GB1534389A - Method and planetary-type lapping machine for lapping a group of workpieces - Google Patents

Abstract

1534389 Lapping MOSKOV YYSSHEE TEKHNICHE UCHILISCHE IM NE BAUMANA 24 Aug 1977 35545/77 Heading B3D A method of lapping a group of parts 14 using a planetary-type plane lapping machine comprises placing the parts in cages 13 between a stationary lapping disc 12 and a rotary lapping disc 11, and driving the rotary lapping disc at an angular speed which is about twice the angular speed of rotation of the centres of the cages about the axis of the rotary lapping disc, whereby the cages are relieved from the action of the parts being machined. In a machine for carrying out the method, the parts 14 are placed in sockets in the cages 13 which have teeth engaging a sun gear 15 and a ring gear 16. The lapping disc 11 has stops 17 engaged by pins 18 of a double-speed multiplier having a carrier 19, spherical bearing 20, cross-piece 21 rigid with a central shaft 22, a support gear 23, planet gears 24 and a ring gear 25. An electric motor 27 drives, through reduction gearing 28 and a shaft 29, the centred shaft 22 and the ring gear 16. The sun gear 15 and cross-piece 21 are secured to the central shaft so as to rotate at the same angular speed and the multiplier rotates the ring gear 25 at twice the speed of the sun gear 15 so that the upper lapping disc rotates at twice the angular speed of the cages about the axis of the lapping disc. In another embodiment, a correction mechanism is provided comprising a second sun-and-planet gear driven by a reversible electric motor for increasing or decreasing the rotational speed of the gear 16 depending on whether the wear of the lapping discs is convex or concave.