Patent ID: 7370630
Filing Date: 2008-05-13
Classification: F01B,F02B,F02D,F02M

Abstract:
1. An engine comprising: a variable volume chamber; inlet valve means controlling admission of charge air into the variable volume chamber; fuel delivery means for delivering fuel to be mixed with the charge air admitted to the variable volume chamber; and exhaust valve means for controlling exhaust to atmosphere from the variable volume chamber of combusted gases resulting from combustion in the variable volume chamber of the fuel with the admitted charge air; wherein: the engine has a first operating mode in which the inlet valve means admits charge air into the variable volume chamber, the fuel delivery means delivers fuel which is mixed with the admitted charge air, the mixture of fuel and charge air is compressed by the variable volume chamber reducing in volume, the compressed mixture of fuel and air combusts, the combusted gases expand and force the variable volume chamber to increase in volume and the expanded combusted gases are exhausted to atmosphere from the variable volume chamber via the exhaust valve means; wherein the engine additionally comprises: a reservoir for storing compressed air which is connected to the variable volume chamber; and gas flow control valve means controlling flow of air between the variable volume chamber and the reservoir for storing compressed air; and wherein the engine has at least the following operating modes: a second operating mode in which the inlet valve means admits charge air into the variable volume chamber, the admitted charge air is compressed by the variable volume chamber reducing in volume and the gas flow control valve means allows the compressed air to flow from the variable volume chamber to the reservoir to be stored therein; and a third operating mode in which the gas flow control valve means allows compressed air to flow from the reservoir into the variable volume chamber and thereafter expand to force the variable volume chamber to increase in volume, the expanded air subsequently being exhausted to atmosphere; and has a fourth operating mode in which the inlet valve means admits charge air into the variable volume chamber, the admitted charge air is compressed by the variable volume chamber reducing in volume and the exhaust valve means allows the compressed air to be exhausted to atmosphere; and the engine being characterised by a fifth operating mode in which: air or combusted gases is/are trapped in the variable volume chamber by closing all of the inlet valve means, the exhaust valve means and the gas flow control valve means, and in which the variable volume chamber with the trapped air or combusted gases operate(s) as a gas spring.