The present invention teaches a gearbox expansion cap that allows a gearbox unit to breathe to atmosphere while preventing the ingress of water or other materials into the gearbox or gearbox oil. According to a first preferred embodiment, the expansion cap of the present invention includes a pressure relief plug to control gearbox pressures. Additionally, the present invention teaches air channels enclosed within a gearbox casting which mate with air channels provided within the expansion cap to channel air from the expansion cap into the atmosphere.

A compact geared reduction unit for application with transmission shaft subjected to radial loads, comprising a box-like body inside which a gear system is accommodated for the transmission of rotary motion from a driving shaft to a transmission shaft, which is provided with an output reduction stage of the epicyclic type; the output reduction stage comprises a driving sun gear which rotates about a main axis and a ring gear which is integrally associated with the box-like body, between which multiple planet gears are engaged which are supported in rotation about respective longitudinal axes which are parallel to the main axis by a transmission planet carrier, which in turn rotates about the main axis and is associated so as to be integral in rotation with the transmission shaft at a connection region. The reduction unit furthermore provides for rolling means adapted to support radial loads associated with the transmission shaft.

A compact geared reduction unit for application with transmission shaft subjected to radial loads, comprising a box-like body inside which a gear system is accommodated for the transmission of rotary motion from a driving shaft to a transmission shaft, which is provided with an output reduction stage of the epicyclic type; the output reduction stage comprises a driving sun gear which rotates about a main axis and a ring gear which is integrally associated with the box-like body, between which multiple planet gears are engaged which are supported in rotation about respective longitudinal axes which are parallel to the main axis by a transmission planet carrier, which in turn rotates about the main axis and is associated so as to be integral in rotation with the transmission shaft at a connection region. The reduction unit furthermore provides for rolling means adapted to support radial loads associated with the transmission shaft.

A seal ring and a sealing structure that reduce the deviation of the central axis of the seal ring from the central axis of a shaft thereby preventing the seal ring from abutting against the tip end of a housing in the operation of inserting the shaft in the housing. The seal ring includes a thin part 100A provided in a range less than 180° with respect to a circumferential direction and a thick part 100B, which is configured to protrude inward in the radial direction from an inner peripheral surface of the thin part 100A, the thin part 100A has an abutment joint part 110, and the thick part 100B has, at respective ends of both side surfaces on an inner peripheral surface side thereof, a concave part 120 over an entire range thereof to form a gap between the ends of the both side surfaces and corner parts at both ends of a groove bottom of the annular groove.

A seal ring and a sealing structure that reduce the deviation of the central axis of the seal ring from the central axis of a shaft thereby preventing the seal ring from abutting against the tip end of a housing in the operation of inserting the shaft in the housing. The seal ring includes a thin part 100A provided in a range less than 180° with respect to a circumferential direction and a thick part 100B, which is configured to protrude inward in the radial direction from an inner peripheral surface of the thin part 100A, the thin part 100A has an abutment joint part 110, and the thick part 100B has, at respective ends of both side surfaces on an inner peripheral surface side thereof, a concave part 120 over an entire range thereof to form a gap between the ends of the both side surfaces and corner parts at both ends of a groove bottom of the annular groove.

A rotary sealing arrangement comprises a housing, a shaft mounted for rotation within the housing about a shaft axis (A) and a rotary seal provided between the housing and the shaft. The rotary seal comprises a static seal element mounted to the housing and a rotary sealing element mounted for rotation with the shaft. The static seal element comprises a mounting part and a flexible lip seal extending from the mounting part in an axial direction relative to the shaft. The rotary seal element comprises a seal body comprising an axially facing sealing face. The lip seal resiliently engages the sealing face of the seal body. The static seal element and the rotary seal element are mounted such that the relative axial positions of the static seal element and the rotary seal element can be adjusted.

A rotary sealing arrangement comprises a housing, a shaft mounted for rotation within the housing about a shaft axis (A) and a rotary seal provided between the housing and the shaft. The rotary seal comprises a static seal element mounted to the housing and a rotary sealing element mounted for rotation with the shaft. The static seal element comprises a mounting part and a flexible lip seal extending from the mounting part in an axial direction relative to the shaft. The rotary seal element comprises a seal body comprising an axially facing sealing face. The lip seal resiliently engages the sealing face of the seal body. The static seal element and the rotary seal element are mounted such that the relative axial positions of the static seal element and the rotary seal element can be adjusted.

A drive includes a housing, an adapter plate, and a cover hood. A flat support surface is provided on the housing, e.g., for placement of the cover hood, and the adapter plate is attached to the housing. A first sealing ring, e.g., an O-ring, is received on the outer circumference of the adapter plate and is arranged between the cover hood and the cover plate, e.g., for sealing. A second sealing ring, e.g., an O-ring or a flat sealing ring, is received and/or attached to the side of the adapter plate facing the support surface, and the second sealing ring is arranged between the adapter plate and the support surface, e.g., for sealing.

A drive includes a housing, an adapter plate, and a cover hood. A flat support surface is provided on the housing, e.g., for placement of the cover hood, and the adapter plate is attached to the housing. A first sealing ring, e.g., an O-ring, is received on the outer circumference of the adapter plate and is arranged between the cover hood and the cover plate, e.g., for sealing. A second sealing ring, e.g., an O-ring or a flat sealing ring, is received and/or attached to the side of the adapter plate facing the support surface, and the second sealing ring is arranged between the adapter plate and the support surface, e.g., for sealing.

A harmonic reducer includes a shaft having a first through hole extending from a first end to a second end of the shaft; a wave generator arranged on the shaft and being rotatable along with the shaft; a flexible spline arranged around the wave generator; a circular spline arranged around the flexible spline; a first flange coupled to the shaft via a first bearing and coupled to the flexible spline; and a second flange coupled to the shaft via a second bearing and coupled to the circular spline. One of the flanges is arranged near to the first end of the shaft. A cavity is provided between the one of the flanges and the first end of the shaft, such that it is in fluid communication with an external environment via the first through hole.