The scope of technique.

The invention is related to a Starting Hydraulic Coupling which is characterised by a continuous tacking of the driving shaft and the driven shaft. The coupling is to be used for driving earth moving machines, heavy trucks, locomotives, as a driving mechanism of engines in power engineering, mining industry and ship building industry.

According to the functional properties the coupling, according to the invention, may be included to the group of the controlled, hydraulic couplings, controlled by throttling, adjustable at the constant dimensions of the working impellers, and to the self-acting, hydraulic couplings, respectively.

Techniques used hitherto In the scope of technique stated above, according to the terminology of the STN 026400 (note : STN-the Slovak National Standard) two types of hydraulic couplings are employed, i. e. the controlled hydraulic couplings and the self-acting hydraulic couplings.

The controlled hydraulic couplings consist of a driving part, constructed as a vane impeller, of a driven part, built as a turbine impeller keyed firmly to the driven shaft, and where liquid is a coupling substance. These couplings transmit torque by the hydrodynamic action of liquid in the vane impeller, while the liquid circulates between both parts, a driving and a driven shaft. The driving part transfers the energy to the liquid and the driven part draws it off. The energy transfer is carried with a certain energy loss, the revolutions of the driven shaft are always a bit lower than revolutions of the driving shaft. Therefore, the coupling is a sliding coupling. These couplings are divided into two groups: the traction coupling. and the adjustable couplings.

A self-acting hydrodynamic coupling, with a constant volume of liquid, differs from the traction couplings with the following accessories: -prior to the vane impeller a front-end rotating liquid tank is incorporated, and openings connect the tank with the vanes; -a cap of the coupling box is furnished with cooling fins for better heat removal, rising from the lost work during the engine starting period.

A disadvantage of the above hydrodynamic couplings is their big weight and a higher volume of the working liquid. With these couplings it is impossible to change driven shaft revolutions smoothly to the maximum speed, or to lower them to zero at the maximum speed of the driving shaft.

Substance of the invention.

The above drawbacks are rectified by the starting hydraulic coupling, which according to the invention, consists of the driving body of the coupling, the driven body of the coupling, an oil pump, an oil tank with an oil, a suction channel and a discharge channel and a control valve. The essence of the coupling : within the driving body of the coupling a minimum one hydraulic pump is placed with the suction channel from the oil tank and the discharge channel to the oil tank. In the discharge line, the oil control valve is placed which is governed by a speed regulator.

With increasing revolutions of the driving shaft, the speed regulator controls the oil control valve in the discharge channel in such away, that the valve is enclosing continuously the flow of liquid, and consequently the pressure of the liquid is increasing, and the driven shaft revolutions are increasing as well.

On the contrary, with opening the oil control valve the pressure of the working fluid is dropping, and consequently, the driven shaft revolutions are decreasing.

With the control valve, the speed of the driven shaft may be lowered, or its revolutions can be equal to the revolutions of the driving shaft. Therefore, the torque of the driven shaft is lower, or equal to the driving shaft torque, at best.

The starting coupling, according to the invention, can transmit the power steadily from the driving shaft to the driven shaft up to the point, where the whole power is transmitted at the balanced revolutions of both shafts, or, in turn, the whole power can be reduced at the driven shaft.

Inside the driving shaft body of the coupling, several hydraulic pumps can be installed, on condition that the driving shaft body, with the built-in pumps, are statically and dynamically balanced.

As a pump, various hydraulic pumps may be employed in case that they are capable to achieve the desired pressure, however the control valve in the discharge channel must be entered.

The outline of thefigures on the drafts.

The invention will be explained in a more detail way in the drawings, on which a cross section of the starting hydraulic coupling, in accordance with the invention, is in the Fig.

1, and its longitudinal section is in the Fig. 2.

Example of the invention's realization.

The starting hydraulic coupling, according to Fig. 1 consists of the driving body of the coupling L in which two hydraulic gear pumps 5 are placed. The pumps consist of the trinity of the meshing spoor wheels. The middle wheel is tightly coupled with the driven body of the coupling 6. The suction channels 2 of the hydraulic gear pumps 5 come out from the oil tanks 7 and their discharge channels 3 enter the tanks 7. In the discharge channels the control valves 4 are placed. The control valve 4, in Fig. 2 is governed by the speed regulator 8 in such a way the short piston 9, moving to and fro in the direction of the coupling axle, closesl opens the cross section of the discharge channel 3, gradually.