Abstract: A ball bearing retainer holds balls disposed between an inner ring and an outer ring, in pockets formed at a plurality of portions, in a circumferential direction, of an annular body. The annular body includes: annular parts disposed on both sides in an axial direction; and pillar parts that are disposed at a plurality of portions in the circumferential direction and that connect between the annular parts. The pockets are formed by the annular parts and the pillar parts adjacent to each other in the circumferential direction, and allow ball guide. First contact portions of the pillar portions, which contact portions contact with the balls in the circumferential direction, are formed by first planes that extend along the axial direction, and the balls are guided by the first planes.

Abstract: An object is to provide a motor-incorporation-spindle ball bearing capable of allowing cooling air which enters inside the bearing of the motor-incorporation-spindle to be discharged smoothly out of the bearing without causing turbulent flow inside the bearing, does not cause a retainer easily to be vibrated, and provides a high level of silent operation. A seal plate has a length to allow air to pass through the bearing from an entrance side toward an exit side substantially straightly without resistance. Therefore, the seal plate is less likely to be exposed to unnecessary force when the air passes through the bearing; the seal plate is prevented from wobble and deformation; stable sealing is ensured; the air is discharged smoothly without causing turbulent flow inside the bearing; a retainer is not easily vibrated, and silent operation is maintained.

Abstract: A ball bearing retainer holds balls disposed between an inner ring and an outer ring, in pockets formed at a plurality of portions, in a circumferential direction, of an annular body. The annular body includes: annular parts disposed on both sides in an axial direction; and pillar parts that are disposed at a plurality of portions in the circumferential direction and that connect between the annular parts. The pockets are formed by the annular parts and the pillar parts adjacent to each other in the circumferential direction, and allow ball guide. First contact portions of the pillar portions, which contact portions contact with the balls in the circumferential direction, are formed by first planes that extend along the axial direction, and the balls are guided by the first planes.

Abstract: An object is to provide a motor-incorporation-spindle ball bearing capable of allowing cooling air which enters inside the bearing of the motor-incorporation-spindle to be discharged smoothly out of the bearing without causing turbulent flow inside the bearing, does not cause a retainer easily to be vibrated, and provides a high level of silent operation. A seal plate has a length to allow air to pass through the bearing from an entrance side toward an exit side substantially straightly without resistance. Therefore, the seal plate is less likely to be exposed to unnecessary force when the air passes through the bearing; the seal plate is prevented from wobble and deformation; stable sealing is ensured; the air is discharged smoothly without causing turbulent flow inside the bearing; a retainer is not easily vibrated, and silent operation is maintained.

Abstract: A ball guide type ball bearing retainer (3) according to the present invention retains balls (4) in pockets (Pt) provided in a circular ring portion (5), and the circular ring portion (5) includes annular portions (6, 7) disposed at both sides in an axial direction and pillar portions (8) which connect the annular portions (6, 7). Each pocket (Pt) is formed by the annular portions (6, 7) at the both sides and the pillar portions (8) adjacent to each other. At outer diameter portions of the pillar portions (8), outer diameter restriction portions (9) are provided which extend toward a pocket side and restrict and guide the balls (4) from an outer diameter side with guide surfaces (9a) thereof, and are inclined flat surfaces which are inclined so as reach a large diameter side as extending from the pillar portions (8) toward a pocket (Pt) center side.

Abstract: Let r be the radius of curvature of the corners of pockets of a cage, and Lw be the length of cylindrical rollers. They are set such that the relation r/Lw?0.1 holds. Further, the relation r/k1?1 holds, where k1 is the minimum dimension on the inner diameter side of the annulus of the cage.

Abstract: A lubricating structure of a rolling bearing capable of achieving an increase in speed and service life and a maintenance-free by using only a grease sealed in the bearing and efficiently using a grease base oil. The lubricating structure comprises a mist recovery mechanism (6) recovering mist produced during the operation near a rolling-element rolling space (5) into a recovery space (11) and a re-inflow mechanism (7) in the inner ring rotating rolling bearing lubricated with the grease sealed in the bearing. The re-inflow mechanism (7) re-flows, by the rotation of an inner race (1), the mist recovered into the recovery space (11) into bearing spaces from the inner diameter side of a retainer (4) by utilizing the outside diameter inclined surface (1b) of the inner ring.

Abstract: To supply a lubricating oil to axial centers of cylindrical rollers where lubrication is the most difficult. A retainer for a cylindrical roller bearing comprises a pair of annular portions and a plurality of column portions for connecting the annular portions to each other, and pockets for accommodating the cylindrical rollers being formed in spaces surrounded by the opposed annular portions and adjoining column portions. In this retainer, lubricant trap portions are formed in guide surfaces of the column portions for guiding rolling contact surfaces of the cylindrical rollers opposed thereto in the circumferential direction of the pockets, the lubricant trap portions gradually decreasing in axial width as extending radially outward in axial centers. An example of the shape of gradually decreasing in width as extending radially outward in the axial center is a generally triangular shape having an apex radially outward.

Abstract: Contact surface pressure P increases rather drastically in proportion to skew angle ? within the range of 0<???T, but because the critical skew angle ? is restricted to be small, the contact surface pressure P changes in a low range below a certain level Po at which wear occurs in contact portions. Thus restricting the critical skew angle ?T to a small angle reduces the contact surface pressure P and suppresses heat generation and wear in the contact portions.

Abstract: Contact surface pressure P increases rather drastically in proportion to skew angle ? within the range of 0<???T, but because the critical skew ?T is restricted to be small, the contact surface pressure P changes in a low range below a certain level P0 at which wear occurs in contact portions. Thus restricting the critical skew angle ?T to a small angle reduces the contact surface pressure P and suppresses heat generation and wear in the contact portions.

Abstract: Let r be the radius of curvature of the corners of pockets of a cage, and Lw be the length of cylindrical rollers. They are set such that the relation r/Lw≧0.1 holds. Further, the relation r/k1≦1 holds, where k1 is the minimum dimension on the inner diameter side of the annulus of the cage.

Abstract: A double-tuned circuit is provided of the type comprising a primary tuning circuit including first and second resonance coils connected in series and a first switching diode interposed between the connection point of the first and second resonance coils and the ground, and a secondary tuning circuit including third and fourth resonance coils connected in series and inductive-coupled with the first and second resonance coils, respectively, and a second switching diode interposed between the connection point of the third and fourth resonance coils and the ground, wherein band switching is preformed by turning on/off both the first and second switching diodes, which is characterized in that a bias voltage for turning on the first and second switching diodes is supplied to one of the switching diodes and through a conductive wire inductive-coupled with a sintered magnetic material to the other of the switching diodes, whereby an enlargement of the bandwidth and degradation of the flatness of the passband characte