Abstract

A piston-in-piston hydraulic unit is disclosed that utilises an elastic volume to store and release energy with each stroke by varying the hydraulic fluid volumes in and out of the hydraulic unit.

IPC Classes  ?

• F03C 1/00 - Reciprocating-piston liquid engines
• F03C 1/28 - Pistons specially adapted therefor
• F15B 15/14 - Fluid-actuated devices for displacing a member from one position to anotherGearing associated therewith characterised by the construction of the motor unit of the straight-cylinder type
• F16D 57/06 - Liquid-resistance brakesAir-resistance brakes comprising a pump circulating fluid, braking being effected by throttling of the circulation
• F16J 1/00 - PistonsTrunk pistonsPlungers

Abstract

A traditional variable compression ratio system for use in a reciprocatmg-piston engine either requires large flows of hydraulic fluid or does not have provision to exchange the hydraulic fluid sufficiently often to prevent overheating of the fluid. A variable compression ratio system (100) for use in a reciprocatmg-piston engine is provided. The system (100) allows the compression ratio in a combustion cylinder (910) of the engine to be varied by varying the distance from a combustion chamber facing surface (113) of a piston (112) to the center of pivotal connection of a connecting rod (114) to a crankshaft (920). The distance is varied responsive to the supply and withdrawal of pressurized hydraulic fluid. The hydraulic fluid is supplied and discharged by a slave pump (140) pivotally connected to the connecting rod (114) at a first end and pivotally connected to a stationary point at a second end. The slave pump (140) supplies and withdraws hydraulic fluid responsive to the rotation of the crankshaft (920) and a hydraulic backpressure controlled using a pressure control valve (170).

IPC Classes  ?

• F01B 31/14 - Changing of compression ratio
• F02B 75/04 - Engines with variable distances between pistons at top dead-centre positions and cylinder heads

Abstract

A regeneration system (100) for use in a vehicle having a reciprocating-piston engine. The regeneration system (100) captures energy (e.g. braking energy), stores the energy, and subsequently uses the stored energy to generate motive power for the vehicle. The motive power can be generated in conjunction with motive power provided by the engine. The regeneration system (100) comprises a variable displacement pump/motor (110) that is connected to a connecting rod (940) in each cylinder (910) of the engine. The pump/motor (110) comprises a fluid chamber (112), a primary piston (114) mechanically coupled to the connecting rod (940) and a slave piston (116) coupled to the primary piston (114) via resilient means (118). A control unit (160) controls a plurality of valves (125, 140, 176, 135) to direct the exchange of pressurized hydraulic fluid between the pump/motor (110) and a hydraulic accumulator (150) in synchronous timing with the operation of the engine.

IPC Classes  ?

• B60K 6/12 - Prime-movers comprising combustion engines and mechanical or fluid energy storing means by means of a chargeable fluidic accumulator

Abstract

A regenerative brake system and a variable displacement pump/motor for use therein. Each cylinder of the pump/motor having a main piston and a second piston between which is defined a space for hydraulic fluid, and a resilient element acting on the second piston to bias it toward the main piston. Variable displacement is achieved by controlling a volume of pressurized fluid that is injected and exhausted between the main and second pistons. Brake, drive and neutral modes of operation of the pump/motor are achieved by controlling the timing (relative to a drive shaft phase) of the injection and exhaust of the fluid. Regeneration is achieved by storing pressurized fluid generated by the pump/motor in an accumulator in brake mode and using the stored pressurized fluid to power the pump/motor in drive mode.

IPC Classes  ?

• B60T 8/40 - Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition comprising an additional fluid circuit including fluid pressurising means for modifying the pressure of the braking fluid, e.g. including wheel driven pumps for detecting a speed condition, or pumps which are controlled by means independent of the braking system