| 摘要 |
A coordinate measuring machine (10) having an improved carriage drive system including a flexible toothed belt (89) mounted on a rigid spar member (88) to be stretched along the carriage (X) axis. The spar member (88) absorbs the tension loading of the stretched flexible belt (89), while the connection (198, 152) of the spar member (88) to the base (12) precludes stressing of the machine (10) by the belt tension or by thermal stresses. A drive package (118) is mounted to one end of the carriage (40) and includes a toothed drum (126) engaging the flexible belt (89) so that upon being rotated by a drive motor (120) acting through a double reduction pulley system (254, 258, 260, 268, 272, 274) to rotate the toothed drum (126) and cause the carriage (40) to be driven along the ways (32, 34). Flexures (86a, 86b) mounting the belt (89) accommodate side to side movement as the carriage (40) is driven along the axis while being rigid to the tension exerted by the belt (89). |
