Rack guide and gear mechanism

A rack guide configured to support a rack bar having a rack gear in mesh with a pinion gear from an opposite side to the rack gear while allowing the rack bar to slide, and to guide the rack bar moving in response to rotation of the pinion gear in an axial direction of the rack bar, the rack guide comprising:

• a rack guide body made of synthetic resin, the rack guide body having a cylindrical shape and an end face including a guide surface configured to slide with a back of the rack bar;
• a plurality of supporting portions made of synthetic resin, the supporting portions each protruding beyond an outer circumferential surface of the rack guide body to be movable in a radial direction of the rack guide body, the supporting portions being located on both sides of the rack guide body, in a direction perpendicular to both an axial direction of the rack guide body and a direction of sliding between the guide surface and the rack bar, each of the supporting portions comprising:
• a primary protrusion having a supporting surface protruding beyond the outer circumferential surface of the rack guide body;
• and
• a pair of secondary protrusions, the secondary protrusions being located on both sides of the primary protrusion in the circumferential direction of the rack guide body, each of the secondary protrusions having a supporting surface protruding beyond the outer circumferential surface of the rack guide body;
• and
• a biasing portion provided for each of the supporting portions and made of synthetic resin, the biasing portion extending along a circumferential direction of the rack guide body from both sides of a corresponding one of the supporting portions in the circumferential direction and connecting to the rack guide body, the biasing portion being configured to bias the corresponding one of the supporting portions outwardly in the radial direction of the rack guide body.