# US 11,028,768 B2 · Rotary internal combustion engine with removable subchamber insert

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- Number: US 11,028,768 B2
- Document ID: US11028768B2
- Status: Granted
- Kind: B2
- Application number: 16/748,016
- Filed: 2020-01-21
- Published: 2020-05-21
- Granted: 2021-06-08
- Earliest claimed: 2011-07-28
- Assignees: Pratt & Whitney Canada Corp.
- Applicants: Pratt & Whitney Canada Corp.
- Inventors: Bruno Villeneuve; Edwin Schulz
- Web page: https://patentgrep.com/patent/US11028768B2

## CPC

- F02B 53/04: Charge admission or combustion-gas discharge
- 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
- F01C 1/344: with vanes reciprocating with respect to the inner member
- F01C 21/06: Heating; Cooling (of machines or engines in general F01P); Heat insulation (heat insulation in general F16L)
- F01C 21/106: {with a radial surface, e.g. cam rings}
- F01C 21/18: Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet
- F02B 19/00: Engines characterised by precombustion chambers
- F02B 19/12: with positive ignition (engines with non-timed positive ignition, and with incandescent chambers F02B9/08)
- F02B 53/10: Fuel supply; Introducing fuel to combustion space
- F02B 55/16: Admission or exhaust passages in pistons or outer members
- F01C 20/28: Safety arrangements; Monitoring
- F02B 2053/005: {Wankel engines}
- F02B 2730/00: Internal-combustion engines with pistons rotating or oscillating with relation to the housing
- 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 engine having an outer body having an internal cavity with a peripheral wall having an insert opening defined therethrough in communication with the internal cavity, and a plurality of coolant passages defined through the peripheral wall in proximity of the insert opening, a rotor body rotatable within the internal cavity, and an insert removably received in the insert opening of the peripheral wall, the insert having a subchamber defined therein communicating with the internal cavity, with a minimum width of the insert opening being at least 0.75 inches. An outer body for a rotary engine and a method of inspecting in an internal cavity in an outer body of a rotary engine are also discussed; also, a rotary engine including a fuel injector having a tip received in the injector hole of the peripheral wall without protruding in the insert opening.

## Claims

### Claim 1

A rotary engine comprising:
an outer body having an internal cavity defined by two axially spaced apart end walls and a peripheral wall extending between the end walls, the peripheral wall having an insert opening defined therethrough in communication with the internal cavity, and a plurality of coolant passages defined through the peripheral wall in proximity of the insert opening, the coolant passages forming part of a cooling circuitry for circulating a liquid coolant therethrough;
a rotor body rotatable within the internal cavity in sealing engagement with the peripheral wall and defining at least one chamber of variable volume in the internal cavity around the rotor body; and
an insert removably received in the insert opening of the peripheral wall, the insert having a subchamber defined therein communicating with the internal cavity, a volume of the subchamber being at least 0.5% of a displacement volume defined as a difference between maximum and minimum volumes of the at least one chamber of variable volume, or the volume of the subchamber being from 5% to 25% of a combustion volume defined as a sum of a minimum volume of the at least one chamber of variable volume and the volume of the subchamber;
wherein a minimum width of the insert opening is defined along a direction of an axis of rotation of the rotor body, the minimum width of the insert opening being at least 0.75 inches.

### Claim 2 (depends on 1)

The rotary engine as defined in claim 1, wherein the subchamber is a pilot subchamber, the engine further comprising a pilot injector communicating with the pilot subchamber, and a main fuel injector extending through the outer body and communicating with the internal cavity at a location spaced from the insert opening.

### Claim 3 (depends on 1)

The rotary engine as defined in claim 1, wherein a width of the internal cavity is defined as a distance between inner surfaces of the end walls along the direction of the axis of rotation of the rotor body, and a width of the insert opening is equal to or greater than ⅓ of the width of the internal cavity.

### Claim 4 (depends on 1)

The rotary engine as defined in claim 1, wherein the minimum width of the insert opening being at least 0.85 inches.

### Claim 5 (depends on 1)

The rotary engine as defined in claim 1, wherein the insert includes an elongated insert body with an enlarged flange at an outer end thereof, the flange being removably mounted to the outer body by at least one fastener.

### Claim 6 (depends on 1)

The rotary engine as defined in claim 1, wherein a threaded hole is provided in an outer surface of the insert opposite to the internal cavity, the threaded hole having a shape complementary to that of a threaded tool for removal of the insert from the insert opening.

### Claim 7 (depends on 1)

The rotary engine as defined in claim 1, further comprising an ignition element in heat transfer communication with the subchamber and having a major part thereof extending within the peripheral wall outside of the insert opening.

### Claim 8

An outer body for a rotary engine comprising:
two axially spaced apart end walls;
a peripheral wall extending between the end walls and defining an internal cavity for receiving a rotor, the peripheral wall having an insert opening defined therethrough in communication with the internal cavity, and a plurality of coolant passages defined through the peripheral wall in proximity of the insert opening, the coolant passages forming part of a cooling circuitry for circulating a liquid coolant therethrough;
an insert removably received in the insert opening of the peripheral wall, the insert having a subchamber defined therein communicating with the internal cavity, the subchamber having a shape forming a reduced cross-section adjacent a flow opening of the insert via which the subchamber communicates with the internal cavity;
a fuel injector in fluid communication with the subchamber; and
an ignition element in heat transfer communication with the subchamber;
wherein a minimum width of a cross-section of the insert opening is at least 0.75 inches.

### Claim 9 (depends on 8)

The outer body as defined in claim 8, wherein a width of the internal cavity is defined as a distance between inner surfaces of the end walls, and the width of the cross-section of the insert opening is equal to or greater than ⅓ of the width of the internal cavity.

### Claim 10 (depends on 8)

The outer body as defined in claim 8, wherein the minimum width of the insert opening being at least 0.85 inches.

### Claim 11 (depends on 8)

The outer body as defined in claim 8, wherein the insert includes an elongated insert body with an enlarged flange at an outer end thereof, the flange being removably mounted on the outer body by at least one fastener.

### Claim 12 (depends on 8)

The outer body as defined in claim 8, wherein the subchamber is a pilot subchamber, the engine further comprising a main fuel injector extending through the outer body and communicating with the internal cavity at a location spaced from the insert opening.