The disclosure relates to a head bearing assembly for a dental or surgical handpiece, comprising an outer sleeve, in which at least four radial bearings are arranged, which enclose an axis of rotation and each have their own bearing outer ring or a common bearing outer rings, wherein the bearing outer rings are surrounded radially on the outside by the outer sleeve in the circumferential direction about the axis of rotation, and each radial bearing has at least one or exactly one rolling element row with rolling elements which are arranged one behind the other in the circumferential direction and rolling in the respective bearing outer ring.

The head bearing assembly according to the disclosure is characterized in that the at least four radial bearings have a common, integral bearing inner ring on which the rolling elements are arranged in rolling contact.

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.

A pulley device for a tensioner roller or winding roller of a transmission element, providing a pulley, and a bearing. The bearing includes a rotating outer ring mounted to the pulley, a fixed inner ring, and at least one row of rolling elements arranged between the rings. The inner ring of the bearing has at least one end portion protruding axially with respect to the outer ring. The pulley is provided with at least one pulley element that is C-shaped in axial section. One of the at least one pulley elements is provided with a lateral portion extending substantially radially to pass into the immediate vicinity of an outer surface of the axially protruding end portion of the inner ring.

A pulley device for a tensioner roller or winding roller of a transmission element, providing a pulley, and a bearing. The bearing includes a rotating outer ring mounted to the pulley, a fixed inner ring, and at least one row of rolling elements arranged between the rings. The inner ring of the bearing has at least one end portion protruding axially with respect to the outer ring. The pulley is provided with at least one pulley element that is C-shaped in axial section. One of the at least one pulley elements is provided with a lateral portion extending substantially radially to pass into the immediate vicinity of an outer surface of the axially protruding end portion of the inner ring.

A Pulley device for a tensioning or winding roller for a transmission element including a pulley, and a rolling bearing provided with a rotating outer ring, the pulley being mounted on an outer surface of the outer ring, a fixed inner ring, the rings being coaxial and forming a radial space between them, and at least one row of rolling elements arranged in the radial space. The pulley device further includes at least one annular protection flange with a radial body. The flange is fixed to the rotating outer ring by crimping an axially protruding portion of the pulley towards an outer edge of the flange.

A motor assembly has an enhanced retention system for minimizing axial and radial movement of the bearings and output shaft. A front endbell assembly is fixed to a front end of the motor, the front endbell assembly including a plastic front endbell and a front bearing assembly through which a driving end of the output shaft extends. The plastic front endbell is over-molded about the front bearing assembly and elasticity of the plastic front endbell operates to preload the front bearing assembly to restrict axial movement of the front bearing assembly. Similarly, a rear endbell assembly is fixed to a rear end of the motor opposite from the front end, the rear endbell assembly including a plastic rear endbell and a rear bearing assembly into which a rear end of the output shaft extends. The plastic rear endbell is over-molded about the rear bearing assembly and elasticity of the plastic rear endbell operates to preload the rear bearing assembly to restrict axial movement of the rear bearing assembly. A spring or an appropriately sized output shaft may be used to preload the bearing assemblies oppositely from the over-molded plastic endbells.

Disclosed is an electronic motor with two bearings. The motor is structured so that, when loaded, the majority of the load (e.g., a radial load) is borne by one of the bearings. The bearing that bears a greater load may be larger and, thus, better suited for a heavy load. In some embodiments, the larger bearing may include rolling elements that have respective radii larger than respective radii of rolling elements of the other bearing by a ratio of at least 1.5 (150%). In some embodiments, the larger bearing may have an outer race with a radius that is greater than a radius of the outer race of the smaller bearing by a ratio of at least 1.5. In some embodiments, the motors may include a third bearing between the two bearings. The third bearing may reduce vibration in the motor.

Disclosed is an electronic motor with two bearings. The motor is structured so that, when loaded, the majority of the load (e.g., a radial load) is borne by one of the bearings. The bearing that bears a greater load may be larger and, thus, better suited for a heavy load. In some embodiments, the larger bearing may include rolling elements that have respective radii larger than respective radii of rolling elements of the other bearing by a ratio of at least 1.5 (150%). In some embodiments, the larger bearing may have an outer race with a radius that is greater than a radius of the outer race of the smaller bearing by a ratio of at least 1.5. In some embodiments, the motors may include a third bearing between the two bearings. The third bearing may reduce vibration in the motor.

A rolling bearing includes: an outer ring including an outer ring raceway surface on an inner peripheral surface; an inner ring including an inner ring raceway surface on an outer peripheral surface; a plurality of rolling elements rotatably arranged between the outer ring raceway surface and the inner ring raceway surface; and a sealing member fixed to a seal mounting groove formed on an axial end portion of the outer ring by a retaining ring, the sealing member sealing an axial end portion of a bearing internal space between the outer ring and the inner ring. The sealing member includes a protruding portion at a radial outer end portion, and an outer diameter of the sealing member is larger than an outer diameter of the retaining ring in the seal mounting groove.

A rolling bearing includes: an outer ring including an outer ring raceway surface on an inner peripheral surface; an inner ring including an inner ring raceway surface on an outer peripheral surface; a plurality of rolling elements rotatably arranged between the outer ring raceway surface and the inner ring raceway surface; and a sealing member fixed to a seal mounting groove formed on an axial end portion of the outer ring by a retaining ring, the sealing member sealing an axial end portion of a bearing internal space between the outer ring and the inner ring. The sealing member includes a protruding portion at a radial outer end portion, and an outer diameter of the sealing member is larger than an outer diameter of the retaining ring in the seal mounting groove.