A rotary internal combustion engine with a rotor body made at least in major part of a first material, including at least one land protruding axially from each of its end faces and defining a contact surface extending at a fixed position with respect to the end faces. The contact surface frictionally engages a portion of the inner surface of the internal cavity of the engine, and at least the outer surface of the land includes a second material. The second material has a greater wear resistance than that of the first material with respect to frictional engagement with the portion of the inner surface of the internal cavity contacting the land. A method of axially positioning a rotor of a rotary engine within an internal cavity of an outer body of the engine are also discussed.

A geared fluid machine has a machine housing and first and second intermeshing gearwheels that are rotatably mounted in the machine housing with respect to an axis of rotation and are arranged at least partially contacting by their end faces. At least one axial washer is arranged in the machine housing with axial play and has on a distal side a pressure field surrounded by a circumferential seal. The seal contacts and seals against a first bearing surface of the axial washer, and also contacts and seals against a second bearing surface of the machine housing. The seal is at least partially U-shaped in section and has a first seal limb contacting the first bearing surface, a second seal limb contacting the second bearing surface, and a connecting limb connecting the first and second seal limbs.

A housing assembly for a rotary engine, has: a rotor housing having an inner face facing a rotor cavity, a first side and a second side opposite to the first side; a first side housing secured to the first side, and a second side housing secured to the second side, the rotor cavity bounded axially between the first side housing and the second side housing; and a seal received within a groove at an interface between the rotor housing and the first side housing, the groove located outwardly of the inner face and overlapping a peripheral section of the first side housing, the seal having: an elastomeric member compressed between the peripheral section and the rotor housing; and a metallic member disposed inwardly of the elastomeric member, the metallic member in contact with both of the peripheral section of the first side housing and the rotor housing.

According to one embodiment of the invention, a gerotor apparatus includes a first gerotor, a second gerotor, and a synchronizing system operable to synchronize a rotation of the first gerotor with a rotation of the second gerotor. The synchronizing system includes a cam plate coupled to the first gerotor, wherein the cam plate includes a plurality of cams, and an alignment plate coupled to the second gerotor. The alignment plate includes at least one alignment member, wherein the plurality of cams and the at least one alignment member interact to synchronize a rotation of the first gerotor with a rotation of the second gerotor.