JPS6230306B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radial fluid machine in which fluid is switched by a control pin provided with a fluid suction/discharge channel.

[Prior Art] An example of a conventional radial fluid machine in which fluid is switched by a control pin provided with a fluid suction/discharge channel will be described with reference to FIG. 1 is the casing,
2 is a control pin fixed to the casing 1, 3 is a rotor loosely fitted to the control pin 2, 4 and 5 are suction and discharge passages bored in the control pin 2, and 6 and 7 are suction and discharge passages 4 and 5. A flow path is bored in the casing 1 so as to communicate with each other, 8 is a plurality of cylinders provided in the radial direction of the rotor 3, 9 is a piston inserted into the cylinder 8 so as to be able to reciprocate, 10 is a piston 9
Shu, 11, which is swingably attached to the tip of the
12 is a universal joint (for example, an Oldham joint) connecting the rotor 3 and the input/output shaft 13, and 14 is a cam surface formed on the inner surface of the casing 1 so that the shoe 10 slides thereon. A bearing 15 interposed between the casing 1 and the input/output shaft 13 is an oil seal inserted into a sliding portion between the casing 1 and the input/output shaft 13. When this radial fluid machine is operated as a pump, rotation is transmitted from the input/output shaft 13 to the rotor 3 via the universal joint 12, and as the shoe 10 slides along the cam surface 11, the piston 9
moves reciprocally within the cylinder 8, and the suction/discharge channels 4 and 5
Fluid is sucked in and discharged through the flow channels 6 and 7. FIG. 6 shows another conventional example, in which 21 is a casing, 22 is a control pin loosely fitted into the casing 21, and whose rotational movement is regulated by a pin or the like (not shown); control pin 22
rotors 24 and 25 which are loosely fitted and supported by the casing 21 by bearings 37;
26 and 27 are flow passages formed in the casing 21 so as to communicate with the suction and discharge passages 24 and 25, and 28 is a suction and discharge passage formed in the control pin 22.
A plurality of cylinders provided in the radial direction of 3.
29 is a piston inserted into the cylinder 28 so as to be able to reciprocate; 30 is a shoe attached to the tip of the piston 29; 31 is a cam surface formed on the inner surface of the casing 21 so that the shoe 30 slides;
33 is coupled to the rotor 23 and the bearing 3
4 is an input/output shaft supported by the casing 21; 35 is an oil seal inserted into the sliding portion between the casing 21 and the input/output shaft 33; and 36 is a seal between the casing 21 and the control pin 22. O-ring seals 38 and 39 are pressure balance grooves provided on the outer periphery of the control pin 22 so as to communicate with the suction and discharge passages 24 and 25, respectively. When this radial fluid machine is operated as a pump, rotation is transmitted to the input/output shaft 33 and the rotor 23, and the shaft 30
As the piston 29 slides along the cam surface 31, the piston 29 reciprocates within the cylinder 28, and fluid is sucked in and discharged through the suction and discharge passages 24 and 25 and the passages 26 and 27. Further, the control pin 22 loosely fitted into the casing 21 at this time is in a state where it is fluidly supported with respect to the casing 21 by introducing fluid on the suction side or pressurized fluid on the discharge side into the grooves 38 and 39. becomes. In the above two embodiments, the shoes 10 and 30 also have a force F1 equal to the product of the area of the end surface x of the pistons 9 and 29 and the fluid pressure in the cylinders 8 and 28, as shown in FIG.
is pressed against the cam surfaces 11, 31, and the reaction force is applied to the cylinder small diameter portions 8a, 28 from the area of the end surface x.
Force F2 obtained by multiplying the value obtained by subtracting the passage cross-sectional area of a and the fluid pressure and the cylinder small diameter portion 8a, 2
It is divided into a force F3 obtained by the product of the passage cross-sectional area of 8a and the fluid pressure. In the radial type fluid machine shown in FIG. 5, the force F2 causes the rotor 3 to
F3 becomes a force that pushes the control pin 2 against the casing 1 and bends it. In addition, in the radial type fluid machine shown in FIG. 6, the force F2 becomes a load applied to the bearing 37, and the force F3
becomes a force that presses the control pin 22 against the rotor 23. In this way, the force F2 or the force F3 becomes a force that brings the control pins 2, 22 and the rotors 3, 23 into close contact, thereby causing the control pins 2, 22 and the rotors 3,
Since seizing occurs on the sliding surfaces between the control pins 2 and 23 and the rotors 3 and 23, as shown in FIGS. is prevented. The configuration will be specifically described below. A symmetrical switching port 4 is provided on the outer periphery of the control pins 2, 22 in contact with the rotors 3, 23.
Balance grooves 42a, 42b, 43a, 43 provided on both sides in the axial direction of 0 and 41, respectively.
b is open. The grooves 42a and 42b are communicated with the switching port 41 through small holes 44a and 44b. Grooves 43a and 43b are small holes 45a and 4
5b communicates with the switching port 40. Therefore, for example, when pressure fluid is flowing into the switching port 40, the pressure fluid is guided from the switching port 40 to the grooves 43a and 43b through the small holes 45a and 45b, and the control pins 2, 22 and the rotors 3, 23 Pressure fluid leaks to the pressure receiving surface including the pressure gradient formed around the switching port 40, grooves 43a and 43b on the sliding surface, and the control pins 2, 22 and rotors 3, 23 are connected to the pressure receiving surface. Pulling force (separation force) 4, 5,
6 respectively. In the radial fluid machine shown in Fig. 5, the force F3 acts on the control pin 2 as a bending moment as described above, and the other forces are
F2+5+6=4, thereby balancing the forces acting on the sliding surfaces of the control pin 2 and the rotor 3, and preventing the control pin 2 and the rotor 3 from seizing. In the radial fluid machine shown in Figure 6, the force
As mentioned above, F2 is the load applied to the bearing 37, and the other forces are F3+4=5+6, so that the forces acting on the sliding surfaces of the control pin 22 and the rotor 23 are balanced, and the force between the control pin 22 and the rotor is balanced. Burn-in with 23 is prevented.

[Problems to be Solved by the Invention] However, in the case of the radial type fluid machine shown in FIG. Since the force on the sliding surface between the control pin 2 and the rotor 3 will be unbalanced, the input/output shaft 13
In order to prevent external forces from acting on the rotor 3, the universal joint 12 is essential, which increases the cost. (2) Since the bearing 14 that supports the input/output shaft 13 is essential, the entire machine inevitably becomes large.

In the case of the radial fluid machine shown in FIG. 6, (1) the bearing 3 interposed between the casing 21 and the rotor 23;
7 is subjected to the fluid pressure in the cylinder acting on the rotor 23, making it large in size, which increases the price and increases the size of the entire machine. (2)
Since the balance grooves 38 and 39 are required in the portion of the control pin 22 that is loosely fitted into the casing 21, the length of the control pin 22 and the casing 21 in the axial direction increases, and the structure of the control pin 22 becomes complicated. The entire machine becomes large.

Further, in the radial type fluid machine shown in FIGS. 5 and 6, the rotors 3 and 23 at the control pins 2 and 22 are
Balance grooves 42a, 42b,
43a, 43b and small holes 44a, 44b, 45a,
45b, the following problems arise. (1) As the price of fluid machinery increases, the structure of the control pins 2 and 22 becomes more complicated. (2) The number of locations where high-pressure fluid leaks increases, reducing the volumetric efficiency of fluid machinery.

The present invention has been made in view of the above problems.
The purpose is to provide a radial fluid machine that has good volumetric efficiency, is simple in structure, and can be downsized.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a control pin fixed to a casing, and a plurality of cylinders rotatably fitted into the control pin in the radial direction. In a radial fluid machine equipped with a rotor, a suction/discharge passage bored in a control pin to communicate with a cylinder, and an input/output shaft connected to the rotor, the amount of clearance between the rotor and the control pin is determined. A bearing is interposed to restrict and support the rotation of the rotor relative to the control pin, the cylinder is provided with a stepped portion that presses the rotor against the control pin by fluid pressure within the cylinder, and the gap is formed on the inner circumferential surface of the rotor. A pressure-receiving surface is provided that causes the rotor to separate from the control pin by the fluid pressure flowing through the casing, and such that the pressing force and the separating force are balanced or the pressing force slightly outweighs the rotor. It is characterized in that the step portion and the pressure receiving surface are formed respectively.

[Function] With the above configuration, the gap on the high pressure side of the sliding surface between the control pin and the rotor is kept small by the bearing and the fluid pressure acting on the step and the pressure receiving surface.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. 51 is a casing, 52 is a control pin fixed to the casing 51, 53 is a rotor rotatably fitted into the control pin 52 via a bearing 67, and 54 and 55 are suction/discharge passages bored in the control pin 52. , 56 and 57 are suction and discharge channels 54 and 55
58 is a plurality of cylinders provided in the radial direction of the rotor 53, and 58a is a passage bored in the casing 51 so as to communicate with the rotor 5.
58b is a stepped portion formed by the cylinder 58 and the cylinder small diameter portion 58a; 58c is a pressure receiving surface provided on the inner peripheral surface of the rotor 53; and 59 is a pressure receiving surface provided in the cylinder 58. A piston inserted so as to be able to reciprocate, 60 a shoe swingably attached to the tip of the piston 59, 61 a cam surface formed on the inner surface of the casing 51 on which the shoe 60 slides, 63 a rotor 53 65 is an oil seal inserted into the sliding part between the casing 51 and the input/output shaft 63, and 66 is an O-ring seal inserted into the fitting surface between the casing 51 and the control pin 52. It is. The relationship between the area sizes of the stepped portion 58b and the pressure receiving surface 58c is such that the rotor 5 due to the pressure fluid applied to the stepped portion 58b
3 to the control pin 52 side
F1 and the separating force F4 which attempts to separate the rotor 53 from the control pin 52 due to fluid pressure being applied to the pressure receiving surface 58c are balanced or the pressing force F1 is slightly superior. Also,
b = suction and discharge flow path 5 in the longitudinal direction of the control pin 52
5 opening length, b' = length of the pressure receiving surface 58c from the opening of the suction/discharge passage 55 in the axial direction of the rotor 53;
1=the length of the pressure receiving surface 58c in the inner circumferential direction of the rotor 53 per cylinder, and the pressing force
Expressing F1 and separation force 4 using the formula, F1=π/4・(D ² − d ² )・P …(1) 4=P・(b・1−π/4・d ² ) +2・b′・1・P/2 ...(2) The relationship between the pressing force F1 and the separating force 4 is F1/4=1 to 1.15. The bearing 67
has rigidity that bends when a load is applied to change the gap between the control pin 52 and the rotor 53, and prevents the control pin 52 and the rotor 53 from coming into contact when a maximum load is applied.

A case where the rotor 53 is rotated via the input/output shaft 63 and used as a pump will be described. When the rotor 53 rotates with respect to the control pin 52 via the bearing 67, the shoe 60 slides along the cam ring 61, the piston 59 reciprocates within the cylinder 58, and the cylinder The fluid sucked into 58 is discharged through suction/discharge channel 55 and channel 57 . At this time, fluid pressure within the cylinder 58 is applied to the end surface y of the piston 59, and its reaction force is applied as a pressing force to the stepped portion 58b, and is also applied to the casing 51 via the control pin 52. Further, fluid pressure flowing into the sliding surface between the control pin 52 and the rotor 53 is applied to the pressure receiving surface 58c as a separating force 4, and a pressing force is applied to the stepped portion 58b.
Almost in balance with F1, the gap between the control pin 52 and the rotor 53 on the sliding surface is positioned by the bearing 67 and is extremely small. The reaction force of the separation force 4 is applied to the casing 51 via the control pin 52. Further, the bearing 67 is connected to the control pin 5.
It supports the rotation of the rotor 53 relative to 2, and receives a pressing force F1 that is greater than the separation force 4.

[Effects of the Invention] According to the radial fluid machine of the present invention described above, the gap on the high pressure side of the sliding surface between the control pin and the rotor can be reduced by the fluid pressure acting on the stepped portion and the pressure receiving surface and the bearing. Since it is kept small and leakage of high-pressure fluid is reduced, volumetric efficiency can be improved. Further, since there is no need to provide the control pin with a groove or a small hole for supporting the rotor with fluid pressure, the structure is simple and the price is low. In addition, since a large load is not applied to the bearing interposed between the rotor and the control pin, the bearing can be made smaller, and the bearing that supports the input/output shaft in the casing can be eliminated. Therefore, the fluid machine itself can be made smaller.

In the above description, a case has been described in which the radial fluid machine is used as a pump, but the same effect can be obtained even if it is used as a motor.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional front view showing one embodiment of the radial fluid machine of the present invention, Fig. 2 is an enlarged view of section C in Fig. 1, and Fig. 3 is an E-E in Fig. 2. 4 is a diagram showing the magnitude of the separation force on the pressure receiving surface, FIGS. 5 and 6 are sectional front views showing conventional radial fluid machines, and FIG. 7 is a diagram showing the magnitude of the separation force on the pressure receiving surface. FIG. 8 is an explanatory diagram showing the control pins of FIG. 7 expanded. 51...Casing, 52...Control pin, 53
... Rotor, 54, 55 ... Suction and exhaust flow path, 56, 5
7...Flow path, 58...Cylinder, 58a...Cylinder small diameter part, 58b...Step part, 58c...Pressure receiving surface, 59...Piston, 60...Shu, 61...
...Cam surface, 63...Input/output shaft, 67...Bearing, 6
5...Oil seal, 66...O ring seal.

Claims (1)

[Claims] 1. A control pin fixed to a casing, a rotor rotatably fitted into the control pin and provided with a plurality of cylinders in the radial direction, and a suction/discharge passage bored in the control pin so as to communicate with the cylinders; In a radial fluid machine equipped with an input/output shaft connected to a rotor, a bearing is interposed between the rotor and a control pin to regulate the amount of clearance and to support rotation of the rotor with respect to the control pin, and A stepped portion is provided that presses the rotor against the control pin by the fluid pressure in the cylinder, and the fluid pressure flowing into the casing through the gap on the inner circumferential surface of the rotor receives pressure that tends to separate the rotor from the control pin. A radial type fluid machine, characterized in that the stepped portion and the pressure receiving surface are each formed so that the pressing force and the releasing force are balanced or the pressing force slightly exceeds the pressing force.