JPH01203696A - Automatic priming centrifugal pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric automatic priming type centrifugal pump for handling liquids such as water, and particularly to a system in which a wet vacuum pump is connected to a main electric motor.

Conventional technology Conventionally, an electric centrifugal pump equipped with an automatic priming device in which a wet vacuum pump is directly connected to the main motor has a pressure-operated control device activated at the same time as the priming of the centrifugal pump is completed, and the vacuum pump suction pipe is connected to the atmosphere. Vacuum pumps were generally operated without load.

Problems to be Solved by the Invention In such conventional automatic priming devices, the pressure detection device and valve drive device of the pressure actuation control device are complicated, large and expensive, and the vacuum pump remains unloaded even after priming is completed. Since the vacuum pump is operated in a constant state, it requires durability, and there is a problem in that the loss of driving force becomes large.

The present invention solves the above-mentioned conventional problems, and provides an automatic priming centrifugal pump that can eliminate the no-load operation of the vacuum pump after priming is completed, reduce load loss of the drive motor, and can be made compact and inexpensive. The purpose is to

Means for Solving the Problems In order to solve the above problems, an automatic priming centrifugal pump of the present invention includes a drive motor, a centrifugal pump connected to the drive motor, and a centrifugal pump connected to the drive motor via a one-way clutch. The pump includes a positive displacement rotary pump, a control unit for reversing the driving motor in forward and reverse directions, and a check valve provided in a bypass that communicates the suction port of the centrifugal pump with the suction port of the positive displacement rotary pump. be.

Effect With the above configuration, first, the drive motor is rotated, for example, in the reverse direction, and water is primed to the centrifugal pump through the bypass by the self-priming force of the positive displacement rotary pump.At this time, although the centrifugal pump is in the reverse direction, The auxiliary action is performed without interfering with the suction action, and when the drive motor is reversed, for example, in the forward rotation direction when priming is completed, the force transmitted from the drive motor to the positive displacement rotary pump is reduced by the action of the one-way clutch. is released, the centrifugal pump rotates in the normal direction, sucks in the priming water that has filled up to the suction port, and starts the discharge action. Furthermore, at this time, the bypass is closed by the action of the check valve, and normal water suction is performed only from the suction pipe of the centrifugal pump.Therefore, the durability of the positive displacement rotary pump is easily ensured, and load loss of the drive motor is reduced. can.

Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a sectional view of essential parts of an automatic priming centrifugal pump according to an embodiment of the present invention. In Fig. 1, 1 is a drive motor consisting of a DC commutator motor with a drive shaft 2 protruding from both sides, and a connection terminal 3 is connected to a small lead-sealed storage battery (not shown) as a driving power source, a timer, and a switch for forward/reverse switching. A control section consisting of a changeover switch is connected to 1ffC. The drive motor 1 is attached to the pump body 5 via a plate 4. In addition, a suction port 6 is provided on the right side of the drive motor 1.
A centrifugal pump 10 is provided, which includes an impeller 7 which is press-fitted onto the drive shaft 2 and a casing 9 having a discharge port 8 and which is fixed to the main body 5 of the bong 1 with screws.

Further, on the left side, a drive gear 12 fixed to the drive shaft 2 via a one-way clutch 11 and a reduction gear 13 meshed with the drive gear 12 are shown.
A gear pump 16 is provided, which is a positive displacement rotary pump driven by a pump and equipped with a suction port 14 and a discharge port 15. A drive shaft 2 is connected between the centrifugal pump 10 and the pump body 5.
The drive motor 1 is kept watertight by an oil seal that is in sliding contact with the drive motor 1 to prevent water from leaking to the drive motor 1 side. Further, a bypass port 20 is formed at the suction port 6 of the centrifugal pump 10, and a bypass port 20 is provided with a check valve 19 made of a synthetic resin ball 17 and a tapered surface 18. It is communicated with.

As shown in FIGS. 1 and 2, the gear pump 16 includes a pair of gears made of an engineering plastic material covered with a pump casing 24 made of sintered carbon or the like sandwiched between a case 22 and a lid 23, and a cover 25. 26, the case 22 is fixed to the pump body 5 by screws (not shown), and is driven via a drive shaft 27. The one-way clutch 11 is the centrifugal pump 10
The impeller 7 is installed in such a direction that it rotates idly when it rotates in the forward direction, and transmits transmission when it rotates in the reverse direction. Further, a water suction pipe 28 is provided at the suction port 6 of the centrifugal pump 10.
A discharge pipe 29 shown in FIG. 3 is connected to the discharge port 8,
Each open end is immersed in liquid 30. Furthermore, a discharge pipe 31 is connected to the discharge port 15 of the gear pump 16, and its open end is immersed in the liquid 30.

Next, the circuit configuration of the control section will be explained based on FIG. 4. The connection terminal 3 of the drive motor 1 and the small sealed lead-acid battery 32 for the drive power source are connected via a changeover switch 33. At this time, the common terminal of the changeover switch 33 with 2 circuits and 6 contacts is connected to both pole sides of the storage battery 32. Both switching terminals are connected to both connection terminals 3, respectively, and when the changeover switch 33 is changed over, the drive motor 1 is rotated in the forward and reverse directions.
The contacts can be simultaneously switched by a cam or the like by the operation of a timer (not shown). 34 is a power switch, and 35 and 36 are capacitors and resistors interposed in parallel between both connection terminals 3 in order to limit the current generated when the changeover switch 33 is switched.

The operation will be explained using the above configuration. power switch 3
4, the drive motor 1 rotates in the direction of driving the gear pump 16 via the one-way clutch 11 (this is the reverse direction), and the self-priming force of the gear pump 16 causes the bypass pipe 21 to be pulled from the suction port 14. Through centrifugal pump 1
The liquid 30 is suctioned from the water suction pipe 28 of 0, filling the entire pipe line of the centrifugal pump 10, and priming is completed. At this time, a portion circulates into the liquid 30 from the discharge pipe 31 of the gear pump 16. Then, by operating a timer set in advance to the time required to fill the pipe line of the centrifugal pump 10, the contacts of the changeover switch 33 are switched, and the drive motor 1 consisting of a DC commutator motor is reversed in the normal rotation direction. The impeller 7 of the centrifugal pump 10 rotates normally and starts a discharge action. At this time, the gear pump 16 is released from transmission by the one-way clutch 11, so the drive time of the gear pump 16 can be minimized and durability can be easily ensured (and the load loss applied to the drive motor 1 can be reduced). In addition, since the check valve 19 is closed by the suction force of the centrifugal pump 10, no air is mixed in, and the open end of the discharge pipe 31 of the gear pump 16 is left open to the atmosphere. You can also do it.

In this embodiment, the open end of the discharge pipe 29 of the centrifugal pump 10 is immersed in the liquid 30, but another check valve is provided near the discharge port 8 to eliminate liquid suction on the discharge pipe 29 side. If the liquid is sucked only on the water suction pipe 28 side, the time required for priming can be shortened, and the liquid 30 filled up to the suction port 6 can be easily cased by the suction force of the centrifugal pump 10 due to the reversal of the drive motor 1. In this embodiment, the axis of the centrifugal pump 10 is oriented horizontally, and the action of its own weight also acts, but even if it is oriented vertically, the drive motor 1 can be smoothly reversed. We have confirmed that the above operation can be achieved by Furthermore, in this embodiment, the gear pump 1
6 was used, but a vane pump may be used for this purpose.In short, a positive displacement rotary pump with self-priming capability is sufficient.The timer may be a mechanical timer driven by a spring spring, or a motor-driven motor timer. Any type of electronic timer using an electronic circuit may be used as long as it can send a drive signal to a control unit that reverses the drive motor 1 after the elapse of time until the completion of priming.

Effects of the Invention As described above, according to the present invention, the structure is simple, the number of components is small, the durability of the positive displacement pump can be easily ensured, the load loss of the drive motor can be reduced, and the pump is small and inexpensive. Since it can be manufactured in many ways, its industrial value is great.

[Brief explanation of the drawing]

FIG. 1 is a partial vertical sectional view of an automatic priming centrifugal pump showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line A-A' in FIG.
3 is a partially cutaway front view of the suction port of the centrifugal pump shown in FIG. 1, and FIG. 4 is a circuit diagram of the control section of the automatic priming centrifugal pump. 1... Drive motor, 6, 14... Suction port, 7...
Impeller, 9...Casing, 10...Centrifugal pump, 11...-direction clutch, 16...Gear pump, 17...Ball, 18...Tapered surface, 19...
Check valve, 20... Bypass port, 21... Connecting pipe, 26... Gear, 32... Small sealed lead acid battery, 3
3... Selector switch, 34... Power switch. Agent Yoshihiro Morimoto Fig. 2 I Fig. 3 Fig. 6 32 - Small seal Gqg electric 5 colors 33 - - Cut arm x 34° - Power switch, V, r

Claims (1)

[Claims] 1. A drive motor, a centrifugal pump connected to the drive motor, a positive displacement rotary pump connected to the drive motor via a one-way clutch, a control section for reversing the drive motor in forward and reverse directions, and a control section for reversing the drive motor in the forward and reverse directions; An automatic priming type centrifugal pump having a check valve provided on a bypass that communicates a suction port with a suction port of the positive displacement rotary pump.