JPH10176666A - Lubrication of piston and valve in piston reciprocating type gas pump and airtight method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively form a lubricating oil film on a sliding part, and prevent seizure and the like by rotating a piston so as to prevent a piston and cylinder from being brought into contact with each other repeatedly at a constant part while the piston performs reciprocating motion, and moving a contact point of the piston and the cylinder in order. SOLUTION: Rotating motion of a crank 1 driven by power in a cylinder main body 9 is transmitted to a piston 7 for reciprocation through a connecting rod 2 and a cross head 3. A cylinder bore 8 is rotated through a piston rotating gear 11 by rotation of a piston rotating pinion 10 which is interlocked with power for rotating the crank 1, and the piston 7 is rotated through engagement of an internal gear 13 and a planetary pinion 12 which revolves around a center of the bore 8. A thin lubricating oil film is formed on the piston 7 by component force 14 in the rotating center direction of both gears in the engaging point of the pinion 12 and the internal gear 13 so as to hold lubricating performance of the sliding part in a high level.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION A piston reciprocating gas pump is widely used for pressurizing or depressurizing gas because of its simple structure.

[Prior art]

(1) Seizure is a problem common to all machines, but measures have conventionally been taken focusing on lubrication. In the case of seizure, when heat accumulates as a result of fixing the contact position between the parts where the seizure occurred, there was no effective technique for dispersing the contact position. (2) It has been common to use a piston ring to prevent gas leakage from a piston. However, as a result, friction increased, power consumption increased, and the temperature also increased, and there was a risk of seizure. (3) Both the suction valve and the discharge valve are arranged in the cylinder head, but are located between the piston and the cylinder head, that is, the gap between the piston top plane (18) and the cylinder head bottom surface (33) at the top dead center. The gas in the space (32) is sent out by the piston, and the gas pressurized in the final stage of the discharge stroke is not sent out and is left in the cylinder. In the subsequent suction stroke, this residual gas is removed. There is no effective way to prevent the gap loss, which causes free expansion and greatly reduces the pumping efficiency of the piston.

[Problems to be solved by the invention]

(1) To move the contact point between the piston and the cylinder by rotating the piston so that the piston and the cylinder do not come into contact repeatedly during the reciprocating motion of the piston at a certain position. (2) A thin oil film is developed with emphasis on the contact point (15) between the piston and the cylinder to ensure lubrication between the two and to transfer heat between the two through the oil film. On the other hand, a small amount of pressure gas is allowed to naturally leak toward the back pressure side of the piston in the minute gap between the two at the point (16) which naturally occurs on the opposite side. (3) Damage to related parts can be avoided even in the event of contact with the discharge valve or suction valve at the top dead center of the piston during the discharge stroke.

[Means for Solving the Problems]

(1) Piston from inside to planetary pinion (12)
To make rolling contact with the inner surface of the cylinder bore (8) with sliding similar to the tooth surface near the meshing pitch point of the gear. In this way, the piston and the cylinder move from one to the next in accordance with the rotation of the piston, and the first contact on the outer periphery of the piston does not come into contact until the piston and the cylinder make one revolution. (2) Provide a very shallow gas path on the outer peripheral side of the piston that allows gas to pass through at the point (16) opposite to the center line of the piston at the contact point (15) but does not allow lubricating oil to pass easily. , The compressed gas leaks spontaneously. (3) The discharge valve (22) and the suction valve (26) are arranged on the center line of the piston (7), and the discharge valve and the suction valve can be freely connected and rotated around the common center line. Damage caused by a series of collisions that can occur in between can be avoided.

The piston reciprocating gas compression pump or vacuum pump is indispensable to the conventional piston reciprocating pump by renewing the method of lubricating and sealing the piston and valve. (1) No piston ring is required. (2) Volumetric efficiency was improved by changing the arrangement of valves. (3) As a result, the number of stages in a multi-stage pump was reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a piston drive type.

FIG. 2 is an explanatory view of a valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Crank 2 Connecting rod 3 Crosshead 4 Piston rod 5 Snap ring 6 Dowel pin 7 Piston 8 Cylinder bore 9 Cylinder main body 10 Piston rotation pinion 11 Piston rotation gear 12 Planetary pinion 13 Piston internal gear 14 Planetary pinion 12 and piston internal gear 13
The direction in which the piston is pressed against the cylinder bore by the component force in the center direction of the two gears generated at the point of meshing with the piston 15 The contact point between the piston and the cylinder bore 16 The gap between the piston and the cylinder bore 17 The rotating bearing part of the piston rod 18 The top plane of the piston 19 Discharge Valve center line 20 Cylinder head 21 Dowel pin 22 Discharge valve 23 Discharge valve seat 24 Discharge valve spring 25 Cylinder head cover 26 Suction valve 27 Valve guide 28 Suction valve spring 29 Spring seat 30 Discharge airway 31 Cylinder head lower surface 32 Clearance space

Claims (3)

[Claims] 1. A rotary motion of a crank (1) driven by power contained in a cylinder body (9) is converted into a reciprocating motion of a crosshead (3) via a connecting rod (2). A piston rod (4) is statically engaged with the crosshead (3), and is axially moved by a snap ring (5).
The two are connected in the rotational direction by the knock pin (6). A piston (7) is slipped into the cylinder bore (8), and a crosshead (3) is inserted through a piston head (4).
The reciprocating motion of the crosshead is transmitted to the piston. Crank (1) on cylinder body (9)
Rotating pinion (1
The piston rotating gear (11) meshing with 0) is always rotating at the same position as the center line of the cylinder bore (8). Above this is a piston driven planetary pinion (12) that orbits a radius R from the center of the bore (8), and meshes with an internal gear (13) provided on the inner wall of the piston to form the piston (7). It is always rotating as it fits in the cylinder bore. The piston moves to the contact point (15) via a thin lubricating oil film on the inner wall of the cylinder bore due to the component force (14) in the direction of the center of rotation of the two gears at the meshing point of the planetary pinion (12) and the piston internal gear (13). As the piston is rotated while being pressed, the outer periphery of the piston that has not yet come into contact with the contact point (15) sequentially contacts the inner wall of the cylinder and rolls. Thus, the temperature at the top of the piston, which has been increased by the compression of the gas, is transmitted to the cylinder to cool the cylinder and cool the contact point (1).
At the point (16), which is symmetrical with the piston center line in (5), the piston is separated from the inner wall of the cylinder bore and a minute gap appears, and a small amount of compressed air leaks to the back pressure side of the piston. A cooling method in which the inner wall of the piston and the cylinder bore in the vicinity thereof is cooled, and further, the gap portion is sequentially moved to an adjacent area as the piston rotates. 2. Lubricating oil at a pressure higher than compressed air passes through an oil passage of a crank (1), passes through a connecting rod (2), a crosshead (3), and passes through a jet hole at a tip end of a piston rod to a piston at a piston top. At the same time as lubricating the rotary bearing (17) of the rod, it flows out to the piston top plane (18),
With the rotation of the piston, the oil reaches the outer periphery of the piston by centrifugal force and forms an oil film on the inner wall of the cylinder to lubricate between the piston and the cylinder. A method in which part of the lubricating oil riding on the flow of compressed air further moistens the discharge valve seat to prevent wear of the valve seat and to increase airtightness of the valve seat when the valve is closed, thereby preventing leakage of high-pressure air. 3. The cylinder head (20) is assembled with the cylinder body (9) and the knock pin (21) so that the center line (19) of the discharge valve coincides with the center line of the cylinder bore (8). The discharge valve (22) is a cylinder head (20)
Cylinder head cover (2)
5) and the discharge valve spring (24) by the discharge valve seat (2).
3) Close contact. The suction valve (26) is connected to the discharge valve (2
It is incorporated in the discharge valve concentrically with 2) and is seated on a suction valve seat provided on the discharge valve by a suction valve spring (28) and a spring seat (29) of a valve guide (27). When the pressure in the cylinder becomes higher than the set output of the discharge valve by the piston during the compression stroke, the discharge valve automatically deflects the spring (24) and separates from the valve seat (23), and the high pressure gas is discharged from the discharge airway in the cylinder head. It flows out to (30) and is stored in the air tank. When the piston goes around the top dead center, the pressure in the gap space (31) sandwiched between the lower surface (30) of the cylinder head and the plane (18) at the top of the piston drops rapidly when the piston starts to descend, and the discharge valve is also operated by the discharge valve spring (24). Return to the original position and close the discharge valve. At this time, since the suction valve is built into the discharge valve, it is possible to distort the possibility that the suction valve will suddenly fall away from the suction valve seat due to the sudden drop of the discharge valve and the impact and inertia at the time of seating and come into contact with the piston top. Absent. Both the suction valve and the discharge valve are arranged coaxially with the center line of rotation of the piston, and can rotate freely, so even if they come into contact, they are pulled by the piston and rotate to avoid damage, minimizing gap loss. A way to maximize volumetric efficiency.