Abstract: Roller bearings, and struts and gas turbine engines using such bearings are provided. In this regard, a representative roller bearing for a gas turbine engine includes: a roller having a rolling surface and an end; a race having a flange and defining a raceway, the raceway terminating at the flange, the raceway being operative to receive the roller such that the rolling surface of the roller engages in rolling contact with the raceway; and a hard coating applied to the flange such that the end of the roller engages in sliding contact with the coating.

Abstract: In order to provide a circulating pump, comprising a stator, a rotor, a bearing device with a convex bearing member and at least one concave bearing shell, via which the rotor is mounted for rotation, and an impeller which is connected non-rotatably to the rotor, which has improved lubrication possibilities and/or with which any axial lifting of the impeller can be prevented in an effective manner, it is provided for a shaft element to be connected non-rotatably to the rotor and non-rotatably to the impeller and for the shaft element to be guided through the bearing member and to be rotatable relative to the bearing member.

Abstract: A cooling fan includes a fan housing (30) having a central tube (34) extending upwardly therefrom; the central tube has a bottom, annular protrusion (31). A bearing (61) is received in the central tube and mounted on the protrusion. A stator (20) is mounted around the central tube. A rotor (10) includes a shaft (18) having a free end (186) extending through the bearing and defining a notch (184) therein. A locking washer (63) engages into the notch of the shaft to limit movement of the shaft along an axial direction thereof. A balance structure (62) is arranged between the locking washer and the bearing. The balance structure is made of magnet and exerts a downwardly pulling force on the shaft to prevent the rotor from moving upwardly when the rotor is rotated.

Abstract: A highly stable and durable fan bearing structure practical for small electronic device application is disclosed to include a bearing block, which has a stepped hub defining a vertically extending axle hole and an inside annular flange inside the axle hole at a distance away from the top opening of the axle hole, a fan blade assembly, which has permanent magnets mounted in a hollow base block thereof and an axle suspending in the hollow base block and inserted into the axle hole and coupled to the inside annular flange of the stepped hub and kept in coincidence with the central axis of the axle hole, and a stator module accommodated in the hollow base block of the fan blade assembly for acting against the permanent magnets to cause rotation of the fan blade assembly upon connection of an electric current.

Abstract: A compressor rotor for a turbomachine including at least two disks on a common axis carrying blades and connected together by a tubular wall, forming a surface of revolution, and a centripetal air bleed mechanism including air passages passing through the tubular wall, together with a wall extending along the tubular wall from the through passages up to one of the disks to channel the air stream inside the tubular wall.

Abstract: An exemplary center housing rotating assembly includes a turbine wheel; a compressor wheel; a center housing (510) that includes a through bore (515), extending from a compressor end to a turbine end along a bore axis; a bearing assembly (530) positioned in the bore where the bearing assembly includes an outer race (532) that includes keyways (535, 535?) extending from an axial end, the keyways radially inset from an outer diameter of the outer race; and a plate (570) attached to the center housing where the plate includes extending keys (578, 578?), each of the keys (578, 578?) being received by a respective one of the keyways (535, 535?) to restrict rotation of the bearing assembly in the bore. Various other exemplary devices, systems, methods, etc., are also disclosed.

Abstract: A method for producing a lubricant feed in an axial bearing, wherein the lubricant feed is designed as a channel guiding lubricant from a lubricant pocket of the axial bearing, includes the following steps: preparing an initial axial bearing mold, stamping a groove in the area of the initial mold in which the channel is planned; embossing and putting through material on at least one or both sides of the groove along at least one segment of the groove; stamping the material on the side of the groove toward the groove so that the material and the groove form the channel.

Abstract: Described is a conveying device for conveying hot, vaporizing liquids, solids and gases in a common conveying flow, which conveying device also allows heating the circuit by means of power loss, masters the cavitation and the contamination of the bearings and seals, and allows a high service life.

Abstract: A bearing support that includes a body through which a bore extends and a plurality of grooves formed in a wall of the bore. Each groove extends from a first end of the bore and terminates prior to a second end of the bore. A bearing can be secured within the bearing support by injecting adhesive into one or more of the grooves.

Abstract: A compressor includes a shaft assembly including a thrust disk disposed on a main shaft and a housing having a first portion and a second portion, the first and second portions adapted to receive the shaft assembly and enclose the shaft assembly therebetween, wherein the shaft assembly is rotatably disposed within the housing, and wherein at least one of the first portion and the second portion includes a shaft assembly retention feature for receiving the thrust disk to regulate a motion of the shaft assembly.

Abstract: The invention provides a blower system of a high performance, which is constructed to have stabilized characteristics, a high efficiency, a reduced thickness and a reduced noise. A blower system according to the invention includes an impeller, a motor for rotating the impeller and having a rotor and a stator, and a bell-mouth for supplying air to an intake port in the impeller, wherein the rotor is fixed to the impeller, and the stator is fixed to the bell-mouth. A gap between the impeller and the bell-mouth is composed of a gap between the rotor and the stator of the motor. Alternatively, the rotor is fixed to the impeller, and the stator is fixed to a fitting for mounting a housing of the blower system or the blower system.

Abstract: A rotor assembly for a gas turbine engine is provided. The rotor assembly includes a compressor rotor, a compressor stator coupled upstream from the compressor rotor, and a bearing assembly coupled between the compressor rotor and the compressor stator for supporting the compressor rotor. The bearing assembly includes a pair of foil thrust bearings coupled to a portion of the compressor stator and a pair of spring packs coupled substantially co-axially to the pair of foil thrust bearings. A method of assembling the same is also provided.

Abstract: A centrifugal water pump for use in a diesel engine cooling system provides an improved water pump construction including multiple features which combine to provide increased operating life for the supporting and wearing components of the pump. The improvements include one or more of: a water seal system is provided having a stationary seal and a rotating seal made of silicon carbide with at least one of the seals having embedded lubricant; an o-ring added to the stationary seal ensures that pressurized water does not get past the stationary seal; metallic bearing seals and covers to prevent leeching of the lubricant from the bearing; optimized spring force on the rotating seal; tapered shaft impeller interface to minimize torsional stresses on these components from the keyway design of the prior art; and the housing engine oil inlet is removed to prevent the direct flow of hot, dirty, and contaminated oil from damaging the water pump bearings.

Abstract: An exemplary thrust collar for a turbocharger includes a substantially annular body that includes an axis of rotation, a bore, opposing end surfaces where one of the end surfaces is substantially normal to the axis of rotation and capable of seating a back end of compressor wheel, and a surface disposed in the bore where the surface is substantially normal to the axis of rotation and capable of seating a surface of a turbocharger shaft. The axial distance between the end surface for seating a back end of a compressor wheel and the surface disposed in the bore for seating a surface of a turbocharger shaft is selected to improve balancing of a rotating assembly. Various other exemplary devices, systems, methods, etc., are also disclosed.

Abstract: In one embodiment, a method for controlling seal clearance in a turbine engine includes positioning a seal ring within a turbine engine, the seal ring having an inner annular surface and an outer annular surface, the inner annular surface and the outer annular surface both being circular but non-concentric, rotating the seal ring within the engine until the seal ring is placed in an aligned orientation at which a center of a circle that defines the inner annular surface coincides with a centerline of the engine, and securing the seal ring while in the aligned orientation.

Abstract: A unison ring assembly for an axial compressor casing is provided. The unison ring assembly includes a unison ring and at least three unison ring supports being radial inwardly and equally spaced arranged along a circumference of the unison ring, wherein each unison ring support has a unison ring bracket attached to the unison ring. Further, the unison ring assembly includes a slide bearing to be sliding along a slide face of an outer surface of the compressor casing and a resilient member being arranged between and coupled to the slide bearing and the unison ring bracket such that the unison ring is rotatable around the compressor casing by sliding the slide bearing along the slide face and to be centered free of clearance about the compressor casing. The resilient member is adapted to accommodate radial displacement of the compressor casing.

Abstract: Rotary hydrodynamic blood pumps have been used to treat over a thousand patients. The Jarvik 2000 has supported a patient for seven years and uses blood immersed bearings washed by high flow to avoid excessive thrombus formation. This permits the pump to be very simple and small. Nonetheless, the present Jarvik 2000 bearings and all other mechanical blood immersed bearings of the prior art have a supporting structure that predisposes to thrombus adjacent to the bearings. The present invention provides a bearing structure that eliminates this predilection site for thrombus formation, and may provide indefinite thrombus free operation. The rotor of the preferred embodiment includes a tapered hub fabricated of wear resistant material supported by three posts at each end of the rotor, upon which the rotor rotates. Blood washes the unobstructed spaces between the posts to prevent the accumulation of a torus of thrombus that could enlarge excessively.

Abstract: A thin fan structure is composed of a driving unit and a rotating unit. The driving unit has a base, a coil circuit board and a shaft, in which the coil circuit board is disposed at the base. The rotating unit has a bearing, a fan blade, an iron-containing metal sheet and a magnet, in which the bearing has an outer ring and an inner ring. The fan blade, the iron-containing metal sheet and the magnet are fixed at the outer ring of the bearing, the inner ring of the bearing is fixed at the shaft of the driving unit and the coil circuit board of the driving unit is able to drive the rotating unit turning around.

Abstract: An assembly for preventing damage to bearings of a gas turbine engine during transportation is provided. The assembly comprises a turbofan gas turbine engine having an engine casing and at least one turbine shaft supported by a plurality of bearings, and, a brace secured relative to the engine casing and biasing the shaft along an axial direction of the shaft.

Abstract: Object The invention provides a supercharger which is provided with a thrust bearing in an outer side of a radial bearing, and can smoothly discharge a fed lubricating oil from a bearing portion so as to reduce a resistance generated by the lubricating oil. Means to Solve the Problems The supercharger is provided with a thrust bearing (30) rotatably supporting a thrust force applied to a turbine shaft (12). The thrust bearing (30) is constituted by a disc-shaped thrust collar (32) rotating together with the turbine shaft, and a turbine side thrust bearing (34) and a compressor side thrust bearing (36) inhibiting a movement in an axial direction of the thrust collar.

Abstract: A bearing retainer unit is formed by an insert-molding technique to cast a molded component of the bearing retainer unit utilizing a bearing bushing. A first mold die, having a circumferential surface shaped to correspond to at least a portion of the inner circumferential surface of a bearing-positioning portion of the molded component, and a second mold die, having an abutment that abuts against an axial end face of the first die, are readied. A molten material is then injected into the mold to form the molded part, thereby forming the die-parting line on the inner circumferential surface of the component's bearing positioning portion, positioned at the radially outer side of the abutment.

Abstract: A fuel pump includes a bearing element disposed in proximity to an impeller. The bearing element is configured to form a fuel seal with the impeller and to drain fuel leaked from the pump chamber back into the pump chamber. The bearing element minimizes leakage of fuel from the pump chamber into an engine coupled to the impeller. The fuel pump also includes redundant lip seals configured to provide redundant sealing relative to a shaft of the impeller within the fuel pump in order to minimize engine oil from entering the pump chamber and to minimize fuel from entering the engine. Integration of both the bearing element and the redundant lip seals as part of the fuel pump results in the fuel pump having a relatively compact size.

Abstract: An arrangement for supporting a shaft of a vacuum pump includes a first bearing for supporting the shaft at one of its end, a second bearing for supporting the shaft at another of its ends and formed as a rolling bearing, a holder for receiving the second bearing and including an oscillating base, a fixation member secured in the vacuum pump housing, metallic connection members for connecting the oscillating base with the fixation member and axial springs arranged between the oscillating base and the fixation member and providing for the axial stiffness of the holder which is greater than its radial stiffness thereof and greater than the axial stiffness of the first bearing.

Abstract: A seal and method of making seals utilises folds in order to form creases in a length of material such that the creases reinforce individual seal elements or surfaces whilst perforations or slots in a seal edge allow air leakage from one side of the seal element or surface to the other. Thus, air pressurisation can take place between spaced seal elements or surfaces and this allows air flotation or riding of a rotating component relative to a static housing component. The perforations are typically graduated from the seal edge in order to provide the best pressurisation and air-riding effect for proximity or gap control between the sealing edge and the rotating component surface. The slots effectively provide flexibility to the sealing edge such that the seal component emulates a brush seal.

Abstract: A single-bearing fan structure includes a fan frame having a bearing cup with a bearing received therein, the bearing cup having a radially inward protruded lip portion formed at a first end to abut on a top of the bearing, and a groove internally formed at a second end; a blade hub having a rotary shaft fixedly connected thereto with a distal end of the rotary shaft inserted into the bearing; a retainer engaged with the groove; a first elastic element fitted around the rotary shaft and located between the blade hub and the bearing; and a second elastic element received in the bearing cup and located between the bearing and the retainer. The first and second elastic elements and the bearing respectively axially and radially support the blade hub, enabling the fan structure to operate stably and have extended service life.

Abstract: Asymmetric loading within such machines as gas turbine engines can cause distortion of a casing surrounding a rotating assembly. Such distortion may cause rub and therefore inefficient energy usage and shorter operational life. By providing driver arms 112, 212, 312 which extend from radially extending links 113, 213 in a first or high pressure compressor inner casing 101, 201 to a second outer casing 108, compensation for asymmetric loading can be achieved. The casings 101, 201, 108, 208 are presented upon relatively stable bearing supports 102, 110 and therefore, reaction loads are compensated for in order to retain concentricity of the casing 101, 201.

Abstract: A helical turbine configured to rotate transversely within a cylindrical pipe under the power of fluid flowing either direction therethrough is operatively coupled with a rotating machine or generator to produce work or electricity. The twisted blades of the turbine define a right circular cylinder when the shaft mounting them rotates under the influence of fluid flow through the pipe. In one embodiment, baffles are provided at least upstream of the cylindrical turbine and within the cylindrical pipe to control flow through the cylindrical turbine. The twisted blades of the helical turbine are airfoil in cross section, as are the radial struts or spokes that mount the twisted blades to the rotatable shaft, thereby to optimize hydrodynamic flow, to minimize cavitation, and to maximize conversion from axial to rotating energy.

Abstract: An engine starter includes a motor housing having an inlet and an outlet for a motive fluid, a fluid-driven motor within the motor housing, the motor including a rotor and a stator, the stator directing a flow of fluid over the rotor, thereby inducing rotation of the rotor about an axis and exerting an axial force on the rotor and an output shaft operably coupled to the rotor such that rotation of the rotor drives rotation of the shaft about the axis. A front and a rear ball bearing assembly support the rotor. A front biasing member is pre-loaded to exert a first biasing load on the front ball bearing assembly and a rear biasing member is pre-loaded to exert a second biasing load on the rear ball bearing assembly in opposition of the axial force exerted on the rotor. The biasing members distribute the axial force between the two ball bearing assemblies.

Abstract: An aerostatic bearing and a linear compressor that includes the aerostatic bearing. In an exemplary embodiment, the aerostatic bearing includes a guide element including holes, and a body structured to move along a surface of the guide element. The holes may include a first section close to the body, of which at least one part area features a cross-sectional surface substantially constant over its entire length which is smaller towards the body than another cross-sectional surface of an area away from the body. A method for producing a hole in an element, using a laser beam, for producing the aerostatic bearing is also disclosed.

Abstract: A bearing support structure is provided for installation in a gas turbine engine between radially inner first and second bearings adapted to rotatably support a first and a second rotor, respectively, and a radially outer engine frame. The support structure includes a first annular plate-shaped part and an arrangement for supporting the first bearing at one end thereof and a second annular plate-shaped part and an arrangement for supporting the second bearing at one end thereof. The first and second plate-shaped parts are joined together forming a one-piece unit for installation in the gas turbine engine.

Abstract: Various “contactless” bearing mechanisms including hydrodynamic and magnetic bearings are provided for a rotary pump as alternatives to mechanical contact bearings. In one embodiment, a pump apparatus includes a pump housing defining a pumping chamber. The housing has a spindle extending into the pumping chamber. A spindle magnet assembly includes first and second magnets disposed within the spindle. The first and second magnets are arranged proximate each other with their respective magnetic vectors opposing each other. The lack of mechanical contact bearings enables longer life pump operation and less damage to working fluids such as blood.

Abstract: A bearing device includes a turbine-side bearing 21 and a compressor-side bearing 22 each of which is a floating-bush type sliding bearing. A gap (turbine-side inner peripheral clearance TI) between the turbine-side bearing 21 and a rotating shaft 13 is set to be larger than a gap (compressor-side inner peripheral clearance CI) between the compressor-side bearing22 and the rotating shaft 13. In the bearing structure, unstable vibration including self-excited vibration can be suppressed.

Abstract: With the multi-stage centrifugal pump assembly, the connection between the motor shaft (7) and the pump shaft (9) is effected by way of a thread (26, 27), which joins the fits (31, 34) lying therebehind, between a pocket hole bore (24) in the pump-side end of the motor shaft (7) and the motor-side end of the pump shaft (9). Thereby, a transition fit (32) is provided in the region of the bearing (11), and a press fit 34 in the free region therebehind.

Abstract: A multi-stage centrifugal pump assembly which is manufactured in the same construction type with cast components on the one hand, and with a stainless steel lining formed of sheet metal on the other hand, includes a bearing carrier (13) which is designed and suitable for the connection of a cast housing component (12) as well as for receiving a sheet metal lining made of stainless steel.

Abstract: A rotor mechanism of a centrifugal compressor connectable to a power output device and configured to block leakage of lubricants and to recycle lubricants to an oil sump is provided, which includes a rotary shaft with a rolling bearing and a screw nut, a bearing housing for receiving the rolling bearing, and a bearing plate connected to the bearing housing. The screw nut has a surface provided with an oil throw seal, and the bearing housing. As the bearing plate is provided with an oil channel in contact with the oil-returning hole and either one of the bearing housing and the bearing plate is provided with a first labyrinth seal in contact with the screw nut, lubricants leaking out of the rolling bearing is allowed to go to the oil sump via the oil channel and oil-returning hole. The oil slinger thus blocks the lubricants from leaking out of the first labyrinth seal.

Abstract: A rotor assembly that includes a shaft to which are mounted an impeller and a bearing assembly. The bearing assembly is located at least partly within the profile of the impeller so as to reduce loading of the bearing assembly as well as reduce the cantilever length of the rotor assembly.

Abstract: A rotor assembly that includes a shaft to which are mounted an impeller, a rotor core and a bearing cartridge. The bearing cartridge is mounted between the impeller and the rotor core and comprises a pair of bearings, a spring that applies a preload to each of the bearings, and a sleeve that surrounds the bearings.

Abstract: A pump pulley is supported on a pump body via a bearing interposed between the outer peripheral surface of the pump body and the pump pulley so that the pump pulley can freely rotate relative to the pump body. A pump shaft extends along the rotation axis of the pump pulley into a pump chamber formed by a pump base and the pump body, and one end of the pump shaft is fitted to the pump pulley and the other end is fitted to an impeller located within the pump chamber. A body side seal member and a shaft side seal member that form a mechanical seal to maintain the leak tightness of the pump chamber are in opposite to and contact each other in the direction of extension of the pump shaft to form a seal surface, and the plane that includes the load support center of the bearing and the plane that includes the seal surface of the mechanical seal are substantially coincidental.

Abstract: The invention relates to a vacuum pump in which the gas bearing is coated with a hard layer, and to a process for preparing such gas bearing of a vacuum pump.

Abstract: A turbocharger has a turbocharger housing and a through opening for a shaft. The shaft is pivotally supported in the housing by way of a bearing arrangement. Lubricating oil is supplied for lubricating the bearings. A section of the shaft is provided on the outside of at least one bearing, the section forming a gap together with the housing. The gap is configured as a lubricating oil regulator in order to at least reduce a passage of lubricating oil from the sides of the bearing.

Abstract: The present invention provides an apparatus and method for rotationally controlling a bearing assembly using a geared coupling system in combination with a supercharger including an input shaft. Generally, the geared coupling system includes a bearing assembly rotatably supporting a high speed shaft associated with an impeller, the bearing assembly including at least one inner bearing and at least one outer bearing; a drive gear associated with the input shaft and including a plurality of engaging members; and a geared coupler extending from a towards a plurality of engaging members adapted for engagement with the low speed gear, the geared coupler presenting an inner surface for receiving said inner bearing and an outer surface for receiving said outer bearing.

Abstract: A shaft support device for a turbomachine including a rotary body and a stationary body. The rotary body is attached to a shaft of the turbomachine, and includes a first portion and a second portion. The first portion has a thrust bearing collar and the second portion has a thrust balance piston. The first and second portions are axially overlapping. The stationary body is fixably attached to a casing of the turbomachine. The stationary body has a first thrust bearing portion that is disposed adjacent to and operatively engages the first portion of the rotary body.

Abstract: A hydrodynamic axial bearing with a floating disk is disclosed wherein two lubricating gaps on the two sides of the floating disk are formed by supporting surfaces of different size. This makes it possible to provide identical lubricating gaps on both sides, despite different rotation speeds between the floating disk and the bearing housing, and between the floating disk and the bearing comb.

Abstract: Various “contactless” bearing mechanisms including hydrodynamic and magnetic bearings are provided for a rotary pump as alternatives to mechanical contact bearings. In one embodiment, a pump apparatus includes a pump housing defining a pumping chamber. The housing has a spindle extending into the pumping chamber. A spindle magnet assembly includes first and second magnets disposed within the spindle. The first and second magnets are arranged proximate each other with their respective magnetic vectors opposing each other. The lack of mechanical contact bearings enables longer life pump operation and less damage to working fluids such as blood.

Abstract: Systems and methods are provided for cooling bearings or other objects. Such cooling may be accomplished by expanding a compressed gas in a cooling channel surrounding a bearing and allowing the expanded air to come into direct contact with the bearing. Expanding a compressed gas in local proximity of the bearing takes advantage of the Joule-Thompson expansion of gas, resulting in a substantial drop in gas temperature, thereby maximizing the cooling potential of the gas being directly applied to the bearing. Cooling bearings in this manner extends their operational life and enables them to operate at the desired speeds. A housing may be provided for receiving a compressed gas, expanding the compressed gas to a predetermined pressure, enabling the expanded gas to directly contact the bearing, and exhausting the expanded gas.

Abstract: A small twin spool gas turbine engine with a bearing support arrangement in which the bearings are dampened by O-rings secured between the bearing races and the support structure, and in which the bearings are arranged in series so that a cooling air can be passed through the bearings to prevent overheating. The aft end of the engine includes high speed and low speed ball bearings supported with preload springs to add additional damping capability. The fore and aft end bearing support assemblies forms a cooling air path for the cooling fluid to flow through a passage within one of the guide vanes, through the bearings and out through a hole in the low pressure turbine rotor disk. the bearing cooling air passage includes a snorkel tube that extends from a guide vane cooling air passage and into the bypass air channel to draw in the cooling air used for the bearings. The snorkel tube includes a slanted opening so that dirt particulates do not enter the bearing cooling air passage.

Abstract: A small twin spool gas turbine engine with a bearing support arrangement in which the bearings are dampened by O-rings secured between the bearing races and the support structure, the bearings are arranged in series so that a cooling air can be passed through the bearings to prevent overheating, and the bearings are dry lubricated. The aft end of the engine includes high speed and low speed ball bearings supported with preload springs to add additional damping capability. The end bearing support assemblies form a cooling air path for the cooling fluid to flow through a passage within one of the guide vanes, through the bearings and a hole in the low pressure turbine rotor disk and out the exhaust of the engine. A snorkel tube extends into the bypass air channel drawing air for the bearings, and has a slanted opening preventing dirt particulates from entering the bearing cooling passage.

Abstract: A wind generator having removable change-out bearings includes a rotor and a stator, locking bolts configured to lock the rotor and stator, a removable bearing sub-assembly having at least one shrunk-on bearing installed, and removable mounting bolts configured to engage the bearing sub-assembly and to allow the removable bearing sub-assembly to be removed when the removable mounting bolts are removed.

Abstract: A method and apparatus to reduce the axial thrust in rotary machines such as compressors, centrifugal pumps, turbines, etc. includes providing additional peripheral restrictive means (7) attached at the peripheral portion of the disk forming the subdividing means (4) on the side facing the rotating rotor (2). An additional ring element at the periphery of the subdividing means forms additional radial (11) and axial restrictive means (15). Such peripheral restrictive means (7, 11 and 15) function as sealing dams, which combined with the outward flow induced by the rotating impeller, form self-pressurizing hydrodynamic bearings in the axial and radial planes, improving rotordynamic stability. Additionally, a stationary ring element in the center of the cavity forms a seal with the rotor, reducing leakage to suction.

Abstract: A fan blade and shaft mounting arrangement for bathroom exhaust fan includes a housing, a fan blade which has a hub, a center tube at the center of the hub and blades arranged around the hub, a fan shaft inserted through the center tube of the fan blade and supported between two bearing members in the housing, and a torsion spring that has a torsionable portion sleeved onto the fan shaft and a positioning portion fastened to the fan blade. When the fan shaft is rotated, the torsionable portion of the torsion spring is twisted and secured firmly to the fan shaft so that the fan blade is rotated with the fan shaft.