JPS58221022A - Variable speed fluid coupling - Google Patents

Abstract

PURPOSE:To aim at enlarging an adjusting range, by constituting a feed-back pump with the use of a Westco pump so that the axial space thereof is made less for obtaining a compact arrangement, and further by making discharge pressure for feed-back large. CONSTITUTION:Working fluid which enters in an impeller 5 rotates together with the latter for rotating an inner runner 12 so that an output shaft 9 integrally incorporated therewith is rotated. When the rotation of the output shaft 9 is lowered, a spool 21 is pushed up by the actuation of a Wesco Pump 22 and the actuation of a pressure detecting device 28 so that a flow adjusting valve is opened, resulting in increasing the supply volume of working fluid into the impeller 5, and therefore, the rotational speed of the output shaft 9 is raised. On the contrary, when the rotational speed of the output shaft 9 is raised, the spool 21 is moved downward so that the open degree of the flow adjusting valve is reduced for decreasing the inlet flow into the impeller 5, thereby the rotational speed of the output shaft 9 is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid coupling, in particular, a runner is rotatably disposed within an impeller attached to an input shaft, the runner is attached to an output shaft, and a working fluid is supplied into the impeller by a pump for supplying working fluid. The rotation of the input shaft is transmitted to the output shaft while supplying working fluid, and the supply amount of the working fluid is continuously controlled by a flow control valve through a small discharge hole provided on the outer periphery of the impeller. This relates to a variable speed fluid coupling that controls the rotational speed of the output shaft by freely adjusting the position of the free surface of the internal fluid of the impeller and runner from the axis center by making the flow rate larger or smaller than the discharge flow rate. .

Generally, in the variable speed fluid coupling of the above type, the supply amount of the working fluid is determined by the rotational speed of the output shaft and the load side state quantity of the driven machine such as a pump or blower rotationally driven by the output shaft, such as the discharge pressure. It is controlled in accordance with a control pressure signal (hereinafter simply referred to as driven machine control pressure) that is generated in response to state variables such as flow rate, suction water tank water level, and discharge water tank water level. A feedback pump is attached to the output shaft and the control pressure signal of the driven machine, and the flow control valve is controlled by the discharge pressure signal.

Conventionally, in this type of fluid coupling, the output shaft is a vertical shaft, and the feedback pump is composed of centrifugal pump vanes.When this is adopted in a so-called horizontal fluid coupling with the input and output shafts oriented horizontally In order to perform its function even when the pump is located above the surface of the working fluid, it is necessary to provide an annular suction port casing around the output shaft to guide the fluid. This system requires a large amount of space, increases the total length of the waist device, and has drawbacks such as the discharge pressure of the centrifugal pump used for feedback operation is insufficient and the adjustment range is small.

The present invention has been made to solve the problems of the conventional variable speed fluid coupling, and by configuring the feedback pump with a Wesco pump, the axial space is small and the structure is compact. Furthermore, it is an object of the present invention to provide a horizontal variable speed fluid coupling that has a large discharge pressure for feedback and can have a wide adjustment range.

The present invention has an input shaft and an output shaft supported substantially horizontally in a main body casing, a runner rotatably disposed in an impeller attached to the input shaft, and the runner attached to the output shaft. A working fluid supply pump rotationally driven by the input shaft supplies working fluid into the impeller to transmit the rotation of the input shaft to the output shaft, and the supply amount of the working fluid is adjusted by a flow rate regulating valve. In the fluid coupling that controls the rotational speed of the output shaft while adjusting the position of the free surface of the internal fluid of the equalizer and runner from the shaft center; a Wesco pump for feedback is provided on the output shaft; The variable speed fluid coupling is characterized in that the flow rate regulating valve is controlled by a discharge pressure signal from the Wesco pump.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a main body casing, and an input shaft 3 is supported by a bearing 2 at one end thereof. An impeller 5 is integrally mounted on the right inner end of the input shaft 3 via a 7 flange 4, and a sleeve 6 is fixed to the impeller 5 and is inserted into the main body casing 1. It is supported in a bearing 8 of a bearing body 7 provided. Therefore, the input-side rotating body consisting of the input shaft 3, 7, the flange 4, the impeller 5, and the sleeve 6 is reliably supported by the bearings 2 and 8, which are spaced apart from each other with a sufficiently large distance.

Reference numeral 9 denotes an output shaft, which is supported by a bearing 10 on the other end side of the main body casing j, and its left inner end is supported by a bearing 11 provided in the 7-ranche 4, and is connected to the output side rotating body. It is also reliably supported by bearings 10 and 11 provided at a sufficiently large interval, and in combination with the above-mentioned method of supporting the input side rotating body, the length of the fluid coupling in the axial direction is reduced. Reference numeral 12 denotes a runner, which is mounted on the output shaft 9 and can freely rotate within the impeller 5.

The lower part of the bearing body 7 is open, and the left and right oil tanks 1
3.14 is communicated. Further, a centrifugal pump 15 for supplying working fluid is attached to the lower part of the bearing body 7 from below. The centrifugal pump 15 is rotationally driven via an intermediate gear 17 by a timing tooth 16 attached to a sleeve 6 that rotates together with the input shaft 3 and impeller 5. Reference numeral 18 denotes a bearing bushing, which rotatably supports the intermediate gear 17 and is fitted into the bearing body 7.

As is clear from FIG.
0a has been contacted. The flow rate regulating device 20 is constructed such that a casing as shown in FIG. 3 is attached to a bearing body 7, and the bearing body 7 also functions as one side wall of the device. A spool chamber 20b is formed in the flow rate adjustment device 20, and a flow rate adjustment valve is configured by moving the spool 21 up and down within the spool chamber 20b. As is clear from FIG. 1, the spool chamber 20b is the outflow chamber 20.
c, the flow path 6a formed between the sleeve 6 and the output shaft 9 communicates with the right chamber of the impeller 5, and a flow path 12 formed inside the boss portion of the runner 12.
It communicates with the left side chamber of the impeller 5 through a.

22 is a Wesco pump for feedback of the output shaft 9, and its impeller 22a is attached to the output shaft 9. The casing of the Wesco pump 22 has a fourth
As shown in the figure, a suction passage 22I) and a discharge passage 22c are formed, and the suction passage 221] communicates with the inflow chamber 20a of the flow rate adjustment device 20, and the discharge passage 22c
communicates with the spool chamber 20cl. In particular, no suction casing is required in the axial direction. Also, wesco pump 2
2. Whispering is operated in a pushing state, not in a sucking state. A spool 23 is housed in the spool chamber 2Od so as to move up and down. The spool 23 is urged downward by a return spring 24. The spool chamber 20cl is connected to the inflow chamber 20a by a communication path 20e, and an appropriate amount of the pressure fluid in the spool chamber 2Od is discharged into the inflow chamber 2Oa by a needle valve 25, and is subjected to feedback operation in the spool chamber 2Ocl. The pressure used can be set appropriately for the return spring 24.

The upper ends of the spools 21 and 23 are pivotally connected to both ends of a lever 26, and the lower end of a rod 27 is pivotally connected to the middle part of the lever 26. The upper end of the port 27 is connected to a pressure detection device 28.

As is clear from FIG. 5, the pressure detecting device 28 is provided with a diaphragm 29, and the pressure detecting device 28 is equipped with a diaphragm 29, which detects the pressure from a driven machine (not shown) such as a pump or blower according to the control pressure corresponding to the state quantity on the load side. It is designed to be suppressed.

An operating rod 31 is attached to the back surface of the diaphragm 29 via a rod 30. The operating rod 31 and the support rod 3
A back pressure spring 33 is inserted in the opening between 2 and 2, and the initial position of the operating rod 31 can be adjusted by setting the supporting rod 32 to an appropriate position using an adjusting screw 34. . One end of an L-shaped link 35 is pivotally connected to the operating rod 31, and the other end of the L-shaped link 35 is pivotally connected to one end of a lever 37 via a rod 36. . The other end of the lever 37 is pivotally attached to the upper end of the rod 27, and its intermediate portion is pivotally supported by an adjustment screw 38. The adjustment screw 38 is set at an appropriate position by a handle 39, and even when control based on the control pressure of the driven machine is not performed, the adjustment screw 38 is set at a pivot point 37b between the rod 36 and the lever 37 as a fulcrum, and the screw is set at an appropriate position by a handle 39. 38 and lever 3
By manually setting the position of the pivot point 37a with respect to the wesco pump 22, control can be performed only by feedback control of the output shaft rotation speed based on the discharge pressure of the Wesco pump 22. Also,
The diaphragm 29 of the pressure sensing device 28 may be replaced with a bellows 29' as shown in FIG.

In addition to the discharge pressure, load state quantities of the driven machine are detected such as discharge flow rate, suction water tank water level, and discharge water tank water level, and are converted into pressure or force using mechanical and electrical methods. It may also be made to act on the operating rod 31.

In this way, control can be performed to keep these load-side state quantities constant. A spirally wound cooling pipe 40 is disposed in the oil tank 13 at the bottom of the main body casing 1, and the hydraulic oil is cooled by an external refrigerant flowing through the cooling pipe 40.

Next, the operation of the above embodiment will be explained.

The input shaft 3 is connected to the input shaft 3 by an appropriate prime mover (not shown) such as an electric motor.
is rotated to rotate the impeller 5, and the centrifugal pump 15 is operated via the intermediate gear 17 by the timing gear 16 which rotates integrally with the impeller 5. When the centrifugal pump 15 begins to rotate, the working fluid pushed up thereby flows into the inflow chamber 2Oa of the flow rate adjustment device 20 through the pipe 19. At the start of operation, the fulcrum 26a of the lever 26 is in the neutral position, and the pivot point 26b is pushed down by the return spring 24, so that the spool 2
4 is located above, and the flow rate control valve is open. Therefore,
A part of the working fluid that has entered the inflow chamber 2Oa as described above passes through the spool chamber 2Ob, and passes through the outflow chamber 20c and the passage 6.
It flows into the right side chamber of the impeller 5 from a, and further flows into the left side chamber of the impeller 5 through the passage 12a.

Since the amount of working fluid supplied is greater than the amount that is continuously discharged from the small discharge hole 43 provided on the outer periphery of the impeller 5, the working fluid gradually accumulates inside the runner 12 and reaches a position where the free surface approaches the central axis. Therefore, the rotational speed of the runner 12 is increased.

The working fluid that has entered the impeller 5 rotates together with the impeller 5, causing the inner runner 12 to rotate and the output shaft 9 integrated therewith to rotate. When the output shaft 9 rotates, the Wesco pump 22 starts to operate, and its suction passage 22
A part of the working fluid in the inlet chamber 2Oa is sucked in from the inflow chamber 2Oa, and the working fluid at a pressure corresponding to the rotational speed of the output shaft 9 is sent into the spool chamber 20d from the discharge passage 22c. The pressure fluid entering the spool chamber 2Od is appropriately pressure-regulated by the needle valve 25 and passes through the communication path 20-e to the inflow chamber 2Oa.
leaked inside.

As long as the rotation speed of the output shaft 9 is low, the control pressure of the driven machine is low, so that the ram 2
9 is weak, the position of the rod 27, that is, the fulcrum 26a of the lever 26 hardly changes, and the discharge pressure of the Wesco pump 22 is also small, so the return spring 24
There is no force to retract the spool 23 in the spool chamber 2Od, and the pivot point 26b of the lever 26 remains in the same position. Therefore, the spool 21 continues to supply working fluid into the impeller 5 for a sufficient period of time.

When the control pressure (for example, discharge pressure) of the driven machine becomes large and the control pressure increases, the Guya 7 ram 2 of the pressure detection device 28
9 is pushed to the left in FIG. 2, causing the operating rod 31 to move to the left against the back pressure spring 33. When the operating rod 31 moves to the left, the L-shaped rod 35 rotates clockwise about the fulcrum 35a and holds the rod 36 upwards. The lever 37 rotates clockwise around the pivot point 37a with the adjustment screw 38, and the rod 27
Press down. When the rod 27 moves downward, the fulcrum 26a of the lever 26 moves downward, as is clear from FIG.

When the fulcrum 26a of the lever 26 moves downward, the lever 26 is rotated to the left, so the spool 21 is pushed down and the amount of working fluid flowing from the inflow chamber 20a to the spool chamber 20b is throttled. When the amount of flow into the spool chamber 2Ob is reduced, an increase in the amount of working fluid in the impeller 5 is suppressed, and an increase in the rotational speed of the output shaft 9 is suppressed.

Furthermore, when the rotational speed of the output shaft 9 is increasing, the discharge pressure of the Wesco pump 22, that is, the pressure inside the spool chamber 20d increases due to the rotational speed of the output shaft 9, so that the spool 23 is pushed up by overcoming the return spring 24. and the position of the pivot point 26 & of the lever 26 is raised. Then, the amount of working fluid flowing from the inflow chamber 20a into the spool chamber 20b is throttled.

This helps to suppress an increase in the rotational speed of the output shaft 9.

When the amount of inflow into the spool chamber 2Ob, that is, the amount of supply into the impeller 5 decreases, the amount approaches the amount that is continuously discharged from the small discharge hole 43 provided on the outer periphery of the impeller 5, and eventually the supply amount and the discharge amount When the rotational speed reaches equilibrium, the increase in rotational speed stops.

Further, when the supply amount exceeds the equilibrium state and becomes smaller than the discharge amount, the amount of working fluid in the impeller 5 starts to decrease, and the rotational speed of the output shaft 9 starts to decrease.

When the rotational speed of the output shaft 9 decreases, the discharge pressure of the Wesco pump 22, that is, the pressure inside the spool chamber 20d decreases, so the spool 23 is pushed down by the return spring 24, and the lever 26 pivots. Arrival, α2
The position of sb is lowered.

Then, as this approaches, the control pressure of the driven machine decreases, and the operating rod 31 is pushed back to the right in FIG. 2 by the back pressure spring 33.
Rotate the L-shaped sink 35 to the left and lower the rod 36.

When the rod 36 descends, the lever 37 rotates to the left to lift the rod 27, and the fulcrum 26a of the lever ''26 moves upward.

As shown in Figure 2 below, when the rotational speed of the output shaft 9 decreases, the pivot point 26b lowers first, and this causes the fulcrum 26a of the lever 26 to move upward, causing the lever 26 to rotate clockwise and release the spool. 23 upward to increase the amount of flow into the spool chamber 20b, that is, the amount of flow into the impeller 5, and increase the rotational speed of the output shaft 9 again.

As shown in (2) below, when the rotation of the output shaft 9 decreases, the spool 21 is pushed up by the action of the Wesco pump 22 and the pressure detection device 28, opening the flow rate control valve, and the working fluid flows into the impeller 5. The amount of supply increases, and the rotational speed of the output shaft 9 increases. Conversely, when the rotational speed of the output shaft 9 increases, the spool 21 is moved downward and the opening degree of the flow control valve becomes smaller, and the amount of flow into the impeller 5 is increased, causing the rotational speed of the output shaft 9 to decrease. is automatically controlled so that the control pressure of the driven machine reaches the set value.

In the above embodiment, the control valve valve "-"
Since the Wesco pump 22 is used in determining the opening of the valve 21, the pressure inside the feedback spool chamber 2Od is increased by changing the relief amount of the needle valve 25 compared to a conventional volute pump. In other words, when the Wesco pump 22 is used, the shutoff discharge pressure is about 2 to 2.5 times higher than that of a centrifugal pump with the same impeller outer diameter. For this reason, the usable pressure is wide-ranging, and by utilizing this, the spool 2 for feedback on the rotation speed on the driven machine side
It is easy to return the position No. 3 and set it so that an appropriate stroke can be obtained between full-speed rotation and low-speed rotation against the action of the spring 24.

The stroke of the feedback spool 23 is directly reversed by the lever 26 to the stroke of the regulating valve spool 21, thereby contributing to the regulating action. Therefore, once the two-dollar valve 25 is initially set, no adjustment is required thereafter. Then, the type of working fluid, temperature, discharge setting pressure, etc. are adjusted so that the stroke position of the spool 23 is appropriate.
By initially adjusting the settings of the needle valve 25 according to the set rotation speed, etc., excellent control with a wide range of application can be performed.

Since the present invention is constructed as follows, the discharge pressure is much higher for the same dimensions than the conventional centrifugal pump type feedback mechanism, and the pressure adjustment range is wide, making control easier. When dealing with pressure, the dimensions can be made very small, and there is no need for an axial suction casing, which has the effect of making the entire device compact.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing one embodiment of the variable speed fluid coupling of the present invention, Fig. 2 is a transverse sectional view taken along the line 1-1 in Fig. 1, and Fig. 3 is a case of the flow rate adjustment device. 4 is an enlarged view showing the case of the Wesco pump, FIG. 5 is an enlarged sectional view showing the pressure detection device, and FIG. 6 is a partial sectional view showing another embodiment of the pressure detection device. It is. 1...Body casing 2...Bearing 3...Input shaft 4...7 Lange 5...Impeller
6... Sleeve 6a... Channel 7...
Bearing body 8...Bearing 9...Output shaft 10
．． 11... Bearing 12... Runner 12a...
・Flow path 13.14... Oil tank 15... Centrifugal pump 16... Timing gear 17... Intermediate gear 18... Bush 19... Piping
20...Flow rate adjustment device 20a...Inflow chamber 20
b... Spool chamber 20c... Flow chamber 20d.
...Spool chamber 20e...Communication path 21...
Spool 22... Unisf pump 22a... Impeller 22b... Suction passage 22c... Discharge passage 2
3... Spool 24... Return spring 25...
Needle valve 26... Lever 26a... Fulcrum
26b... Pivot point 27... Rod 28
...Pressure detection device 29... Guyafram 29'.
... Bellows 30 ... Rod 31 ... Operating rod 32 ... Support rod 33 ... Back pressure spring 34 ...
・Adjustment screw 35...I-type link, 35a...
・Fulcrum 36...Rod 37...Lever
37a, 37b... Pivot point 38... Adjustment screw 39... Handle 40... Cooling pipe 4
3...Discharge hole patent applicant: Ebara Corporation, patent attorney, Go Hatayama - 1) Minoru, Figure 3, Figure 4

Claims (1)

[Claims] 1. An input shaft and an output shaft are supported substantially horizontally in a main body casing, a runner is rotatably disposed within an impeller attached to the input shaft, and the runner is attached to the output shaft; A working fluid supply pump rotationally driven by the input shaft supplies working fluid into the impeller to transmit the rotation of the input shaft to the output shaft, and the amount of the working fluid supplied is adjusted by a flow rate control valve. In the fluid coupling, the rotational speed of the output shaft is controlled while adjusting the position of the free surface of the four-part fluid of the impeller and the runner from the shaft center; a Wesco pump for feedback is provided on the output shaft; A variable speed fluid coupling characterized in that the flow control valve is controlled by a discharge pressure signal from the Wesco pump. 2. An input shaft and an output shaft are supported substantially horizontally in the main body casing, and a runner is rotatably disposed within an impeller attached to the input shaft, and the runner is attached to the output shaft and is rotationally driven by the input shaft. A working fluid supply pump supplies working fluid into the impeller to transmit the rotation of the input shaft to the output shaft, and a flow control valve adjusts the amount of working fluid supplied to the inside of the impeller and runner. In a fluid coupling that controls the rotational speed of an output shaft while adjusting the position of the free surface of the fluid from the shaft center;
A feedback Wesco pump is provided on the output shaft, and the flow rate regulating valve is controlled by a discharge pressure signal from the Wesco pump and a load side state quantity signal corresponding to the load side state of the driven machine rotationally driven by the output shaft. A variable speed fluid coupling characterized in that it is controlled.