A bearing cage assembly is disclosed. The assembly includes a stiffening ring formed from a first material, and a cage formed from a second material that is different than the first material. The cage includes a plurality of arms extending axially away from a base rim. The plurality of arms define a plurality of rolling element pockets therebetween. Each of the plurality of arms defines a slot dimensioned to receive a portion of the stiffening ring, such that the stiffening ring is secured to the cage via engagement within the slots of the plurality of arms.

A transmission unit includes a transmission housing, a transmission element rotatably accommodated in the transmission housing, a bearing seat, and an angular contact ball bearing accommodated in the bearing seat, for mounting the transmission element, as well as a double-row angular contact ball bearing having: an inner bearing ring; a first inner concave rolling element raceway formed in an outer peripheral region of the inner bearing ring; a second inner concave rolling element raceway axially offset to the first inner rolling element raceway and formed in the outer peripheral region of the inner bearing ring; an outer bearing ring; a first outer concave rolling element raceway formed in an inner peripheral region of the outer bearing ring; a second outer concave rolling element raceway axially offset to the first outer rolling element raceway and formed in the outer bearing ring; a first ball-cage assembly with first balls which are accommodated in a first track space extending between the first inner rolling element raceway and the first outer rolling element raceway; and a second ball-cage assembly with second balls which are accommodated in a second track space extending between the second inner rolling element track and the second outer rolling element track. In this way, the central tracks of the two ball-cage assemblies adopt certain axial and radial relative positions.

A double-row four-point contact ball bearing 100 according to the present invention includes an outer ring 102, an inner ring 104, and balls 106 and 108 that are arranged in two rows between the outer ring 102 and the inner ring 104 and each have four contact points. Inner side contact angles α of the balls 106 and 108 arranged in the two rows are set such that lines of action L1 and L2 that extend respectively connecting center points of the balls 106 and 108 and contact points of the balls do not cross each other in the outer ring 102.

A retained roller set includes first and second individual tube-shaped members each having first and second axially spaced rings connected by bar elements that define pockets therebetween, the tube-shaped members being coaxially arranged and radially spaced to define a circumferentially extending intermediate space therebetween in which a plurality of roller elements are received and retained by the pockets of the first and second tube-shaped members.

A cage is asymmetrical to a radially extending straight line extending. Supposing that is the angle of contact of the rolling element, is defined as 3045. The relationship defined in the numerical expression is satisfied, where D is the outer diameter of the outer ring, d is the inner diameter of the inner ring, and Da is the diameter of the rolling element. With center axes of the whole bearing in an axial direction and of the cage in the axial direction overlapping each other, at least one of the following relationships is satisfied;

A/Da0.020 (2), and

2A/PCD0.010 (3),

where A is the smallest dimension value of a clearance in a radial direction between surfaces of a pocket of the cage facing the rolling element and of this rolling element, and PCD is the pitch diameter of each rolling element.

A multi-row rolling element housing band is provided which can promote an increase in the degree of precision of a guide. At least three rolling element rows (17) to (19) are arranged in a band (15). Each second rolling element (18a) of the second rolling element row (18) is displaced by P/n in a length direction of the band (15) from each first rolling element (17a) of the first rolling element row (17). Each third rolling element (19a) of the third rolling element row (19) is displaced by P/n in the length direction of the band (15) from each second rolling element (18a) of the second rolling element row (18). P is the pitch between the first rolling elements (17a), and n is the number of rows.

A bearing system for a rotating vertical shaft includes a first ball bearing, having a first pitch diameter and a first axial stiffness and a second ball bearing having a second pitch diameter and a second axial stiffness. The first ball bearing is a deep groove Conrad bearing. The second ball bearing is an angular contact bearing. The first and second ball bearings are coaxial, secured to one another and rotatable together. The first pitch diameter is at least 1.5 times greater than the second pitch diameter. The bearing system has an axial stiffness ratio defined by the first axial stiffness divided by the second axial stiffness. The axial stiffness ratio is based on an axial preload force applied to the second outer ring such that an operating torque of the bearing system is within a predetermined range at temperatures from minus 40 to positive 85 degrees Celsius.

A ball bearing assembly includes a one piece outer ring having a first and second outer race and an exterior surface; and a one piece inner ring having a first and second inner race, the inner ring is integrally formed on a shaft. A first plurality of balls is disposed between the first outer race and the first inner race; and a second plurality of balls is disposed between the second outer race and the second inner race. The first plurality of balls has a first contact and the second plurality of balls has a second contact angle.

A multi-row rolling element housing band is provided which can promote an increase in the degree of precision of a guide. At least three rolling element rows (17) to (19) are arranged in a band (15). Each second rolling element (18a) of the second rolling element row (18) is displaced by P/n in a length direction of the band (15) from each first rolling element (17a) of the first rolling element row (17). Each third rolling element (19a) of the third rolling element row (19) is displaced by P/n in the length direction of the band (15) from each second rolling element (18a) of the second rolling element row (18). P is the pitch between the first rolling elements (17a), and n is the number of rows.

Provided is a double-row four-point contact ball bearing in which deformation of an outer ring can be suppressed while suppressing an increase in dimensions. A double-row four-point contact ball bearing 100 according to the present invention includes an outer ring 102, an inner ring 104, and balls 106 and 108 that are arranged in two rows between the outer ring 102 and the inner ring 104 and each have four contact points. Inner side contact angles of the balls 106 and 108 arranged in the two rows are set such that lines of action L1 and L2 that extend respectively connecting center points of the balls 106 and 108 and contact points of the balls do not cross each other in the outer ring 102.