Fluid lubricated bearing device
An inner space of a housing sealed with a seal member as well as internal pores of a bearing member (pores in a porous structure) are filled with a lubricating oil without the presence of air, so that the oil surface of the lubricating oil is within a seal space. Under a reduced pressure of 100 Torr, no lubricating oil leaks outside of the housing even at any attitude of the fluid lubricated bearing device such as normal, inverted, or horizontal attitude.
1. A fluid lubricated bearing device comprising:
a housing with an opening portion provided on one end and a bottom portion provided on the other end;
an axial member and a bearing member accommodated in the housing;
a radial bearing portion, provided between an inner peripheral surface of the bearing member and an outer peripheral surface of the axial member, for allowing an oil film of a lubricating oil produced in a radial bearing gap to provide radial non-contact support to the axial member;
a thrust bearing portion for supporting an axial end portion of the axial member in a direction of thrust; and
a seal member, provided in an opening of the housing, for forming a seal space between an outer periphery of the axial member and the seal member, wherein
an end face of the seal member is in contact with one end face of the bearing member, and wherein circulation grooves are provided to communicate a space around an axial end portion of the axial member in the thrust bearing portion with the seal space, and the lubricating oil flows along the circulation grooves between the seal space and the space around the axial end portion, and wherein the circulation grooves comprise a radial groove configured on the end face of the seal member; and an inner space of the housing that is sealed with the seal member, together with the circulation grooves, is filled with the lubricating oil such that an oil surface of the lubricating oil is located in the seal space.
2. A motor comprising the fluid lubricated bearing device according to claim 1 .
3. The fluid lubricated bearing device according to claim 1 , wherein the seal space between the outer peripheral surface of the axial member and the seal member has a tapered shape.
4. The fluid lubricated bearing device according to claim 1 , wherein the seal space between the outer peripheral surface of the axial member and the seal member has a cylindrical shape.
5. The fluid lubricated bearing device according to claim 1 , wherein the circulation grooves further comprise another radial groove configured on a surface of the housing opposite to the other end face of the bearing member.
6. The fluid lubricated bearing device according to claim 5 , wherein the circulation grooves further comprise an axial groove configured on an inner peripheral surface of the housing.
7. The fluid lubricated bearing device according to claim 1 , wherein the circulation grooves further comprise an axial groove configured on an inner peripheral surface of the housing.