# US 5,343,838 A · Dual radius rotor for pre-mixed-charge rotary engine combustion

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- Number: US 5,343,838 A
- Document ID: US5343838A
- Status: Granted
- Kind: A
- Application number: 08/099,105
- Filed: 1993-07-29
- Granted: 1994-09-06
- Earliest claimed: 1993-07-29
- Assignees: Gas Research Institute
- Inventors: John Abraham
- Web page: https://patentgrep.com/patent/US5343838A

## CPC

- F02B 55/02: Pistons
- F01C 1/22: of internal-axis type with equidirectional movement of co-operating members at the points of engagement, or with one of the co-operating members being stationary, the inner member having more teeth or tooth- equivalents than the outer member
- F02B 53/00: Internal-combustion aspects of rotary-piston or oscillating-piston engines (internal-combustion aspects of rotary pistons or outer members for co-operation therewith F02B55/00)
- F02B 2053/005: {Wankel engines}
- F02B 2275/14: Direct injection into combustion chamber
- Y02T 10/12: Improving ICE efficiencies
- F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G)
- F01C: ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES (internal-combustion aspects F02B53/00, F02B55/00)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A rotary piston for a rotary piston, internal combustion engine, said rotary piston comprising a plurality of contiguous, convex, arcuate peripheral surfaces which, in combination with the engine housing, define combustion-working chambers. Each of the convex, arcuate peripheral surfaces of the rotary piston defines a convex, arcuate rotor recess having a radius greater than the radius of the arcuate peripheral surface of the rotary piston.

## Claims

### Claim 1

In a rotary piston, internal combustion engine having a rotary piston eccentrically mounted for rotation in a multi-lobe, trochoidal-shaped engine housing and defining, with the housing, intake, compression, expansion and exhaust working chambers, each of which vary in volume as the rotary piston rotates within the housing in combination with ignition means for initiating fuel combustion disposed within the housing at a point relative to the direction of rotary piston rotation preceding the lobe junction between the compression and expansion combustion-working chambers, the improvement comprising:
a rotary piston comprising a plurality of contiguous, convex, arcuate peripheral surfaces which, in combination with said engine housing, define said combustion-working chambers;
said rotary piston further comprising a plurality of apex seals and a plurality of side seals disposed between said rotary piston and said engine housing;
each of said convex, arcuate peripheral surfaces defining a convex, arcuate rotor recess, said convex, arcuate rotor recess having a recess radius greater than a peripheral surface radius of said rotary piston; and
said convex, arcuate rotor recess comprising a crescent-shaped cross-section.

### Claim 2 (depends on 1)

In a rotary piston, internal combustion engine in accordance with claim 1, wherein each said convex, arcuate rotor recess occupies between about 40% and about 80% of each corresponding said convex, arcuate peripheral surface.

### Claim 3 (depends on 1)

In a rotary piston, internal combustion engine in accordance with claim 1, wherein said convex, arcuate rotor recess has a generally rectangular shape, the edges of said convex, arcuate rotor recess being between about 1.5 cm and about 2.0 cm in distance from said apex seals and said side seals.

### Claim 4 (depends on 1)

In a rotary piston, internal combustion engine in accordance with claim 1, wherein each said convex, arcuate rotor recess is dimensionally centered within each corresponding said convex, arcuate peripheral surface.

### Claim 5 (depends on 1)

In a rotary piston, internal combustion engine in accordance with claim 1, wherein each said convex, arcuate rotor recess is disposed toward a leading edge of said convex, arcuate peripheral surface.

### Claim 6 (depends on 1)

In a rotary piston, internal combustion engine in accordance with claim 1, wherein each said convex, arcuate rotor recess is disposed toward a trailing edge of said convex, arcuate peripheral surface.