Ntn Corporation

Masatsugu Mori

Yuushi Onda

Takuji Kobayashi

Yoshinobu Akamatsu

Mamoru Mizutani

Kenji Tamada

Yasuyoshi Hayashi

Sun-Woo Lee

Masato Yoshino

Kenji Hibi

Kikuo Fukada

Hiroshi Takiuchi

Mineo Koyama

Keiichi Ueda

Futoshi Kosugi

Yohei Yamamoto

Yoshimi Ohta

A bearing device has rolling bearings each having an inner ring mounted on a main shaft and an outer ring; an inner ring spacer interposed between the inner rings of the neighboring rolling bearings and mounted on the main shaft; an outer ring spacer interposed between the outer rings of the neighboring rolling bearings; and a cooling structure. The cooling structure includes a nozzle provided in the outer ring spacer to supply a cooling fluid to the rolling bearings by blowing the cooling fluid to an outer peripheral surface of the inner ring spacer. The nozzle has a discharge port side that is inclined forwardly with respect to a direction of rotation of the main shaft. The outer peripheral surface of the inner ring spacer is shaped to guide the cooling fluid, discharged from the nozzle, towards the neighboring rolling bearings on both sides.

Cooling structure for bearing device

A bearing device includes a rolling bearing having an outer ring and an inner ring, an outer ring spacer disposed adjacent to the outer ring, and an inner spacer disposed adjacent the inner ring. The outer ring and the outer ring spacer are fitted to a housing, and the inner ring and the inner ring spacer are fitted to a rotary shaft. The outer ring spacer is provided with a nozzle, which is configured to inject a cooling fluid (R) toward an outer circumferential surface of the inner ring, and is inclined so that an injection port thereof is inclined forwardly in a rotation direction of the inner ring. An inclination angle &#x3b1; of the nozzle with respect to an axial direction is set to a value within a range from 50&#xb0; to 90&#xb0;.

A bearing device includes an outer ring spacer and an inner ring spacer, which are interposed between outer rings of a plurality of axially juxtaposed rolling bearings and inner rings of such rolling bearings, respectively. The outer ring and the outer ring spacer are disposed within a housing while the inner ring and the inner ring spacer are mounted on a main shaft. A cooling structure including a nozzle is provided in the outer ring spacer for blowing a cooling fluid to an outer peripheral surface of the inner ring spacer to thereby supply the cooling fluid to the rolling bearing. The nozzle is provided with its discharge port side inclined forwardly with respect to the direction of rotation of the main shaft.

A rolling bearing device includes a rolling bearing unit having rolling elements retained by an annular retainer and intervening between raceways of inner and outer rings, and a nozzle member provided proximate to the outer ring. The nozzle member is provided with an annular collar portion inserted in a bearing space delimited between the inner ring and the outer ring and having a nozzle hole. This collar portion has an outer diametric surface in the form of a retainer guide surface, and an inner diametric surface of the retainer is guided by this retainer guide surface.

Rolling bearing device

A rolling bearing assembly has an inner race, an outer race and a plurality of rolling elements interposed between respective raceway surfaces of the inner and outer races. A stationary raceway member, which is one of the inner and outer races that are a raceway member and which is non-rotatable, is provided with a stepped face continued with the corresponding raceway surface and located in a direction away from the rolling elements, and is also provided with a gap defining piece having a tip held in face-to-face relation to the stepped face with a gap intervening between it and the stepped face and defining a flow path between a peripheral wall thereof and the stationary raceway member; there being provided a grease reservoir communicated with the flow path.

Rolling bearing

To provide a rolling bearing assembly, in which a grease filled within the bearing assembly is utilized to achieve a high speed feature, a long life and a maintenance-free and a lubricant oil can be stably supplied from a minute gap, a stepped face continued from the raceway surface is provided in a stationary raceway ring unit of an inner and outer ring units in a direction away from rolling elements. A gap forming piece having a free end confronting the stepped face is provided to define therebetween a flow passage and a grease reservoir communicated with the flow passage. The rolling bearing assembly is so designed that a heat cycle can be induced in the grease reservoir and, base oil of the grease can be urged to flow out from the gap by the effect of a pressure variation caused by the temperature rise.

A lubricating device for a rolling bearing includes a lubricating oil introduction member () that has a discharge opening () opened to a circumferential groove () provided in an end face of an inner race () of a bearing (). A slope section () is provided on an outer peripheral surface of the inner race () and guides the lubricating oil in the groove () to a raceway surface () of the inner race () by centrifugal force and surface tension acting on the lubricating oil. The introduction member () is provided with a flange-like section () that overlays the slope section () with a minute gap &#x3b4; between the flange-like section () and the slope section () and that controls the flow amount of the lubricating oil flowing through the gap &#x3b4; to the raceway surface ().

Lubricating device for rolling bearing

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&#x2267;0.1 holds. Further, the relation r/k&#x2266;1 holds, where kis the minimum dimension on the inner diameter side of the annulus of the cage.

Cylindrical roller bearing and cage for cylindrical roller bearings

There is provided a lubricating method for a rolling bearing assembly capable of achieving a reliable lubrication and exhibiting a stable temperature rise. The method is for supplying a lubricant oil to the rolling bearing assembly during the operation thereof, in which in order to keep the temperature of a rolling bearing assembly () within a predetermined tolerance, the amount of the lubricant oil to be supplied during the operation is automatically or manually adjusted by means of a supply adjusting unit (). Supply of the lubricant oil is performed in the form of an air/oil mixture by the use of a lubricant supply unit (). The amount of the lubricant oil supplied varies depending on the rotational speed of the rolling bearing assembly (). Change of the amount of the lubricant oil supplied depending on the rotational speed of the rolling bearing assembly () is carried out based on a result of sampling of data showing increase in temperature of the rolling bearing assembly () depending on the rotational speed thereof under a plurality of different lubricating conditions in which a different amount of the lubricant oil to be supplied is employed.

Method of and device for lubricating rolling bearings

A spindle unit which can offset any displacement of the spindle due to thermal expansion and which can adjust the preload on the bearings according to the revolving speed of the spindle. Between the outer casing and the spindle are provided a high-rigidity elastic member and a pressure chamber connected to an oil pressure control valve. A displacement sensor provided at the end of the spindle and a tachometer are connected to the pressure control valve. As the revolving speed of the spindle increases, oil pressure is introduced into the pressure chamber to reduce the preload. By reducing the preload, the spindle moves axially, thus offsetting its displacement due to thermal expansion.

Growing community of inventors

Kuwana, Japan

Masatsugu Mori