JPH03260377A - Reciprocating pump - Google Patents

Abstract

PURPOSE:To obtain a reciprocating pump of high efficiency with no leakage of fluid by fitting a tubular unit possible to turn and reciprocate in a cylinder, in which suction and delivery ports are provided in the opposed position, and fitting a piston into this tubular unit so as to reciprocate while rotating. CONSTITUTION:A flange part 1a is provided in one end of a tube-shaped cylinder 1, and suction and delivery ports 2, 3 are formed in opposed surface positions in a peripheral wall in the other end side of the cylinder 1 in which a tubular unit 4 is rotatably and slidably fitted. A pair of long grooves 6 are opposedly formed in the axial length direction on one end side of the internal peripheral surface of the tubular unit 4 while drilling a flow hole 5 connected to a pump chamber 16 in the tubular unit 4 in the other end side peripheral surface thereof, and two pins 9 of the peripheral surface of a piston 8, fitted possible to reciprocate and turn in this tubular unit 4, are fitted to each long groove 6. Fluid is sucked through the suction port 2 and the flow hole 5 into the tubular unit 4, at retraction time followed by rotation of this piston 8, and delivered from the delivery port 3 at advancing time followed by continued rotation of the piston 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a reciprocating pump, and more particularly to a reciprocating pump that can be used without the need for a check valve.

(Prior Art) Conventionally, as this type of reciprocating pump, there exists, for example, an invention disclosed in Japanese Patent Application Laid-Open No. 64-41679 by the present applicant.

That is, as shown in FIG. 6, in this conventional type, a piston 8 is placed in a cylinder 1 having an inlet 2 and an outlet 3 on the peripheral wall.
It is fitted so that it can reciprocate while rotating.
A suction hole 24 and a discharge hole 25, which communicate with the pump chamber 16 in the cylinder 1 through a conduction hole 23 formed in the distal end surface of the piston 8, are formed on the outer peripheral surface of the piston 8. The suction hole 24 is arranged in face-to-face communication with the suction port 2 of the cylinder 1 when the piston 8 moves backward, and the discharge hole 25 is arranged in face-to-face communication with the discharge port 3 of the cylinder 1 when the piston 8 moves forward.

By reciprocating the piston 8 while rotating, the fluid in the pump chamber 16 is sucked and discharged. According to this, a separate check valve is not required.
This has the advantage that the configuration of the pump itself can be simplified.

(Problem to be Solved by the Invention) Incidentally, in this type of pump, it is necessary to provide a seal to prevent fluid leakage from between the cylinder 1 and the piston 8, but the piston 8 does not only reciprocate but also Since the O-ring rotates and slides, it is not possible to prevent fluid from leaking, so in the past, sealing was achieved by minimizing the clearance between the two.

In order to reduce the clearance in this way, it is possible to improve machining accuracy, but this also has certain limits and has the major problem of significantly increasing machining costs. It was.

Furthermore, if damage such as scratches occurs on the sliding surfaces of each member during use, it is extremely difficult to maintain a sufficient sealing effect even if the sliding surfaces are repaired by machining or the like.

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and while maintaining the conventional advantages, the present invention provides a sealing property that can satisfactorily prevent leakage of fluid from the pump chamber by an extremely simple means. The object of the present invention is to provide an excellent reciprocating pump.

(Means for Solving the Problems) That is, in order to solve the above problems, the present invention provides a cylinder 1 having an inlet port 2 and a discharge port 3, in which a through hole 5 is bored in the curved surface. A cylindrical body 4 is fitted into the cylindrical body 4, and a piston 8 is provided in the cylindrical body 4 so as to reciprocate while rotating. This is a reciprocating pump in which the cylinder body 4 is configured to rotate together with the piston 8 so as to provide face-to-face communication with the suction port 2 of the cylinder 1 and face-to-face communication with the discharge port 3 of the cylinder 1 when the piston 8 moves forward.

(Function) Therefore, in the reciprocating pump characterized by the above configuration, when the piston 8 moves backward as it rotates, the through hole 5 of the cylinder 4 that rotates together with the piston 8 faces the suction port 2 of the cylinder 1. Therefore, fluid is sucked into the cylindrical body 4 from the suction port 2 through the through hole 5, and when the piston 8 moves forward with rotation, the cylindrical body 4 rotates and the through hole 5 is injected into the cylinder 4. Since the fluid is connected to the discharge port 3 of the cylinder 1, the fluid sucked into the cylinder body 4 is discharged from the discharge port 3, and an appropriate pump operation can be performed.

In this case, since the cylinder 4 that rotates together with the piston 8 is interposed between the cylinder 1 and the piston 8, the piston 8, which reciprocates while rotating, reciprocates in relation to the cylinder 4. Therefore, the seal between the piston 8 and the cylinder 4 only needs to consider such reciprocating sliding, and the seal between the cylinders 1 only needs to consider the rotational sliding of the cylinder 4. All you have to do is put a seal between the two.

(Example) An example of the present invention will be described below with reference to the drawings.

First Embodiment In FIG. 1, 1 indicates a cylindrical cylinder with a flange 1ah installed at one end, and an inlet 2 and an outlet 3 are formed facing each other on the peripheral wall at the other end. It becomes.

4 is a cylindrical body provided with a flange 4a at one end;
It is rotatably and slidably fitted inside.

Reference numeral 5 denotes a through hole bored in the outer circumferential surface of the other end of the cylinder 4 and communicating with the pump chamber 16 inside the cylinder 4, and is formed into a long hole shape in the radial direction as shown in FIG. Numerals 6 and 6 are long grooves formed facing each other and having a desired length in the axial direction on one end side of the inner circumferential surface of the cylindrical body 4. 7 is a thrust bearing interposed between the flange 4a of the cylindrical body 4 and the flange 1a of the cylinder 1, which allows the cylindrical body 4 to rotate relative to the cylinder 1.

A piston 8 is fitted into the cylindrical body 4 so as to be able to reciprocate and rotate.
9 is fitted into the long grooves 6, 6 of the cylindrical body 4, so that when the piston 8 is driven to rotate, the cylindrical body 4 rotates together.

That is, the cylindrical body 4 is capable of only rotational movement, and the piston 8 is configured to be capable of rotational movement and reciprocating movement.

Figure 2 shows an example of a pump drive mechanism.
shows a gear-shaped cam follower fixed to one end side of the piston 8. 11 is electric! 112 is a rotatable cylindrical cam, and a cam groove 15 is formed on the outer circumferential surface of the cam follower 0710, which is carved into teeth 14 that mesh with teeth I3 formed on the outer circumferential surface of the cam follower 10 in order to reciprocate while rotating the cam follower 0710. It will be done.

The shape of the cam groove 15 of the cylindrical cam 11 is set so that the cam follower 10 and the piston 8 rotate once while performing one reciprocating operation, and the cylindrical body 4 rotates and the piston 8 rotates. The piston 8 moves forward during the discharge stroke
the switching stroke in which the cylinder 4 reaches the bottom dead center and only continues to rotate together with the cylinder 4; the suction stroke in which the cylinder 4 rotates and the piston 8 moves backward while rotating; the piston 8 reaches the top dead center and the cylinder Together with the body 4, they are formed so as to perform a switching stroke in which only the rotational operation continues.

Further, as shown in FIG. 1(c), the conduction hole 5 formed in the cylinder body 4 is arranged so as to communicate face-to-face with the suction port 2 on the cylinder 1 side when the piston 8 retreats. They are arranged so as to face and communicate with the discharge port 3 on the cylinder 1 side and communicate with the pump chamber 16 in the cylinder body 4, respectively.

Since the reciprocating pump according to the present invention has the above-described configuration, first, when the piston 8 rotates and retreats in the direction indicated by the arrow as shown in FIG. At the same time, the conduction hole 5 of the cylinder 4 is connected to the suction port 2 on the cylinder 1 side.
The other discharge port 3 is closed by the outer peripheral surface of the cylinder 4. Therefore, from the suction port 2 to the conduction hole 5
Fluid can be sucked into the pump chamber 16 via the pump chamber 16 . On this occasion,
Since the conduction hole 5 is formed in the shape of a long hole in the radial direction, the state of conduction between the conduction hole 5 and the suction port 2 is maintained over substantially the entire suction stroke of the piston 8.

After the piston 8 reaches the top dead center, the piston 8 does not move forward immediately but continues to rotate together with the cylinder 4, so that the suction port 2 is connected to the outer peripheral surface of the cylinder 4. At the same time, the passage hole 5 is prepared to be connected to the discharge port 3. That is, due to the existence of this switching stroke, it is possible to prevent the piston 8 from immediately starting to move forward while the conduction state between the conduction hole 5 and the suction port 2 is not released, and the fluid in the pump chamber 16 is transferred to the discharge port. This prevents inconveniences such as backflow to the third side.

Thereafter, when the piston 8 moves forward in the direction B, as shown in FIG. The fluid in the pump chamber 16 is connected to the through hole 5 which is closed on the outer peripheral surface of the body 4.
The liquid can be discharged from the discharge port 3 of the cylinder 1 via the cylinder 1. Then, the pump operation is performed by repeating such suction stroke, switching stroke, and discharge stroke.

In this case, since the cylinder 4 that rotates together with the piston 8 is interposed between the cylinder 1 and the piston 8, the piston 8, which reciprocates while rotating, does not reciprocate in relation to the cylinder 4. Therefore, for the seal between the piston 8 and the cylinder 4, only such reciprocating sliding needs to be considered, and for the seal between the cylinders 1, it is necessary to consider the rotational sliding of the cylinder 4.
), it is only necessary to provide a sealing means between the two. Therefore, the seal between the cylindrical body 4 and the cylinder 1 may be provided with, for example, a circle, and strict machining accuracy is required to ensure the clearance between the cylindrical body 4 and the piston 8. There is no need for additional finishing processing.

The radial dimension of the through hole 5 formed in the cylinder body 4 is determined based on the intended use of the pump, taking into account the reciprocating speed of the piston 8 and the rotational speed of the piston 8 and the cylinder body 4. Any design changes can be made as required.

In short, when the piston 8 retreats, it is in face-to-face conduction with the suction port 2 on the cylinder 1 side, and when the piston 6 is moved forward, it is in face-to-face conduction with the discharge port 3 on the cylinder 1 side, so that it can communicate with the pump chamber 16. The conduction hole 5 may be formed as shown in FIG.

Further, in the above embodiment, since a combination of a cylindrical cam mechanism and a gear mechanism is used as the drive means for the cylinder body 4 and the piston 8, the structure has the advantage of being extremely simple. , the specific configuration of this driving means does not matter.

Second Embodiment In the first embodiment described above, the through hole 5 is formed in the outer peripheral surface of the cylindrical body 4.
It is also possible to arrange the tip end surface at an eccentric position.

That is, the tip of the cylindrical body 4 is formed into a substantially truncated conical shape, and an elongated through hole 5 is bored in the circumferential direction of the inclined surface thereof, as shown in FIG. Further, the cylinder 1 has a discharge hole 17 bent in one end side of the cylinder main body 1a having a discharge port 3 on the peripheral wall thereof and communicates with the discharge port 3, and a suction hole 18 extending in the axial direction.
A bushing 19 having a shape formed therein is fitted into the bushing 19, and a cylindrical guide tube 20 is fitted into the other end thereof. moreover,
An O-ring 21 is installed in the concave groove provided on one end side of the piston 8.
is attached.

Incidentally, a bottle 9 protruding from a predetermined position of the piston rod 22
are fitted into the long grooves 6, 6 of the cylindrical body 4, so that the piston 8 rotates together with the cylindrical body 4, and the driving means for the cylindrical body 4 and the piston 8 are constructed in the same manner as in the first embodiment. are doing.

In this case as well, the piston 8 reciprocates while rotating together with the cylinder body 4, and communicates with the through hole 5 of the cylinder body 4 and the suction port 2 of the bushing 19 or the discharge port 3 of the cylinder body 1a, thereby performing pump operation. is carried out well, and the cylinder 4 rotates together with the piston 8 as in the first embodiment, so the cylinder 4 and the piston 8. The sealing performance between the cylindrical body 4 and the cylinder 1 can be easily improved.

Furthermore, if the through hole 5 is provided at the tip of the cylinder 4 as in this embodiment, the cylinder 4 will rotate while being pressed against the upper surface of the bushing 19 during the discharge stroke. That is, since the conduction hole 5 of the cylindrical body 4 and the discharge hole 17 of the bushing 1 are electrically connected to each other under a constant pressing force, leakage of fluid from between the two is well prevented. Fluid can be discharged.

In particular, there is an advantage in that it is possible to prevent so-called bypass backflow that occurs between the suction port 2 and the discharge port 3 when the discharge pressure becomes high.

In this embodiment, the tip of the cylinder 4 is formed into a substantially truncated cone shape, but it is also possible to simply form it into a cylindrical shape, and the specific shape is not critical. .

Further, as shown in FIG. 5, the piping is connected so that a part of the fluid discharged from the discharge port 3 can be branched and the discharge pressure of the fluid can press the upper surface of the flange 1b of the cylinder body 1a in the axial direction. This causes the cylinder 4 to come into contact with the bushing 19 in a pressed state via the flange 4a of the cylinder 4.
There is an advantage that leakage of fluid between the two can be better prevented. Since this pressing force varies depending on the level of the fluid discharge pressure, an appropriate pressing force can be obtained depending on the fluid discharge state, and the cylinder body 1a and the cylindrical body 4
There is no inconvenience in which this pressing force decreases due to wear of the sliding surfaces.

(Effects of the Invention) As described above, the present invention has a cylindrical body interposed between the cylinder and the piston, which rotates together with the piston.
A piston that reciprocates while rotating only reciprocates in relation to the cylindrical body, so the seal between the piston and the cylindrical body only needs to be considered for such reciprocating sliding, and the seal between the cylinders is based on the cylindrical body. Since only the rotational and sliding movement needs to be taken into account, it is possible to easily seal between the two.

Therefore, unlike the conventional sealing method, which uses a small clearance between the cylinder and the piston as a sealing means, strict machining accuracy is not required, and the manufacturing cost can be significantly reduced. Moreover, a particularly remarkable effect was obtained in that a good sealing state could be maintained.

Further, if a conduction hole is provided at an eccentric position on the tip surface of the cylinder,
When the piston moves back and forth during discharge, the through hole communicates with the cylinder's discharge port while it is pressed against the cylinder, so this pressing force prevents fluid from leaking and effectively directs the fluid from the discharge port. This has the unique effect of being able to be discharged.

This makes it possible to prevent so-called bypass backflow that occurs between the cylinder's suction port and discharge port when the discharge pressure becomes high.

Furthermore, if a part of the fluid discharged from the discharge port is branched and supplied so that the discharge pressure of the fluid can press the distal end surface of the cylindrical body toward the cylinder side, this will allow the distal end of the cylindrical body to Since the surface abuts against the cylinder in a suppressed state, it is possible to more effectively prevent leakage of fluid between the two.

Since this pressing force varies depending on the level of the fluid discharge pressure, an appropriate pressing force can be obtained depending on the fluid discharge state, and due to wear of the sliding surfaces of the cylinder and cylindrical body, etc. There is no inconvenience such as a decrease in this pressing force.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the present invention; FIG. 1A is a cross-sectional view of the main parts of a reciprocating pump, FIG.
No. C in the figure is a partially enlarged perspective view of the cylinder. FIG. 2 is an explanatory diagram showing an example of a driving means. FIG. 3 is a sectional view of main parts showing the state of use. Fig. 4 (A) ([1) and Fig. 5 show other embodiments, Fig. 4 (A) is a cross-sectional view of the main part, Fig. The figure is a sectional view of a main part. Fig. 6 is a sectional view of a main part showing a conventional example.

Claims (1)

[Claims] 1. A cylindrical body 4 having a through hole 5 formed on its circumferential surface is fitted into a cylinder 1 having an inlet 2 and an outlet 3; is provided so that the piston 8 reciprocates while rotating, and moreover, connects the through hole 5 of the cylinder 4 to the suction port 2 of the cylinder 1 when the piston 8 moves backward, and when the piston 8 moves forward. A reciprocating pump characterized in that the cylindrical body 4 is configured to be able to rotate together with the piston 8 so as to provide face-to-face electrical communication with the discharge port 3 of the cylinder 1. 2. A cylindrical body 4 having a through hole 5 bored eccentrically from the axis and bored in the tip surface is fitted into the cylinder 1 having an inlet port 2 and a discharge port 3. is provided so that the piston 8 reciprocates while rotating, and moreover, connects the through hole 5 of the cylindrical body 4 to the suction port 2 of the cylinder 1 when the piston 8 retreats, and connects the inlet 2 of the cylinder 1 when the piston 8 moves forward. A reciprocating pump characterized in that the cylindrical body 4 is configured to rotate together with the piston 8 so as to be electrically connected to the discharge port 3 of the cylinder 1. 3. A part of the fluid discharged from the discharge port 3 is branched and supplied so that the discharge pressure of the fluid can press the distal end surface of the cylindrical body 4 toward the cylinder 1.
Reciprocating pump as described.