JP3640412B2 - Reciprocating pump unit - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a reciprocating pump unit including a piston pump, a diaphragm pump, and the like, and more particularly to a reciprocating pump unit in which a plurality of reciprocating pumps are driven by a drive shaft of a driving source.
[0002]
[Prior art]
As shown in FIG. 3, the piston pump unit 1 is configured by arranging piston pumps 3 </ b> A and 3 </ b> B at both ends of the electric motor 2, the piston pump 3 </ b> A functions as a compressor, and the piston pump 3 </ b> B functions as a vacuum pump. The pistons 4 of the piston pumps 3 </ b> A and 3 </ b> B are integral with the connecting rod 5, and are connected to drive shafts 6 protruding from both ends of the electric motor 2 so that the cylinder 7 can be reciprocated.
[0003]
In the piston pump unit 1 as described above, a phase difference of 180 degrees is set between the piston 4 of the piston pump 3A and the piston 4 of the piston pump 3B in order to maintain a good dynamic balance between the piston pumps 3A and 3B. Has been.
[0004]
[Problems to be solved by the invention]
However, when a phase difference of 180 degrees is set for the pistons 4 of the piston pumps 3A and 3B, the piston pump 3B moves from the top dead center toward the bottom dead center as shown in FIGS. 3 (A) and 3 (B). The piston pump 3A functions as a compressor from the bottom dead center to the top dead center. Therefore, at this time, the force that impedes the movement acts on the pistons 4 of both piston pumps 3A and 3B, and the load acting on the electric motor 2 from both piston pumps 3A and 3B becomes remarkably large.
[0005]
On the other hand, when the piston pump 3B moves from the bottom dead center to the top dead center, the piston pump 3B moves in a direction to eliminate the negative pressure. At this time, the piston pump 3A is in a state where no pressure acts from the top dead center to the bottom dead center. Become. For this reason, the load which acts on the electric motor 2 from both piston pumps 3A and 3B will be in an almost no load state .
[0006]
As described above, in the conventional piston pump unit 1, the load acting on the electric motor 2 from the piston pumps 3 </ b> A and 3 </ b> B is greatly varied during one cycle of the electric motor 2, and the load on the electric motor 2 becomes large. There is a possibility that the temperature of the electric motor 2 will rise.
[0007]
The same applies to a system using a diaphragm pump as well as the piston pump unit.
[0008]
The present invention has been made in consideration of the above-described circumstances, and an object thereof is to provide a reciprocating pump unit capable of realizing a stable operation without applying a high load to a driving source.
[0009]
[Means for Solving the Problems]
According to one aspect of the present invention, a drive source having a drive shaft, and two reciprocating pumps, each having a reciprocating member driven by the drive shaft of the drive source, one of these reciprocating pumps The reciprocating pump has a large load acting on the drive source by functioning as a vacuum pump when the reciprocating body of the one reciprocating pump moves from top dead center to bottom dead center. The load hardly acts when going to the point, and the other reciprocating pump functions as a compressor when the reciprocating body of the other reciprocating pump goes from bottom dead center to top dead center . large load acting, in the reciprocating pump unit load is configured almost like does not act when toward the bottom dead center from the top dead center, the two reciprocating Pump in which reciprocating motion of said reciprocating member having each characterized by being carried out in the same phase.
[0011]
[Action]
Therefore, according to the reciprocating pump unit according to the present invention, the reciprocating operations of both the reciprocating pumps are performed in the same phase. When moving to a point, the load acting on the drive source from the reciprocating pump functioning as a vacuum pump is large, and the load hardly acts from the reciprocating pump functioning as a compressor. Further, when the reciprocating body moves from the bottom dead center to the top dead center, the load acting on the drive source from the reciprocating pump functioning as a compressor is large, and almost no load acts from the reciprocating pump functioning as a vacuum pump.
[0012]
In this way, in one cycle of the drive source, the load from the two reciprocating pumps to the drive source acts almost evenly and the load fluctuation is reduced, so that a high load does not act on the drive source and the temperature of the drive source rises. This can prevent the reciprocating pump unit from operating stably.
[0013]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a sectional view showing an embodiment of a piston pump unit according to the present invention. FIG. 2 is a block diagram showing the operation of the piston pump unit of FIG.
[0014]
As shown in FIG. 1, the piston pump unit 10 is configured by disposing a piston pump 12A functioning as a compressor and a piston pump 12B functioning as a vacuum pump on both ends of an electric motor 11 as a drive source. .
[0015]
The electric motor 11 is an AC motor in which a stator 14 is accommodated in a motor case 13 and a rotor 15 rotates in the stator 14. Drive shafts 16 project from both ends of the rotor 15.
[0016]
The piston pumps 12 </ b> A and 12 </ b> B are configured such that a piston 18 is reciprocally moved in a cylinder 17, and a connecting rod 19 is integrally formed with the piston 18. A piston ring 31 is interposed between the piston 18 and the ring presser 30, and the piston ring 31 slides on the inner wall surface of the cylinder 17. A flywheel 20 is fitted to the drive shaft 16 of the electric motor 11, and a balance weight 21 is fixed to the flywheel 20 with bolts 22. The flywheel 20 and the balance weight 21 reduce vibration caused by the reciprocating movement of the piston 18.
[0017]
An eccentric pin 23 projects from the flywheel 20, and the connecting rod 19 is rotatably supported by the eccentric pin 23 via a bearing. When the drive shaft 16 rotates, the eccentric pin 23 rotates around the drive shaft 16 of the electric motor 11, so that the piston 18 reciprocates in the cylinder 17 via the connecting rod 19.
[0018]
The cylinder 17 is fitted into the motor case 13 of the electric motor 11 and is covered with a cylinder head 24. A valve mechanism 25 is installed between the cylinder 17 and the cylinder head 24. With the valve mechanism 25 as a boundary, the inside of the cylinder head 24 is an air introduction chamber 26 and the inside of the cylinder 17 is a cylinder chamber 27.
[0019]
In the piston pump 12 </ b> A, air is sucked from the inlet 28 into the cylinder chamber 27 through the valve mechanism 25 through the air inlet chamber 26 in the process of moving the piston 18 from the top dead center to the bottom dead center. Further, in the process of moving the piston 18 from the bottom dead center to the top dead center, the air in the cylinder chamber 27 is compressed, and this compressed air is projected from the projection port 29 via the valve mechanism 25 and the air introduction chamber 26, Compressed air is supplied to the device connected to the protruding port 29. Thus, the piston pump 12A functions as a compressor.
[0020]
Further, in the piston pump 12B, air is sucked from the inlet 28 into the cylinder chamber 27 through the air inlet chamber 26 and the valve mechanism 25 in the process of the piston 18 moving from the top dead center to the bottom dead center. The device connected to is set to negative pressure. Thus, the piston pump 12B functions as a vacuum pump. In the process of moving the piston 18 from the bottom dead center to the top dead center, the air in the cylinder chamber 27 is discharged from the protruding port 29 via the valve mechanism 25 and the air introduction chamber 26.
[0021]
By the way, the pistons 18 of the piston pumps 12A and 12B are set to the same phase. Therefore, as shown in FIGS. 2A and 2B, when the pistons 18 of both piston pumps 12A and 12B go from the top dead center to the bottom dead center, the piston pump 12B functioning as a vacuum pump is transferred to the electric motor 11. The acting load is large, and the load hardly acts from the piston pump 12A functioning as a compressor. Further, when the piston 18 moves from bottom dead center to top dead center, the load acting on the electric motor 11 from the piston pump 12A functioning as a compressor is large, and the load hardly acts from the piston pump 12B functioning as a vacuum pump. .
[0022]
In this way, in one cycle of the electric motor 11, the load from the piston pumps 12A and 12B to the electric motor 11 acts almost evenly and the load fluctuation is reduced, so that a high load does not act on the electric motor 11, The temperature increase of the electric motor 11 can be prevented, and the piston pump unit 10 can be operated stably.
[0023]
Even if the pistons 18 of the piston pumps 12A and 12B are set to the same phase, the action of the balance weight 21 and the stroke of the piston 18 are short from the solid line position to the two-dot chain line position in FIG. There is little inconvenience of dynamic imbalance.
[0024]
In the above embodiment, an example in which the drive shaft 16 protrudes from both ends of the electric motor 11 as a drive source and the piston pumps 12A and 12B are disposed at both ends of the electric motor 11 has been described. A drive shaft may be extended from one side, and both piston pumps may be arranged along this extending direction.
[0025]
Moreover, in the said Example, although the piston pump was demonstrated as an example as a reciprocating pump, it is good also as a diaphragm pump.
[0026]
【The invention's effect】
As described above, according to the reciprocating pump unit according to the present invention, stable operation of the reciprocating pump unit can be realized without applying a high load to the drive source.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a piston pump unit to which an embodiment of a reciprocating pump unit according to the present invention is applied.
FIG. 2 is a configuration diagram showing an operation of the piston pump unit of FIG. 1;
FIG. 3 is a block diagram showing the operation of a conventional piston pump unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Piston pump unit 11 Electric motor 12A, 12B Piston pump 16 Drive shaft 17 Cylinder 18 Piston 23 Eccentric pin 25 Valve mechanism

Claims (1)

A drive source having a drive shaft and two reciprocating pumps each having a reciprocating body driven by the drive shaft of the drive source, and one of the reciprocating pumps is one of the reciprocating pumps. When the reciprocating body of the dynamic pump moves from top dead center to bottom dead center, the load acting on the drive source is large by functioning as a vacuum pump, and almost no load acts when moving from bottom dead center to top dead center. The other reciprocating pump has a large load acting on the drive source by functioning as a compressor when the reciprocating body of the other reciprocating pump moves from bottom dead center to top dead center. In the reciprocating pump unit configured so that the load hardly acts when going to the bottom dead center from
The reciprocating pump unit characterized in that the reciprocating motions of the reciprocating bodies respectively included in both the reciprocating pumps are performed in the same phase.

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