GB983714A - An improved crank pin grinding machine - Google Patents

Abstract

983,714. Grinding crank-pins. MIRRLESS NATIONAL Ltd. June 19, 1963 [May 30, 1962], No. 20764/62. Heading B3D. A machine for grinding a crankpin of a crank-shaft in situ in its engine bearings comprises means adapted to support and fixedly secure a housing for a generally annular rotor, which is adapted to be rotatably mounted therein, in such a manner that said rotor is disposed coaxially about said crank-pin, at least one grinding tool mounted on said rotor and adapted to engage operatively the peripheral surface of said crankpin, means for rotating said rotor within said housing whereby said grinding tool is carried around said crank-pin, means for driving said grinding tool, and means for traversing said grinding tool axially with respect to said rotor and over said crank-pin. A machine for grinding the crank-pin P comprises an annular housing 10 formed in halves 10a, 10b secured together by bolts 17. The half 10a is slidably supported between arms 14 having brackets 16 bolted, over the journals J, to the bearing blocks B from which the upper caps have been removed. The half 10a is vertically adjustable relative to the arms 14 by setscrews 29, and secured in adjusted position by bolts 15. A rotor 11 formed in two parts 11a, 11b secured together by bolts is rotatable within the housing 10, having on its outer rim inclined faces 18 engaging mating surfaces on the inside of the housing. The rotor 11 has a peripheral worm thread 19 engaging a worm 20 located in the housing half 10a and driven through a flexible coupling by a motor remote from the machine whereby the rotor 11 is rotated about the crank-pin P within the housing. The worm may be adapted to disengage automatically from the worm thread under excessive load. The rotor part 11b is a three-quarter sector and carries a 3-phase electric motor 13 supplied through slip-rings 28 arranged around the periphery of the rotor 11 and brushes secured in the housing 10. The motor 13 drives, through a flexible coupling 24, a grinding tool 12 carried by the rotor part 11a, which is a quarter sector. The grinding tool 12 comprises a grinding wheel 22 on a spindle in bearings in a casing 23 carried on a slideway 25, being inched therealong in response to actuation of a ratchet wheel 26 by a fixed pawl 27 carried by the housing 10, on each complete revolution of the rotor 11, whereby the grinding wheel is inched axially along the crank-pin P throughout the grinding operation. Micrometer gauges 30 are provided for ensuring coaxial alignment and for measuring the diameter of the crank-pin at any stage of the operation.