摘要:
A marine crane includes a high speed winch having a hydraulic heave compensating system that automatically controls the crane winch to compensate for the vertical movement of a load during offloading operations. The heave compensating system includes a reversing valve (59) for overriding manual. control valve (20) and for directing control pressure to stroke the pump (13) of a hydrostatic winch drive into its raise mode of operation, and a compensating valve (75) that regulates the displacement of the pump permitting it to develop and maintain only a predetermined pressure in the high pressure main fluid line (14). The heave compensating system includes a lift control system, comprising a lift selection valve (52), for automatically hoisting a heaving load only at or near the crest or trough of a wave.
摘要:
A drive system for a crawler vehicle includes an endless tread belt consisting of identical tread belt links and a cooperating drive wheel (40). Each link has connecting ears along its forward and aft sides which interdigit with and are hinged to the ears of other links so as to form the belt. Each link also has a guiding cog (13) projecting from its central region, a bearing surface on each lateral side of the guiding cog, aligned drive surfaces on the forward and aft sides of the guiding cog, and a slot (27, 28) in alignment with the drive surfaces. The drive wheel (40) has a plurality of circumferentially spaced teeth (41), two rows of segmented bearing rims (44, 45) alternately offset laterally from each other on the sides of the teeth, the segments of each row being circumferentially spaced and being formed such that the teeth (41) project radially beyond the segments, and a plurality of pockets (42, 43) located between the teeth that open radially outward, and open laterally from the wheel between the rim segments.
摘要:
An hydraulic control circuit for the hydraulic rams (1) of the boom of an excavator includes a servo-controlled hydraulic selector valve (14) for selectively connecting a source of hydraulic pressure (12, 13) to the rams for raising or lowering the boom. Load control valves (4) connected to the raising sides of the rams include pilot-operated relief valves (7) for controlling the outlet of hydraulic fluid from the rams during lowering of the boom. In order to provide for a fast rate of descent of the boom, when required, the relief valves (7) are controlled by an hydraulic intensifier (11a) which is responsive to operation of the servo hand controller (16) upon lowering of the boom. The hydraulic pressure signal from the appropriate line (15) connecting the servo controller to the selector valve (14) is applied to the input (24) of the hydraulic intensifier, upon selection of the lowering mode, and its output signal is fed to the pilot lines (10) of the relief valves (7).
摘要:
A drive system for a crawler vehicle includes an endless tread belt consisting of identical tread belt links and a cooperating drive wheel (40). Each link has connecting ears along its forward and aft sides which interdigit with and are hinged to the ears of other links so as to form the belt. Each link also has a guiding cog (13) projecting from its central region, a bearing surface on each lateral side of the guiding cog, aligned drive surfaces on the forward and aft sides of the guiding cog, and a slot (27, 28) in alignment with the drive surfaces. The drive wheel (40) has a plurality of circumferentially spaced teeth (41), two rows of segmented bearing rims (44, 45) alternately offset laterally from each other on the sides of the teeth, the segments of each row being circumferentially spaced and being formed such that the teeth (41) project radially beyond the segments, and a plurality of pockets (42, 43) located between the teeth that open radially outward, and open laterally from the wheel between the rim segments.