Abstract: A butterfly valve that is capable of reducing torque and improves sealing performance. The butterfly valve 10 includes a shaft member 100, a tabular valve body that is provided on the shaft member 100, a case 310 that is attachable to and detachable from a through-hole 510 formed in an attachment member 500 to which the butterfly valve 10 is configured to be attached, a pair of bearings 320 that is provided in the case 310 and rotatably supports the shaft member 100, and a magnetic fluid seal that is provided between the pair of bearings 320 in the case 310 and seals an annular gap between the case 310 and the shaft member 100.

Abstract: A butterfly valve that is capable of reducing torque and enables a manufacturer that manufactures and sells the butterfly valve to implement management on qualities such as sealing performance. A butterfly valve 10 includes a shaft member 100, a tabular valve body that is provided on the shaft member 100, a case 310 that is attachable to and detachable from a through-hole 510 formed in an attachment member 500 to which the butterfly valve 10 is configured to be attached, a pair of bearings 320 that is provided in the case 310 and rotatably supports the shaft member 100, and a magnetic fluid seal that is provided between the pair of bearings 320 in the case 310 and seals an annular gap between the case 310 and the shaft member 100.

Abstract: A fishing reel that includes a reel body, a housing part that defines an opening part, a driving member that includes a pinion that is supported by the reel body and extends through the opening part of the housing part, and a magnetic seal device affixed to the housing part that includes a central opening through which the pinion extends. The magnetic seal device includes first and second magnetic plates that maintain a magnet therebetween and a magnetic fluid that is maintained at a gap between the driving member and at least one of the first and second magnetic plates.

Abstract: 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.

Abstract: A fishing reel that includes a reel body, a housing part that defines an opening part, a driving member that includes a pinion that is supported by the reel body and extends through the opening part of the housing part, and a magnetic seal device affixed to the housing part that includes a central opening through which the pinion extends. The magnetic seal device includes first and second magnetic plates that maintain a magnet therebetween and a magnetic fluid that is maintained at a gap between the driving member and at least one of the first and second magnetic plates.

Abstract: 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.