JPS626131B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid coupling installed between a prime mover and a pump to transmit rotational force.

As shown in FIG. 1, a conventional typical fluid coupling connects an input shaft 3 to a prime mover shaft 1 via a coupling 2, supports the input shaft 3 by bearings 4, 4a, and supports the end portion of the input shaft 3. An impeller 5 is attached to the driven shaft 6, and an output shaft 8 is similarly connected to the driven shaft 6 via a coupling 7, and the output shaft 8 is connected to a bearing 9,
9a, and a runner 10 is attached to the casing 11 attached to the impeller 5. Hydraulic oil in an oil tank 12 is supplied from an oil supply port 14 by an oil pump 13, and a speed governor (not shown) is installed. Oil tank 1 by interlocking scoop tube 15
2, and the amount of oil in the casing 11 is changed depending on the set position of the scoop tube 15, thereby controlling the rotation speed of the driven shaft 6.

However, since this type of conventional fluid coupling uses hydraulic oil in circulation, it not only requires an oil cooler in addition to the oil pump mentioned above, but also requires periodic replacement of the hydraulic oil, and also requires a scoop tube. Since the motor is operated within the rotating casing to control the rotational speed of the driven shaft, the structure is complicated, which not only requires time and effort to assemble, but also has the drawback of being prone to breakage.

Conventionally, as a partial solution to the above problems, there is a fluid coupling that uses part of the fluid handled by the driven machine as the working fluid and does not require a special pump or cooler. As a result, the structure was complicated and assembly and maintenance remained difficult.

In addition, some conventionally known fluid couplings control the amount of oil supplied into the impeller, but the control mechanism is complicated, and because a predetermined fluid is circulated, special This had the disadvantage that it required pumps, coolers, etc., and could not be constructed compactly.

The present invention supplies a part of the fluid handled by a pump, which is a driven machine, to a fluid coupling and uses it as a working fluid, and also maintains a constant pressure of the supplied fluid that enters a throttle valve installed in the water supply pipe. It is an object of the present invention to provide a fluid coupling that not only simplifies the configuration and operation of the throttle valve and enables highly accurate flow rate control, but also enables active use of the fluid handled by the pump.

The present invention provides a fluid coupling that is installed between a prime mover and a pump to transmit rotational force, and includes a constant pressure water supply device that sends a part of the handled fluid discharged from the pump to a water supply pipe at a constant pressure. Connect the water supply pipe to the supply port of the fluid coupling, install a throttle valve in the middle of the water supply pipe, detect the discharge pressure or discharge flow rate of the pump, and operate the throttle valve based on the detection signal to adjust the water supply amount. The fluid coupling is characterized in that it adjusts and controls the discharge pressure or discharge flow rate of the pump.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 2, reference numeral 16 denotes a prime mover consisting of, for example, a constant speed electric motor, and its rotating shaft 1
An impeller 18 is attached to the tip of 7. A casing 19 is attached to the outer periphery flange of the impeller 18, and is adapted to rotate together with the impeller 18. Several ejection nozzle holes 19a are bored in the outer circumference of the casing 19, and the working fluid (water in this embodiment) filled inside is ejected. 20
is attached to the tip of the rotating shaft 22 of the pump 21, which is a runner and is a driven machine, so that they rotate together.

The impeller 18, casing 19, runner 20, etc. are surrounded by a box 23 to prevent water ejected from the ejection nozzle hole 19a from scattering. A water supply port 24 is provided on the side surface of the box 23, and the impeller 18,
Water is supplied to the inside of the runner 20 and casing 19. Further, the rotating shafts 17 and 22 pass through both sides of the box 23, and a shaft sealing device 25 having a labyrinth structure is provided to prevent leakage of the jetted water.

The lower part of the box 23 is a drain tank 26, which stores the water ejected from the ejection nozzle hole 19a as a drain, and discharges the water via the return pipe 27 to the suction water tank 28 of the pump 21. The downstream end of the return pipe 27 may be connected to the suction pipe 29 of the pump 21 as shown by the two-dot chain line.

Reference numeral 30 denotes a tank as a constant pressure water supply device, which takes in a portion of the discharged water through a water intake pipe 32 branched from a discharge pipe 31. An orifice 33 is provided in the middle of the water intake pipe 32 to feed the required amount of water to the tank 30. The tank 30 is designed to always store water at a constant level due to overflow or LIC, and the surplus water is discharged to the drain tank 26 through the drain pipe 34. The outlet of the drain pipe 34 is connected to the suction water tank 28
Alternatively, it may be connected to the suction pipe 29. A water supply pipe 36 is connected to the bottom of the tank 30 via a solenoid valve 35, and a throttle valve 37 is disposed in the middle of the water supply pipe 36. The throttle valve 37 is connected to the pressure detection line 3
The opening degree of the pump 21 is changed by the discharge pressure of the pump 21 detected through the pump 8. A downstream end of the water supply pipe 36 is connected to the water supply port 24 . 41 and 39 are pressure gauges.

Therefore, when performing constant discharge pressure control operation of the pump 21 using the device of this embodiment, first the solenoid valve 35 is
With the tank 30 closed, prime water is poured into the tank 30. Note that once the pump 21 has been operated, this priming water is always stored in the tank 30 by closing the solenoid valve 35 each time the pump 21 is stopped, so the priming water must be prepared every time the pump 21 is started. There's no need to.

After preparing the priming as described above, the prime mover 1
6 is activated and the solenoid valve 35 is opened, the priming water is sent to the water supply port 24 through the throttle valve 37 and flows into the impeller 18, runner 20, and casing 19. When the amount of water in the impeller 18 increases, the runner 2
0 rotates, causing the pump 21 to rotate. pump 21
When it starts to rotate in earnest, the water in the suction water tank 28 is sucked up and discharged from the discharge pipe 31. Discharge pipe 3
A part of the pressure water from 1 is transferred from the water intake pipe 32 to the tank 3.
Water is sent to 0. As mentioned above, since the tank 30 always maintains a constant water level, it acts as a constant pressure water supply device, and the water supply pipe 3 upstream of the throttle valve 37
6 is designed to always have water at a constant pressure sent to it. The throttle valve 37 detects the discharge pressure in the discharge pipe 31 via the detection pipe line 38, and if the discharge pressure is higher than the set pressure, it throttles its opening, and if it is lower, it opens and reduces the flow rate to the water supply port 24. The rotational speed of the pump 21 is controlled to control its discharge pressure to a set value.

As described above, in this embodiment, after the pressure in the water supply pipe 36 is made constant by the tank 30, the flow rate is controlled by the throttle valve 37. In this way, as a constant pressure water supply device that keeps the pressure of the water supply pipe 36 constant, other than the tank 30 described above,
For example, as shown by the chain line in FIG. 2, the upstream end of the water supply pipe 36 is directly connected to the discharge pipe 31, and a constant pressure valve 40 is interposed, or if the pump 21 is a centrifugal pump, the balance hole chamber is connected. An outlet may be provided from which water at a substantially constant pressure is taken out and connected to the water supply pipe 36. In addition, this pressure water may be taken out from the suction side in the case of pump pushing.

It also converts the discharge pressure into an electrical signal and
7 may be controlled, or the discharge flow rate may be further detected and the water supply amount may be adjusted to control the discharge flow rate.

According to the present invention, the water supply amount adjustment mechanism is not only a simple throttle valve configuration, but also easy to maintain.
The amount of water supplied can be smoothly adjusted, and stable pump discharge pressure control or discharge flow rate control can be performed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional fluid coupling, and FIG. 2 is an explanatory diagram showing a first embodiment of the fluid coupling and its circuit device according to the present invention. 16... Prime mover, 17... Rotating shaft, 18... Impeller, 18a... Water supply hole, 19... Casing, 19a... Spray nozzle hole, 20... Runner,
21... Pump, 22... Rotating shaft, 23... Box, 24... Water supply port, 25... Shaft sealing device, 26
...Drain tank, 27...Return piping, 28...
Suction water tank, 29... Suction pipe, 30... Tank, 3
1... Discharge pipe, 32... Water intake pipe, 33... Orifice, 34... Drain piping, 35... Solenoid valve, 3
6... Water supply pipe, 37... Throttle valve, 39... Pressure gauge, 40... Constant pressure valve, 41... Pressure gauge.

Claims (1)

[Claims] 1. In a fluid coupling installed between a prime mover and a pump to transmit rotational force, a constant pressure water supply device is provided to send a portion of the handled fluid discharged from the pump to the water supply pipe at a constant pressure, and the water supply pipe is connected to the supply port of the fluid coupling, a throttle valve is installed in the middle of the water supply pipe, the discharge pressure or discharge flow rate of the pump is detected, and the flow rate is adjusted by operating the throttle valve based on the detection signal, A fluid coupling that controls a discharge pressure or a discharge flow rate of the pump.