Bearing member, belt unit, and image forming device

A belt unit comprising:

• a rotational body that includes first and second ends;
• an endless belt that is placed in tension by the rotational body;
• and
• a bearing member including a bearing part that is attached to, and rotationally supports, the first end of the rotational body and that includes a sliding contact area where the rotational body continuously slidably contacts the bearing part during rotation thereof, and a non-sliding contact area that is formed outside of the sliding contact area and where the bearing part is free from contact by the rotational body during the rotation thereof;
• and
• a force receiving surface that is formed outside the bearing member, wherein
• a load application part is formed in the sliding contact area, where the load application part is configured to contact the rotational body and to continuously apply a load to the rotational body in a radial direction of the rotational body,
• a plurality of holding grooves are formed in the sliding contact area in the rotation axis direction of the rotational body, the plurality of holding grooves each have an opening at only one end, and the plurality of holding grooves are adapted to hold a lubricant that is to be supplied to the sliding contact area between the rotational body and the load application part,
• each opening of the plurality of holding grooves opens toward the second end of the rotational body,
• a pass-through groove is formed in a part of the non-sliding contact area in a rotation axis direction of the rotational body,
• the force receiving surface is configured to receive a force and to transmit the force to the load application part, thereby resulting in the load applied by the load application part,
• openings of the plurality of holding grooves are formed on the same side of the bearing part in the rotation axis direction of the rotational body.

An image forming device comprising:

• a recording medium tray that loads a recording medium;
• a carrying unit that carries the recording medium;
• an image forming unit that forms an image on the recording medium;
• a belt unit that is formed close to the image forming unit;
• a stacker unit that stacks the recording medium formed with an image, wherein
• the belt unit comprises:
• a rotational body that includes first and second ends,
• an endless belt that is placed in tension by the rotational body,
• a bearing member including a bearing part that is attached to, and rotationally supports, the first end of the rotational body and that includes a sliding contact area where the rotational body continuously slidably contacts the bearing part during rotation thereof, and a non-sliding contact area that is formed outside of the sliding contact area and where the bearing part is free from contact by the rotational body during the rotation thereof, and
• a force receiving surface that is formed outside the bearing member,
• a load application part formed in the sliding contact area, wherein the load application part is configured to contact the rotational body and to continuously apply a load to the rotational body in a radial direction of the rotational body,
• a plurality of holding grooves formed in the sliding contact area, the plurality of holding grooves each have an opening at only one end, and the plurality of holding grooves are adapted to hold a lubricant that is to be supplied to the sliding contact area between the rotational body and the load application part,
• each opening of the plurality of holding grooves opens toward the second end of the rotational body,
• an injection groove is formed in a part of the non-sliding contact area in a rotation axis direction of the rotational body,
• the force receiving surface is configured to receive a force and to transmit the force to the load application part, thereby resulting in the load applied by the load application part, and
• openings of the plurality of holding grooves are formed on the same side of the bearing part in the rotation axis direction of the rotational body.