GB1334064A - Gear cuttiang machines - Google Patents

Abstract

1334064 Gear-hobbing COMBINED ENGINEERING PRODUCTS Ltd 23 Nov 1971 [30 Nov 1970] 56726/70 Heading B3K A machine for cutting large gears 1, comprises a gear support 10, a carriage 8 guided for movement around the gear 1, drive means 19 for propelling the carriage, a gear-cutting tool 26, mounted on the carriage, and means for controlling the position of the tool in relation to the position of the carriage so as to ensure a predetermined path of movement of the tool with respect to the workpiece. Gear 1 is secured to pillars 10 and carriage 8 is adapted to run around the workpiece by rollers 14-18, rollers 15, 16 being driven by an hydraulic motor 19 through a variable speed drive. The pressure of engagement of the rollers can be adjusted by hydraulic motors 20-23. As carriage 8 rotates around the gear 1 it rotates a radial indexing arm 24, whose position is continuously monitored, and a signal derived by a sensor 37. Tool 26 is a hob which is connected to a sensor so that a signal corresponding to the rotational position of the hob can be compared with the signal from sensor 37 and any correction can be made so as to rotate the hob drive motor 27. In operation, the movement and position of carriage 8 are determined by drive motor 19. The signal from sensor 37 is representative of the carriage position, and the movement and position of the hob are determined by motors 27, 30, 32. When a closed loop servo-control is used, Fig. 3, the signal at 36 is compared with the signal at 37, and if required control 34 varies the position of the hob by actuating motors 27, 30, 32. The servo-control may be replaced by a gear drive. The weight of carriage 8 is taken by a chassis 38 mounted on castors 39 and carrying jacks 41, 45.