Mounting for rotary machine tool particularly for gear hobbing machines

A tool mounting for a gear hobbing machine which comprises a hobbing spindle, a hob detachably mounted on said spindle, a bearing assembly supporting the outboard end of said hobbing spindle, a supporting member and means detachably connecting said bearing assembly to said supporting member, said bearing assembly including a bearing housing, a bearing sleeve surrounding the spindle, live bearing elements interposed between the bearing sleeve and the bearing housing, wedge means between the bearing sleeve and the spindle, means urging said wedge means to a position in which it eliminates significant radial play between the bearing sleeve and the spindle, release means for moving said wedge means to an alternative position in which it permits movement of the sleeve with respect to the spindle to enable the hob to be changed, an end cap at the inboard end of the bearing housing having an aperture therethrough for the spindle to enter the bearing housing, a sealing ring in the aperture and surrounding the spindle, a pad slidably fitted within a bore of the wedge means and a spring urging the pad against the end of the spindle so that at all times the bearing housing is sealed against the ingress of foreign matter.