Abstract: A drive unit has improved precision and requires fewer manufacturing steps than the prior art. The drive unit comprises a base plate 1 having a predetermined shape in cross-section so as to form a pair of frame portions 2 in its opposite sides. The plate 1 is made of metal, formed by using an extrusion process, and provided with: a concave portion 4 with a central hole 3a through which a motor M is mounted on the plate 1; and, a mounting hole 3c through which a swing arm is mounted on the plate 1. The motor M has its spindle 5 mounted in the central hole 3a of the plate 1 in an insertion manner. The swing arm 6 has its base portion supported by a pivot 8 through a pair of ball bearings 7. The pivot 8 is mounted on the plate 1 through the mounting hole 3c in an insertion manner.

Abstract: A single-piece outer race ring 3, a sleeve-like spacer 11, a plurality of first balls 4, a conventional ball bearing unit 7, a stepped-diameter shaft 1 and the like are assembled into a compound bearing assembly by a bearing maker with high accuracy to enable a user to be free from a cumbersome assembling work of rotating portions or cylindrical rotary shaft and its bearing means of a computer and its peripheral devices. In use, the compound bearing assembly is coaxially mounted in the cylindrical rotary shaft and the like at the user's end to rotatably support the cylindrical rotary shaft and the like in the computer and its peripheral devices.

Abstract: A magnetic disk unit of the present invention has a construction in which: a rotor, on which a magnetic disk is loaded, is integrally formed with a sleeve portion of a ball bearing unit, or with a spindle of a spindle motor for driving the disk, or with an inner or an outer race of the ball bearing unit in a disk drive unit of the magnetic disk unit, so that: alignment operations of the rotor with the ball bearing unit are eliminated in assembling operations of the magnetic disk unit; and, the rotor is free from radial vibrations to improve the disk in recording density and reliability, whereby the number of parts of the magnetic disk unit and the number of assembling operation or steps of the magnetic disk unit are reduced, which leads to reduction of the manufacturing cost of the magnetic disk unit.

Abstract: The invention permits stacking of seals without possibility of the sticking of their synthetic rubber seal members to one another. Moreover, when assembling the seals to produce anti-friction bearings, the invention permits storing the seals as a stack in a stocker of an automatic assembler and, unlike the case of using silicon or like prior art anti-sticking material, substantially eliminates generation of fine particles or the like adversely affecting precision apparatuses and deteriorating the reliability thereof. In an anti-friction bearing comprising an inner ring (1), an outer ring (2), and rolling elements (3) provided between the inner and outer rings, a side gap between the inner and outer rings is closed by seals (4) of the invention, which each include a synthetic rubber seal member (6) and a surface active material (7) coated thereon.

Abstract: A compound ball bearing comprises a bearing assembly including a spindle 1, a sleeve 2 surrounding the spindle 1, and an inner ring 6 fitted on the spindle or an outer ring fitted in the sleeve, and balls 5, 9 provided between the spindle 1 and the sleeve 2, between the spindle and outer ring or between the inner ring 6 and sleeve 2. A base 16 of a motor is formed as a one-piece unit with the spindle. The vibration accuracy of the spindle 1 can be improved.

Abstract: A compound ball bearing type pulley comprises a bearing assembly including a spindle 1, a sleeve 2 surrounding the spindle 1 with outer flanges 22a, 22b formed on upper and lower ends of the sleeve and an inner ring fitted on the spindle. Balls 5, 9 are provided and between the spindle 1 and sleeve 2, between the inner ring 6 and sleeve 2. Conventional outer rings are not necessary and the outer diameter of the pulley can be made smaller.

Abstract: A compound bearing assembly for a swing arm of a hard disc drive is disclosed, which comprises a stepped shaft 1 having a large-diameter portion and a small-diameter portion 1b, the large-diameter portion 1a having an inner raceway groove 2a directly formed in the outer periphery, a distinct-component outer race ring 3 disposed around the large-diameter portion 1a and having an outer raceway groove 2b formed in the inner periphery, a plurality of balls provided between the inner and outer raceway grooves 2a and 2b, a ball bearing unit 5 having an inner and an outer race ring 5a and 5b and a plurality of balls 6 provided therebetween, the inner race ring 5a being fitted on the small-diameter portion 1b of the stepped shaft, and a sleeve-like spacer 1 between the distinct-component outer race ring 3 and the outer race ring 5b of the ball bearing unit 5 and having opposite end small-diameter portions, on which the outer race rings 3 and 5b are fitted, respectively.

Abstract: A single-piece outer race ring 3, a sleeve-like spacer 11, a plurality of first balls 4, a conventional ball bearing unit 7, a stepped-diameter shaft 1 and the like are assembled into a compound bearing assembly by a bearing maker with high accuracy to enable a user to be free from a cumbersome assembling work of rotating portions or cylindrical rotary shaft and its bearing means of a computer and its peripheral devices. In use, the compound bearing assembly is coaxially mounted in the cylindrical rotary shaft and the like at the user's end to rotatably support the cylindrical rotary shaft and the like in the computer and its peripheral devices.

Abstract: A double row bearing apparatus comprises a stepped shaft having larger and smaller diameter shaft portions, an inner race way groove provided on the outer peripheral surface of the larger diameter portion, balls interposed between the inner race way groove and an outer race way groove formed on an inner surface of an outer race surrounding the larger diameter portion, and a ball bearing including inner and outer races and balls interposed therebetween, wherein the ball bearing is fitted removably at its inner race over the smaller diameter portion of the stepped shaft.

Abstract: A miniature inner rotor type of rotary machine having a high durability and anti-vibration property, includes a double row bearing apparatus (2) and comprises a stepped shaft (10). The shaft has a larger diameter shaft portion (10a) around which an inner rolling contact recess (11a) is formed and a reduced diameter shaft portion (10b), a first outer race (12), first balls (13) interposed between the large diameter shaft portion and the first outer race, and a ball bearing (17) comprising an inner race (14) to be fitted over the reduced diameter shaft portion (10b), a second outer race (15), and second balls (16) to be interposed between the inner race (14) and the second outer race (15).

Abstract: To permit stacking of seals without possibility of the stacking of their synthetic rubber seal members to one another, permit, when assembling the seals to produce anti-friction bearings, storing the seals as a stack in a stocker of an automatic assembler and, unlike the case of using silicon or like prior art anti-sticking material, substantially eliminate generation of fine particles or the like adversely affecting precision apparatuses and deteriorating the reliability thereof. In an anti-friction bearing comprising an inner ring (1), an outer ring (2), and rolling elements (3) provided between the inner and outer rings, the side gap between the inner and outer rings is closed by seals (4), which each include a synthetic rubber seal member (6) and a surface active material (7) coated thereon.

Abstract: The object of the present invention is to provide a vibration-proof miniature motor of high endurance including a compact enough double row bearing apparatus having a shaft of sufficient mechanical rigidity.

Abstract: To provide a stainless steel for anti-friction bearings, which is obtained by making its eutectic carbide contents finer in particle diameter and suppressing the generation of non-metallic substances to an extremely low level, thus having a homogenious and dense structure and permitting highly accurate machining. The provided stainless steel is composed of 0.60 to 0.75% of carbon, 10.5 to 13.5% of chromium, 1.0% or below of silicon and 0.3 to 0.8% of manganese, % being by weight, the remainder of the composition being iron and inevitably introduced impurities, has a hardness of HRC 58 or above, contains eutectic carbide particles of 10 .mu.m and below in diameter, and has oxygen and titanium concentrations each of 10 ppm or below.

Abstract: The screw comprises a circular thread portion 2a formed in a base portion of the screw, in which a helical thread is formed at the same depth and at the same crest angle; a special non-circular thread portion 2b which follows the portion 2a and has its thread depth gradually vary so as to assume a polygonal shape in cross section and permit the crest portion of thread to reach its highest points A-J in a turn of the thread, the highest points A-J being equal in thread depth and crest angle to the thread of the portion 2a; the portion 2b has its crest angle gradually increase as the thread moves from the highest points A-J to its lowest points along the length of the thread; and, lines connecting axially adjacent ones of the highest points A-J are tilted from the axis of the screw at a predetermined angle so that the portion 2b assumes a twisted polygonal prism-like shape as a whole.

Abstract: In the motor, the compound bearing assembly is assembled from stepped-diameter shaft 1, sleeve-like outer race ring 5, first balls 4, second balls 8a, and inner race ring 7 a, and has a base-end portion of large-diameter portion la of the stepped-diameter shaft 1 fixedly mounted on a base member 10 of the motor at right angles to permit the stepped-diameter shaft 1 to extend upward. After that, the compound bearing assembly is fixedly mounted in a central hub portion 12 of a rotor 11 of the motor in an insertion manner to complete the motor provided with the compound bearing assembly. Consequently, it is easy for the motor manufacturer to assemble his product or motor with the compound bearing assembly at high accuracy. (See FIG.

Abstract: A compound ball bearing comprises a bearing body including a spindle 1, a sleeve 2 surrounding the spindle 1, and an inner ring fitted on the spindle or an outer ring fitted in the sleeve, and balls 5, 9 provided between the spindle 1 and sleeve 2, between the spindle and outer ring or between the inner ring 6 and sleeve 2. A motor component such as a hub 11 for the rotor, a flange for the motor base or a yoke yolder is molded as a one-piece molding with the sleeve, spindle or inner ring. The inner or outer ring can be secured in a proper position by facilitating its pre-loading, and the vibration accuracy of the spindle can be improved.

Abstract: A hard disc drive is disclosed, which comprises a compound bearing assembly including a stepped shaft 1 having a large-diameter portion 1a and a small-diameter portion 1b, the large-diameter portion 1a having an inner raceway groove 2a formed in the outer periphery, an outer race ring 3 surrounding the large-diameter portion 1a and having an outer raceway groove 2b, a plurality of balls 4 provided between the inner and outer raceway grooves 2a and 2b, a ball bearing unit 5 having an inner and an outer race ring 5a and 5b and a plurality of balls 6 provided therebetween, the inner race ring 5a being fitted on the small-diameter portion 1b, and a sleeve-like spacer 7 surrounding the stepped shaft 1and having opposite end small-diameter portions, the outer race ring 3 and the outer race ring 5b of the ball bearing unit 5 being fitted on the opposite end small-diameter portions, respectively.

Abstract: A hard disc drive is disclosed, which comprises a compound bearing assembly including stepped shaft 1 having a large-diameter portion 1a and a small-diameter portion 1b, a plurality of balls 4 provided between an outer raceway groove 2b formed in the inner periphery of an outer race ring 3 and an inner raceway groove 2a directly formed in the outer periphery of the large-diameter portion 1a, and a plurality of balls 8a provided between an inner raceway groove 6a formed in the outer periphery of an inner race ring 7a fitted on the small-diameter portion 1b of the stepped shaft 1 and an outer raceway groove 6b directly formed in the inner periphery of a portion of a sleeve-like outer race ring 5 adjacent an end thereof. A hub 12 of a rotor 11 of a motor of the hard disc drive is fitted on the compound bearing assembly.

Abstract: A compound ball bearing for swing arm unit acomprises a bearing assembly including a spindle 1, a sleeve 2 surrounding the spindle 1, an inner ring fitted on the spindle, with balls 5 and 9 being provided between the spindle 1 and sleeve 2, between the inner ring 6 and sleeve 2. A swing arm 22 is mounted on the sleeve 2. Conventional outer rings are not necessary and the outer diameter of the sleeve can be made smaller than conventional devices.

Abstract: A first outer race ring 3, a sleeve-like spacer 7, a plurality of first balls 4, a conventional ball bearing unit 5 and a stepped-diameter shaft 1 are assembled into a compound bearing assembly by a bearing maker to enable a user or motor manufacturer to be free from a cumbersome assembling work of the bearing assembly. Consequently, upon receipt of the bearing assembly, the motor manufacturer may immediately mount the bearing assembly in a central hub portion of a rotor of the motor in an insertion manner to complete his product, i.e., high-performance motor.