Abstract: An electromagnetic clutch has an armature, a rotor housing accommodating a stator housing and an exciting coil having negative and positive terminals. A passage is formed to extend from an outer peripheral surface of the stator housing to the negative terminal and the positive terminal. The passage is filled with a conductive metal member having a melting point lower than that of the stator housing between the outer surface of the stator housing and the negative terminal. When frictional heat generated between the armature and the rotor housing exceeds a preset value, the metal member melts and flows to the positive terminal, thereby short-circuiting the coil. As a result, a fuse between a power source and the clutch is fused, thereby turning off the clutch. Therefore, the clutch does not need to have a thermal fuse therein and is reduced in size without increasing power consumption.

Abstract: There are disclosed a method of and an apparatus for regulating the operation of a friction clutch or another torque transmission system in the power train of a motor vehicle. The regulation is such that the operator of the vehicle is informed of a prevailing or impending condition which entails or is about to entail damage to the system or to the entire power train. Such situation can arise in response to excessive and/or prolonged slip of abutting friction surfaces in a friction clutch, overheating of one or more parts of the system for any other reason(s), as a result of improper selection of the transmission speed for starting of the vehicle and/or due to excessive wear upon the friction linings and/or other parts. The remedial undertaking can include such regulation of the system that the ride become uncomfortable to the occupant(s) of the vehicle and/or automatic elimination of the cause(s) of unsatisfactory torque transmission.

Abstract: A hydraulic coupling including a multi-plate clutch assembly operably connecting two relatively rotatable members and an actuator assembly for actuating the clutch assembly in response to speed differentiation between the two rotary members. The actuator assembly includes a hydraulic pump, a piston disposed in a piston chamber, and a fluid distribution system including a first flow path for supplying hydraulic fluid from a sump to the hydraulic pump and a second flow path for supplying hydraulic fluid from the hydraulic pump to the piston chamber. Hydraulic pressure in the piston chamber controls the magnitude of the clutch engagement force exerted by the piston on the clutch assembly. The fluid distribution system further includes a third flow path between the piston chamber and a clutch chamber.

Abstract: A temperature sensitive fluid type fan coupling apparatus is provided which can prevent "an accompanying rotation" phenomenon from being generated so as to reduce fan sound and improve fuel consumption. The fan coupling apparatus comprises a sealing device box including a cover and a case which is separated into an oil reserving chamber and a torque transmission chamber by a partition plate. A drive disc is fixed to a rotary shaft body and is disposed inside the torque transmission chamber to support the sealing device box. A circulating flow passage delivers oil from the torque transmission chamber to the oil reserving chamber. A valve member for opening and closing a supply hole communicating between the torque transmission chamber and the oil reserving chamber is provided so as to increase and reduce an effective contact area for the oil in the drive disc and torque transmission gap portion, thereby controlling a torque transmission to the side of the sealing device box driven by the rotary shaft body.

Abstract: A flow control valve for regulating the flow across an orifice to eliminate the effects of viscosity changes throughout a range of temperatures for the hydraulic fluid. The valve includes a base with an orifice and a slide valve element that registers with the orifice and that is movable by a double, helix-wound, bimetallic spring. The bimetallic spring extends linearly in the direction of motion of the slide valve element so that its effective length will change a predictable amount for a given temperature change, thereby progressively changing the size of the orifice as the spring moves the slide valve element to which it is connected.

Abstract: The power train of a motor vehicle has an automated clutch and a control unit which causes one or more actuators to change the rate of torque transmission by the clutch from the engine to the transmission of the power train in response to appropriate signals from various sensors. When the transmission is shifted into gear while the engine is idling, while the brake or brakes are not applied and while the gas pedal is not depressed, the setting of the clutch is such that the transmission causes the motor vehicle to carry out a crawling movement as a result of a change of the rate of torque transmission by the clutch from the idling engine to the transmission from a first value (e.g., zero) to a second value as a function of the monitored temperature of the clutch.

Abstract: An arrangement for controlling the rotational speed of an output rotational part of a fluid friction coupling is provided. A fan for cooling components of a motor vehicle is coupled with a driving rotational part by way of a shearing fluid whose effective fluid quantity determines the transferrable torque. The arrangement contains an adjusting unit (which can be electrically driven in a timed manner) for the variable adjustment of the effective shearing fluid quantity and contains a temperature controller stage to which the temperature of at least one medium whose temperature can be influenced by the output rotational speed is fed. The invention, the temperature controller stage is followed by a rotational speed controller stage to which, on the input side, the output signal of the temperature controller stage is fed as the dessired rotational output speed as well as the rotational driving speed and which, via of its output signal, drives the shearing fluid quantity adjusting unit of the coupling.

Abstract: Oil recovery dams 24 and 25 are disposed on the side of the outer periphery of a drive disk 21 and in a torque transfer chamber 20. An oil circulating passage 26 guides oil from the side of the oil recovery dam 24 of the torque transfer chamber 20 to an oil reservoir chamber 19. A seal 27 is disposed between a drive shaft 11 and a hub 14 of the casing 12 with being appropriately outward separated from a bearing 15 in the axial direction of the drive shaft 11, and forms an oil supply chamber 28 defined by these components. An oil supply passage 29 guides the oil from the side of the oil recovery dam 25 of the torque transfer chamber 20 to the oil supply chamber 28.

Abstract: A control system for a 4WD vehicle has a rotation transmission device which can prevent a two-way clutch of the rotation transmission device from vibrating by repeatedly locking and unlocking when the vehicle is started in a cold environment. The rotation transmission device is mounted in the transfer. The transfer is provided with a temperature sensor for measuring the temperature of oil in the transfer. If the oil temperature as measured by the temperature sensor is below a predetermined value when the vehicle is started with the drive mode set at the 2WD position, the hub clutches are engaged to reduce the idling speed of the two-way clutch and thus to prevent the two-way clutch from locking.

Abstract: A transmission assembly and method for controlling a torque converter of a transmission assembly in which an electronic controller monitors the load on the vehicle power train in addition to a number of other vehicle dynamics, including the currently engaged gear ratio and the temperature of the transmission fluid. The electronic controller is operable for causing the activation of the converter clutch in response to a number of predetermined operating conditions, one of which includes the operation of the vehicle when the fluid in the torque converter exceeds a predetermined temperature and the vehicle power train is operated under a heavy load for a period of time which exceeds a predetermined time interval. Engagement of the converter clutch during such times inhibits relative rotation between the torque converter turbine and impeller, improving fuel economy and preventing the torque converter from generating a substantial amount of heat.

Abstract: A fluid coupling device of the type including an external bimetal coil (45) operable to move a valve arm (41) from a closed position (FIG. 4) toward an open position (FIG. 5) as the external temperature increases. An internal bimetal coil (61) is provided within the fluid reservoir chamber (35), having an inner end (65) fixed to a disc-like member (63) which rotates with the valve shaft (39), and an outer end (67) fixed to the valve arm (41). The internal coil (61) is preloaded such that, when the internal fluid temperature increases, the preload is relieved, and the valve arm (41) rotates from its open position (FIG. 5) back toward a closed position (FIG. 6), thus protecting the fluid from overheating and being damaged.

Abstract: A transmission control system is proposed for reducing thermal load on engaging elements (2, 3, 4, 5) in a gearbox (1) during the starting operation. The gearbox (1) has an input shaft (7) and an output shaft (9) and at least two engaging elements or clutches (2, 3, 4, 5) each of which is allocated to a gear and comprises a first clutch half (21, 31, 41, 51) which transmits the force coming from the direction of the input shaft (7) onto a second clutch half (22, 32, 42, 52) which in turn transmits the force in the direction of the output shaft (9). Transmission elements (11, 12, 13) and shafts (7, 8, 9, 23, 33, 40, 50) are mounted between the input shaft (7) and a first clutch (2, 3) and/or between the first clutch (2, 3) and a second clutch (4, 5) and/or between the second clutch (4, 5) and a further clutch or the output shaft (9).

Abstract: A vehicle engine cooling system includes a coupling assembly to be connected to and rotated by a vehicle engine output shaft. An electric motor includes a motor shaft having first and second ends. An impeller is coupled to the first end of the motor shaft. A clutch structure is integral with the electric motor and includes an input member carried by the second end of the motor shaft for rotation therewith. An end of the coupling structure is operatively associated with the input member to cause rotation of the input member upon rotation of the coupling assembly. An electro-magnet structure is disposed about the input member. The clutch structure also includes output structure having a mounting member fixed to the motor shaft. A movable element, including magnetically permeable material, is mounted with respect to the mounting member for rotational movement therewith and for movement between a non-engaging position and an engaging position. A spring biases the movable element towards the non-engaging position.

Abstract: A hydraulic coupling including a multi-plate clutch assembly operably connecting two relatively rotatable members and an actuator assembly for actuating the clutch assembly in response to speed differentiation between the two rotary members. The actuator assembly includes a hydraulic pump, a piston disposed in a piston chamber, and a fluid distribution system including a first flow path for supplying hydraulic fluid from a sump to the hydraulic pump and a second flow path for supplying hydraulic fluid from the hydraulic pump to the piston chamber. Hydraulic pressure in the piston chamber controls the magnitude of the clutch engagement force exerted by the piston on the clutch assembly. The fluid distribution system further includes a third flow path between the piston chamber and a clutch chamber.

Abstract: A viscous fluid clutch includes a rotor attached to an output from an engine, a stator attached to a fan assembly and a coil assembly having at least a portion attached to the stator. A first gap is defined between the rotor and the stator and a second gap is defined between the rotor and the coil assembly. The first and second gaps are filled with a magnetorheological (MR) fluid. The coil assembly creates a magnetic field in the first and second gaps to vary the viscosity of the MR fluid to produce a variable speed viscous fluid clutch.

Abstract: A fluid coupling assembly for driving a cooling fan from an engine comprising a housing (10) defining a fluid chamber (12) having a volume and a drive member rotatably supported in the fluid chamber (12) of the housing (10) for transmitting torque between the housing (10) and the drive member through the shearing action of fluid (14) in the chamber (12). In some embodiments the housing (10) is adapted to drive the fan with the drive member adapted for connection to the engine and in the other embodiments the housing (10) is driven by the engine and the drive member is adapted for connection to the fan. A displacement device means is disposed in the fluid chamber (12) for adjusting the volume of the said chamber (12) to vary the coverage of the drive member by the fluid (14) to vary the shearing action of the fluid (14) to adjust the torque transmitted between the drive member and the housing (10).

Abstract: A hydraulic fan coupling comprises a hermetically sealed case that is driven by the engine. The case is made of metal. Fan blades made of resin are molded onto elongated outer portions of the case.

Abstract: A clutch mechanism is provided for a cooling fan of a size capable of fitting into the limited envelope available in an over-the-road diesel tractor. A compact housing has a belt drive input and an output connected to the fan hub. The housing includes a pressure chamber in fluid communication with a pressurized air supply and a controllable valve in the air supply line for regulating the pressure in the pressure chamber when the clutch must be operated. The air pressure actuates an internal piston to translate the clutch in a continuously variable manner between engaged and disengaged conditions.A small envelope clutch, having an outer diameter less than about 9.8 inches in diameter within the fan hub and less than about 6 inches under the belts and 7.3 inches overall so the housing may be positioned between the radiator and the engine, is capable of generating 150 foot-pounds of torque, running a 55 horsepower fan at 2100 rpm, and dissipating 10 horsepower of heat while in the slip mode.

Abstract: A viscous fluid coupling which includes an input member having a rotatable shaft and a rotor secured to the shaft is disclosed.

Abstract: A passive magnetorheological clutch includes an input member that is constantly driven at engine speed, or some selected proportion thereof. An output member is journaled on the input member so as to be supported thereon in a nonrotating state and to be concentrically rotatable in concert therewith. A space presented between the input and output members contains a quantity of magnetorheological fluid. The space also contains an engagement mechanism including a permanent magnet and a ferromagnetic ring concentrically positioned with an operative gap therebetween, wherein the operative gap's dimension is variable to effect changes in the magnetic field passing between the magnet and the ring. When an actuator effects a reduction in the distance between the magnet and ring, the amount of magnetic field increases in density adjacent the ring. The resultant torque transfer from the input member to the output member is effected across the operative gap and through the magnetorheological fluid.

Abstract: A magnetorheological fluid fan clutch effects modulated rotational motion transmission between a rotatable input shaft carrying an input clutch plate and a housing having a front cover and a rear cover forming a cavity about the input clutch plate wherein a core carried in the front and rear covers operates as output clutch plates. Bearings support the housing on the input shaft through the front and rear covers so that the input clutch plate is rotatable on the input shaft relative to the housing. Magnetorheological fluid is carried in the cavity, through which torque is variably transferred between the input clutch plate and the housing. A coil is positioned radially outside the non-magnetic spacer and carries a variable electrical current to effect a variable magnetic field across the input clutch plate and through the magnetorheological fluid providing modulated torque transmission between the input clutch plate and the core.

Abstract: A clutch includes an input shaft with a clutch plate engaged with the input shaft to rotate in concert therewith. The clutch plate has an annular disk portion with a clutch plate set of lands and grooves. A housing includes a body supported on the input shaft by a bearing with a body set of lands and grooves mating with the clutch plate set of lands and grooves. A cover is included as part of the housing and engages with the body. A pump plate is captured between the cover and the body separating out a working chamber. The pump plate includes an engage port and a pump-out port positioned further radially outward in the pump plate than the engage port. A control arm normally closes the engage port and is rotatable to open the engage port. A slide-block is carried in a pocket of the cover with a spring biasing the slide-block toward engagement with the control arm. The slide-block locks the control arm against rotation when the clutch is inactive.

Abstract: An actuator (A) includes a body (10) in which a plurality of chambers or bores (34) are defined. The bores are interconnected at an inner end by an elongated passage (30). A heater element (32) extends along the elongated passage. The elongated passage and the inner portion of each chamber or bore are filled with a polymeric material which expands and flows on heating, preferably undergoing a solid to liquid phase change. Extensible members (12), such as pistons, diaphragms, bellows, or the like, are mounted in the bores or wells. When the heater heats the polymeric material causing it to expand and flow, the extensible elements (12) extend under high force with limited travel. In one embodiment, the extension of the extensible members moves a thrust bearing (B) causing frictionally engageable plates (18, 22) of a friction member assembly (C) to engage.

Abstract: There are disclosed a method of and an apparatus for regulating the operation of a friction clutch or another torque transmission system in the power train of a motor vehicle. The regulation is such that the operator of the vehicle is informed of a prevailing or impending condition which entails or is about to entail damage to the system or to the entire power train. Such situation can arise in response to excessive and/or prolonged slip of abutting friction surfaces in a friction clutch, overheating of one or more parts of the system for any other reason(s), as a result of improper selection of the transmission speed for starting of the vehicle and/or due to excessive wear upon the friction linings and/or other parts. The remedial undertaking can include such regulation of the system that the ride become uncomfortable to the occupant(s) of the vehicle and/or automatic elimination of the cause(s) of unsatisfactory torque transmission.

Abstract: An apparatus and method for controlling a damper clutch for an automatic transmission of a vehicle are disclosed. The apparatus includes a shift lever for shifting a transmission gear of the vehicle, a handle for moving the shift lever, a damper switch disposed on the handle for manually selecting an operation of the damper clutch, and a control unit for controlling the damper clutch according to the damper switch and predetermined conditions.

Abstract: A fluid clutch comprises a driving disc rotationally driven by a driving section, a rotatable casing enhousing the driving disc, a blower attached to the casing, and an oil supply means for supplying an oil from an outside to a torque transmission gap between the driving disc and the casing. Further, a driving section may be connected by means of a flexible joint to either one of the casing or the disc. The fluid clutch can always attain optimum control by adjusting the amount of the oil at a high accuracy and rapidly depending on various kinds of operation conditions. A breezer also is provided for releasing gas from the torque transmission chamber when pressure exceeds a predetermined upper limit, and for enabling inflow of atmospheric air to the torque transmission chamber when pressure is less than a predetermined lower limit. The clutch is endurable to external vibrations.

Abstract: A temperature-responsive fluid-type fan coupling has a sealing casing with a partition plate disposed therein. The partition plate divides interior portions of the casing into an oil reservoir chamber and a torque transmission chamber. A port extends through the partition plate to provide communication between the chambers. The casing is rotatably mounted around a rotary shaft such that an end of the shaft is disposed in the torque transmission chamber. A drive disc is fixedly mounted to the shaft and is disposed in the torque transmission chamber. Fluid in the torque transmission chamber functions to transmit torque from the disc to the casing. The valve member has one end mounted to the partition plate and an opposed end movably positioned in proximity to the port through the partition plate. Intermediate portions of the valve member are engaged by a pin, which in turn is movable in response to a temperature-responsive member. The valve member is biased to instantaneously open and close at set temperatures.

Abstract: A unit for controlling the retraction of a mobile structure such as a mirror used for calibrating an optical system on board a spacecraft, which includes a spring which permanently forces the mobile structure towards its retracted position and a memory material member, wherein a change of state of the memory material disconnects a connecting system placed in a transmission mechanism normally connecting a control motor to the mobile structure. The connecting system normally ensures the joining by friction of two parts of the transmission mechanism between which the spring acts. A heating system controls the change of state of the memory material member.

Abstract: In a fluid friction clutch, the circulation of shearing fluid is controlled by a control of the return flow of the shearing fluid from a clutch working chamber into a clutch storage chamber. The return flow is controlled by a control piston which is movable axially of the clutch to selectively block and open a radially extending return flow duct. In certain embodiments the control piston also controls an inflow bore.

Abstract: A clutch mechanism for a cooling fan of a size capable of fitting into the limited envelope available in an over-the-road diesel tractor. A compact housing has a belt drive input and an output connected to the fan hub. A wet clutch is included within the housing lubricated by oil from the engine lubrication system. The housing includes an internal positive displacement booster pump cooperating with a controllable valve in the oil return line to the engine sump. When it is desired to operate the clutch, the valve is controllably closed to restrict flow from the clutch mechanism to the engine sump line. The positive displacement pump thereupon causes an increase in pressure in a pressure chamber in the housing, which acts on an internal piston to translate the clutch in a continuously variable manner between engaged and disengaged conditions.

Abstract: A speed limiting accessory drive for use with an engine in a vehicle. A speed limiting drive pulley (16) is affixed to a crankshaft (14) via a hub (42) and includes a pulley member (24) which drives the accessory belt (18). A Clutch assembly (36) is operatively located between the hub and pulley member, with a piston (54) or bellows biased against and engaging the clutch assembly. Oil located throughout the clutch assembly is acted on by centrifugal force when the drive pulley is rotating and acts to push against the biases of the piston. This allows the clutch to slip at high engine speeds, thus limiting the speed of the pulley member. A heat compensating mechanism acts to counter the pushing force of the oil if the temperature of the oil rises too high due to the clutch slippage, thereby reducing clutch slip.

Abstract: An electrohydraulic control device for a drive train of a machine including an engine, a transmission, a torque converter, and an impeller clutch is disclosed. A manually operated impeller clutch pedal produces an impeller clutch pedal signal in response to the position of the impeller clutch pedal. An impeller clutch electrohydraulic valve produces fluid flow to the impeller clutch to controllably engage and disengage the impeller clutch. An impeller clutch pressure curve that is responsive to the impeller clutch pedal position is stored in memory. A rotary position switch selects a desired rimpull setting indicative of a desired reduction in rimpull and produces a desired rimpull signal. An electronic controller receives the desired rimpull signal and reconfigures the impeller clutch pressure curve.

Abstract: A speed limiting accessory drive and crankshaft damper for use with an engine in a vehicle. A speed limiting drive pulley (16) is affixed to a crankshaft (14) via a hub (42) and includes a pulley member (24) which drives the accessory belt (18). A damper mass (40) is elastically attached to the hub via damper springs (44). A Clutch assembly (36) is operatively located between the damper mass and pulley member, with a piston (54) or bellows biased against and engaging the clutch assembly. Oil located throughout the clutch assembly is acted on by centrifugal force when the drive pulley is rotating and acts to push against the biases of the piston. This allows the clutch to slip at high engine speeds, thus limiting the speed of the pulley member. A heat compensating mechanism acts to counter the pushing force of the oil if the temperature of the oil rises too high due to the clutch slippage, thereby reducing clutch slip.

Abstract: A fluid friction coupling includes a housing defining a work chamber and rotatably journalled on a drive shaft. The housing contains a viscous medium and a drive disc for transmitting torque to said housing via fluid friction in the viscous medium. The housing has an inner housing part having a first peripheral edge and an outer housing part having a second peripheral edge. The peripheral edges conjointly define a form-tight interlocked interface. A plurality of raised portions and a plurality of recesses between the raised portions are provided on one of the peripheral edges. The other peripheral edge is a flange having a periphery and the flange has a plurality of outermost edge regions along the periphery. The outermost edge regions on the one hand and the raised portions and the recesses on the other hand are joined together to conjointly define the form-tight interlocked interface.

Abstract: A fluid coupling for an engine includes a shaft, a housing rotatably supported on the shaft, a cover fixed to the housing, a separation plate which separates a chamber defined by the housing and the cover into a store chamber and an operation chamber, wherein the store chamber is formed with at least a first store chamber and a second store chamber which are mutually arranged in a circumferential direction of the fluid coupling. The fluid coupling for an engine further includes a first opening disposed on the separation plate connecting the first store chamber and the operation chamber, a second opening disposed on the separation plate connecting the second store chamber and the operation chamber, valve mechanism opens and closes the first opening and the second opening and a rotor disposed in the operation chamber and fixed on the shaft.

Abstract: A method of controlling a viscous fluid coupling (15) in which, when the vehicle engine (E) is operating at low speeds, if the speed of rotation (SF) of the fan exceeds a predetermined speed limit (L3), the input signal (29) to the coupling is modified to move the valve member (49) toward a closed position (FIG. 3A). This action reduces the occurrence of an overfill condition, thus reducing undesired fan noise when the engine again accelerates. Another aspect of the invention is to sense the speed (SE) of the engine, and whenever the sensed speed (SE) is high enough that operation in an excess slip heat region (ESH) is possible, compare the demanded fan speed (29) to the lower limit (CHP) of the slip heat region. Whenever the demanded fan speed exceeds the limit, the input signal (29) to the coupling is modified to operate the coupling at a speed safely above or below the slip heat region (ESH) depending on the state of control inputs such as engine temperature.

Abstract: A power plant is provided which includes a drive apparatus actuated clutch which can be rapidly engaged to selectively connect a prime mover to a driven device after prolonged exposure of the power plant to cold ambient temperatures. The drive apparatus utilizes a fluid coupling connected, connected in parallel with the clutch for rapidly heating a control volume of fluid used for actuating the clutch. In a preferred embodiment, the fluid coupling also motors the drive mechanism at 5-10% of rated speed to help circulate fluid heated by the fluid coupling through the drive mechanism to thereby reduce start-torque and drag torque experienced by the clutch on start-up. The clutch thus may be made smaller with less risk of burn-out, while still being capable of rapidly engaging following prolonged exposure to cold ambient temperatures.

Abstract: A fluid coupling device is disclosed in which flow of fluid from a reservoir chamber (35) into a fluid operating chamber (33) is controlled by a valve member (41), rotatable with a valve shaft (39). Rotation of the valve shaft (39) is normally controlled, in response to variations in ambient air temperature, by means of a bimetal coil (45), In accordance with the invention, a normally fixed outer tab (75) of the bimetal coil is attached to an output plunger (85) of an electromagnetic actuator (83). As a result, the operating condition of the fan drive can be changed between a disengaged condition and an engaged condition, in response to variations in a predetermined condition (73), other than ambient air temperature.

Abstract: A viscous fluid coupling device comprises a housing; a partition board dividing an internal space in the housing into a storage chamber and an operation chamber, the partition board having first communicating holes to communicate the storage chamber with the operation chamber; a rotor which is provided in the operation chamber and is secured to one end portion of a drive shaft so as to rotate together with the drive shaft; a valve provided in the storage chamber to open and close the first communicating holes; and a rod having one end secured to the valve and the other end secured to the inner peripheral portion of a spiral bimetal. The rod is rotatably supported by the housing and the housing and the rotor have labyrinth grooves in the surfaces which are confronted with each other.

Abstract: A fluid coupling device is disclosed including a cover member (11) and an actuator assembly (35) disposed adjacent thereto for actuating a valve member (31). The cover includes an annular fluxring (49), which may be cast into the cover (11) and defines a radially inner surface (57). Extending radially inward from the surface (57) is an annular dovetail portion (59) defining radially outer surfaces (61,63). The cover member includes a cast central portion (55) disposed radially inward of the fluxring (49). As the cast central portion (55) cools, subsequent to casting, it shrinks and seals against the outer surfaces (61,63) of the dovetail (59), because the cover member (11) has a coefficient of thermal contraction which is greater than that of the fluxring (49), thus eliminating the formation of radial clearances between the cast central portion (55) and the inner surface (57) of the fluxring (49).

Abstract: A viscous fluid coupling includes a labyrinth device for transmitting rotational torque from an input member to an output member through viscous fluid and a temperature sensing bi-metal spiral spring element for controlling a flow of the viscous fluid toward the labyrinth device. A part of the spring element located outside with respect to a part for supporting a concentrated part of the stress in the spring element is welded to a holder plate.

Abstract: A driving disc in a temperature-sensitive fluid fan coupling has a substantially C- or I-shaped cross section defined by a cylindrical wall projecting from its outer periphery coaxially therewith. The disc has at its outer periphery including the projecting wall a width which is equal to at least 7% of its outside diameter. The disc, its projecting wall and a housing in which the disc is mounted define at least one chamber for the temporary storage of oil. The disc has on at least one side thereof a plurality of radially extending partitions which divide the oil storage chamber into a plurality of portions.

Abstract: A viscous fluid clutch includes a housing rotatably mounted to a drive shaft and a clutch plate attached to the drive shaft. These relatively rotatable members have a fluid shear space therebetween and cooperable with a fluid medium in the shear space to provide a shear-type fluid drive therebetween. The housing includes a reservoir, an operating chamber and a pump outlet opening communicating between the operating chamber and the reservoir. An annular wall is secured at its inner and outer peripheral edges to the clutch plate and includes an annular bend between the outer and inner peripheral edges to define an annular auxiliary reservoir in cooperation with the clutch plate. The housing has an annular recess accommodating the annular bend. The annular recess is defined by a conical surface increasing its radial distance from the axis of rotation of the drive shaft.

Abstract: Rotation slip between the rotor and the armature of an electromagnetic clutch results in the exciting current I in the electromagnetic coil decreasing locally abruptly to form a unique waveform. The locally abruptly rising variations in the current is taken out as a locally abruptly variation (an alternating current component) in an inverted and amplified voltage, and the alternating current component is applied to a comparing circuit (400). The instantaneous value of the alternating current component is compared with a threshold which rises as the rotational speed of the rotor becomes higher, and while the instantaneous value exceeds the threshold, a comparison output is outputted. The comparison output is applied to a continuous waveform confirming circuit (500), and if the predetermined number of comparison outputs are detected with a predetermined time after a first comparison output has been generated, it is determined that a rotation slip has occurred.

Abstract: A viscous fluid clutch includes relatively rotatable first and second drive members having a fluid shear space therebetween and which are cooperable with a fluid medium in the shear space to provide a shear-type fluid drive therebetween, a fluid reservoir for storing the fluid medium, and a baffle wall located in the reservoir for restraining flow of the fluid medium from the reservoir to the shear space.

Abstract: A pressure activated rotary clutch includes a sealed unit including a casing and a cover mounted to and rotatable about a rotating shaft. The unit includes a circumferentially extending outer wall and a circumferentially extending inner wall having an outwardly extending lobe having major and minor dimensions from said shaft and also a fluid passageway having an inlet on one side of said minor dimension and an outlet on the other side of said minor dimension. A flow control valve is disposed in the fluid passageway for controlling fluid flow through the passageway. A flow control valve actuator in communication with the flow control valve operates the flow control valve. A rotor fixed to the rotating shaft includes at least one vane for moving or pumping fluid through the fluid passageway when it is open and the shaft is rotated. The unit rotates independently of the shaft and rotor when the passageway is unrestricted.

Abstract: A fluid clutch includes a rotatably driven shaft. A closed casing is rotatably mounted on the shaft by bearings. The casing includes an oil basin chamber and a torque transfer chamber. A driving disc is rigidly mounted to the shaft and in the torque transfer chamber. An exhaust passage extends from an outer position in the torque transfer chamber to the oil basin chamber. A dam in the torque transfer chamber urges oil into the exhaust passage and to the oil basin chamber. A pump is disposed between the oil basin chamber and the torque transfer chamber and is operative to urge oil from the oil basin chamber downstream into the torque transfer chamber. A valve is operative to selectively open or close access to the pump in accordance with sensed temperature. Thus, the dam and exhaust passage urge oil from the torque transfer chamber to prevent accompanying rotation. However, the pump urges oil into the torque transfer chamber in accordance with cooling needs.

Abstract: A torque coupling device for use as, for example, a so-called center differential provided between front and rear road wheel axles of a four-wheeled vehicle comprises a cup-shape front housing, a rear housing closing an open end of the front housing, a rotational shaft co-axially rotatably supported by the front and rear housings therewithin, and a clutch disc assembly interposed within the front housing between an axial inner end of the front housing and an axial inner end of the rear housing. The initial clearance in axial direction between the clutch assembly and the inner ends of the front and rear housings is tuned so that when the relative rotation between the housings and said rotational shaft causes a certain temperature difference between the housing and the clutch assembly, the difference in thermal expansion between the front housing and the clutch assembly brings clutch discs of the clutch assembly into friction contact to transmit a rotational torque between the housings and the rotational shaft.

Abstract: A temperature sensitive fluid-type fan coupling device is provided. The device includes a rotating shaft having a hollow housing rotatably mounted on one end. The housing is divided into an oil basin chamber and a torque transmission chamber. A driving disc is securely mounted to the driving shaft and is disposed within the torque transmission chamber of the housing. The driving disc is substantially hollow and includes a plurality of radially aligned walls extending inwardly from outer circumferential portions thereof. A through hole extends through a central portion of a side wall of the driving disc opposite the rotating shaft. A plurality of apertures extend through the opposed side wall of the driving disc at radially outer positions thereon. Oil flow into and out of the hollow driving disc is controlled to avoid accompanying rotation during the short period of time after starting the engine.

Abstract: To increase the idling rotational speed of a fluid friction coupling, the static pressure in the reservoir space is increased by a differential pressure valve which opens toward the reservoir chamber at a defined differential pressure between the working chamber and the reservoir chamber. The fluid friction coupling includes a driving element; a driven-end coupling housing including a reservoir chamber and a working chamber; a partition for separating the reservoir chamber from the working chamber; a return passage arranged in the coupling housing between the working chamber and the reservoir chamber; and a differential pressure valve arranged within or in the region of the return passage.