Jtekt Corporation

Toyoda Koki Kabushiki Kaisha

Hiroki Yamato

Kazuyuki Ichikawa

Masayuki Takeshima

Yoshiaki Ando

Tomonori Ohwaki

A hydrostatic bearing apparatus includes a bearing metal having a hydrostatic portion that allows a grinding wheel shaft to be rotatably supported. The hydrostatic portion has a bearing clearance, a bearing surface portion, a plurality of pockets, and partition plates. Clearances are each formed between the corresponding partition plate and an edge of the corresponding pocket in a rotating direction of the grinding wheel shaft. The clearances are formed in the pocket at upstream and downstream ends in the rotating direction. The bearing clearance has a first bearing clearance and a second bearing clearance. The second bearing clearance is larger than the first bearing clearance.

Hydrostatic bearing apparatus, machine-tool main-spindle apparatus including hydrostatic bearing apparatus, and method for manufacturing hydrostatic bearing apparatus

In a hydrostatic fluid guide device, a damping mechanism is provided. A fluid is supplied to the damping mechanism by a hydrostatic pressure caused by natural fall, instead of being pressurized and supplied. Thus, it is possible to suppress a decrease in the pressure of the fluid in a hydrostatic fluid guide mechanism, and to position a movable body with high accuracy by setting rigidity for load support during linear movement of the movable body to a value substantially equal to a design value.

Hydrostatic fluid guide device

A hydrostatic guide device includes: a fixed member having vertical guide faces; a movable member having vertical slide faces; a fluid supply device; a hydrostatic pocket to which a first fluid pressure based on a dimension of a gap is applied, and that urges the movable member with a first urging force; and a hydraulic pocket to which a second fluid pressure based on a dimension of a gap is applied, and that urges the movable member with a second urging force. A variation of the second fluid pressure is smaller than a variation of the first fluid pressure. When the first urging force and the second urging force are balanced with each other in a horizontal direction, the gap between the vertical guide face and the vertical slide face becomes a set value.

Hydrostatic guide device and machine tool using the hydrostatic guide device

A shaft has a shank with a splined portion and a large diameter portion formed in an outer peripheral surface of the shank, the large diameter portion having a diameter that is larger than a diameter of an external periphery of the splined portion. A tapered portion is provided at a side surface of the large diameter portion on the splined portion side. This tapered portion stops a fitting member that is fitted onto the splined portion. In addition, a cut back portion formed at an end portion of the splined portion at the large diameter portion side and the tapered portion are interposed by and continuously connected by a first curved portion, a flat portion and a second curved portion.

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Kariya, Japan

Hiroki Yamato