Ntn Corporation

Hiromitsu Kondo

Michiyoshi Ishimaru

Hideto Torisawa

Norihide Sato

Masahiro Nobutomo

Hiroshi Yamada

Takahiro Mizutani

Tasuku Sato

Tokumasa Nakamura

Akihiko Tomiya

A rolling bearing provided with measures to suppress a rise in temperature. The rolling bearing comprises inner and outer races, a plurality of rolling elements interposed between the inner and outer races, and a cage for retaining the rolling elements . On the use conditions that the direction of load is stationary to the outer/inner race and rotational with respect to the inner/outer race of the two races, the cage is guided for rotation with outer/inner regions of its pocket surfaces in contact with the rolling elements . It is also intended to facilitate satisfactory lubrication by means of grease and to enhance the durability and life of the bearing. For that purpose, a bearing incorporated into a main motor is arranged with both end faces adjoining end members and that have grease pockets and formed therein, respectively. The bearing includes an outer race whose bore surfaces and on its ribs and are flush with the inner peripheries and of the grease pockets and in the end members and , respectively.

Rolling bearing and bearing apparatus

A ball screw for a vacuum apparatus which includes a screw shaft having a spiral inner raceway formed on an outer peripheral surface thereof, a ball nut having a spiral outer raceway formed on an inner peripheral surface thereof, a plurality of balls disposed in a spiral space defined between the inner raceway and the outer raceway, and circulating members connecting ends of the spiral space to each other to define a continuous ball circulating passage. The plurality of balls are first balls formed of high polymer material containing polytetrafluoroethylene as a main component and second balls formed of either a metallic material or a ceramic material. The first balls circulate through the circulating passage together with the second balls. The second balls have lubricating films of crystalline polytetrafluoroethylene formed on the surface thereof.

Ball screw for vacuum apparatus

A linear ball bushing comprises a cylindrical retainer (1) having a number of pockets (1a), a number of balls (2) received in the pockets (1a), respectively, and a retaining sleeve (3) having a number of retaining holes (3a) corresponding to the pockets (1a) in the retainer (1) center (O3) of the retaining hole (3a) being offset by a distance (S) from center O1 of the pocket (1a) axially of the retainer so that a portion of peripheral edge of the retaining hole overhanging the pocket (1a), thereby preventing the balls (2) from dropping out of the pockets (1a).

Linear ball bushing

The outer ring 3 is formed of COPNA resin. The inner ring 1 and balls 4 are formed of martensitic stainless steel SUS440C or the like, and the retainer 5 is formed of SUS304 or the like.

Rolling contact bearing

The raceway surfaces of the inner and outer rings 1 and 2 and the surfaces of the rolling elements 3 are formed with lubricating films 1a, 2a and 3a of polytetrafluoroethylene having average molecular weight of not more than 5000 {PTFE (A)}. PTFE heretofore used for rolling bearings is a polymer having average molecular weight of more than 1.times.10.sup.5 mostly 1.times.10.sup.6 -1.times.10.sup.7, but PTFE(A) is very low in shear strength and soft as compared with PTFE polymer.

Growing community of inventors

Kuwana, Japan

Hiromitsu Kondo