A planetary gear system includes a plurality of planet gears, each having a journal bearing and a pin, end supported in a planet carrier. Each pin has a small diameter central portion axially extending for end support. A larger diameter outer portion is integral with the central portion at an inboard merged zone, and has cantilever sections extending outboard from the merged zone. Each pin is sized such that bending of the merged zone in one direction is countered by bending of the cantilever sections in the other direction to achieve a substantially linear bearing surface under load.
A planetary gear has a lower hole which communicates with a radial groove formed in a carrier plate formed at a position near the end portion of an outer peripheral surface of a pinion shaft on a radially inner side thereof. In the inside of the pinion shaft, an internal lubricating oil path is formed which makes an inner wall of the lower hole communicate with an axial center portion of the outer peripheral surface of the pinion shaft on a radially outer side thereof. The lower hole is perforated in an oblique direction with respect to the axis line of the pinion shaft so that a bottom portion of the lower hole is positioned nearer to the end portion than an aperture portion of pinion shaft. The internal lubricating oil path is constituted by a slant oil path, which opens at the inner wall of the lower hole and extends in an oblique direction, and a radial oil path, which opens at the axial center portion of the outer peripheral surface of the pinion shaft on the radially outer side thereof and extends radially to communicate with an end portion of the slant oil path. The axis line of the lower hole is perpendicular to the axis line of the slant oil path.
A torsional vibration damper is provided with a transmission element on the driving side, at least one planet carrier which is provided with at least one bearing for receiving a planet gear engaging with at least one ring gear, and a transmission element on the driven side. One of the transmission elements has a controller for elastic elements of a damping arrangement. At least one lubricant feed is associated with the planet gear. The lubricant feed extends, at least along part of its extent, within the range of extension of the planet gear and opens out in the region of the bearing. Lubricant can flow through this lubricant feed due to the pumping action of the planet gear as it rotates relative to other elements of the planetary gear unit.
A speed reducer has a sun gear for connection to a turbine of an engine and a planet carrier supporting a number of planetary gears meshing with the sun gear and with the ring gear fitted to the engine mounting. According to the present invention, the planet carrier has a first annular element having pairs of seats for pins on each of which rotates one of the planetary gears. A second annular element for connection to a compressor of the engine has a number of axial arms fitted inside respective cavities of the first annular element. An end of each axial arm is connected to a portion of the first annular element that is substantially equidistant between to the seats of each of the pairs of seats.
A star configured epicyclic gear train includes a sun gear 10, a plurality of star gears 16 supported on bearings 18, a ring gear 51 and a set of baffles 44 disposed between the star gears. A single lubricant circuit serves as the exclusive means for supplying lubricant successively to the bearings, the sun/star mesh and the star/ring mesh. A variant of the gear system includes an auxiliary lubricant circuit featuring a set of spray bars 82 for supplying lubricant to the sun/star mesh and the star/ring mesh. The primary and auxiliary circuits share a common lubricant discharge path representing the exclusive means for evacuating both the primary and auxiliary lubricant from the gear system. Preferably, the auxiliary lubricant circuit is selectively operable. The inventive gear system addresses a number of difficulties related to lubricating and evacuating lubricant from a star configured epicyclic gear system.
The production of a bearing surface by coating a known bearing material directly on the surface of a gear bore. A process of coating bearing materials directly onto the surface of a gear and the product thereof. The surface is preferably the inner bore surface of a planet gear. The coating methods include sputtering and vapor deposition. The bearing material applied as a coating is preferably a copper-lead composition. The resultant gear having a bearing coating can be useful in any high density, high efficiency epicyclic gear train for aircraft, marine or land based power transmissions.
