GB1198625A - Improvements in or relating to Rotary Internal Combustion Engines. - Google Patents

Abstract

1,198,625. Rotary internal combustion engines; motor power plant. J.W. MARSHALL. July 21, 1967 [July 27, 1966; April 6, 1967 (2)], Nos. 33702/66, 15779/67 and 15780/67. Headings F1F and F1Q. A rotary internal combustion engine comprises a casing 4, Fig. 1, having intersecting parallel bores within which is respectively mounted for rotation in opposite directions a male rotor 1 having as shown, cycloidal lobes 5 four in number, involute lobes and any number of lobes may be employed, and a female rotor 2 having twice as many cavities 28 as the male rotor has lobes with the rotors having close running clearance with respect to each other and to the bores to provide friction less running without lubrication. Ports 6<SP>1</SP>, 6<SP>11</SP>, in the casing end-walls 18, Fig. 3, admit air to both bores. The air admitted through the ports 6<SP>1</SP> being compressed with and mixed with fuel admitted through an injector 10 on rotation of the rotors in the direction of the arrows 29. This air also together with the air admitted through the ports 6<SP>11</SP> scavenges the bores. The compressed gaseous fuel/air mixture is ignited by glow-plugs 9, 9<SP>1</SP> in combustion chambers 69, 70 formed in a combustion chamber body 85 mounted with clearance for insulation purposes in the casing end-walls 18. The expanding gases rotate the rotors and finally exhaust through peripheral casing ports 7, 7<SP>1</SP>. The exhaust gases which leave the ports 7, 7<SP>1</SP> at high velocity and appreciable pressure may be used to drive a turbine coupled to the shaft mounting the male rotor 2 to give added torque or drive a super-charger and at the same time suppress engine noise. Instead of glow-plugs ignition may be by means of spark-plugs or the chambers may be sufficiently hot to ignite the gases in which case the glow-plugs would cut in and out automatically as required. The rotors are made of material having a low co-efficient of thermal expansion, e.g., high nickel/iron alloy known under the Registered Trade Mark, "Invar". Cooling air circulates through cavities 83 to cool the casing and excess scavenge air passes through bores 61, 84 to cool the rotors. Water may be injected into the scavenage air to assist cooling. Alternatively the bores 61, 84 may be plugged at their ends and cooling oil or other liquid coolant then passes through axial and radial holes in the rotors into and out of the bores 61, 84 and bores 90 at the tips of the female rotor 2. Labyrinth grooves at the rotor tips assist sealing of the rotors with respect to each other and the bores.