Linear motion mechanism, balancer device and machine tool

A balancer device including a linear motion mechanism, comprising:

• a shaft;
• a base member including a through hole through which the shaft is configured to be inserted;
• a static pressure bearing provided between the shaft disposed in the through hole and the base member and configured to slidably support the shaft relative to the base member by introducing a pressurized fluid to the shaft;
• and
• an annular member provided between the static pressure bearing and the base member and configured to elastically support the static pressure bearing, wherein the balancer device reduces gravity acting on a slider that is movable along a guide shaft, comprising:
• a cylinder, fixed to the base member so as to cover one opening side of the through-hole, and having an interior space into which the shaft protruding from the opening is inserted;
• and
• a regulator, provided on a pipe connected to the interior space of the cylinder, and configured to adjust a gas pressure of the compressed gas in the interior space of the cylinder to a predetermined pressure, wherein:
• the shaft is arranged along the guide shaft;
• and
• the base member is fixed to the slider and configured to move together with the slider.