Rotary internal combustion engine with removable subchamber insert

Patent metadata

Field	Value
Publication number	US-2016252010-A1
Application number	US-201615153277-A
Country	US
Kind code	A1
Filing date	May 12, 2016
Priority date	Jul 28, 2011
Publication date	Sep 1, 2016
Grant date	—

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.

First 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; 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.

2 . 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.

3 . 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 the width of the insert opening is equal to or greater than ⅓ of the width of the internal cavity.

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

5 . 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.

6 . 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.

7 . 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.

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; 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.

9 . 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.

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

11 . 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.

12 . 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.

13 . A method of inspecting in an internal cavity in an outer body of a rotary engine, the method comprising:
detaching an insert from the outer body, the insert received in an insert opening of a peripheral wall of the outer body and including a subchamber configured for receiving fuel for ignition; removing the insert from the insert opening; and performing an unaided visual inspection of the internal cavity through the insert opening to determine if a subsequent maintenance or repair operation is required.

14 . The method as defined in claim 13 , wherein removing the insert includes inserting a threaded tool into a threaded hole defined in the insert and applying a pulling force on the threaded tool.

15 . The method as defined in claim 13 , wherein removing the insert is performed without removing a fuel injector received in the peripheral wall and in communication with the subchamber.

16 . The method as defined in claim 13 , wherein a minimum width of a cross-section of the insert opening is at least 0.75 inches.

17 . The method as defined in claim 13 , wherein performing the unaided visual inspection of the internal cavity through the insert opening includes inspecting an apex seal of a rotor received in the internal cavity.

18 . The method as defined in claim 13 , wherein performing the unaided visual inspection of the internal cavity through the insert opening includes verifying a presence of cracks in a rotor received in the internal cavity.

19 . The method as defined in claim 13 , wherein performing the unaided visual inspection of the internal cavity through the insert opening includes verifying if liquid coolant or oil is present in at least one chamber defined in the internal cavity.

20 . The method as defined in claim 13 , wherein inner surfaces of the outer body have a coating applied thereon, and wherein performing the unaided visual inspection of the internal cavity through the insert opening includes inspecting the coating.

21 . The method as defined in claim 13 , wherein the insert is in fluid communication with a fuel injector and in heat transfer relationship with an ignition element, and removing the insert from the insert opening is performed without prior removal of at least one of the fuel injector and of the ignition element from the outer body of the engine.

22 . A method of performing maintenance on a rotary engine, including inspecting the internal cavity of the rotary engine following the method as defined in claim 13 , disassembling at least part of the rotary engine upon determination that a subsequent maintenance or repair operation is required, and then performing the subsequent maintenance or repair operation on the rotary engine.

23 . 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 an injector hole defined therein in communication with the insert opening; a rotor body rotatable within the internal cavity in sealing engage

Assignees

• Pratt & Whitney Canada

Inventors

• Villeneuve Bruno
• Schulz Edwin

Classifications

• F02B53/04 Primary

  Charge admission or combustion-gas discharge · CPC title

• F01C1/22

  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 · CPC title

• F01C21/06

  Heating; Cooling (of machines or engines in general F01P); Heat insulation (heat insulation in general F16L) · CPC title

• F02B55/16

  Admission or exhaust passages in pistons or outer members · CPC title

• F01C21/18

  Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet · CPC title