GB674065A - Improvements in or relating to machines for grinding the main bearing pins and crank pins of crankshafts - Google Patents

Abstract

674,065. Grinding crankshaft pins. MUSYL, R. April 26, 1949 [June 10, 1948], No. 11077/49. Class 60. A device for grinding the main bearing pins and crank pins of a crankshaft 2 which during the grinding process is revolved about the main bearing axis and in which device the grinding wheel axis and the axis of the pin to be machined perform congruent motions is characterized in that the congruence of the motions of both latter axes is achieved by the grinding wheel being mounted for rotation in bearings rotatable with the same eccentricity as that of the pin to be machined and which bearings are rotated in synchronism and in phase with the rotation of the pin, the congruence of the motions being obtained by adjustment of means permitting continuous variation between predetermined limits of the eccentricity of the grinding wheel centre so that this eccentricity equals the crank throw. The crankshaft 2, Fig. 2, is rotated at uniform circumferential velocity in contact with the grinding wheel 4 which is eccentrically mounted in a sleeve 6 mounted eccentrically in a drum 7 rotatable in a support 13; a motor 8 drives the drum through gearing 9, 10 and the sleeve and drum are then locked together. For adjusting the eccentricity of the grinding wheel spindle, the sleeve and drum are coupled by planetary gearing 16, 17, 18, 19, the gear 16 being rotatable relatively to the drum, the gears 17, 18 being journalled in the drum, and the gear 19 formed on the sleeve. Adjustment of the eccentricity is effected by locking the gear 16 by a pin 12, disengaging the lock between the sleeve and drum, and then rotating the drum by a hand-wheel 14. After this adjustment, release of the gear 16, and re-engagement of the lock between the sleeve and drum, the handwheel 14 may be turned to adjust the drum relatively to the workpiece without affecting the eccentricity. During operation of the grinding wheel in an orbital path by the motor 8, it is also rotated by a motor 22, Fig. 4, carried by the support 13 and acting through two belt drives 23, 24, the intermediate pulley 27 being mounted at the junction of two pivotally-connected arms 28, 29 which are pivoted, respectively, on the motor shaft and grinding wheel spindle 5. To compensate for the weight of the rotating grind-. ing wheel, a lever 30, Fig. 6, carrying the grinding wheel spindle 5 is connected at its upper end to a double lever 31 mounted on the support 13; a compression spring 37 acts upon the second arm of the lever 31 at a variable distance from the pivot of the lever. The crankshaft may be mounted between a headstock and tailstock 40 on a bed 38 as shown in Fig. 9, and the undersurface of the support 13 is mounted on a surface inclined downwardly towards the crankshaft. If desired, a machine may be constructed to operate on four crankshafts simultaneously, a grinding wheel together with its support 13 being provided for each crankshaft.