JPH01178779A - Oscillation motor - Google Patents

Abstract

PURPOSE:To effectively discharge a mixed air by forming oil passages inside an oscillator so that the oil passages go from the outer periphery of the oscillator toward a selector valve. CONSTITUTION:A switching pressure, or an output of a selector valve 80 leaves an opening 33a, or 33b of a sleeve 33 in accordance with the position of rotation of the valve, then passes through the inside of a piston 36 through either of two oil passages 86a, 87a radially drilled and located in the piston 36, and is supplied into either of operation chambers 44, 42 through either of openings 86a, 87a located on the outer peripheries of the chambers. The oil passages 86, 87 are formed by drilling themselves radially inside the piston 36 by means of a drill. The system can therefore be easily manufactured, and further the oil pressure switching valve 80 is formed so that it is located in a straight line with the higher position of the cylinder, so that the rosponsibility of the system can also be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hydraulically driven swing motor, and more specifically to an improvement in a cylinder supply oil path for a swing motor.

(Prior Art) One of the motors driven by hydraulic pressure is called a swing motor. This type of motor is a rotary motor that rotates repeatedly within a limited angular range, and has the advantage of a simple structure and the ability to seal the inside relatively easily compared to infinitely rotating motors. It is often used for a certain reason. An example of such a swing motor is the technique described in Japanese Unexamined Patent Publication No. 55-51107.

(Problems to be Solved by the Invention) Regarding the output torque of a hydraulically driven swing motor, the larger the radius of the piston (oscillator), the greater the torque. In other words, the area near the axis of the piston has a low proportion of the output torque, so it is not an effective space for output. Therefore, when the control valve of the rocking motor is also integrated, the control valve is often placed at the center of the piston. Assuming that the rotating shaft of the swing motor is positioned approximately horizontally during work, it is important for the hydraulic system to ensure that the oil and air in the cylinder are well separated and the air is discharged as quickly as possible. This is desirable in terms of ensuring responsiveness. From this point of view, the position of the supply port to the cylinder should be set as high as possible, and for this reason, conventionally, pressure oil was supplied from the switching valve located at the shaft center once through the motor casing, and then the supply port was opened in the supply boat. The location was selected at the highest point of the cylinder. However, with this method, the length of the oil path from the switching valve to the cylinder is long (which is inconvenient as it is not possible to achieve high system responsiveness), and the design of a long oil path requires considerable space and expense. was needed.

The present invention has been made in view of the above circumstances, and its purpose is to simplify the structure by directly forming a pressure oil supply passage within the piston, and to also ensure the discharge of mixed air. The object of the present invention is to provide a swing motor that can perform the following functions.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a rotatable rocker inside a cylinder and a hydraulic switching valve at the axis of the cylinder. The rocking motor is configured such that an oil passage is formed inside the rocker from its outer periphery toward the switching valve.

(Function) An oil passage is drilled inside the piston to directly connect the hydraulic switching valve located at the axial position with the supply port I to the cylinder, which simplifies the structure and reduces the oil passage bored inside the piston. Since the opening is located at the outer periphery of the screw I/N, the supply port is set at a high location and the mixed air can be effectively discharged.

(Example) Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is an explanatory cross-sectional view showing the entirety of the swing motor according to the present invention, and is an explanatory cross-sectional view of the swing motor housed in the joint of a multi-joint arm such as a working robot. In the same figure, the two ends of the arm 10 are connected to a casing 11 that houses a swing motor according to the present invention, and the swing motor has its output in a space formed by this casing 11 and a cover 12. It is housed in such a way that the shaft 13 is rotatably supported. In the figure, there is a spline 14 on the right end side of the output shaft 13.
is carved, and the output torque of the swing motor is transmitted to the other arm 20 via this spline 14.

The lower end of the other arm 20 has a yoke shape, and in the figure, the left yoke 21 is rotatably connected to the cover 12 by a bearing 22, and oil passages 24 and 25 are formed inside the right yoke 23. It is connected to the output shaft 13 via a joint 26 so as to hug the output shaft. The joint 26 is connected to the spline 14 in order to transmit the torque described above.
It is fixed to the yoke 23 via a plurality of bolts 27 while meshing with the yoke 23. The yoke 21 and the yoke 23, as shown in the partially cutaway left side view of FIG. 2, the right side view of FIG. 3, and the sectional view of FIG.

23a and caps 21b and 23b,
They are fixed with ports T-21c and 23c, respectively. Further, as shown in FIG. 3, the joint 26 is slotted and is constructed so that after the spline 14 is fitted, it is tightened with the pole l-23d to remove looseness of the spline. Note that the yoke 21 has a washer 2 for fixing the bearing 22.
It is attached with 8 plates and 29 plates.

Returning to FIG. 1 again, a motor flange 15 for regulating the movement of the bearing 22 in the axial direction is also attached to the cover 12 via bolts 16 on the left side of the figure. The motor flange 15 is integrally molded with a casing 100 of the controlled DC motor, as will be described later. In order to detect the movement angle of the swing motor, a potentiometer (not disclosed) is provided at an appropriate position on the arm 20 side, and a timing bell l-17 and a potentiometer (not shown) are provided at an appropriate position on the arm 20 side to detect the movement angle of the swing motor. A helmet IJ18 is provided for hanging a heddle.

The output shaft 13 of the swing motor described above is rotatably supported by a second bearing 30 provided on the casing 11 and a third bearing 31 provided on the cover 12. A center shirt I/32 forming an oil passage is press-fitted into the right half of the output shaft 13 (in FIG. 1), and a sleeve 33 forming a rotary valve is press-fitted into the left half. Two annular grooves 34 and 35 surround this sleeve 33.
is provided.

The portion of the output shaft 13 sandwiched between the second and third bearings 30 and 31 has a relatively large diameter and forms the rotary piston 36, which is the oscillator described above.
The cover 12 and the side plate 60 are assembled so as to sandwich them. The shape of the rotary piston 36 is such that the upper part thereof is fan-shaped, as clearly shown in FIG. two groups of grooves 38.3 of constant width extending outward in the direction
9 is drilled. Vanes 40 are slidably inserted into these groove groups 38 and 39, respectively. Therefore, -Group Groove 3
8 is formed in one of the working chambers 42 defined by the piston via an oil passage (groove) 41 bored in the side surface of the piston 36, and the other groove group 39 is also formed in the side surface of the piston 36. They are each hydraulically connected to a further working chamber 44 via a groove 43 . The vanes 40 described above are forced outward by the hydraulic pressure generated in each of the small holes 37 and inwardly by the hydraulic pressure acting on their tips, and the resultant force tends to push the vanes 40 outward to some extent. However, it is held in the position shown by a cylinder 45 formed around the circumference of the working chamber. A leaf spring 46 is provided on each vane to apply an initial tension to the vane so that the vane 40 is normally held in the position shown in the figure even before hydraulic pressure is generated (FIG. 1). The length of the cylinder 45 in the axial direction is slightly longer than the length of the piston 36 in FIG.
The length of the piston 36 is manufactured to be approximately equal to the length of the piston 36. Referring again to FIG. 5, a stator 48 is provided at a lower position within the cylinder 45. The stator 48 is identical in axial length to the cylinder 45 and slidably accommodates a plurality of second vanes 47 therein. 2nd han 4
7 is completely the same in structure and function as the vane 40 on the piston side described above, and each working chamber 42 (44) is provided in each small longitudinal groove (not shown) in the stator 48 that accommodates the second vane. A leaf spring (not shown) is provided in the small hole. The stator 48 and the cylinder 45 are manufactured separately, and then they are joined by applying an adhesive to their mating surfaces, and after joining, the lengths are simultaneously machined to make the lengths the same. Further, since the stator 48 receives a reaction force from the piston when the swing motor is operated, a pin 49 protrudes from the cover 12 and is inserted into a hole drilled on the stator side to prevent the stator from rotating. Furthermore, in order to prevent the side plate 60 described later from following the rotation of the rocking morph, the stator 48 and the side plate 60 are
A second pin 50 having a relatively small diameter is also provided between the two pins.

As shown in FIGS. 1 and 6, a groove 61 of a constant depth is bored in the back side of the side plate 60 opposite to the working chamber, and a rubber seal member 62 is inserted into the groove 61. It is fitted. As clearly shown in FIG. 6, the sealing member 62 is integrally molded and has a generally semicircular shape, and has eight windows on its periphery and an annular hole in its center. Its lower part is cut out to form an area outside the seal, thereby forming a plurality of pressure chambers f33, 64, 65°66.
67.68, 69, 70, 71.72 are formed. These pressure chambers are hydraulically separated from each other after assembly. The central chamber 63 is designed to be concentric with the output shaft 13, and pressure from a hydraulic source is directly introduced into this chamber as will be described later. Further, the eight chambers 64 to 71 at the peripheral edge are all configured in the same shape and are arranged at equal intervals circumferentially so as to be equidistant from the output shaft 13. Further, each chamber is provided with a pore 73 that communicates between the front and back sides of the side plate 60. Furthermore, this communication hole 7
3 is formed at the upper position of each chamber, that is, at a high position above in the vertical direction when assembled to the arm 10.20,
This promotes air removal of the pressure oil passing through the slag. Further, the diameter of the pore 73 is formed to be smaller than the thickness of the vane 40 on the piston side described above. In order for each chamber 64 to 71 to function reliably as a pressure chamber, shallow recesses 64a to 71a having a depth of about 1 mm are provided. Note that the above-described outside seal area 72 will be located on the back side of the stator 48 in the assembled state.

Returning again to FIG. 1, reference numeral 80 designates a hydraulic switching valve, which together with the aforementioned sleeve 33 constitutes a rotary valve. This hydraulic switching valve 80 is well known, and is rotatably housed within the sleeve 33 as shown in FIG.
2. One side of 44 is connected to hydraulic pressure a (not shown) and the other side is connected to a tank (not shown) to drive and control the swing motor. Formally, this valve is a type of four-way switching valve, but since the gist of the present invention is not in this valve itself, further explanation will be omitted. A control DC motor 81 is provided to give a predetermined displacement angle to the hydraulic switching valve 80, and the DC motor 81 is housed in a goose sink 100 formed integrally with the motor flange 15, as shown in FIG. A pin 82 protrudes radially from the output shaft 83 of the DC motor, and is inserted into a groove 84 bored on the switching valve 80 side (
(Better shown in Figure 7). A rotary encoder 85 for detecting the rotation angle of the DC motor 81 is installed adjacent to the DC motor 81, and a reduction gear is combined therewith as required (not shown).

The feature of the present invention is the improvement of the oil supply path to the cylinder, and with this in mind, the switching valve 80 will be explained below.
The switching pressure which is the output of the sleeve 33 depends on the rotational position of the valve.
After exiting the opening 33a or 33b of the piston, the piston passes through two oil passages 86 or 87 bored in the screw I/N 36 in its radial direction, as shown in FIGS. 5 and 7. The sleeve opening 33b in FIG. ). Since the oil passages 86 and 87 are formed by drilling holes inside the piston along its radial direction with a drill, they are not only easy to manufacture, but also allow the hydraulic switching valve and the cylinder to be placed at high locations, as shown in Fig. 7. Since the oil passage 87 is formed so as to be connected with a straight line (only the oil passage 87 is shown in FIG. 7), the responsiveness of the system is also improved. Note that the oil passage openings 86a and 87a are 3
Among the individual vanes 40 arranged in parallel, the vanes are arranged as close as possible to the outermost vane and on the outside thereof to minimize the amount of residual air when connecting to the tank (when returning).

11 ~ Furthermore, pressure oil is supplied to the working chamber from a hydraulic source (not shown) through the switching valve 80, or unnecessary pressure oil is transferred to a tank (
(not shown), two oil passages are provided inside the arms 10 and 20. That is, in the arm 10 there are 2
Wooden pipes 90° and 91 are inserted with O-links 92 for sealing, and in Figure 1 these two wooden pipes appear to overlap, but in the figure, the pipe 91 on the near side is the one for the outbound passage. The pipe 90 on the back side is for the return path. Therefore, as shown by the arrow, the outbound pipe 91
Pressure oil supplied from the bottom of the figure through the casing 11 is guided to the axis of the center shaft 32 of the front i-ho through a hole 93 drilled in the casing 11, and the switching is carried out through this axis. Supplied to the high pressure port of valve 80. In addition, as shown by the arrow, the pressure oil on the return side flows from the oil passages 86 and 87 in the piston, through the oil pressure switching valve, through the oil passage 94 provided on the outside of the center shaft 32, and once into the annular groove 95. A second hole (oil passage) 9 is collected and drilled into the casing 11 from there.
A return pipe 90-1. 2-- is guided by. It is assumed that the outward pipe 91 is connected to a hydraulic power source (not shown), and the return pipe 90 is connected to a tank (also not shown). Further, as shown in FIG. 4, in the yoke 23, the pressure oil from the axis of the center shaft 32 passes through the oil passage 24 on the left side (in the same figure) to the rocking morph (not shown) of the next joint. The return oil from the joint is sent back through the oil passage 25, and this return oil is also sent to the oil passage 96 through an annular groove 95 provided on the outside of the center shaft 32. They are collected and returned to the tank (Figure 8).

As shown in FIG. 4, a suitable sealing material 97 is provided on the surface of the output shaft 13 to prevent the pressure oil sent to the next joint from leaking to the return path side.

Further, as shown in the upper part of FIG. 1, a second set of pipes 90' and 91° are provided on the arm 20 side, and thus a multi-joint arm drive machine, such as a factory robot arm or It can be used to build the powershaher arm of construction machinery, etc. In FIG. 1, reference numerals 93a=14- and 24a (25a) indicate plugs that close the open ends of the oil passages.

Next, the operation of the swing motor according to the present invention will be explained.

When the DC motor 81 receives a command from a control device (not shown) and rotates its output shaft 83, the switching valve 80 also relatively displaces and switches the oil passage to either the oil passage 86 or 87 in the piston. One of the working chambers 42 and 44 is connected to a hydraulic source via the
Connect the other end to the tank. As a result, a pressure difference is generated between the left and right sides of the piston 36, and the swing motor is hydraulically driven, and its output shaft 13 is rotated in a predetermined direction. The rotational force generates a bending moment between the two arms 10.degree. 20 through the spline 14, so that the two arms articulate with respect to each other around the swing motor. In this embodiment, the pressure chambers 64 to 71 for balance are provided on the back surface of the side plate 60 on the opposite side from the piston 36, and are communicated with the working chamber side through the small hole 73, so that the piston 36 As the vanes 40 move and sequentially pass through the eight pores 73, the pressure in the working chamber is also guided to the balance pressure chamber, increasing the effective pressure receiving area where the balance pressure acts with the stroke, and increasing the pressure in the side plate. 60, the force of clinging is minimized.

In the above, as described above, the pressure oil flows through the oil passages 86 and 87 bored in the piston to the openings 86a and 87a.
Since the hydraulic oil and mixed air are separated inside the working chamber due to the difference in specific gravity, the air accumulates in the upper part of the chamber, but the supply path to the working chamber is located at the highest point. Since it is open, it is possible to efficiently drain the hydraulic oil when returning it to the tank. Further, when the pressure oil is returned to the tank, since the openings 86a and 87a are close to the vanes as described above, there is little chance of air remaining.

Although the present invention has been explained by taking as an example a swing motor equipped with a pressure balance mechanism on the side plate, it goes without saying that the gist of the present invention is also applicable to a swing motor without such a mechanism.

(Effects of the Invention) -15= The present invention provides a swing motor including a rotatable rocker in a cylinder and a hydraulic switching valve at the axis of the cylinder. Since it is configured to form an oil path from its outer periphery to the switching valve, it not only has a simple structure and is easy to manufacture, but also has good discharge performance for mixed air, and also improves the responsiveness of the system. It also has excellent advantages.

[Brief explanation of the drawing]

Fig. 1 is an explanatory cross-sectional view showing the swing motor according to the present invention as a whole in a state housed in a joint between two arms, Fig. 2 is a partially cutaway left side view of Fig. 1, and Fig. 3 is a left side view of FIG. 1, FIG. 4 is a sectional view taken along the line IV--IV of FIG. 1, FIG. 5 is a sectional view taken along the line V-V of FIG. FIG. 8 is an explanatory perspective view showing the sleeve inserted into the swing motor output shaft and the hydraulic switching valve, and FIG. 8 is an explanatory perspective view of the sleeve. 10.20...Arm, 11...Casing, 12
... Cover, 13 ... Swing motor output - 16 = Shaft, 14 ... Spline, 15 ... Motor flange, 21.23 ... Yoke, 24.25 ... Oil path, 2
6...Joint, 22, 30.31...Bearing, 32...
・Center shaft, 33...Sleeve, 33a, 33
b... Sleeve opening, 34.35... Annular groove, 3
6... Piston (oscillator), 37... Small hole, 38.
39...Groove, 40...Vane, 42.44...Working chamber, 41.43...Groove, 45...Cylinder, 48
...Stator, 60...Side plate, 8o...Hydraulic pressure switching valve, 86.87...Oil passage, 86a, 87a...Oil passage opening-R: 1p Fig. 2 Fig. 3 Figure 4

Claims (1)

[Claims] In a rocking motor that includes a rotatable oscillator in a cylinder and a hydraulic switching valve at the axis of the cylinder, an oil path is provided inside the oscillator from its outer periphery to the switching valve. An oscillating motor characterized by forming: