JPH089988B2 - Reciprocating vacuum pump - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating vacuum pump which can be assembled and disassembled quickly and easily.

2. Description of the Related Art In the conventional reciprocating vacuum pump, in order to take out the piston 1, as shown in FIG. 6, the nut 2a is removed and the cylinder head cover 2 is removed, and the bellows type piston rod shaft is sealed from the distance piece window 3. Bolt of device 4
4a, 4b are removed, bolt 5a of oil stopper 5 is removed from the day stunt piece window 3, bolt 6a of the wiper ring box 6 is removed from the distance piece window 3, crank case window cover (not shown) is opened, and crank Loosen the lock nut 8a of the piston rod 8 from the case window 7, remove the piston 1 with the piston rod 8 still attached from the cylinder 9, piston nut 8b
Was removed and the piston 1 was removed from the piston rod 8.

Further, the assembly is such that the piston rod 8 is attached to the piston 1 by the piston nut 8b, and the piston 1 attached with the piston rod 8 is inserted into the cylinder 9.
The piston rod 8 is passed through the bellows type piston rod sealing device 4, the oil stopper 5, the wiper ring box 6 and the lock nut 8a, and the port 4a, 4b of the bellows type piston rod shaft sealing device 4 is inserted from the day piece piece window. The bolt 6a of the wiper ring box 6 is tightened, the lock nut 8a of the piston rod 8 is tightened from the crankcase window 7, and the cylinder head cover 2 is attached.

Therefore, in the conventional reciprocating vacuum pump, the piston,
Piston rod, bellows type piston rod shaft sealing device,
Assembling and disassembling the oil stopper, wiper box, etc. requires a great deal of time and labor.In addition, the workability of the small machine becomes extremely poor. Since a tool must be used, there is a risk of damaging the piston rod and the like.

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention enables assembly work only from the cylinder bottom cover side, and first attaches a piston rod and a bellows type piston rod sealing device to a crosshead. , Next, attach the piston to the piston rod,
The bellows type piston rod sealing device and the pistol can be easily and quickly assembled, and the disassembling work can be performed only after removing the cylinder top cover from the cylinder bottom cover side to the piston, bellows type piston rod sealing device and piston rod order. It is intended to provide a reciprocating vacuum pump which can be easily and quickly disassembled.

In order to achieve the above object, the reciprocating vacuum pump according to the present invention includes a piston rod 23 having a collar portion 231 formed at a rear end portion thereof, as shown in FIGS. 1 to 5. Provided is a bellows-type piston rod sealing device 26 having a head flange 261 formed at one end and a bottom flange 262 formed at the other end, and a piston 21 adapted to be attached by a lock bolt device 29 at the front end portion of the piston rod 23. A reciprocating vacuum pump, in which a collar portion 231 is fitted between a crosshead 11 and a bottom flange 262 of a bellows type piston rod sealing device 26, and the piston rod 23 is crossheaded together with the bellows type piston rod sealing device 26. 11, the head flange 261 of the bellows type piston rod sealing device 26 is attached to the cylinder bottom cover 25, and the piston 21 is fixed. Rotsukuboruto equipment to the front end portion of the rod 23
After mounting with 29, the cylinder top cover 24 is connected to the cylinder bottom cover 25, and the piston rod 23,
The bellows type piston rod sealing device 26, the piston 21, and the cylinder top cover 24 can be assembled in this order, and can be disassembled in the reverse order.

In the present invention, the piston rod 23 is fitted into the piston through hole 210, and the lock bolt device 29 shown in FIG. 5 is inserted from one direction between the inner peripheral surface of the through hole 210 and the outer peripheral surface of the piston rod 23. The piston rod 23 is centered and fixed, and this lock bolt device 29 is composed of at least two or more lock bolts 291, a rod outer fitting 292, and a sliding tool 293. The lock bolt 291 is mounted on the rod outer fitting. As the screw rod 2930 of the sliding tool 293 is screwed through the hole 2920 of the 292, the piston rod 23 can be centered and the piston rod 23 can be fixed to the through hole 210. There is.

Further, the bellows type piston rod shaft sealing device 26 is a thin metal which is welded in an accordion ion shape so that it can be expanded and contracted, and the piston rod 23 is sealed between the crosshead 11 and the cylinder bottom cover 25. .

Embodiment An embodiment of a reciprocating vacuum pump of the present invention is shown in the drawings.

The vacuum pump of this example includes a crank movement mechanism 10, a piston movement mechanism 20, a flywheel portion 30, and a drive motor portion 40.

The crank movement mechanism 10 includes a crosshead 11 that reciprocates via a pair of crosshead guide portions 12, a connectin rod 14 that is rotatably connected through a crosshead pin 13, and a pair of connectin rods. A crank shaft 16 that is rotatably connected to the bridge 14 via a crank pin 15 and a pair of bearings that support the crank shaft 16.
A crankcase 19 is provided with a shaft seal device 18 for shaft-sealing the crankshaft 16.

It should be noted that the pair of crossheads 11 are provided with air circulation holes 110, respectively, and a space 190 inside the crankcase 19 and
Space where the bellows type piston rod sealing device 26 is installed
It communicates with 260. A water jacket 120 is provided on the outer circumference of the crosshead guide portion 12.

A pair of cross head guide bush 121, cross head pin bush 131, crank pin metal 151 are made of a sintered alloy containing a solid lubricant, and a pair of crank shaft bearings 17 are made of a shield type bearing. For the crankshaft shaft sealing device 18, a grease-sealed oil seal is used, and each can be lubricated without oil.

The piston moving mechanism 20 includes two laterally opposed pistons 21 and 21 (the pistons on the receiving side and the left side both operate toward bottom dead center and both toward top dead center), and a pair of pairs. , A cylinder 22, a piston rod 23 that is connected to the piston 21 at one end and is fitted to the crosshead 11 at the other end, a cylinder bottom cover 25 that is tightly connected via a cylinder head cover 24 and a V-shaped band coupling 28, and a bellows type piston rod seal. A device 26 and a gas communication pipe (not shown) are provided.

The V-shaped band coupling 28, as shown in FIG.
When the two flanges 221 and 221 are combined to form a V-shaped protrusion, it is composed of a V-shaped band 281 divided into two parts that fit into the V-shaped protrusion and a plate band 282 that tightens the two.
The one and the two 221 are closely bonded.

The piston 21 is fitted with a piston ring 211 containing a tetrafluoroethylene resin as a main component, and a rider ring 213 containing a tetrafluoroethylene resin as a main component is fitted to each of the inner walls of the cylinder 22. It can be slid without oil. An intake / exhaust valve 214 is provided on the upper surface of each of the pair of pistons 21. Further, the cylinder head cover 24 is provided with a suction valve 241 at a position corresponding to the intake / exhaust valve 214 of the piston 21. Further, the cylinder bottom cover 25 is provided with a discharge valve 251 at a position corresponding to the intake / exhaust valve 214 of the piston 21.

As shown in FIGS. 1 and 2, the bellows-type piston rod sealing device 26 has a head flange 261 formed at one end and a bottom flange 262 formed at the other end, so that the head flange 261 is attached to the cylinder bottom cover 25. Bolt to this 271
The bottom flange 262 is fitted into the rod through hole 252 of the cylinder bottom cover 25.
Also, the bolts 272 are inserted from the rod through holes 270 of the holding plate 27 and screwed into the cross head 11 so as to be fixed thereto.

The piston rod 23 has a flange portion 231 formed at a rear end portion thereof, and the flange portion 231 is fitted between the bottom flange 262 and the cross head 11 so that the cross head 11 together with the bellows type piston rod sealing device 26 can be formed. Attached to the
Further, the piston 21 is attached to the front end portion by the lock bolt device 29 so as to be centered and fixed.

Further, in this example, as in the conventional opposed reciprocating vacuum pump, the weights of the reciprocating parts facing each other are equalized, and
In addition to balancing the unbalanced inertial force of the rotary motion part, in addition to the crankshaft 16, each cylinder 22
Are arranged horizontally opposite to each other so that the axes of the cylinders 22 are aligned, and the crankshaft 16 is provided with three adjacent crankpins 15 with an angle of 180 degrees, and the central crankpin 15 is straight. It is connected to the class head 11 of one piston rod 23 via the connectin rod 14, and the crank pins 15 and 15 on both sides of the central crank pin 15 are connected.
However, it is connected to the crosshead 11 of the other piston rod 23 through a connectin rod 14 having a bifurcated shape.

The reciprocating vacuum pump of the present invention draws gas into the suction chamber 242 from the suction port 240 of the right cylinder head cover 24 as the right piston 21 moves from the top dead center to the bottom dead center (drawing stroke). Once in, the gas is sucked into the cylinder 22 through the suction valve 241. At this time, since the intake / exhaust valve 214 of the piston 21 is closed, the gas in the cylinder 22 on the bottom dead center side of the piston 21 is discharged from the discharge valve 251 of the cylinder bottom cover 25 as the piston 21 moves toward the bottom dead center. From outlet 250
To the suction chamber 2 through a gas communication pipe (not shown) and the suction port 240 of the left cylinder head cover 24.
42 (at this time, the left-side piston 21 moves toward the bottom dead center while the right-side piston 21 moves toward the bottom dead center), and then enters the cylinder 22 from the suction valve 241 and sucks and exhausts the piston 21. Piston 21 due to valve 214 being closed
The gas in the cylinder 22 on the bottom dead center side of the discharge valve 25 of the cylinder bottom cover 25 moves as the piston 21 moves toward the bottom dead center.
It is discharged from 1 to the discharge port 250 and guided to the outside. When the pistons 21 on the right side and the left side respectively go from the bottom dead center to the top dead center (push stroke), the intake / exhaust valve 214 thereof functions as an intake valve. That is, as the right-side piston 21 moves from the bottom dead center to the top dead center as shown in FIG. 2, the intake / exhaust valve 214 of the right-side piston 21 receives the gas pressure sucked in the pull stroke and the valve leaf spring. Due to the difference in pressure, the piston 21 opens
Gas is sucked into the cylinder 22 on the bottom dead center side of. At this time, the discharge valve 251 is closed. Similarly to the piston 21 on the right side, the piston 21 on the left side performs the suction operation.

EFFECTS OF THE INVENTION The reciprocating vacuum pump of the present invention has a collar portion 231 at the rear end portion.
Piston rod 23 formed with a head flange at one end
261 and a bottom flange 262 at the other end of the bellows type piston rod sealing device 26 and the piston rod 23.
Since the piston 21 is attached to the front end portion of the piston 21 by the lock bolt device 29, the assembly and disassembly work of the piston movement mechanism 20 is performed by the cylinder bottom cover 25.
The lock bolt device 29 is used when the piston 21 is attached to the piston rod 23, and the crosshead 11, the piston rod 23, and the piston 21 can be accurately centered. Moreover, since the assembly work is performed in the order of the piston rod 23, the bellows type piston rod sealing device 26 and the piston 21, it becomes easy,
Can be done quickly. Further, the disassembling work can be carried out simply and quickly in the reverse order of the assembling work.

Further, since the tool is not used by digging through the distance piece window and the crankcase window, the piston rod 23 is not damaged.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention, in which FIG. 1 is an overall front view showing a part in section, FIG. 2 is a sectional view of an essential part, and FIG. FIG. 4 is an explanatory view showing the assembly, FIGS. 4 (a) and 4 (b) are a usage state diagram of the V-shaped coupling and a cross-sectional view of a main part, and FIG. FIG. 6 is a sectional view showing a conventional example. 11 …… Cross head 21 …… Piston 22 …… Cylinder 23 …… Piston rod 231 …… Crimper 24 …… Cylinder top cover 25 …… Cylinder bottom cover 26 …… Bellows type piston rod sealing device 261 …… Head flange 262 …… Bottom Flange 29 ...... Lock bolt device

Claims (1)

[Claims] 1. A bellows type piston rod sealing device 26 having a piston rod 23 having a collar portion 231 formed at a rear end portion thereof, a head flange 261 formed at one end thereof and a bottom flange 262 formed at the other end thereof, the piston rod 23 being provided with a piston rod 23. A reciprocating vacuum pump having a piston (21) attached to the front end portion by a lock bolt device (29), comprising a collar portion (23)
1 is fitted between the crosshead 11 and the bottom flange 262 of the bellows type piston rod sealing device 26, the piston rod 23 is attached to the crosshead 11 together with the bellows type piston rod sealing device 26, and the head of the bellows type piston rod sealing device 26 is attached. After attaching the flange 261 to the cylinder bottom cover 25 and attaching the piston 21 to the front end portion of the piston rod 23 by a lock bolt device 29,
By connecting the cylinder top cover 24 to the cylinder bottom cover 25, the piston rod 23, the bellows type piston rod sealing device 26, the piston 21 and the cylinder top cover 24 can be assembled in this order, and can be disassembled in the reverse order. Reciprocating vacuum pump characterized by.