A pulley device provides a pulley, and a bearing. The pulley has at least one C-shaped pulley part having an inner portion mounted on the bearing, an outer portion having an outer cylindrical surface dedicated to interact with a belt or a chain, and an intermediate portion extending substantially radially between axial ends of inner and outer portions on one axial side of pulley device. A grip surface portion is provided to one surface among the outer cylindrical surface of the outer ring and the inner cylindrical surface of the inner cylindrical portion of the pulley part, the grip surface portion including a plurality of indentations and recesses.

Provided is an electrophotographic electro-conductive member including a support having an electro-conductive outer surface, and an electro-conductive layer. The electro-conductive layer has a matrix containing a crosslinked product of a first rubber and domains containing a crosslinked product of a second rubber and an electron conductive agent. When measuring an impedance by applying alternating voltage between the outer surface of the support and a platinum electrode on an outer surface of the electro-conductive layer while changing a frequency, a slope at specific frequencies is −0.8 to −0.3 in a double logarithmic plot, and an impedance at specific frequency range is 1.0×10.sup.4Ω to 1.0×10.sup.11Ω. When measuring an impedance by applying alternating voltage between the outer surface of the support and a platinum electrode on an outer surface of the electrophotographic electro-conductive member while changing a frequency, an impedance at specific frequency range is 1.0×10.sup.5Ω to 1.0×10.sup.11Ω.

An elastic roller is capable of elastic deformation at low load, lightweight and low-cost, and the surface speed of the roller has been made stable. At a drawing showing the view from the side of pipe 2 and flange 3 which make up roller 1, roller 1 which has pipe 2 and flange 3 is supported by shaft 8 which is inserted therein along axis 8a of shaft 8, the situation being such that elastic deformation occurs upon being pressed downward by pressure P from pressure-applying body 11 above pipe. None of the four outermost ribs 7a disposed in outermost gap 6a between outermost ring 4a of flange 3 and middle ring 4b which is mutually adjacent thereto and toward the interior therefrom is present in the upper portion of pipe 2.

An elastic roller is capable of elastic deformation at low load, lightweight and low-cost, and the surface speed of the roller has been made stable. At a drawing showing the view from the side of pipe 2 and flange 3 which make up roller 1, roller 1 which has pipe 2 and flange 3 is supported by shaft 8 which is inserted therein along axis 8a of shaft 8, the situation being such that elastic deformation occurs upon being pressed downward by pressure P from pressure-applying body 11 above pipe. None of the four outermost ribs 7a disposed in outermost gap 6a between outermost ring 4a of flange 3 and middle ring 4b which is mutually adjacent thereto and toward the interior therefrom is present in the upper portion of pipe 2.

Provided is a paper feeding roll that prevents paper transportation failures over a long time. A paper feeding roll 10 is provided with an axial body 12 and an elastic layer 14 formed on an outer periphery of the axial body 12. The circumferential surface of the elastic layer 14 has a plurality of projections 16 forming surface unevenness. Each projection 16 of the plurality of projections 16 is shaped such that a position X of a distal-end part preceding in an opposite direction to a paper feeding direction precedes, in the opposite direction to the paper feeding direction, a position Y of a base-end part preceding in the opposite direction to the paper feeding direction.

A pass roll for a hot-dip galvanized steel sheet manufacturing facility, the pass roll includes: a roll body; and a heat-resistant felt layer covering the roll body, wherein the heat-resistant felt layer has a thermal decomposition temperature of 420° C. or higher and has a surface hardness evaluation index at 400° C. of more than 0.11 μm/N.

A pass roll for a hot-dip galvanized steel sheet manufacturing facility, the pass roll includes: a roll body; and a heat-resistant felt layer covering the roll body, wherein the heat-resistant felt layer has a thermal decomposition temperature of 420° C. or higher and has a surface hardness evaluation index at 400° C. of more than 0.11 μm/N.

A roller hydraulic valve lifter includes a body having a longitudinal central axis and an interior area defined by an inside surface which has a pair of flat surfaces opposite one another and connected by a pair of walls. A first bore, essentially perpendicular to the longitudinal axis, extends through the flat surfaces. A bearing is disposed partially in the interior area. The bearing includes an outer ring having substantially cylindrical exterior and interior bearing surfaces. A shaft extends through the first bore and the outer ring and between the pair of flat surfaces. A plurality of needle rollers is disposed between and rollingly engage the shaft and the cylindrical inner bearing surface. The shaft and the plurality of needle rollers are manufactured from an AISI 52100 alloy steel that is carbo-nitrided. The shaft and the plurality of needle rollers have a surface hardness of a minimum of HRc 65.

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 2.0 micrometers and is equal to or less than 8.4 micrometers. The average of intervals between apexes of the convex portions on the surface of the surface layer is equal to or greater than 6.7 micrometers and is equal to or less than 39.8 micrometers.

Provided is an electrophotographic electroconductive member including an electroconductive support and an electroconductive layer on the support, an electroconductive member is used, in which an electroconductive layer has a matrix comprising a first rubber, and domains dispersed in the matrix, the domains each comprising a second rubber and an electronic electroconductive agent, and for impedance measured by applying an AC voltage with an amplitude of 1 V to the electroconductive layer while varying frequencies between 1.0×10.sup.−2 Hz to 1.0×10.sup.7 Hz under a specific environment, when a double logarithmic plot with a frequency on an abscissa and an impedance on an ordinate is obtained, a slope on a high frequency side is −0.8 or more and —0.3 or less, and the impedance a low frequency side is from 1.0×10.sup.3 to 1.0×10.sup.7Ω.