10 is formed on the inner surface.

  Further, in the figure, reference numeral 16 denotes a casing that also serves as a cylinder, and has a cylindrical shape, and the openings at both ends are closed by closing members 17 and 17. The piston heads 14, 14 reciprocally slide in the casing 16 in synchronization with the piston member 13 via ring-shaped seal members 18, 18. This reciprocal sliding is performed by pressing the piston heads 14 and 14 by the flow of pressure fluid from the inlets formed in the closing members 17 and 17, and this sliding causes the rack gear 15 to rotate the pinion gear 10. The rotating shaft 12 that is fitted to the shaft is rotated.

  In this type of rotary actuator, there is one piston head 14 that receives a high-pressure fluid during operation. Therefore, the piston head 14 needs to have a large area.

  In the case of the second conventional example shown in FIG. 5, a partition plate 19 is arranged at a half position along the axial direction in the casing 16 that also serves as a cylinder, and the casing 16 is divided into two. The piston members 13 a and 13 b are arranged in parallel in the bisected chambers, and the piston members 13 a and 13 b form rack gears 15 and 15 that mesh with the pinion gear 10. Each piston member 13a, 13b reciprocally slides in the opposite direction by the high-pressure fluid supplied from the inlets of the closing members 17, 17 and rotates the pinion gear 10 by this reciprocating sliding to rotate the rotating shaft 12. It is the composition which makes it.

Since the rotary actuator as the second conventional example has two piston members 13a and 13b, the area of the pressure receiving surface of the piston member is half that of the first conventional example in the same rotational output specification. As a whole, the overall size and weight can be significantly reduced. However, the casing 16 which also serves as a cylinder becomes large and heavy as a part, and the machining cost for cutting the inner diameter surface with high accuracy is increased because of a cast product.
Regarding the invention of the present application, the applicant investigated prior technical documents, but could not find any documents that were remarkably similar to or related to the present invention.

  The problem to be solved by the present invention is that a piston member having a pair of rack gears is conventionally placed in a casing that also serves as a cylinder, and the piston member is slid in the opposite direction by a high-pressure fluid to rotate the rotating shaft. The rotary actuator that rotates the pinion gear fitted with the cylinder has a casing that also serves as the cylinder, so the inner diameter surface needs to be cut with high precision, and the cost for the machining becomes very high. It is a point.

  In order to solve the above-described problems, a rotary actuator according to the present invention includes a piston member that forms a rack gear that reciprocates in a linear direction facing each other in a cylinder, and the rack gear of each piston member has one pinion gear. In the rotary actuator that shares and rotates a shaft fitted to the pinion gear, the piston member has a piston head at both ends, and the cylinder is configured by using an existing sanitary pipe. The sanitary pipe cylinder is sandwiched between a casing and an end plate, and the casing and the end plate are each provided with a receiving groove into which the periphery of the sanitary pipe, which is a cylinder, is fitted. It is characterized by The corners of the receiving groove that describes is characterized by taper guide is formed.

  The rotary actuator according to the present invention is configured as described above. Therefore, there is no need to process the inner surface of existing sanitary pipes, and the sanitary pipe is used as a cylinder and is fitted and sandwiched in a groove formed in the casing and end plate. The pipes are accurately parallel and set as an accurate straight line without distorting the angle.

  In addition, the sanitary pipe does not need to be cut at a right angle with respect to the shaft, making it easy to manufacture and reducing the cost. Furthermore, sanitary pipes usually have an inner diameter tolerance, and their cross section is usually slightly elliptical, but this can be corrected by fitting it into the groove, and can be made into an exact circular shape. And since the taper is formed in the groove part, the operation | work of a fitting and insertion becomes very easy.

  The configuration shown in the drawings and described in the embodiment is realized.

  Next, an example of a preferred embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front sectional view showing a rotary actuator embodying the present invention, FIG. 2 is a side sectional view, and FIG. 3 is an enlarged view showing a groove portion.

  In these drawings, reference numerals 1 and 1 denote casings, and reference numeral 6 denotes a pinion gear having a rotating shaft 7 fitted in the center thereof. The casing 1 has a relatively short cylindrical shape, and a pair of the casings 1 are arranged in parallel, and the pinion gear 6 and the rotating shaft 7 are arranged at the central portion of the casings 1 and 1 at the opposite portions. A notched portion is formed.

  Annular grooves 1a, 1b, 1c, and 1d for inserting and fitting sanitary pipes, which will be described later, are formed at both ends of the casings 1 and 1, and the grooves 1a, 1b, 1c, and 1d are formed. In order to facilitate the fitting operation of the sanitary pipe, the corner portions are formed with tapered surfaces 1t and 1t for guide.

  In the figure, 3a, 3b, 3c, and 3d indicate cylinder portions in the present embodiment, and the cylinder portions 3a, 3b, 3c, and 3d are existing sanitary pipes having a thickness of about 3 mm that are commercially available. What was cut | disconnected by the same dimension is used, The one opening edge of the cylinder parts 3a, 3b, 3c, 3d is inserted and fitted in the groove parts 1a, 1b, 1c, 1d of the above-described casings 1, 1.

  On the other hand, reference numerals 2a and 2b in the figure denote end plates each having a disk shape. Each end plate 2a and 2b has an annular shape from the vicinity of the peripheral edge to the vicinity of the center on the inner surface side. Groove portions 2c and 2d are formed, and the opening edge which is the other side of the above-described cylinder portions 3a, 3b, 3c and 3d is inserted and fitted. That is, the cut sanitary pipe constituting the cylinder portions 3a, 3b, 3c, and 3d is sandwiched between the casings 1 and 1 and the end plates 2a and 2b.

  In the figure, reference numerals 4a and 4b denote piston members. The piston members 4a and 4b are integrally formed with rack gears 4c and 4d that mesh with the above-described pinion gear 6 in common. The piston members 4a and 4b are each integrally provided with piston heads 5c and 5d and 5a and 5b at both ends thereof, and ring-like surfaces are provided on the peripheral surfaces of the piston heads 5c, 5d, 5a and 5b. Seal members 5e, 5e... Are fitted.

  In the piston member 4a, the piston head 5c receives pressure from the pressure introduction port B, and the piston head 5d receives pressure from the pressure introduction port A, and reciprocates in the left-right direction in FIG. . At this time, the piston head 5c slides in the cylinder portion 3b, and the piston head 5d slides in the cylinder portion 3a.

  Further, in the case of the piston member 4b, the piston head 5a receives pressure from the pressure introduction port C, and the piston head 5b receives pressure from the pressure introduction port D, and reciprocates in the left-right direction in FIG. However, this sliding direction is always opposite to the above-described piston member 4a, so that a rotational force in the same direction is applied to the pinion gear 6. At this time, the piston head 5a slides in the cylinder portion 3c, and the piston head 5b slides in the cylinder portion 3d. In the figure, reference numerals 8a and 8b denote bearings.

  And the sanitary pipe used for cylinder part 3a, 3b, 3c, 3d has an inside diameter tolerance, for example, 150A, it is +0.4, -1.2 mm. This dimension is usually different for each lot, and as described above, the cross section is usually deformed into an ellipse. In carrying out the present invention, the actual circumference of the sanitary pipe is measured each time it is purchased, and the inner and outer dimensions of the grooves 1a, 1b, 1c, 1d and 2c are set according to the measured values.

  As described above, since the grooves 1a, 1b, 1c, 1d and 2c have tapers 1t and 1t at their corners, the sanitary pipe can be easily inserted, and the thickness is about 3 mm. Therefore, the shape is easily corrected by the groove and becomes a perfect circle. Even if the inner surface of the sanitary pipe is not specially machined, the surface roughness is about 0.1 μm and it is sufficiently smooth and can be used as it is as a cylinder part, which can greatly reduce the cost.

It is front sectional drawing which shows the rotary actuator which implemented this invention. It is side surface sectional drawing. It is an enlarged view which shows a groove part. It is a figure which shows a 1st prior art example. It is a figure which shows a 2nd prior art example.

Explanation of symbols

1 Casing 1a Groove 1b Groove 1c Groove 1c Groove 1d Groove 2a End Plate 2b End Plate 2c Groove 2d Groove 3a Cylinder 3b Cylinder 3c Cylinder 3d Cylinder 4a Piston Member 4b Piston Member 4c Rack Gear 5d Piston Head 5d Head 5d Piston head 5e Seal member 6 Pinion gear 7 Rotating shaft 8a Bearing 8b Bearing A Pressure inlet B Pressure inlet C Pressure inlet D Pressure inlet

Claims (4)

  A piston member that forms a rack gear that reciprocates in a linear direction opposite to each other in the cylinder, and a rotary actuator that rotates the shaft that is fitted to the pinion gear, with the rack gear of each piston member sharing one pinion gear The rotary actuator is characterized in that the piston member has a piston head at both ends, and the cylinder is constructed using an existing sanitary pipe.   2. The rotary actuator according to claim 1, wherein the cylinder by the sanitary pipe is sandwiched between a casing and an end plate.   The rotary actuator according to claim 1 or 2, wherein the casing and the end plate are each provided with a receiving groove into which a peripheral edge of a sanitary pipe serving as a cylinder is fitted.   The rotary actuator according to claim 3, wherein a guide taper is formed at a corner of the receiving groove.

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