ROTATION TRANSMISSION DEVICE FOR ROTARY GUIDE BUSH FOR AUTOMATIC LATHE FOR MACHINING BAR

摘要

PURPOSE:To improve a yield, by a method wherein the tip of the driven shaft of a deepmost core part is securely supported to a bearing disposed on a seal stun located to the side of a bush holder, and a transmission gear secured to the drive shaft and a drive gear secured to the rear end part of the bush holder are intercommunicated through an idle gear. CONSTITUTION:A timing belt 208 is spanned between a drive pulley 203 secured to a spindle 202 of a spindle stock 201 and a drive pulley 207 assembled to a shaft 209 secured to a pulley support 204 located to the side of a spindle stock 201. Multistage drive shaft groups in the drive shaft 209 having multiplex tube structure are intercoupled through a spline transmission mechanism formed by engagement of a drive pin 210a with axially extended slide grooves 209a and 209b. The tip of a drive shaft 210 of a deepmost core part is securely supported to a bearing 212 located to the side of a bush holder 218, and a transmission gear 214 is coupled to a drive gear 229 through an idle gear 233. As a result, the stroke of the spindle stock 201 can be made equal to that of a guide bush 225, and a yield can be improved.