Said reamer can be used for reaming the axis hole of a piston.

An axle hole (124) is arranged in the circular groove (122).

The roller pin hole penetrates the inside of the roller pin shaft and is inserted by the first shaft.

The roller pin plate has a roller pin role, which is formed on the surface opposite to the surface from which the roller pin shaft is protruded.

The thrust collar is attached to the carrier by inserting the pin into the first pin hole in the thrust collar and the second pin hole in the carrier.

The pilot stage axle (41) is matched to an axle hole on the upper valve block (11), and the power stage axle (51) is matched to an axle hole on the lower valve block (13).

The shaft hole (19) is oblong and comprises a spring (20) maintained in its housing.

Accordingly, the axle hole in the bottom part of the pressing screw has a corresponding segmented structure.

A second pin hole is provided in the face of the carrier that opposes the planetary gears.

Apply engine oil to the connecting rod small end and piston pin hole.

The pin hole portions of the outer link plates (37) are largely deformed, and the strength thereof is increased due to a residual stress.

This invention addresses the problem of providing a spark plug for which the central electrode is satisfactorily anchored within the shaft hole.

An electric motor shaft (8) of the machine base passes through a centre hole (24) in the bottom face of the casing matching an axle hole (9) of the rotating axle (9).

The protect plate is arranged in the holding groove and has an opaque plate (121) and an axis hole (122) opened on the opaque plate.

A boss (209) with an axle hole is provided at one end of every hook, while an inverted-tooth (212) and an inverted-tooth groove (211) are respectively provided at the other end of the hook.