JP2951994B2 - Fluid coupling transmission - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed change mechanism of a fluid coupling, and more particularly, to a speed change device for shortening a speed change time of a charge / discharge oil type speed change mechanism.

[Conventional technology]

Conventionally, a fluid coupling is of a fixed filling type that always operates with a fluid (hydraulic oil) filled in a circuit, and a fluid coupling that can change a transmission torque capacity by adjusting the amount of fluid (hydraulic oil) in the circuit. There is a variable filling type, and the variable filling type includes a variable speed type and a charging / discharging type.

FIG. 9 (a) is a schematic view of the variable speed fluid coupling, in which an impeller (pump impeller) 102 connected to a drive shaft 101 and a runner (turbine impeller) connected to a driven shaft 104. 103 are mounted facing each other to form a fluid circuit, and the hydraulic oil in the circuit is an oil tank 105, an oil pump 10
6. A part can be exchanged (increase / decrease) via an oil cooler 107 and a scoop tube 109 operated by an operation device 108.

This device functions for the purpose of controlling the number of rotations of the driven side and starting the drive side motor with no load, and has effects of reducing running costs and driving machine costs.

FIG. 9 (b) is a schematic view of the fluid refill / discharge type fluid coupling, in which the hydraulic oil in the circuit enters the circuit via a charge / discharge oil switching valve 111 connected to the outlet of the oil cooler 107. The oil in the circuit is always returned to the oil tank 105 by a fixed amount via the nozzle 114 via a replenishing pipe 112 or a return pipe 113 to the oil tank 105.

It functions for the purpose of power cutoff (clutch action), absorption of torsional vibration, no-load start of the prime mover and reduction of start-up resistance, independent operation of the engine, on / off operation of the driven machine, and easy start-up of the prime mover. And acceleration.

FIG. 9 (c) is a schematic view of the above-mentioned constant speed (constant filling type) fluid coupling, in which the circuit is always operated with a fluid filled therein. It functions for the purpose of reducing the starting resistance, reducing and absorbing vibration and impact, absorbing torsional vibration and torque limiter, and has the effect of protecting the electric motor and the connecting device.

[Problems to be solved by the invention]

Conventional variable speed fluid coupling described above (FIG. 9 (a))
Can be set to an arbitrary rotation speed by changing the position of the scoop tube 109, and the rotation speed control range is wide and suitable for many essential operations, but the speed change response speed between the maximum rotation speed and the minimum rotation speed is fast. It took about 10 seconds.

In addition, the refill / discharge type fluid coupling (FIG. 2 (b)) switches only the maximum rotation speed and the minimum rotation speed by opening and closing the refill / discharge oil switching valve 111, so that the driving machine operates independently and the driven machine operates independently. Is suitable for the on / off operation of the engine, but the operating oil is always discharged from the nozzle 114 during the operation of the driven machine, and the efficiency is reduced with a small type, and the amount of hydraulic oil discharged from the nozzle 114 is limited. Therefore, there is a problem that the shift response speed is slow.

A constant-speed fluid coupling (FIG. 3C) is mainly suitable for absorbing and mitigating an impact force, but cannot control the speed.

Therefore, when these conventional structures are applied to a device that performs an intermittent operation such as a descaling pump used to remove scale on the surface of a steel material being manufactured at an ironworks, the speed change response speed is low, so that it is very practical to use. There was a problem that it was difficult. Therefore, during the no-load operation, the operation is continuously performed at the maximum rotation speed of the driven shaft, and the operation is performed with the valve being squeezed.

The present invention solves the above-mentioned problems of the prior art, remarkably improves the speed change response speed from the highest speed to the lowest speed, and from the lowest speed to the highest speed of the transmission mechanism of the fluid coupling, and improves the speed. It is an object of the present invention to set the number control range to two points of a maximum rotation number and a minimum rotation number so that the minimum rotation number can be set according to the application.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a valve for opening and closing an oil drain hole by a differential pressure of hydraulic oil on an outer peripheral portion of an impeller or an impeller casing of a fluid coupling connected to a drive shaft. To reduce and accelerate from the highest rotation speed to the lowest rotation speed and from the lowest rotation speed to the highest rotation speed, and provide a dam protruding radially inward inside the oil drain hole in the impeller casing. The minimum rotation speed is changed by changing the oil level of the hydraulic oil held in the impeller casing according to the height of the dam.

(Operation)

Since the present invention is configured as described above, neither the operating oil nor the valve operating oil is supplied in the stopped state before the start or the state where only the drive shaft is rotating.

Then, the hydraulic oil is supplied into a circuit formed by the impeller and the runner, and the valve is driven in a state where the valve hydraulic oil is supplied to a valve provided on an outer peripheral portion of the impeller or the impeller casing and opened and closed by a differential pressure of the hydraulic oil. When the shaft rotates, due to the difference between the force acting on the valve in the closing direction by the valve operating oil and the force acting in the opening direction by the operating oil in the circuit, the valve causes the oil drain hole in the circuit to drain. Fully close and rotate the driven shaft at the maximum speed.

Then, when the supply of the valve hydraulic oil is stopped, the force acting in the direction to close the valve becomes zero, while the valve is fully opened instantaneously by the pressure of the hydraulic oil in the circuit acting in the direction to open the valve. Therefore, the hydraulic oil in the circuit is discharged from the oil drain hole in a very short time.

At this time, the hydraulic oil in the circuit is held at the level of the impeller casing by the lowest speed setting dam provided in the vicinity of the oil drain hole, usually in the radial direction and provided in the radially inward direction, and the driven shaft is Operated at minimum speed.

As described above, by opening and closing the valve (control valve), the driven shaft can shift between the two operations of the maximum rotation speed and the minimum rotation speed in a very short time.

〔Example〕

 Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an upper half of a fluid coupling provided with a transmission mechanism according to an embodiment of the present invention.

In the figure, an impeller 2 is attached to a drive shaft 1, and a runner 3 constituting a fluid circuit is attached to a driven shaft 4 so as to face the impeller 2. An impeller casing 5 surrounding the outer periphery of the runner 3 is attached to the impeller 2,
The impeller casing 5 further includes an inner casing 6 on the side, and a valve seat (valve seat) on a radial outside of the oil drain hole B.
7, a valve body (valve disc) 8 and a valve cover 9 are respectively mounted.

On the opposite side of the valve body 8 from the valve seat, a valve operating pressure chamber 9a is formed by the inner surface of the valve cover 9, and the outside in the radial direction of the pressure chamber 9a is opened to the outside through a small hole C. The inside is communicated with a working oil supply oil supply nozzle 10 attached to the bearing casing 11. Note that the refueling nozzle
10 may be omitted, and the operating oil of the valve body 8 may be supplied from a valve operating oil supply hole F bypassed from an operating oil supply chamber E formed in the bearing casing 11.

On the other hand, the runner 3 is provided with a hydraulic oil supply hole A communicating with the hydraulic oil supply chamber E on the radially inner side, and the impeller casing 5 has the oil drain hole B and the oil drain hole. A minimum rotational speed setting dam is provided on the inner side in the axial direction of B so as to protrude inward in the radial direction. In the figure, reference numeral 12 denotes a bearing.

 Next, the operation will be described.

(I) In the stopped state before start or in the state where only the drive shaft 1 is rotating, as shown in FIG. 2, the hydraulic oil in the circuit formed by the impeller 2 and the runner 3 The valve operating oil is not supplied together, and the valve body 8 has opened the oil drain hole B.

(Ii) Next, while the drive shaft 1 is being driven, the hydraulic oil is filled into the circuit from the oil supply chamber E through the oil supply hole A, and the valve hydraulic oil is supplied from the oil supply nozzle 10 to the back surface (right side in the figure) of the valve body 8. Pressure chamber
When supplied to 9a, as shown in FIG. 3 and FIG. 3a, which is an enlarged view of the valve element 8, the valve seat 7 is quickly closed, and the working oil is filled in the circuit as shown by oblique lines. And the driven shaft 4
Rotates at 100% speed.

At this time, the force acting in the direction to close the valve body 8 in FIG. 3a
F ₁ is F ₁ = P ₁ × A ₁ ... Here, P ₁ is a pressure acting in a direction to close the valve body 8, and P ₁ = γ / 2g × ω ² × R ² × 1/10 A ₁ : Pressure receiving area on the back (right side in the figure) of the valve body 8 γ: Specific gravity of hydraulic oil ω: Rotational angular velocity of the impeller 2 R: Radius of the valve body 8 On the other hand, the force F ₂ acting in the direction of opening the valve body 8 is F ₂ = P ² × A ² Here, P ₂ is a pressure acting in a direction to open the valve body 8, and P ₂ = γ / 2g × ω ₂ × R ₂ × 1/10 A ₂ : A front surface of the valve body 8 ( According to both formulas, F ₁ −F ₂ = P ₁ × A ₁ −P ₂ × A ₂ Here, small holes such that P ₁ × A ₁ −P ₂ × A ₂ > 0 Upon determining the C and the pressure receiving area a ₁ and _{a 2, F 1 -F 2>} 0 ie F _1> F ₂ and becomes the valve body 8 is fully closed.

Because although a small amount of the valve operating oil q ₁ is leaking constantly (leak) Q _1> q ₁ comprising valve hydraulic fluid Q ₁ is supplied from the small holes C in this state, pressure drop P ₁ is very small is there.

(Iii) Next, as shown in FIG. 4, when the supply of the valve operating oil from the oil supply nozzle 10 is stopped, as shown in the enlarged view of FIG. 4a, the force F acting in the direction to close the valve element 8 is obtained. ₁ becomes zero, the force F ₂ acting in a direction to open the valve body 8, F ₂ = P ₂ × a
> 0 and therefore F ₂ > F ₁ , the valve element 8 will
It is opened as shown in FIG.

(Iv) In the state shown in FIGS. 5 and 5a, the valve element 8 is open, the hydraulic oil (indicated by hatching in the figure) is held at the level of the minimum speed setting dam D, and the remainder is The driven shaft 4 is discharged as indicated by the arrow and is driven at the minimum rotation speed. The level of the hydraulic oil changes according to the height of the dam D, and the minimum rotation speed changes.

The system of the above-described hydraulic oil and valve hydraulic oil will be described with reference to FIGS. 6 to 8. FIG. 6 shows a basic system diagram, in which the hydraulic oil is supplied from an oil tank a via a strainer b to an oil pump c. And a valve operating oil are supplied, and a relief valve d for oil pressure adjustment and an oil cooler e are installed as necessary.

When the control valve f is fully opened, the hydraulic oil and the valve hydraulic oil are both supplied, the valve body 8 in FIG. 1 is closed, and the driven shaft 4 is operated at the maximum rotational speed (FIGS. 3 and 3a).

When the control valve f is fully closed from this state, no valve hydraulic oil (shown by a broken line in the figure) is supplied, the valve hydraulic oil is discharged from the small hole C in FIG. 1, the valve body 8 is opened, and the impeller is opened. The hydraulic oil in the circuit between the runner 2 and the runner 3 is discharged in a very short time, and the driven shaft 4 is operated at the minimum rotational speed. That is, the fourth
The state shown in FIGS. 5 and 5a is obtained through the state shown in FIG. 4 and FIG. 4a.

When the control valve f is fully opened again from this state, the operating oil and the valve operating oil are both supplied, the valve body 8 in FIG. 1 is closed, and the driven shaft 4 is operated at the maximum speed.

As described above, by opening and closing the control valve f, the driven shaft 4 shifts between the two operations of the highest rotation speed and the lowest rotation speed in an extremely short time, and FIG. 3 → FIG. 4 → FIG. 5 → FIG. The operation shown in FIG.

In order to perform heat exchange of hydraulic oil when the control valve f is fully closed, an appropriate amount of hydraulic oil is supplied via an oil amount adjusting orifice h in a bypass line. If the operation time at the minimum rotation speed is short, or if the calorific value of the hydraulic oil at the minimum rotation speed is small, the bypass line can be omitted.

FIG. 7 is an example of a system in which the control valve f in FIG. 6 is divided into a hydraulic oil control valve f and a valve hydraulic oil control valve g for the purpose of improving and adjusting the responsiveness.

FIG. 8 shows the simplest system applied when the power is small. In this case, the oil supply nozzle 10 shown in FIG. 1 is unnecessary, and the valve hydraulic oil is supplied from the valve hydraulic oil supply hole F branched from the hydraulic oil supply chamber E.

〔The invention's effect〕

As described above, according to the present invention, the impeller of the fluid coupling connected to the drive shaft or the outer peripheral portion of the impeller casing is provided with a valve that opens and closes the oil drain hole by the differential pressure of the hydraulic oil, and is filled in a short time. By performing the drainage, the shift time can be remarkably reduced from the highest rotation speed to the lowest rotation speed and from the lowest rotation speed to the highest rotation speed.

In addition, a dam is provided inside the oil drain hole in the impeller casing, and the minimum number of revolutions can be set according to the application depending on the height of the dam. For example, a descaling device pump or the like can be operated at the minimum rotation speed during no-load operation, and a great energy saving effect can be obtained with simple control.

[Brief description of the drawings]

1 and 2 are longitudinal sectional views showing different operating states of a fluid transmission provided with a transmission mechanism according to an embodiment of the present invention, and FIGS. 3, 4 and 5 are operation explanatory views. FIG. 3a, FIG. 4a and FIG.
FIGS. 7, 7 and 8 are different system diagrams of hydraulic oil and valve hydraulic oil, and FIGS. 9 (a), 9 (b) and 9 (c) are explanatory views of a conventional fluid coupling. 1 ... drive shaft, 2 ... impeller, 3 ... runner, 4 ...
Driven shaft, 5 ... impeller casing, 6 ... inner casing, 7 ... valve seat, 8 ... valve body, 9 ... valve cover, 10 ...
... oil supply nozzle, 11 ... bearing casing, A ... hydraulic oil supply hole, B ... oil drain hole, C ... small hole, D ... minimum speed setting dam, E ... hydraulic oil supply chamber, F ... valve Hydraulic oil supply hole.

Continuation of the front page (56) References JP-A-51-86665 (JP, A) JP-A-63-104734 (JP, U) JP-A-35-9015 (JP, Y1) JP-A 15-18142 (JP) , Y1) (58) Field surveyed (Int. Cl. ⁶ , DB name) F16D 33/10

Claims (1)

(57) [Claims] In a transmission mechanism of a fluid coupling, a valve is provided on an outer peripheral portion of an impeller or an impeller casing of the fluid coupling connected to a drive shaft to open and close a drain hole by a differential pressure of hydraulic oil to supply and discharge oil. So as to reduce and accelerate from the highest rotation speed to the lowest rotation speed and from the lowest rotation speed to the highest rotation speed, and provide a dam protruding radially inward inside the oil drain hole in the impeller casing, A transmission device for a fluid coupling, wherein a minimum rotation speed is changed by changing a level of hydraulic oil held in an impeller casing according to a height of the dam.