66results about How to "Increase dynamic pressure" patented technology

The present invention relates to a friction part (2) for a frictionally acting device, having an annular friction face (18) which has an inner edge (20) and an outer edge (22), wherein at least one set of grooves (24) is provided in the friction face (18), which set of grooves (24) has a first groove (32) which extends from the inner edge (20) or the outer edge (22) to a branching point (34) between the inner edge (20) and the outer edge (22), and a second and third groove (40, 42) which extend in each case from the branching point (34) to the other edge (22, 20). According to the invention, the second groove (40) is inclined in the one peripheral direction (28) and the third groove (42) is inclined in the other peripheral direction (30) of the friction face (18) with respect to a radial line (38) through the branching point (34). The present invention also describes a frictionally acting device having a friction part (2) of said type.

A motor with fluid dynamic pressure bearing is disclosed. The motor includes a dynamic pressure bearing member having a concave section that is concave in an axial direction, a rotary shaft that is rotatively supported by the dynamic pressure bearing, and a rotary member that is joined to the rotary shaft in one piece along a joint section between the rotary member and the rotary shaft, and rotatively driven by electromagnetic drive force, an expanded diameter section that is provided on the dynamic pressure bearing member. A fallout preventing member is provided on the rotary member, which overlaps the expanded diameter section of the dynamic pressure bearing member in the axial direction to prevent the rotary shaft from falling out of the dynamic pressure bearing member. The concave section of the rotary member opposes in the axial direction the expanded diameter section of the dynamic pressure bearing member, wherein the expanded diameter section is placed inside the concave section, and the joining section between the rotary member and the rotary shaft overlaps the expanded diameter section in the radial direction.

Stub for discharging drained fluids for a propulsion unit. The stub includes a cavity for storing the drained fluids and at least one orifice for discharging the fluids contained in the storage cavity, and elements for measuring a difference in pressure outside the stub and a member for draining the storage cavity. The member is able to move between a first position of closing the discharge orifice and a second position of releasing the orifice, and is configured so as to move from the first to the second position when the difference in pressure is greater than, or equal to, a predetermined value.

A disk drive device includes a bearing unit and a drive unit. The bearing unit includes: a shaft; a sleeve configured to allow relative rotation, with the shaft as the axis; a flange projected in the radial direction of the shaft and configured to rotate integrally with the shaft; a flange housing space portion provided continuously from the sleeve and configured to rotatably house the flange; a counter plate structured with both a first surface, which faces the end surface in the axial direction of the flange and seals the flange housing space portion, and a second surface that is opposite to the first surface. The projected dimension of the flange is designed to be larger than the wall thickness of the flange surrounding wall portion in the radial direction of the flange, the flange surrounding wall portion defining the flange housing space portion.

Provided is an internal-gear-type oil pump for a vehicle, the oil pump being provided with a driven gear in which the self-aligning effect of the driven gear can be obtained while preventing the fluid friction acting on the driven gear from increasing. First dynamic pressure generation grooves (46c) that concave are formed on the outer circumferential surface (46b) of a driven gear (46). The depths (D1) of said grooves are set such that the gap ratio (m1) of a gap (H1) extending from the deepest part of the first dynamic pressure generation grooves (46c) to the inner circumferential surface (34c) of a pump body (34) relative to a gap (H2) extending from the outer circumferential surface (46b) of the driven gear (46) to the aforementioned inner circumferential surface (34c) is within a predetermined range including the maximum value of the dynamic pressure (P1) generated by means of the first dynamic pressure generation grooves (46c) and the minimum value of a fluid friction coefficient (mu1) acting by means of the first dynamic pressure generation grooves (46c). As a consequence, the fluid friction coefficient (mu1) acting on the driven gear (46) is reduced to a minimum and the dynamic pressure (P1) generated by means of the first dynamic pressure generation grooves (46c) reaches a maximum, thereby obtaining a self-aligning effect of the driven gear (46) while preventing the fluid friction acting on the driven gear (46) from increasing.

In order to prevent lubricating oil leakage due to bubbles in a thrust dynamic pressure bearing having herringbone grooves, and to stabilize the bearing performance, and enhance the reliability and durability, auxiliary grooves deeper than pump-in type herringbone grooves for generating dynamic pressure are provided. The bearing inner periphery and bearing outer periphery are linked by a pressure gradient descending slowly, and therefore bubbles present in the bearing inner periphery can be guided to the bearing outer periphery through the auxiliary grooves, and discharged outside of the bearing from the air-liquid interface, so that lubricating oil leakage due to bubbles can be prevented.

In a radial minute gap between a substantially columnar shaft and an inner peripheral face of a substantially cylindrical sleeve, oil is retained and a radial dynamic pressure bearing is formed. A plurality of recessed portions are arranged in a circumferential direction on at least one of an outer peripheral face of the shaft and the inner peripheral face of the sleeve and a first hill portion is provided to an axial end portion of each the recessed portion. Thus, it is possible to achieve a dynamic pressure bearing with which sufficient radial shaft support can be obtained in spite of a short axial length.

A disk drive device includes a rotating body, a fluid dynamic bearing unit that rotatably supports the rotating body, and a drive unit. The fluid dynamic bearing unit has: a lubricant holding portion in which lubricant is held; a first thrust dynamic pressure groove with which a first thrust dynamic pressure generating portion for generating the dynamic pressure in the pump-in direction, which is oriented toward the inside of the lubricant holding portion, is structured; and a second thrust dynamic pressure groove with which a second thrust dynamic pressure generating portion for generating at least the dynamic pressure in the pump-out direction, is structured. The first thrust dynamic pressure generating portion and the second thrust dynamic pressure generating portion have dynamic pressure generation characteristics in which, when the rotating body is biased in the rotational axis direction from the state where the rotating body is floating in the lubricant, the sum of the changes in the dynamic pressure in the pump-out direction is larger than that of the changes in the dynamic pressure in the pump-in direction.

A lifting foil having a lower trailing course having a margins and an upper leading course margins connected in a manner to enhance lift of the foil.