GB1043118A - Seismic transducer for generating seismic waves in the earth - Google Patents

Abstract

1,043,118. Hydraulic reciprocating motors, pumps, &c. CONTINENTAL OIL CO. Sept. 21, 1964, No. 38445/64. Heading F1A. [Also in Divisions F2 and G1] A motor used to vibrate a mass 12 comprises a cylinder 31 in the base of a steel block 12 and a piston 18 reciprocated in the cylinder by admitting fluid alternately to chambers 36, 38. An electrically controlled servo-valve 54 controls the flow of fluid through ports 50, 52 to chambers 36, 38 respectively. Inner bearing inserts 32, 34 for the piston 18 form high pressure oil seals around the piston rods 20, 22 respectively and behind the inserts are low pressure packing glands 40, 42 held in place by bearing inserts 44, 46 which are bolted to the block 25. Piston 18 is machined to the finished outer dimensions and provided with grooves 150 for piston rings 152. Pins 154 extend from opposite faces of the piston into steel pipes 156 welded at 158 and at the joint 164 with closure plug 160, which is tapped to receive a bolt 88 extending through a plate 64. A key 169 prevents rotation of the cylinder sleeve 31 in the block 25. To reciprocate the motor high pressure fluid from a source (not shown) is admitted through a bore 360 by control valve 54, which is provided with five ports communicating with the power fluid source, the fluid sump, and cylinder chambers 36, 38. A bore 362 in block 25 communicates with the two exhaust ports of valve 54. Fluid entering bore 360 is alternately directed by valve 54 to one of the ports 50, 52 and hence through openings 176, 178 respectively to chambers 36, 38 alternately, the other of the ports 50, 52 being simultaneously connected to the exhaust bore 362. As the piston reciprocates the block 12 reciprocates also, but moves in the opposite direction and its movement is communicated to the support frame 24, cushioning members 252 being housed in uprights 80, to act as buffers for the block 12. To maintain the centring of the block 12 a transformer 260 is provided and comprises a rod 262 screwed into the block and extending into a control winding 270 mounted in the upright 80. By varying the length of the inserts 32, 34, the stroke of the piston may be altered, and hence the operating frequency. Reference has been directed by the Comptroller to Specification 903,496.