Abstract: A bearing assembly includes a housing having an annular recess, an inner ring disposed within the recess and having an inner raceway, and an outer ring disposed about the inner ring and within the housing recess and having an outer raceway. At least one intermediate ring is disposed radially between the inner ring and the outer ring and has an inner intermediate raceway and an outer intermediate raceway. A first set of rolling elements is disposed between the inner ring and the at least one intermediate ring and a second set of rolling elements is disposed between the outer ring and the at least one intermediate ring. A biasing member(s) is configured to bias the inner ring or the outer ring axially toward the other one of inner ring and the bearing outer ring so as to establish a preload within the two sets of rolling elements.

Abstract: Only an outer spacer (33) is cooled by an outer spacer cooling structure, thereby causing a temperature difference between an inner spacer (32) and the outer spacer (33). According to this temperature difference, an inner ring (37) of a bearing (31) is displaced relatively to an outer ring (38) in a direction in which a preload inside the bearing (31) decreases.

Abstract: A gas turbine engine, has: a case extending circumferentially around a central axis of the gas turbine engine; a boss protruding from the case away from the central axis, the boss defining an internal passage; a tubular member received within the internal passage of the boss and secured to the boss; an annular gap extending all around the tubular member and located between the tubular member and the boss; and a fitting hydraulically connecting a fluid source to the tubular member, the fitting having a portion received within the tubular member and encircled by both of the annular gap and the tubular member, the fitting sealingly engaged to the tubular member.

Abstract: An assembly with a housing, a bearing, which is received in a bearing bore formed in the housing, and an annular compensation member. The housing and the compensation member are formed of materials having a larger coefficient of linear thermal expansion than a material from which the outer bearing race is formed. The compensation member is fixedly coupled to the housing and mounted about an outer bearing race of the bearing. The compensation member is configured to grow in a radial direction into contact with an inside circumferential surface of the outer bearing race when a temperature of the assembly increases from a first predetermined temperature to a second predetermined temperature.

Abstract: A device for cooling a rolling bearing (112), in particular for a turbine engine. The device includes an annular bearing support (124) having a substantially cylindrical wall (134) of which an inner peripheral face (136) is configured to surround an outer ring (122) of the rolling bearing. The wall is able to dispense cooling fluid via a fluidic network for circulating the fluid and for supplying annular cooling grooves (144) of the bearing with fluid.

Abstract: A control method configured to control the preload of a bearing includes estimating the preload on the bearing; comparing the estimated preload with a predetermined acceptance range; and correcting the preload on the bearing when the preload is outside the acceptance range.

Abstract: A plain bearing composite material (2), has a supporting layer (4), optionally a porous substrate layer (6), in particular made of bronze, and a sliding layer material (8) made of a matrix-forming thermoplastic plastic material (10) and fillers (12) accommodated therein, wherein the sliding layer material (8) has a fraction of 1-40 vol % wollastonite as a mineral filler (14) and at least half of the wollastonite is present with needle-shaped modification.

Abstract: A bearing unit, for supporting a pinion shaft having at one side a pinion head, includes a taper roller bearing and an angular ball bearing, the bearings having a common outer race ring and separate inner race rings. The inner race rings are spaced apart a distance along the pinion shaft, and the taper roller bearing has a contact angle ? from 15° to 20° for absorbing mainly the radial force component of the tooth force at the pinion head, and the one-row angular ball bearing has a contact angle ? of between 35° and 45° for absorbing mainly the axial force coming from the gear mesh and that induced by the taper roller bearing.

Abstract: A device with a rotating element includes a housing body formed from a light alloy, wherein the housing body has a housing body thermal expansion coefficient, a bearing liner formed from a liner material disposed within the housing body, wherein the bearing liner has a bearing liner thermal expansion coefficient, and a bearing to support the rotating element with an outer race, wherein the bearing has a bearing thermal expansion coefficient, the outer race is press fit within the bearing liner, and the bearing liner thermal expansion coefficient is lower than the bearing thermal expansion coefficient.

Abstract: An outer ring for a rolling-element bearing includes a first region having a first diameter on an outer surface of the outer ring, a second region on the outer surface of the outer ring, the second region having a second diameter larger than the first diameter, a circumferential groove at a boundary between the first region and the second region, and a filler in the groove. The filler is configured such that a temperature compensation ring can be mounted to the outer ring at the first region so that it abuts on an axial end of the second region, the temperature compensation ring having an inner diameter, at least in the region which is disposed over the groove in the radial direction, that corresponds to the outer diameter of the first region.

Abstract: A spacer in a rotary electric machine according to the present invention complements by thermal expansion a gap between a bearing housing portion and an outer ring of an outboard bearing that arises due to differences in thermal expansion between the bearing housing portion and the outer ring of the outboard bearing that result from heat generated during driving, and a flat portion is disposed on an inner circumference of the spacer at least one position around a circumference, the flat portion being formed so that press an outer circumferential surface of the outer ring of the bearing constantly.

Abstract: The present invention provides an AC generator for a vehicle, in which a resin case (26) includes convex portions (33) formed on an outer circumferential surface of the resin case (26) so as to extend in an axial direction of the resin case (26) to be brought into pressure-contact with an inner circumferential wall surface of a counter drive-side bearing housing portion (24), and convex portions (34) formed on an inner circumferential surface of the resin case (26) so as to be opposed to the convex portions (33). The concave portions (34) allow displacement of the convex portions (33) in a radially inward direction of the resin case (26). By an elastic force generated by the displacement of the convex portions (33), the resin case (26) is integrated with the counter drive-side bearing housing portion (24).

Abstract: A bearing system, which may be used particularly for hot-air valves, comprising a fixed roller bearing and a floating roller bearing is provided wherein a spherical shape of the inner raceways of each bearing, a spherical shape of the rollers of each bearing, a spherical shape of the fixed bearing's outer raceway and a cylindrical shape of the floating bearing's outer raceway may enable the bearing system to compensate for all mechanically and thermally induced deflections and linear expansion of a valve's shaft relative to the valve's housing, thus reducing a risk of shortening the useful lifetime of either the fixed roller bearing or the floating roller bearing.

Abstract: A thermal compensation element which has an inner ring, an outer ring, and a washer. The washer is arranged within the inner ring and the outer ring is mounted over the inner ring, encapsulating the washer, which can be a split wave spring. The inner ring and the outer ring each have retention features to ensure they are retained relative to each other. The thermal compensation, which is positioned between a housing or a shaft, can account for variations in loading and/or temperature that may occur to a bearing and a shaft system when the shaft and an associated component are made of different materials and have different coefficients of thermal expansion by ensuring a proper axial preload is maintained on the bearing.

Abstract: A system for cooling a transmission of a hover-capable aircraft, the system having: a stator; a heat exchanger connectable thermally to the transmission; a fan for creating a current of a first heat-carrying fluid from the heat exchanger to the fan itself, to remove heat from the heat exchanger; a rotary member, which rotates about an axis to rotate an impeller of the fan about the axis; and a bearing supporting the rotary member for rotation about the axis; the system also having cooling means for cooling the bearing, and in turn having conducting means for conducting a current of a second heat-carrying fluid along a path from an outside environment, external to the bearing, to and to cool the bearing itself.

Abstract: A chain wheel arrangement for chain drives of mining machines, with a chain wheel shaft, with a chain wheel, with bearing shells receiving bearings for the chain wheel shaft, with a chain wheel-side sliding ring seal and with a bearing-side sliding ring seal. In order to improve the service life of the chain wheel arrangement, at least one of the bearings, preferably that of the movable bearing system, is arranged in a bearing bush which is arranged between the bearing shell and outer bearing ring and received in the bearing shell in an axially displaceable manner. The additional bearing bush allows the necessary gap between the rotating parts and the non-co-rotating, bearing shell-side parts to remain substantially constant and to this extent to become independent of the bearing play of the respective bearings.

Abstract: In an electric auxiliary power steering system a rotating component driven by a servomotor includes a rolling bearing for axially and radially supporting the component. At least one inner race or one outer race of the rolling bearing is split into two race parts along a parting plane that runs approximately perpendicular to a longitudinal axis of the rotating component. The two parts are axially spring-loaded against one another. The ends of the race parts facing one another are aligned at an angle from the radial outer side thereof to the radial inner side thereof. The element with a conical cross section and having a higher coefficient of thermal expansion than the coefficient of thermal expansion of the outer ring or the inner ring is placed between the ends so that when heat is introduced, the element expands and the race parts are able to move toward one another. When the element cools the race parts can move apart axially.

Abstract: A bearing is provided that includes a first ring having at least one first raceway defined by a radially inward facing surface of the first ring; and a second ring concentric with the first ring and having at least one second raceway defined by a radially outward facing surface of the second ring. The bearing includes a plurality of rolling elements disposed between the first and second rings. The rolling elements rollingly engage the first and second raceways. The first ring has a first gap therein and the second ring has a second gap therein. One or more race reliefs extend into the first raceway and/or the second raceway.

Abstract: A rolling bearing arrangement, which has at least one angular contact rolling bearing arranged within a housing and at least one lash compensation element that is supported axially in one direction on the housing and is capable of being biased against a bearing ring of the angular contact rolling bearing with the bearing ring being axially movable relative to the housing, and a U-shaped ring which has two radially opposing legs directed in an axial direction. The U-shaped ring rendering the lash compensation element radially immovable by positive engagement while being guided on the bearing ring of the angular contact rolling bearing for axial displacement relative to the bearing ring, and the axial section of the bearing ring projecting axially between the legs of the ring profile.

Abstract: A rolling bearing, which has at least one bearing ring and at least one lash compensation element possessing temperature-dependent extendibility arranged on the bearing ring. The rolling bearing has ring profile, which at least partially surrounds the lash compensation clement. The ring profile has at least one hollow cylindrical section oriented axially parallel to an axis of rotation of the rolling bearing and at least one radially oriented disk section. Also, at least one slit is formed in the ring profile.

Abstract: A rolling bearing which has at least one lash compensation element possessing temperature-dependent extendably arranged on one bearing ring of the rolling bearing. The lash compensation element is surrounded at least partially by an angular ring profile. The angular ring profile has at least one leg directed axially parallel to an axis of rotation of the angular contact roller bearing. The ring profile is retained by the leg by positive axial engagement for limited axial movement on the bearing ring such that the lash compensation element is supported by the ring profile by positive engagement so as to be radially immovable on the bearing ring while being guided for axial movement on the bearing ring.

Abstract: An example bearing support arrangement includes a support and a race of bearing assembly. A flange extends radially from the race. The flange and the support are configured to be held against a housing to secure the bearing assembly relative to the housing.

Abstract: A ball bearing having external surfaces coated with ceramic materials is provided. The raceways of the ball bearing may advantageously be formed of metal such as stainless steel. The ceramic coating acts as an insulator increasing the resistance of the ball bearing to heat within the ball bearing environment. The balls within the raceway of the ball bearing may advantageously be coated with a lubricant to decrease friction in the ball bearing because the insulating ceramic coating prevents the environmental heat from causing the degradation of the lubricant.

Abstract: An electric motor having a rotation shaft includes a motor housing into which the electric motor is accommodated, at least one pair of rolling bearings positioned in the motor housing and rotatably supporting both ends of the rotation shaft, and a displacement restriction member provided inside the motor housing and restricting a displacement of the rolling bearing in an axial direction of the rolling bearing. Each rolling bearing includes an inner race, an outer race, and rolling elements rotatably supported between the inner race and the outer race. The inner race is press fitted without any gaps onto an outer peripheral surface of the rotation shaft, and the outer race is press fitted without any gaps into a bearing attachment portion provided inside the motor housing.

Abstract: The invention is directed to a roller bearing arrangement comprising two rings arranged mutually concentrically and at least regionally inside each other, and comprising a gap between these rings, so that they are rotatable in opposite directions about an imaginary axis at the center of the rings and approximately perpendicular to the ring plane, wherein disposed in the region of a gap portion situated between the rings and surrounding the axis of rotation at an approximately constant radius is at least one raceway for at least one row of rollers, each having a rotationally symmetrical shape and rolling displacingly between the rings, each of which rollers, when the rings and the rollers are at the same temperature, has at least one point or region of contact with the raceway portions on each of the two rings, so that the radial and/or axial clearance between the two rings is equal to zero or at least is negligibly small; and comprising a mechanism for compensating for temperature-induced radial changes in th

Abstract: A thermal compensation element which has an inner ring, an outer ring, and a washer. The washer is arranged within the inner ring and the outer ring is mounted over the inner ring, encapsulating the washer, which can be a split wave spring. The inner ring and the outer ring each have retention features to ensure they are retained relative to each other. The thermal compensation, which is positioned between a housing or a shaft, can account for variations in loading and/or temperature that may occur to a bearing and a shaft system when the shaft and an associated component are made of different materials and have different coefficients of thermal expansion by ensuring a proper axial preload is maintained on the bearing.

Abstract: A rolling bearing arrangement, which has at least one angular contact rolling bearing arranged within a housing and at least one lash compensation element that is supported axially in one direction on the housing and is capable of being biased against a bearing ring of the angular contact rolling bearing with the bearing ring being axially movable relative to the housing, and a U-shaped ring which has two radially opposing legs directed in an axial direction. The U-shaped ring rendering the lash compensation element radially immovable by positive engagement while being guided on the bearing ring of the angular contact rolling bearing for axial displacement relative to the bearing ring, and the axial section of the bearing ring projecting axially between the legs of the ring profile.

Abstract: A rolling bearing which has at least one lash compensation element possessing temperature-dependent extendably arranged on one bearing ring of the rolling bearing. The lash compensation element is surrounded at least partially by an angular ring profile. The angular ring profile has at least one leg directed axially parallel to an axis of rotation of the angular contact roller bearing. The ring profile is retained by the leg by positive axial engagement for limited axial movement on the bearing ring such that the lash compensation element is supported by the ring profile by positive engagement so as to be radially immovable on the bearing ring while being guided for axial movement on the bearing ring.

Abstract: A power transmitting device includes a front housing member, an inner shaft, and a main clutch that selectively permits and shuts off transmission of torque between the front housing member and the inner shaft. The power transmitting device is rotatably supported by a bearing arranged outside the front housing member. An intermediate member having a thermal expansion coefficient lower than the thermal expansion coefficient of the front housing member is arranged between the front housing member and the bearing.

Abstract: Various embodiments relate to a bearing assembly including a support ring configured to reduce thermal warping under operational temperature conditions, a bearing apparatus that may utilize such a thrust-bearing assembly, and applications that incorporate the disclosed bearing apparatuses such as downhole motors in subterranean drilling systems, directional drilling systems, and many other apparatuses. In an embodiment, a bearing assembly includes a plurality of superhard bearing elements distributed circumferentially about an axis. The thrust-bearing assembly further includes a support ring having the plurality of superhard bearing elements mounted thereto.

Abstract: A floating bearing has a rotating, rotationally symmetric machine part (6), with an outer ring (10), which is non-rotatably supported in an intermediate bearing (1) that is located in the installation space of a housing (3, 8). An inner ring (11) is non-rotatably connected with the rotating machine part (6). A locking mechanism inhibits a relative motion in the circumferential direction between the housing (3, 8) and intermediate bearing (1) and permits a relative motion between the housing (3, 8) and intermediate bearing (1) along the rotation axis of the machine part (6).

Abstract: A drive gear includes a plurality of internal radial channels extending between the axial bore and the periphery of the gear, and an axial bore includes a lubricant distribution structure therein to provide lubrication where the teeth of the drive gear mesh with the teeth of a gear driven by the drive gear.

Abstract: A rotary bearing system that supports a shaft for rotating machinery in a housing comprises: at least one stationary rotary bearing mounted in the housing for supporting a respective journal of the shaft in a desired axial and radial alignment; at least one slidable rotary bearing, with an outer surface mounted within a respective inner support surface of the housing to form a respective linear bearing such that each slidable bearing may slide axially along the inner support surface of the housing, for supporting another respective journal of the shaft with the desired radial alignment; and at least one layer of a crystalline material that exhibits a high degree of basal cleavage bonded to at least one of the linear bearing surfaces; wherein each layer of crystalline material allows each slidable rotary bearing to slide axially along each respective linear bearing to compensate for differences in the coefficient of expansion of the housing and the shaft so as to prevent the bearing system from binding due to

Abstract: Bearing systems for high speed rotating shafts, such as turbocharger shafts, include a first ball bearing in one end of an elongated cylinder capable of carrying axial thrust in both directions and a second ball bearing in the opposite end of the elongated cylinder with its outer race slideably mounted in the cylinder against the biasing force of a preload spring. The second ball bearing is free to move axially with the shaft upon axial expansion of the shaft when exposed to high temperature. The inner races of the ball bearings are clamped to and rotate with the shaft as part of the rotating assembly.

Abstract: The invention relates to a radial roller bearing, having an outer bearing ring and an inner bearing ring, and rolling bodies located between the rings. Some of the rollers are formed by individual hollow rollers of a shape memory alloy. The cross-section of the shape memory alloy rollers is deformed during the assembly of the radial roller bearing to fit the dimensions of the free space between the rims of the rings. The rollers are introduced into the radial roller bearing through the free space between the rims of the bearing rings. After introduction into the radial roller bearing and once they have reached a specific temperature, the rollers independently regain their original shape.

Abstract: In a bearing unit for a drive shaft mounted cantilevered in a housing by means of two rolling bearings and having a driving bevel gear wherein the drive shaft is mounted in the drive housing via a bearing bush and the bearing bush is axially supported at one end by a bearing bush support part and the rolling bearings are supported in the bearing bush spaced from the one end thereof so that, during heating, the bearing bush expands inwardly toward the driving bevel gear mounted on the shaft whereas the drive housing expands outwardly away from the driving bevel gear, the gear drive housing and the bearing bush consist of a light metal alloy and the bearing bush support part consists of an iron material.

Abstract: The anti-friction bearing has an outer bearing ring, an inner bearing ring and rolling bodies that are located between the bearing rings. The race of the outer bearing ring and the inner bearing ring are laterally delimited by two continuous rims that are formed as one piece with the races. The bearing is filled with the rolling bodies through the free space between the two rims. A partial quantity of the rolling bodies is made of a shape memory alloy, the cross-section of the bodies being deformed to fit the dimensions of the free space between the rims. After introduction into the bearing and once they have reached a specific temperature, the bodies regain their original shape.

Abstract: It is an object of the present invention to provide a cage that can be used in a cryogenic-temperature environment or a vacuum without providing the cage with a complicated construction and without performing special treatment and a bearing using the cage. A cage made of resin has an annular main body having a plurality of pocket portions radially penetrating the main body; and a plurality of pocket members, provided on the annular main body, which hold rolling elements of a rolling bearing. The main body is a molding of a first resin composition consisting of a first resin and a solid lubricant mixed therewith; and at least a rolling element-retaining surface of each of the pocket members is made of a second resin composition containing fluorocarbon resin as a main component thereof. The molding of the first resin composition has a tensile strength of not less than 30 MPa and a heat-resistant temperature of not less than 200° C. The second resin composition is a fluorocarbon resin composition.

Abstract: A bearing in which the thickness of the bottom of at least one of the inner ring and the outer ring is 50% or more of the diameter of the balls. Further, the bearing includes an outer ring having an outer diameter of 65 mm or less and balls having a diameter of 4 mm or less and has a width dimension of 45% or less of the inner diameter dimension thereof wherein the pitch diameter of the balls is closer to the outer side of the bearing than to the center of the section of the bearing. The outer side of the outer raceway grooves is tapered, and the inner side of angularly arranged outer raceway grooves is positioned closer to the central axis of the bearing than to the outer side of the outer raceway grooves.

Abstract: According to the invention, the high-speed moving bearing is embodied as an automatically-compensating movable ball bearing with several adjacent races of balls with operation-dependent radial thermal expansion of the bearing rings, the bearing rings of which are only in supporting contact with one ball race in the cold state for the high-speed movable bearing, by means of a convex embodiment of the running surfaces for the roller bodies on the inner bearing ring. With increasing thermal expansion and expansion due to centrifugal force of both bearing rings, the further ball races come sequentially into such a contact position with both bearing rings as a result of an elastic radially-flexible embodiment of both bearing rings, that the bearing rings at the operating temperature for the high-speed moving bearing are in supporting contact with all ball races.

Abstract: An x-ray target assembly is provided comprising a drive shaft and an outer shaft housing element. A primary integral duplex bearing assembly is positioned between the outer shaft housing element and the drive shaft and comprises a primary fixed outer race and a primary dual inner race comprising a first primary inner race element and a second primary race element. A plurality of primary ball elements are positioned therebetween. A secondary integral duplex bearing assembly is positioned between the outer shaft housing element and the drive shaft and comprises a secondary floating outer race comprising a single secondary race element. A secondary dual inner race is comprised of a first secondary inner race element and a second secondary race element. A plurality of secondary ball elements are positioned between the secondary floating outer race and the secondary dual inner race.

Abstract: An improved bearing system for use in high speed rotating machinery, such as a turbocharger, wherein a shaft is rotatably supported by a floating bearing cartridge having axially spaced angular contact bearings each with a set of bearing balls supported between inner and outer races. The bearing cartridge includes an inner spacer sleeve for axially spacing the inner bearing races, and a rotationally floating outer sleeve having a pair of radially inwardly open grooves for removably receiving snap-type retaining rings which engage and axially space the outer bearing races. The axial dimension of the inner spacer sleeve is elongated slightly relative to an axial dimension defined between outboard faces of the installed retaining rings, thereby slightly unloading the sets of bearing balls from their respective outer bearing races. Such slight axial unloading enhances smooth-running operation with minimal bearing wear, while accommodating transient loads during operation.

Abstract: A compound bearing apparatus including a shaft, a cylindrical outer ring member surrounding the shaft, and a plurality of balls of the first and the second rows interposed between the shaft and the outer ring member is provided. The bearing apparatus of the present invention is characterized in that: the outer ring member includes upper and lower portions and a central portion therebetween, two rows of outer raceways for the first and the second row of balls are formed on the inner peripheral surface of the upper and lower portions of the outer ring member, a squeeze ring of the same material as that used in making the outer ring member or of any other material of substantially the same factor of linear thermal expansion as that of the outer ring member is press fit around the outer periphery of the central portion of the outer ring member to elastically deform the outer ring member inwardly to form an inwardly protruding squeezed portion.

Abstract: A bearing apparatus including inner and outer rings and balls interposed therebetween, the apparatus being characterized in that it comprises: a low expansion ring press fit around the outer periphery of the outer ring, wherein the low expansion ring is made of a material with lower factor of linear thermal expansion than the outer ring material.

Abstract: An expansion turbine for low-temperature applications containing a turbine stage into which a cold gas is admitted. A turbine rotor is mounted on a shaft. Also provided is a roller support for the shaft being lubricated with a minimum amount of oil or grease. The roller support contains a roller bearing located adjacent to the turbine stage. The roller bearing is comprised of an inner bearing ring, rollers, and an outer bearing ring supported on the side of the housing. An insulating bush made of ceramic engineering material is arranged between the inner bearing ring and the shaft. The bush thermally separates the inner bearing ring from the cold shaft.

Abstract: Method and apparatus for automatically dynamically adjusting prestressed bearings of shaft are provided. The apparatus comprises a sleeve assembly having outer and inner sleeves sandwiched between the bearings. An inner diameter of outer sleeve is smaller than an outer diameter of inner sleeve. Hence, outer and inner sleeves are fitted together after cooling. Further, inner sleeve is compressed by the outer sleeve to extend axially. During rotation of shaft, the axial extension of inner sleeve is reduced because the radial expansion of outer sleeve is larger than that of inner sleeve due to an thermal expansion coefficient of outer sleeve larger than that of inner sleeve. This can reduce prestress of bearings without degrading a rigidity thereof.

Abstract: A bearing device includes a pair of bearings. One of the bearings is exposed to a higher temperature condition than the other. Each of the bearings has an outer ring, an inner ring, a plurality of rolling members disposed in a space between the outer ring and the inner ring and a pair of sealing members fixed to the outer ring. Each of the sealing members has an elastic lip in contact with an outer surface of the inner ring, and the lip of the bearing exposed to a higher temperature condition is made of a material that is more heat-resistant than the lip of the other sealing member.

Abstract: A rolling-contact bearing for a shaft journal wherein the outside diameter of the shaft journal is thermally insulated relative to the shaft through which a heat transfer medium flows. The bore of the inner race on the shaft journal is provided with a ceramic layer predominantly of zirconium oxide and a smaller among of yttrium oxide to reduce the heat transfer from the shaft journal to the rolling-contact bearing. The inner race also has lateral surfaces toward the elements securing the bearing on the shaft journal. Those lateral surfaces may be provided with a ceramic layer as well.

Abstract: A quill spindle includes a quill assembly within which a spindle assembly is rotationally mounted. The quill assembly includes a coolant flow path, and the spindle assembly includes a plurality of coolant flow paths. The quill assembly flow path and one of the plurality of spindle assembly flow paths provide cooling to bearings that allow the rotation of the spindle assembly within the quill assembly. Another of the plurality of coolant flow paths within the spindle assembly provides cooling flow to a cutting tool installed on an end of the quill spindle.

Abstract: A shaft having thermal expansion, thermal pre-load yielding and dynamic pre-load adjusting systems. The shaft is made by the zero expansion or very low expansion materials. The shaft has two bearing assemblies. Each bearing assembly has two parallel bearings. A partition ring set is disposed between them. The partition ring set is made of multiple low and negative thermal expansion materials. It includes an inner partition ring and an outer partition ring. The inner partition ring is tightly contacting with corresponding sides of inner annular seats of the bearing. The outer partition ring is disposed outside of the inner partition ring without any contact. And, the outer partition ring is tightly contacting with corresponding sides of outer annular seats of the bearings.