There is described herein an apparatus comprising a shoulder washer that comprises a shank, a shoulder coupled with the shank, a bore passing through the shank and the shoulder, and a step. The step is coupled with the shoulder and at least partially encircles the shank where the shank meets the shoulder. In other embodiments, the apparatus is employed with a bearing, where the step is selected to provide a gap that allows the bearing to freely rotate while engaged with the aforementioned apparatus. In yet other embodiments, flat washers may have employed shoulder bearings that do not have steps for engaging a bearing and providing a gap that is allows the bearing to freely rotate while engaged with the shoulder washers.

A roller tappet including bearing sleeves is disclosed. The roller tappet includes a housing having a circumferential sidewall with a first sidewall portion including a first bore and a second sidewall portion including a second bore diametrically opposed to the first bore. A roller is positioned at least partially inside the housing between the first sidewall portion and the second sidewall portion. A first bearing sleeve is arranged in the first bore of the housing and a second bearing sleeve arranged in the second bore of the housing. An axle extends through the first bearing sleeve and the second bearing sleeve and through the roller, such that the roller is rotatably mounted on the axle within the housing. Axial ends of the axle are respectively positioned in and rotatable relative to the first bearing sleeve and the second bearing sleeve.

A roller tappet including bearing sleeves is disclosed. The roller tappet includes a housing having a circumferential sidewall with a first sidewall portion including a first bore and a second sidewall portion including a second bore diametrically opposed to the first bore. A roller is positioned at least partially inside the housing between the first sidewall portion and the second sidewall portion. A first bearing sleeve is arranged in the first bore of the housing and a second bearing sleeve arranged in the second bore of the housing. An axle extends through the first bearing sleeve and the second bearing sleeve and through the roller, such that the roller is rotatably mounted on the axle within the housing. Axial ends of the axle are respectively positioned in and rotatable relative to the first bearing sleeve and the second bearing sleeve.

A bearing assembly includes a shaft, a first bearing, and a nut. The nut has a thread, which is screwed onto a threaded region formed on the shaft, and a bearing seat formed on the shaft adjoins the threaded region. The inner ring of the first bearing contacts the bearing seat, and the nut contacts the inner ring of the first bearing. The inner ring of the first bearing is arranged spaced apart from the threaded region of the shaft. A runout region of a thread cut into the threaded region of the shaft is arranged in a subsection of the bearing seat adjoining the threaded region.

There is described herein an apparatus comprising a shoulder washer that comprises a shank, a shoulder coupled with the shank, a bore passing through the shank and the shoulder, and a step. The step is coupled with the shoulder and at least partially encircles the shank where the shank meets the shoulder. In other embodiments, the apparatus is employed with a bearing, where the step is selected to provide a gap that allows the bearing to freely rotate while engaged with the aforementioned apparatus. In yet other embodiments, flat washers may have employed shoulder bearings that do not have steps for engaging a bearing and providing a gap that is allows the bearing to freely rotate while engaged with the shoulder washers.

There is described herein an apparatus comprising a shoulder washer that comprises a shank, a shoulder coupled with the shank, a bore passing through the shank and the shoulder, and a step. The step is coupled with the shoulder and at least partially encircles the shank where the shank meets the shoulder. In other embodiments, the apparatus is employed with a bearing, where the step is selected to provide a gap that allows the bearing to freely rotate while engaged with the aforementioned apparatus. In yet other embodiments, flat washers may have employed shoulder bearings that do not have steps for engaging a bearing and providing a gap that is allows the bearing to freely rotate while engaged with the shoulder washers.

Cylindrical rolling bodies, methods of producing the rolling bodies, and anti-friction bearings including the rolling bodies are disclosed. A method of producing the rolling bodies may include a) providing a spherical blank having a diameter (D) and a radius; and b) grinding the spherical blank into a cylindrical shape having a predefined diameter (d) and a length (L) that corresponds to the diameter (D) to form a cylindrical rolling body. After grinding, the cylindrical rolling body may have crowned end surfaces each having a radius corresponding to the radius of the spherical blank. Centerless cylindrical plunge grinding or centerless cylindrical throughfeed grinding may be used as the grinding method.

Cylindrical rolling bodies, methods of producing the rolling bodies, and anti-friction bearings including the rolling bodies are disclosed. A method of producing the rolling bodies may include a) providing a spherical blank having a diameter (D) and a radius; and b) grinding the spherical blank into a cylindrical shape having a predefined diameter (d) and a length (L) that corresponds to the diameter (D) to form a cylindrical rolling body. After grinding, the cylindrical rolling body may have crowned end surfaces each having a radius corresponding to the radius of the spherical blank. Centerless cylindrical plunge grinding or centerless cylindrical throughfeed grinding may be used as the grinding method.

This transmission shaft is used in a transmission and has a raceway surface on which needle rollers roll. The transmission shaft includes a base material and a triiron tetraoxide film. The base material includes any one of chromium steel, chromium-molybdenum steel, or nickel-chromium-molybdenum steel, and has, on a surface thereof, a diffusion layer including crystal grains of at least one of iron carbide, iron nitride, or iron carbonitride. The triiron tetraoxide film is formed on the surface of the base material and is disposed at least on the raceway surface.

This transmission shaft is used in a transmission and has a raceway surface on which needle rollers roll. The transmission shaft includes a base material and a triiron tetraoxide film. The base material includes any one of chromium steel, chromium-molybdenum steel, or nickel-chromium-molybdenum steel, and has, on a surface thereof, a diffusion layer including crystal grains of at least one of iron carbide, iron nitride, or iron carbonitride. The triiron tetraoxide film is formed on the surface of the base material and is disposed at least on the raceway surface.