Abstract: A drive device includes a housing forming a sump. A pump and motor are mounted on a center section having a porting system and a pair of ports with check plugs disposed therein. A bypass arm is engaged to one end of a bypass shaft external to the housing and rotates the bypass shaft to selectively cause engagement fingers to move each check plug to an open position. A housing projection is contacted by the bypass arm to selectively limit rotation thereof. The axes of rotation of a swash plate trunnion shaft, a pump input shaft and a motor output shaft may all be disposed in a single plane. The input shaft is supported by a housing bearing and an opening in the center section and is restrained from axial movement by the bearing and a thrust surface on the center section.

Abstract: A drive device having a shaft support structure located within its housing, such as an axle support structure for providing additional support to a pair of output axles under load. The axle support structure comprises at least one aperture sized to receive a bushing that may have a non-rotation feature. The housing may also include a shaft support structure for other shafts, such as a jackshaft of a gear reduction system disposed between a transmission and the driven output axles.

Abstract: A drive device incorporating a hydraulic pump having a swash plate. At least two structural ribs and skirting ribs are located on and extend along the length of the swash plate. A plurality of thrust ribs may be formed on an inner housing surface and adjacent to respective contact surfaces on the swash plate, the thrust ribs being located so that at least one, but fewer than all, of the ribs can be in contact with its respective contact surface on the swash plate at a time, permitting rotation while limiting axial movement of the swash plate. A trunnion shaft includes a free end disposed so as to be accessible from outside the housing through a bore formed therein, and a control arm having a shaft portion extends into and supports the distal free end of the trunnion shaft within the bore.

Abstract: A hydraulic drive device having a pump and motor is disclosed, where the pump swash plate includes a pair of structural ribs and the housing has a pair of thrust ribs on an inner surface. Only one thrust rib is in contact with one of the structural ribs at a time, to permit arcuate rotation of the swash plate while limiting axial movement of the swash plate. The axes of rotation of the swash plate trunnion, input shaft and output shaft are in a common plane. A rotary bypass shaft for engaging transmission check plugs includes an external bypass arm. A pair of detents are externally formed on the housing, and the bypass arm includes separate pairs of openings to engage the pair of detents when the bypass arm is in different positions.

Abstract: An improved coil construction for the voice coil motor of a transducer positioning system of a magnetic disk drive results in increased coil strength while eliminating the tendency of volatile materials associated with either the assembly process or the coil insulation to be entrapped between turns. Insulated aluminum ribbon wire having a rectangular cross-section is edge wound on a mandrel with adjacent turns being bonded together and then subjected to a curing process. By subjecting the ribbon wire to a knurling process prior to winding, the flat surfaces of the ribbon wire are provided with a plurality of knurl prints on each side which extend between opposite edges of the wire in a direction transverse to the lengthwise dimension of the ribbon wire. After winding, the knurl prints serve as interturn vents to prevent entrapment of any volatile materials generated during the curing process. The construction substantially doubles the tensile strength of the coil.