Abstract: A drive transmission apparatus for a twin-screw extruder is provided which transmits a rotational driving force from a single prime mover to a first screw and a second screw disposed in parallel to each other, which comprises a transmission shaft, two idler spur gears attached to the transmission shaft, a pair of mutually parallel idler shafts, two idler helical gears, and a helical gear engaging the two idler helical gears. A meshing adjustment device is incorporated into the design that is capable of adjusting the phase of meshing of the gears and tooth bearing in the gear trains of the drive transmission apparatus without the need to disassemble the components, which is a necessary inconvenience of the prior-art apparatus.

Abstract: Disclosed is a method of effectively dressing a grinding wheel of high grain concentration having a high wheel number usable for an ultrahigh precision processing. When a grinding wheel (10) is trued (i.e., formed into a predetermined shape) by using a truing tool (11), the grinding wheel (10) is dressed by feeding a coolant W in which abrasive grains (12) for dressing are dispersed into a space between the truing tool (11) and a surface (13) of the grinding wheel (10). Therefore, it is possible to easily true and dress the ultra-fine grinding wheel usable for ultra-high precision processing, without being affected by the manufacturing limit of the dressing tool, being different from the dressing method using a dressing tool.

Abstract: The driving power transmitting apparatus for use in twin shaft type extruder is constituted by a first screw driven by a power transmission shaft through a coupling member, and a second screw is driven by two parallel sets of idle plane gear, an idle shaft and an idle helical gear and a helical gear secured to the drive end. The two sets of idle plane gear are driven by a plane gear which is mounted on the power transmission shaft to be rotatable. The plane gear is driven by a prime mover through a coupling.