Sundstrand Corporation

Lucas Aerospace Power Equipment Corporation

Mohammad Shahamat

Tyrone A Johnsen

Walter J Iseman

Hassan Mansir

Michael R Hernden

Frank W Allen, Iii

Stephen F Brucker

A bearing failure detector for an electrical generator includes a disc located within the bearing assembly near the location of the main bearings. The disc includes an electrically conductive ring encased in an insulation layer. The ring is exposed along inside diameter of the detector disc adjacent to the periphery of the shaft, but the dimensions of the inside diameter of the ring are slightly greater than the normal internal clearance of the main bearings, so that the shaft does not contact the ring unless the bearings are significantly worn. The detector ring is connected to a resistor with a large resistance which is monitored by a control circuit at all times. When the internal clearance of the main bearings has been enlarged by a predetermined amount, the ring contacts the shaft, changing the resistance monitored by the control circuit. This causes the control circuit to provide an indication that the bearings need replacement. The detector eliminates the need for preventive replacement of bearings at scheduled maintenance periods when the bearings may not actually need replacement because they are not sufficiently worn, saving service time and costs. Auxiliary bearings are provided to support the shaft when the shaft has contacted the detector, providing safe operation of the generator for a sufficient period of time after a bearing replacement indication has been provided until the bearing assembly is replaced.

Bearing failure detector for electric generator

A two-pole generator rotor assembly including a one-piece shaft, a prewound field coil assembly and a one-piece shaft. The one piece shaft includes a pair of axially spaced shaft end portions and a substantially cylindrical portion integrally formed with the spaced shaft end portions and interposed therebetween. The substantially cylindrical central portion includes a through slot for accommodating the prewound field coil assembly, with the through slot including a pair of opposed wall portions adapted to engage an outer peripheral portion of the prewound field coil assembly and provide means for retention of the prewound field coil.

One-piece rotor shaft for two-pole rotor

The problem of assembling and maintaining good electrical contact in a rotating rectifier assembly (40) is solved using brazed connections. The rectifier assembly (40) includes a cylindrical housing (44) receiving a pair of coaxial copper plates (50,52) which act as outputs. Each copper plate (50,52) has three angularly spaced, square-shaped diode wafers (64,70) brazed thereto on one face. The opposite face of each diode wafer (64,70) is brazed to a conductive strap (68,74). The straps (68,74) extend radially outwardly. The two plates (50,52) are angularly aligned so that their respective diode wafers (64,70) are in angular alignment, with the straps (68,74) for the aligned diode wafers (64,70) of each plate (50,52) being soldered together to provide a phase connection. A conductive strap (58,60) is brazed to each of the two plates (50,52) for connection to conductive posts (48) which connect to the main field (32).

Rotating rectifier assembly

The problem of assembling and maintaining good electrical contact in a rotating rectifier assembly (40) is solved using brazed connections. The rectifier assembly (40) includes three planar, tear-shaped copper phase plates (62) which are equally angularly spaced about an axis (68) in a cylindrical housing (44). Six diode wafers (70) are arranged in two parallel planes which are perpendicular to the axis (68). Three diodes (70) in each plane are brazed (72) to one of the oppositely directed planar faces (63, 64) of the copper phase plates (62). The three diodes (70) in each plane are connected by an additional copper plate (78, 80) which forms an output.

Rotating rectifier in brazed assembly

The problem of effectively and quickly detecting fault conditions in an electromotive machine (10) is solved using a current transformer assembly (28) having a neutral lead (44). The neutral lead (44) comprises a single piece copper strap (80) having laterally extending strips or posts (81-83) provided for connection to the neutral end conductors (31-33) of armature windings (22 and 24). The strap (80) is punched and bent into shape to include the three neutral posts (81-83). Each neutral post (81-83) carries a current transformer (46-48).

Growing community of inventors

Rockford, IL, United States of America

Mohammad Shahamat