JPS6172882A - Radial plunger pump - Google Patents

Abstract

PURPOSE:To aim at reduction in a mechanical loss of a pump, by making a head part of a convex spherical plunger contact with a concave part in an inner surface of a guide ring apart from the center, and constituting both so as to do rolling contact. CONSTITUTION:A shoe is not installed in a head part 3a of a plunger 3, and there is merely a convex sphere so that even in time of rotation at high speed, it will not act on a pump driving source as load. And, the plunger 3 and a reinforcing ring 4d fitted in an inner circumference of an inner ring 4a of a guide ring 4 installed in an outer circumference of a rotor 2 are not made contact with each other at a tip end 3a of the plunger 3 and a most concave part 4d2 of a groove 4d1 formed on an inner circumferential surface of the reinforcing ring 4d, but they come into contact with each other at points f and g separated as far as eccentricity l, that is, separated as far as l from a central shaft of the plunger 3. Therefore, it there is a relative speed difference between the rotor 2 and the guide ring 4, the plunger 3 rotates, becoming rolling contact with the groove 4d1 of the guide ring 4 so that a mechanical loss is reducible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radial plunger pump having plungers arranged radially.

[Conventional technology]

2. Description of the Related Art Conventionally, there are radial plunger pumps in which the relative sliding friction between the head of the plunger and a guide ring is reduced to improve the mechanical efficiency of the pump. One of them was to place a shoe on the head of the plunger and supply lubricating oil to reduce the frictional force with the inner surface of the guide ring.

[Problem that the invention seeks to solve]

However, in the conventional type, the shoe is placed on the plunger head, which increases the number of parts. Furthermore, there is a problem in that the weight of the shoe acts as a load on the rotational drive source during high-speed rotation.

Therefore, in view of the above points, it is an object of the present invention to provide a radial plunger pump that has a small number of parts and does not reduce mechanical efficiency even during high-speed rotation.

[Means for solving problems]

As a means for solving the above-mentioned problems, the present invention includes a rotor having a plurality of radially provided cylinder parts built into a housing, and a plurality of plungers abutting against a guide ring installed on the inner surface of the housing. In a radial plunger pump that is slidably inserted into the cylinder portion of a rotor and makes the plunger reciprocate at least once per rotation of the rotor by making the rotor and the guide ring eccentric, the guide ring has a groove along the inner circumferential surface. An arc-shaped recess is formed, and a convex spherical surface with a radius of curvature smaller than the radius of curvature of the arc-shaped recess on the inner circumferential surface of the guide ring is formed on the head of the plunger, and the plunger The recesses are arranged in two rows so as to be in contact with the recesses at a distance from the center of the recesses.

[Function] The head of the plunger can be used without a shoe.
Since it is a convex spherical surface and abuts the guide ring at a distance from its center, the plunger rotates and rolls due to friction.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

Figure 1 tag, (bl is a sectional view of the main part of the radial plunger pump of the present invention, Figure 2 is a partial sectional view showing the pump of the present invention, Figure 3 is the I-■ line of the pump shown in Figure 2. FIG.

In FIG. 2, 1 is a housing that forms the outer shape of the pump, and 2 is a rotor that is built into the housing 1 and rotates around zero in response to external power.

The rotor 2 has six cylinder holes 21 arranged radially.
A plunger 3 is inserted into each of the cylinder holes 21 in an oil-tight and slidable manner, urged outward from the center 0 by a spring 22. The head of the plunger 3 has an R shape, that is, a convex spherical surface. Further, inside the rotor 2, a pump operating chamber 23 is formed by the cylinder hole 21 and the plunger 3.

A coupling plate 2a is integrally fixed to the left end of the rotor 2 in FIG. The tip 202 of the shaft 200 is inserted, and the rotation of the shaft 200 causes the coupling plates 1 and 2a, the rotor 2, etc. to rotate. The hole 10 provided in the center of the rotor 2
3 and are fitted in an oil-tight manner and can slide and rotate freely.
The hole 10 has the same number of communicating holes 20 as the cylinder holes 21 . This communication hole 20 has a diameter smaller than that of the cylinder hole 21, and has a structure in which one end of a spring 22 disposed within the cylinder hole 21 is supported by this portion.

As can be seen in FIG. 3, a discharge groove 14 is provided at an angle corresponding to the discharge stroke of the bottle 13, and a suction groove 15 is provided at an angle corresponding to the suction stroke. Plunger 3
In the discharge stroke, which is approximately in the upper half of the figure, pump chamber 2
3 is the communication hole 20, the discharge groove 14 of the bottle 13, and the discharge hole 1
6.Communicates with discharge port 1■. In addition, in the suction stroke when the plunger 3 is approximately in the lower half of the figure, the pump chamber 23 is connected to the communication hole 20, the suction Wj15 of the bottle 13, the suction hole 17,
It has a structure that communicates with the suction port 12. Furthermore, annular grooves 19a and 19b are provided on the outer periphery of the bottle 13, and these annular grooves 19a and 19b are connected to the rotor 2 and the bottle 1.
Balances the hydraulic pressure with 3. Note that the bottle 13 is fixed to the housing 1 with bolts 6'.

On the other hand, the outer circumference of the rotor 2 includes an inner ring 4a and an outer ring 4b.
, steel balls 4c are provided, and a reinforcing ring 4d is fitted on the inner periphery of the inner ring 4a. A groove 4dl having a radius of curvature larger than the radius of curvature of the convex spherical surface of the head of the plunger 3 is formed along the inner peripheral surface of the reinforcing ring 4d.

As shown in FIG. 1, the center of the groove 4dl and the center of the plunger 3, that is, the center of the cylinder hole 21 bored in the rotor 2, are slightly eccentric or separated by p as shown in FIG.

Further, the cylinder holes 21 are not drilled on the same surface within the rotor 2, but are drilled in two rows alternately at distances l with the center of the groove 4dl of the guide ring 4 interposed therebetween. 1st
In the figure, +a) indicates the first column, and fb) indicates the second column. Therefore, the plunger 3 and the reinforcing ring 4d of the guide ring 4 are connected to the recessed part 4. of the groove 4dl with the tip end 3a of the plunger 3. Instead of contacting at points f and g, which are separated by eccentricity p, that is, points separated from the center axis of plunger 3. Therefore, when there is a relative speed difference between the rotor 2 and the guide ring 4, the plunger 3 rotates and causes rolling friction with the groove 4dl of the guide ring 4.

Next, the operation will be explained based on the configuration described in section 2.

When the rotor 2 rotates clockwise in Fig. 3, the rotation center 0 of the rotor 2 and the midpoint 0' of the guide ring 4 are eccentric, so the plunger 3 performs reciprocating motion to suck in and discharge hydraulic oil. That will happen. In the suction stroke when the plunger 3 is at the lower half of the zero point, the working fluid is sucked into the pump chamber 23 from the suction port 12 through the suction hole 17, the suction grooves 1 and 15, and the communication hole 20. Next, in the discharge stroke in which the rotor 2 rotates and the piston reaches the upper half of the zero point, the fluid in the pump chamber 23 is transferred to the communication hole 20, the discharge groove 14, and the discharge hole 16.
The liquid is discharged through the discharge port 11.

The plunger 3 and the guide ring 4a are in contact with each other, but the center points o and o' of the rotor 2 and the guide ring 4 are eccentric, so the plunger 3 and the guide ring 4, which rotate together with the rotor 2, are relative to each other. A speed difference occurs. At this time, the contact position between the head 3a of the plunger 3 and the groove 4dl of the guide ring 4 is not at the center of the plunger 3, but at a point f or g that is shifted by the eccentricity l, so the plunger 3 is moved only by this speed difference. Rotate. Since the direction of force acting at the contact point f or g between the plunger 3 and the guide ring 4 is inclined with respect to the axial direction of the plunger 3, a force in the thrust direction is generated in the rotor 2. However, since the plungers 3 of the rotor 2 are arranged in two rows alternately within the groove 4dl of the guide ring 4, the thrust force exerted on the rotor 2 by the plungers 3 in the first row is opposite to that in the second row. direction, and the thrust forces of both cancel each other out. Therefore, no force in the thrust direction acts on the rotor 2.

Further, the head 3a of the plunger 3 is connected to the groove 4 of the guide ring 4.
Since they abut on the inside of dl, it is possible to reduce the distance between the first and second rows of plungers 3 arranged in two rows.

That is, by reducing the interval, the axial length of the rotor 2 on which the plunger 3 is disposed can be reduced.

〔Effect of the invention〕

As described above, in the present invention, since the head of the plunger is not provided with a shoe and is simply a convex spherical surface, it does not act as a load on the pump drive source even during high-speed rotation. Further, since the head of the plunger is spaced apart from the center and comes into contact with the recess in the inner circumferential surface of the guide ring, the two come into rolling contact, thereby reducing mechanical loss of the pump.

[Brief explanation of drawings]

Fig. 1 ta+, (bl are both sectional views of essential parts of the radial plunger pump of the present invention, Fig. 2 is a sectional view of the radial plunger pump of the present invention, and Fig. 3 is an I-I of the pump shown in Fig. 2. It is a sectional view taken along the line. 1... Housing, 2... Rotor, 3... Plunger, 3a... Head of plunger 3, 4... Guide ring, 4dl... Guide ring 4. reinforcement ring 4d
Groove (recess) provided in.

Claims (1)

[Claims] A rotor having a plurality of radially arranged cylinder portions is housed in a housing, and a plurality of plungers that abut a guide ring provided on the inner surface of the housing are slidably inserted into the cylinder portions of the rotor, and the By making the rotor and the guide ring eccentric, the rotor 1
In a radial plunger pump that reciprocates the plunger at least once per rotation, the guide ring is formed with an arc-shaped recess along the inner circumferential surface, and the head of the plunger is formed with a circular concave portion along the inner circumferential surface of the guide ring. A radial plunger pump characterized in that a convex spherical surface with a radius of curvature smaller than the radius of curvature of the arc-shaped recess is formed, and the plungers are arranged in two rows so as to abut the recess of the guide ring at a distance from the center thereof. .