A gyroscopic roll stabilizer comprises a gimbal having a support frame and enclosure configured to maintain a below-ambient pressure, a flywheel assembly including a flywheel and flywheel shaft, one or more bearings for rotatably mounting the flywheel inside the enclosure, a motor for rotating the flywheel, and bearing cooling system for cooling the bearings supporting the flywheel. For smaller units, the bearing cooling system is effective to enable a flywheel with a moment of inertia less than 11.7 kg.m.sup.2 (40000 lbm in.sup.2) to be accelerated at a rate of 5 rpm/s or greater. For larger units, the bearing cooling system is effective to enable a flywheel with a moment of inertia greater than 11.7 kg.m.sup.2 (40000 lbm in.sup.2) to be accelerated at a rate of 2.5 rpm/s or greater.

A hub unit including an end cap for preloading and retaining a bearing unit on an axle. The end cap is provided with a sensor unit for detecting at least one of vibrations and temperature of the bearing unit.

A bearing assembly comprising a rolling element bearing having a first row of rolling elements arranged in a first bearing cavity between a first inner raceway and a first outer raceway of the bearing, and having a second row of rolling elements arranged in a second bearing cavity between a second inner raceway and a second outer raceway of the bearing. The assembly further comprises an annular grease cartridge arranged between the first and second rows of rolling elements. The annular grease cartridge is at least partly formed from a honeycomb structure having axially extending passageways filled with a grease lubricant, wherein at least some of passageways are open towards the first and second bearing cavities.

A seal configured to seal a gap between a first component and a second component to at least partially retain a fluid on a first side of the seal in a space between the first component and the second component, the seal including a seal body having a radially outer periphery and a central opening configured to receive the first component or the second component, at least one sensor configured to detect a characteristic of the fluid and an adapter. The at least one sensor is disposed on the adapter, and the adapter has a first portion extending through the seal body at a location spaced from and radially between the radially outer periphery and the central opening and a second portion axially abutting the seal body on the first side of the seal.

A temperature compensation ring configured to compensate for changes in a temperature-dependent distance between two components includes a base body made from an elastic material and a first reinforcing body and a second reinforcing body, each of the first and second reinforcing bodies including a harder material than the material of the base body. The first and second reinforcing bodies are disposed at opposite end surfaces of the base body and partially define an outer periphery of the temperature compensation ring.

A gear box includes a housing, an actuator coupled to the housing, and a bearing assembly pivotably coupled to the actuator. The bearing assembly including an outer raceway, a cylindrical housing positioned within the outer raceway, and an annular bearing positioned between the outer raceway and the housing. The cylindrical housing has a first end and a second end opposite the first end. A sensor is coupled to the first end of the cylindrical housing and configured to monitor an operating condition of the annular bearing. A linkage couples the actuator to the second end of the cylindrical housing and an output shaft is rotatably coupled to the bearing assembly.

A housing for a bearing cavity in a gas turbine engine is disclosed. The housing comprise features that mitigate heat transfer from a heat source in the gas turbine engine to the nearby bearing cavity to prevent exposing the oil in the bearing cavity to excessively high temperatures. The housing comprises an annular flange that defines one or more barriers to heat transfer from the heat source to the bearing cavity.

A measurement system including: a radial external hole on a cover of a railway axle-box on the side of an edge of the cover facing towards a rolling bearing of the axle-box; a smaller axial hole made on the edge of the cover facing towards a ring of the bearing and opening in the radial hole; a cup-shaped body accommodated in the radial hole; a fork shaped spring integrally carried by a bottom wall of the cup-shaped body, projecting in front of the axial hole; a temperature probe slidingly accommodated within the axial hole and including a tubular element incorporating an electrical temperature sensor and an electric cable protruding from a first end of the tubular element accommodated within the cup-shaped body; and an abutting element removably coupled to the first end to cooperate with the spring, which pushes a second end of the probe out of the axial hole.

A gyroscopic roll stabilizer comprises a gimbal having a support frame and enclosure configured to maintain a below-ambient pressure, a flywheel assembly including a flywheel and flywheel shaft, one or more bearings for rotatably mounting the flywheel inside the enclosure, a motor for rotating the flywheel, and bearing cooling system for cooling the bearings supporting the flywheel. The bearing cooling system enables heat generated by the bearings to be transferred through the flywheel shaft to a heat sink disposed within a cavity in the end of the flywheel shaft, or to a liquid coolant circulating within the cavity.

A method of providing electrical insulation for at least one portion of a bearing element is disclosed herein. The method includes electrostatically spraying a polymer coating to the at least one portion of the bearing element, and the polymer coating comprises a thermoset epoxy coating or a self-adhering nylon powder coating. The bearing element can be grounded during the electrostatic spraying. The method includes heating the polymer coating in an oven at a temperature less than or equal to 220° C. for a predetermined time, such that after removal from the oven, the polymer coating has a porosity of less than 10%. The coated bearing element has a resistance of at least 50 MΩ resistance under dry conditions and 10 MΩ resistance under wet conditions.