An oil-impregnated sintered bearing comprises a bearing hole. In the bearing, sliding surfaces supporting an outer circumferential surface of a shaft and an oil supply surface whose diameter is larger than that of the sliding surfaces are formed on an inner circumferential surface of the bearing hole into which the shaft is inserted. The sliding surfaces and the oil supply surfaces are adjacent to each other in the axial direction of the bearing hole. A height gap “d1” between the sliding surfaces and the oil supply surface is not less than 0.01% and not more than 15% of an inner diameter of the sliding surfaces. A surface opening percentage of the sliding surfaces is not higher than 10%. A surface opening percentage of the oil supply surface is higher than 10%. An average circle-equivalent diameter of opening parts of pores on the sliding surfaces is not larger than 20 μm.

The present application provides a gearbox and an intelligent cleaning apparatus. The gearbox is used for the intelligent cleaning apparatus, and includes a rotatable part and a porous bearing. The rotatable part can rotate around a rotation axis to transmit power for a cleaning head of the intelligent cleaning apparatus, and has a contact surface. The porous bearing is fixedly arranged and has a support surface, and the support surface of the porous bearing is in contact with the contact surface of the rotatable part to support the rotatable part in rotating relative to the porous bearing. At least one of the contact surface and the support surface is provided with a recess.

Provided are a lubricating oil composition which contains a base oil (A) containing an ester-based oil (Al), and a polymer (B) having a constituent unit (b) derived from an alkyl (meth)acrylate, wherein the content of the polymer (B) is 0.1 to 10% by mass based on the total amount of the lubricating oil composition, the lubricating oil composition has a viscosity index of 350 or more, the lubricating oil composition has a BF viscosity at −40° C. of 4000mPa.Math.s or less, and the lubricating oil composition is used for an impregnated bearing, and an impregnated bearing impregnated with the lubricating oil composition. The lubricating oil composition has excellent lubricity in use in a wide temperature environment from a low temperature region to a high temperature region, is capable of maintaining excellent infiltration property even in an environment in which a temperature change between a low temperature and a high temperature is severe, and is suitable for use in an impregnated bearing.

A sliding bearing having a sealing arrangement for water pumps, configured to radially mount and seal a shaft in a housing between a wet side and a dry side. The sliding bearing and the sealing arrangement include a sliding bearing bushing made of a sintering material for radial mounting of the shaft, and a dry-side shaft seal arranged between the sliding bearing bushing and the dry side. A wet-side shaft seal is arranged between the wet side and the sliding bearing bushing and a lubricant reservoir with a substrate, made of a non-sintered material, which is porous in at least some sections, is arranged at least between the wet-side shaft seal and the sliding bearing bushing. The lubricant reservoir includes, in pores of the substrate, a lubricant insoluble in water. A volume of the lubricant reservoir and a volume of a lubricant filling take up a total volume of spaces between the wet-side shaft seal and the dry-side shaft seal.

A sintered bearing includes a bearing main body which has a substantially cylindrical shape and is made of a sintered material, a through-hole being formed in a center of the bearing main body; a sealing member in a disk shape, the sealing member being configured to be disposed such that one surface side of the sealing member is in contact with the bearing main body, and an opening being formed in a center of the sealing member; and a locking member in a block shape, the locking member being configured to be in contact with at least another surface side of the sealing member and holding the sealing member between the locking member and the bearing main body.

A sliding bearing may include an uncoated shaft and a bearing bush. The uncoated shaft may include a shaft material. The bearing bush may include a sintered bearing bush material. The shaft may be slidingly and moveably guided, relative to the bearing bush, within the bearing bush. The bearing bush material may have a residual porosity of 8 percent or more. A volume of the residual porosity may be filled with an oil up to 80 percent or more.

A sintered bearing bush material for a sliding bearing may include: 0.5 to 1.7 percentage by weight carbon; 0.2 to 1.2 percentage by weight manganese; 0.2 to 1.2 percentage by weight sulphur; 1.2 to 2.4 percentage by weight nickel; 1.0 to 2.1 percentage by weight molybdenum; 3.0 to 7.0 percentage by weight copper; 0.2 to 1.2 percentage by weight tin; 0 to 0.8 percentage by weight phosphorus; and a residual component.

A power tool includes a housing having a motor housing portion and a front casing coupled to the motor housing portion. The power tool also includes an electric motor positioned within the motor housing portion, a drive assembly having an output shaft to which a tool element for performing work on a workpiece is attachable, and a powdered metal bushing disposed within the front casing that rotatably supports the output shaft.

The Cu-based sintered sliding material has a composition including, by mass %, 7% to 35% of Ni, 1% to 10% of Sn, 0.9% to 3% of P, and 0.5% to 5% of C, with a remainder of Cu and inevitable impurities, wherein the Cu-based sintered sliding material includes a sintered body including: alloy grains that contain Sn and C and contain a CuNi-based alloy as a main component; grain boundary phases that contain Ni and P as main components and are dispersedly distributed in grain boundaries of the alloy grains; and free graphite that intervenes at the grain boundaries of the alloy grains, the Cu-based sintered sliding material has a structure in which pores are dispersedly formed in the grain boundaries of the alloy grains, and an amount of C in a metal matrix including the alloy grains and the grain boundary phases is, by mass %, 0.02% to 0.20%.

A sintered bearing is made of a sintered compact containing nickel silver (CuNiZn) as a base. In the sintered bearing, P is not added in the sintered compact. Alternatively, a content of P in the sintered compact is less than 0.05 mass % in terms of mass ratio to a total mass. Consequently, crystal grains constituting the sintered compact can be micronized. In particular, in the sintered bearing, an average crystal particle diameter of the crystal grains constituting the sintered compact is 20 m or less. Consequently, the mechanical strength and the vibration resisting properties can be improved, and the rotation shaft can be prevented from being damaged.