Only an outer spacer (33) is cooled by an outer spacer cooling structure, thereby causing a temperature difference between an inner spacer (32) and the outer spacer (33). According to this temperature difference, an inner ring (37) of a bearing (31) is displaced relatively to an outer ring (38) in a direction in which a preload inside the bearing (31) decreases.

A cartridge-type magnetic fluid seal device has a flanged sleeve fixed to an external peripheral surface of the radially inside member of two members and which rotates together with the inside member is provided facing a pair of magnetic pole members. A packing is disposed in an annular space formed by the radial inside of a magnetic source and the pair of magnetic pole members. The packing is provided in the annular space so as to slide on an external peripheral surface of the flanged sleeve, and a magnetic fluid seal part, the packing, and the flanged sleeve form a unit.

One object is to provide a fishing reel including a magnetic fluid sealed bearing wherein foreign substances are shut out from the magnetic fluid seal to prevent degradation of the magnetic fluid (degradation of the magnetic sealing function). In accordance with one aspect, the fishing reel of the present invention includes a magnetic fluid sealed bearing rotatably supporting a drive shaft (pinion). Protection walls are disposed opposite to each other on or near the sides of the bearing body so as to shut out foreign substances from the bearing body of the magnetic fluid sealed bearing.

Provided is a magnetic fluid sealed bearing with which torque can be reduced without impairing a water and dust proof effect. A magnetic fluid sealed bearing according to the present disclosure includes a magnetic fluid retained by a ring-shaped magnet in an opening between an inner ring and an outer ring to seal a plurality of rolling members. The magnet is magnetized such that their magnetic poles point to an axial direction. The bearing further includes a ring-shaped outer polar plate and a ring-shaped inner polar plate sandwiching the ring-shaped magnet therebetween, one side of the polar plates being fixed to one of the inner ring and the outer ring, and the other side of the polar plates facing a clearance.

A sealing device employing a magnetic fluid for sealing off a vacuum side and an atmosphere side includes two rolling bearings disposed on both sides of the magnetic fluid seal. The magnetic fluid fills the lubrication part of the rolling bearing disposed toward the vacuum side and a magnet is attached to the outer ring toward the vacuum side of said rolling bearing. A ring-shaped yoke formed from a magnetic material and freely fitting into a rotation shaft is attached to the side of the magnet opposite the outer ring of the rolling bearing.

A magnetic fluid sealing structure (1) for high-speed rotation for sealing a gap (S) between a shaft member (2) and a housing member (3) disposed around the shaft member (2), which are rotatable, includes: magnetic force generating means (4) which is fixed to the housing member (3) and generates a magnetic force; magnetic pole members (5) disposed on both sides in an axial direction of the magnetic force generating means (4); and a magnetic fluid (7) which is magnetically held between the magnetic pole members (5) and the shaft member (2) by the magnetic force of the magnetic force generating means (4) and seals the gap (S) therebetween, in which the shaft member (2) has a plurality of different material layers concentrically laminated in a radial direction, and an outermost diameter layer (23) of the shaft member (2), which holds the magnetic fluid (7), is made of a magnetic material.

An even number of magnets (5) are incorporated in a housing (3) while sandwiched by pole pieces (6). A rotating shaft (2) has a boundary which is provided in a hollow portion (3a) of the housing (3) and nearer to an airtight chamber (1) than a pole piece (6) nearest to the airtight chamber (1), and an area of the rotating shaft (2) which is nearer to the airtight chamber (1) than the boundary is formed of a non-magnetic material. In the housing (3), an area located near the airtight chamber (1) from a site which is in contact with a pole piece (6) nearest to the airtight chamber (1) is formed of a magnetic material.

A magnetic fluid seal (20) sealing between an apparatus end (14) and a rotating shaft (22) going through the apparatus end, comprising a housing (38) comprising a magnetic flux generating means (28) generating a magnetic flux and a magnetic flux transfer means (24, 26) facing to the rotating shaft with a fine clearance and transferring the magnetic flux, and placed so as to move relatively in a radial direction of the rotating shaft with respect to the apparatus end and a magnetic fluid (44) held in the fine clearance by the magnetic flux generated by the magnetic flux generating means.

According to various embodiments, a space suit joint is disclosed. The space suit joint includes a contact bearing having a plurality of contact points with an angular offset of a centerline in a radial direction and an angular offset from the centerline in an axial direction. The space suit joint further includes a ferrofluid pressure seal comprising an inner and outer race with a magnetic circuit embedded therein.

A magnetic fluid sealing device includes: a housing; a shaft rotatably penetrating through the housing; a first shaft sleeve made of a magnetic conductive material, and fitted over the shaft; a plurality of pole shoes arranged in the housing and fitted over the shaft and the first shaft sleeve, an inner circumferential surface of the pole shoe being provided with a plurality of pole teeth arranged at intervals in an axial direction of the shaft, the shaft and a first part of the plurality of pole teeth being arranged at intervals in a radial direction of the shaft to form a first gap, the first shaft sleeve and a second part of the plurality of pole teeth being arranged at intervals in the radial direction of the shaft to form a second gap; and a permanent magnet arranged in the housing and fitted over the shaft.