Abstract: In a wheel supporting rolling bearing unit in which pitch circle diameters of balls 6a, 6b in an outside row and an inside row are made different, contact angles ?OUT, ?IN of the balls 6a, 6b in the two rows in a completed state are equal to each other. Initial contact angles ?OUT, ?IN of the two rows are smaller than predetermined contact angles ?OUT, ?IN. The extent [?IN??IN] to which the initial contact angle ?IN of the balls 6b, 6b in the inside row is made smaller than the predetermined contact angle ?IN of the balls 6b, 6b is made larger than the extent [?OUT??OUT] to which the initial contact angle ?OUT of the balls 6a, 6a in the outside row is made smaller than the predetermined contact angle ?OUT of the balls 6a, 6a {[?IN??IN]>[?OUT??OUT]}. By this configuration, imparting the predetermined contact angles ?OUT, ?IN to the balls 6a, 6b in the two rows in the completed state, and the preloads and contact angles of the balls 6a, 6b in the two rows are made proper.

Abstract: With respect to an outer ring 2b in which a diameter DB1 of a first outer ring raceway 10c is greater than a diameter DB2 of a second outer ring raceway 10b (DB1>DB2), a method is realized which facilitates the entry of a grinding tool 12 into an inner side of the outer ring when these both outer ring raceways 10c and 10b are subjected to a grinding process. The grinding tool 12 is made to enter the inner side of the outer ring 2b through an opening on a side close to the first outer ring raceway 10c.

Abstract: In a wheel supporting rolling bearing unit in which pitch circle diameters of balls 6a, 6b in an outside row and an inside row are made different, contact angles ?OUT, ?IN of the balls 6a, 6b in the two rows in a completed state are equal to each other. Initial contact angles ?OUT, ?IN of the two rows are smaller than predetermined contact angles ?OUT, ?IN. The extent [?IN??IN] to which the initial contact angle ?IN of the balls 6b, 6b in the inside row is made smaller than the predetermined contact angle ?IN of the balls 6b, 6b is made larger than the extent [?OUT??OUT] to which the initial contact angle ?OUT of the balls 6a, 6a in the outside row is made smaller than the predetermined contact angle ?OUT of the balls 6a, 6a {[?IN??IN]>[?OUT??OUT]}. By this configuration, imparting the predetermined contact angles ?OUT, ?IN to the balls 6a, 6b in the two rows in the completed state, and the preloads and contact angles of the balls 6a, 6b in the two rows are made proper.

Abstract: With respect to an outer ring 2b in which a diameter DB1 of a first outer ring raceway 10c is greater than a diameter of a second outer ring raceway 10b (DB1>DB2), a method is realized which facilitates the entry of a grinding tool 12 into an inner side of the outer ring when these both outer ring raceways 10c and 10b are subjected to a grinding process. As shown in (A) to (B), the grinding tool 12 is made to enter the inner side of the outer ring 2b through an opening on a side close to the first outer ring raceway 10c between the openings at both ends of this outer ring 2b. This resolves the above-described problem.

Abstract: An electrorheological fluid damper for a slide mechanism including a base and a table, is made up of base-side conductive arcuate pipes different in diameter (serving as a positive electrode), and table-side conductive arcuate pipes different in diameter (serving as a negative electrode) which are arranged alternately in such a manner that they are coaxial with one another, so that the contact areas of the electrodes which are in contact with the electrorheological fluid are increased without increase of the size of the damper itself. When the table is being slid, no voltage is applied to the electrorheological fluid, so that the viscosity of the electrorheological fluid is minimum, being of only its solution, and when the table is stopped, voltage is applied to the electrorheological fluid, so that the viscosity of the electrorheological fluid is increased.

Abstract: In measuring the accuracy of a thread groove of a ball thread formed in a nut by using an electric micrometer, a displacement of one point on each of a pair of flanks of the thread groove is measured along a longitudinal direction of the thread groove, and a pair of measured data sequences are obtained respectively for the pair of flanks. The data elements of the pair of measured data sequences are grouped into a plurality of groups so that each group includes a pair of data elements which are respectively contained in the pair of measured data sequences and which are corresponding to each other. The accuracy in the depth direction of the thread groove with respect to a reference thread groove is obtained on the basis of a sum of the data elements in each group, and the accuracy in the thread axis direction is obtained on the basis of a difference between the data elements in each pair.