A conveying system and a battery production system are provided. The conveying system is used for sheet conveying, and includes: a driving roller making contact with a sheet; and a press roller arranged correspondingly to the driving roller, the press roller abutting against at least part of the surface of the sheet facing away from the driving roller and pressing the sheet against the driving roller. The press roller includes: a main shaft with a central axis; at least one hollow rubber roller detachably sleeving the main shaft; and at least one pair of fixing clamp rings arranged on two sides of the hollow rubber roller along the central axis so as to fix the position of the hollow rubber roller on the main shaft along the central axis, where an outer diameter of the fixing clamp ring is less than that of the hollow rubber roller.

Provided is a conductive roll for an electrophotographic machine. The conductive roll is a charging roll and includes a shaft body, and an elastic body layer formed on an outer periphery of the shaft body. The elastic body layer is a crosslinked body of a composition containing a diene-based polymer (a), a sulfur or peroxide crosslinking agent (b), carbon black (c), and a coupling agent (d). (c) has a specific surface area of 40 to 300 m.sup.2/g. (d) is a coupling agent having a NHR.sup.1 group and a SSO.sub.3H group, or a coupling agent having a NHR.sup.1 group and an ene structure (where R.sup.1 is H or a hydrocarbon group having 1 to 8 carbon atoms). The contents of (c) and (d) in the composition are respectively 10 to 45 parts by mass and 0.5 to 20 parts by mass with respect to 100 parts by mass of (a).

Provided is a conductive roll for an electrophotographic machine. The conductive roll is a charging roll and includes a shaft body, and an elastic body layer formed on an outer periphery of the shaft body. The elastic body layer is a crosslinked body of a composition containing a diene-based polymer (a), a sulfur or peroxide crosslinking agent (b), carbon black (c), and a coupling agent (d). (c) has a specific surface area of 40 to 300 m.sup.2/g. (d) is a coupling agent having a NHR.sup.1 group and a SSO.sub.3H group, or a coupling agent having a NHR.sup.1 group and an ene structure (where R.sup.1 is H or a hydrocarbon group having 1 to 8 carbon atoms). The contents of (c) and (d) in the composition are respectively 10 to 45 parts by mass and 0.5 to 20 parts by mass with respect to 100 parts by mass of (a).

An electroconductive member for electrophotography including a support having electro-conductivity and an electroconductive layer on the outer surface of the support, the electroconductive layer including a matrix containing a crosslinked product of a first rubber and first electroconductive particles and domains each containing a crosslinked product of a second rubber and second electroconductive particles, wherein at least part of the first electroconductive particles are present as a primary particle in the crosslinked product of the first rubber, wherein, the first electroconductive particles of the matrix observed in a specific observation region have dl of 200 nm or more, the second electroconductive particles in the domains observed therein have d2 of 50 nm or less, and 80 number % or more of the domains satisfy specific conditions.

A bearing housing is provided with a cooling channel in at least part of the circumference around the bearing. The cooling channel is provided with a flow guide member at least in part of its flow section to construct a tortuous passage whose flow distance is longer than the corresponding circumferential length of the flow section. On the basis of the above-mentioned bearing housing, the present invention also provides a bearing housing unit, a continuous casting roll line and a continuous casting machine that use the bearing housing. The above-mentioned bearing housing adopts an optimized cooling channel design, which can obtain a better cooling effect without changing other structures of the bearing housing. Therefore, it is particularly suitable for upgrading existing equipment and has a huge cost advantage and a wide range of application prospects.

An electroconductive roll includes a core member, a rubber base material disposed around the core member, and a surface layer disposed around the rubber base material. The surface area of the surface layer per unit projected area is equal to or greater than 1.255, and is equal to or less than 6.635.

The electro-conductive member has an electro-conductive support, and an electro-conductive layer, in which the electro-conductive layer has a matrix including a first rubber cross-linked product and domains dispersed in the matrix, each of the domains includes a second rubber cross-linked product and electro-conductive particles, an outer surface of the electro-conductive member has concave portions, a surface of at least a part of the domains is exposed to the outer surface of the electro-conductive member at bottom portions of the concave portions, a volume resistivity of the matrix is greater than 1×10.sup.12 Ωcm, a volume resistivity of the electro-conductive layer is 1×10.sup.5 Ωcm to 1×10.sup.8 Ωcm, and A2 is 20 times or more of A1.

A charging roll includes a core member, a rubber base material disposed around the core member, and a surface layer disposed around the rubber base material. The average of heights of contours of convex portions on a surface of the surface layer relative to an average cylindrical surface obtained by averaging surface irregularities of the surface layer is equal to or greater than 0.8 micrometers and is equal to or less than 2.1 micrometers. The average of intervals between apexes of the convex portions on the surface of the surface layer is equal to or greater than 6.6 micrometers and is equal to or less than 11.5 micrometers.

An electroconductive roll includes a core member, a rubber base material disposed around the core member, and a surface layer disposed around the rubber base material. The arithmetic mean peak curvature S.sub.pc of a surface of the surface layer is equal to or greater than 1,880 (1/mm), and is equal to or less than 14,024 (1/mm) The density of peaks S.sub.pd of the surface of the surface layer is equal to or greater than 93,406 (1/mm.sup.2), and is equal to or less than 151,476 (1/mm.sup.2). The surface area of the surface layer per unit projected area is equal to or greater than 1.255, and is equal to or less than 5.132.

An electroconductive roll includes a core member, a rubber base material disposed around the core member, and a surface layer disposed around the rubber base material. The arithmetic mean peak curvature S.sub.pc of a surface of the surface layer is equal to or greater than 1,880 (1/mm), and is equal to or less than 14,024 (1/mm) The density of peaks S.sub.pd of the surface of the surface layer is equal to or greater than 93,406 (1/mm.sup.2), and is equal to or less than 151,476 (1/mm.sup.2). The surface area of the surface layer per unit projected area is equal to or greater than 1.255, and is equal to or less than 5.132.