| 摘要 |
1,042,778. Gear pumps and motors. B. & G. HYDRAULICS Ltd. June 9, 1965 [June 9, 1964], No. 23940/64. Heading F1F. A gear motor (or pump) comprises a number of pinions 21, Fig. 1, rotatable on fixed spindles 20 and positioned between a control gear 11 splined to a drive (or driven) shaft 10 and a ring gear 22. The spindles 20 are carried in an annular pressure pad 19, Fig. 2, stepped on its outer and inner peripheries to provide with corresponding steps on a casing part 14 and an annular pad 9 surrounding the shaft 10 annular pressure chambers 29, 30, 29a, 30a communicating through passages in the pressure pad 19 with diagonally disposed inlet ports 37, 38 and diagonally disposed outlet ports 39, 40 opening into chambers in which the pinions rotate. Each spindle 20 is formed with a transverse relief passage 24 and an axial relief passage 25 which opens at one end through a passage, 32 with a chamber 33 surrounding the ring gear 22 and at its other end through passages 26, 34 with chambers 35, 36 surrounding the shaft 10. The passage 26 is connected by cross passages 27, 28 each provided with a pressure relief valve (not shown) with the annular pressure chambers 29, 29a and 30, 30a respectively so that it is relieved into the annular chambers at pressure lower. In operation as a motor, working fluid is supplied to one of the supply passages in the casing part 14 and passes into the annular pressure chambers 30, 30a to press the pad 19 which is freely movable into sealing engagement with the pinions, control and ring gears. Pressure fluid also passes through passages 37a, 38a and inlet ports 37, 38 into the pinion chambers to rotate the pinions which intermesh with the control and ring gears to drive the shaft 10. The pressure fluid afterwards escapes through the outlet ports 39, 40 and passages 39a, 40a to exhaust. The operative surfaces of the annular pressure chambers and the chambers within which the pinions rotate are arranged so that should excess pressure occur within the latter the annular pressure pad will move to allow fluid to escape across the faces of the gear wheels to prevent damage to the motor (or pump).
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