Power plants – Pressure fluid source and motor – With control means for structure storing work driving energy
Patent
1976-11-04
1977-12-27
Geoghegan, Edgar W.
Power plants
Pressure fluid source and motor
With control means for structure storing work driving energy
60418, 60DIG2, F15B 102, F16H 3946
Patent
active
040646947
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to the charging of an accumulator by a heat engine driving a hydraulic pump and more precisely to a device ensuring the automatic charging of an oleopneumatic accumulator by the intermediary of a heat engine driving a hydraulic pump of variable displacement.
Hybrid vehicles are already known, provided with a hydrostatic transmission and an oleopneumatic accumulator (Product Engineering, October 1973: transport conference at DENVER in September 1973).
In this type of vehicle, an oleopneumatic accumulator serves to store energy. The energy is conducted to the accumulator in the form of a discharge of hydraulic fluid, when the discharge of the transmission pump is greater than the discharge taken in by the hydraulic engine. Inversely, some energy is returned in the form of a flow of hydraulic fluid conveyed to the hydraulic engine when the discharge of the pump is less than the discharge of the hydraulic engine. It is also possible to recover the energy normally wasted in the brakes by the reversal of the engine's direction of flow, so that it functions as a pump supplying a flow of fluid to the accumulator.
One of the problems posed by hybrid vehicles of the above-mentioned type is the necessity of having available at all times an adequate reserve of energy in the accumulator.
This involves an accumulator discharging through one or several hydraulic engines as a function of the energy requirement of a consumer. It is therefore advisable to maintain at all times in the accumulator a charge of energy which is sufficient to meet the needs of the consumer.
A pump of variable displacement is available for recharging the accumulator, being made to operate by the intermediary of a heat engine operating intermittently.
When the pressure in the accumulator falls below a first listed value P.sub.1, the heat engine is started up after the reconnecting of its ignition by the hydraulic pump operating as a motor. By controlling the displacement of the pump, the adjustment thus ensures the charging of the accumulator, the heat engine supplying a predetermined power for a predetermined rotational speed. The supply conditions of the heat engine are fixed which indicates, for example that the gas butterfly valve is locked in a certain position. It should be noted that the torque and power supplied by the heat engine are thus functions only of its rotational speed. Therefore, the charging of the accumulator may take place at an operation point of the power-speed plan of the heat engine corresponding to a minimum, specific consumption and to reduced emissions of pollutants. When the pressure in the accumulator exceeds a second listed value P.sub.2, the adjustment switches off the heat engine by cutting the ignition, or supply in the case of a diesel and returns the displacement of the pump to zero.
The process according to the invention, which allows the pressure to be maintained inside an oleopneumatic accumulator, between two listed pressures P.sub.1 and P.sub.2, with P.sub.1 less than P.sub.2 by means of a heat engine driving a hydraulic pump of variable displacement used for charging the accumulator, P.sub.2 being the maximum pressure inside the accumulator, is characterised in that:
if the pressure inside the accumulator is greater than P.sub.1, when the engine is switched off and the ignition cut off, the regulation maintains a zero displacement for the pump,
if the pressure inside the accumulator is less than P.sub.1, when the engine is switched off, the regulation reconnects the ignition and brings the pump to operate as a motor, it renders its cubic capacity negative until in mechanical abutment, while the rotational speed .omega. of the engine is less than a speed .omega..sub.0 from which the engine may accelerate by itself,
if .omega. exceeds .omega..sub.0, the displacement C of the hydraulic pump is increased, becomes positive and the regulation selects the value of it so that it is greater than a value C.sub.2 in order to avoid racing the engine,
the regulation therefore controls the d
REFERENCES:
patent: 2326821 (1943-08-01), Boyle
patent: 2827763 (1958-03-01), Govan et al.
patent: 3922854 (1975-12-01), Coeurderoy
Geoghegan Edgar W.
Regie Nationale des Usines Renault
LandOfFree
Charging an accumulator by a heat engine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Charging an accumulator by a heat engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Charging an accumulator by a heat engine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1032516