Abstract: A viscous clutch according to the present invention, which is composed of a main body having a fluid storage chamber of a concave shape formed at a central portion thereof and a cover having a concave fluid operation chamber formed at a central portion thereof, comprises: a fan housing in which the main body is stacked on an upper side of the cover so that an opening of the fluid operation chamber can be covered; a drive shaft which extends in a vertical direction and has a lower end inserted through a bottom plate of the main body; a rotor fixedly coupled to the lower end of the drive shaft so as to be rotatable in the fluid operation chamber; a rotary assembly integrally coupled to the main body so as to cover an opening of the fluid storage chamber; a coil core mounted on an upper surface of the rotary assembly and generating an electromagnetic force when an electric current is applied from the outside; and a valve assembly for opening or closing a fluid outlet according to whether or not an electric curre

Abstract: An external control type fan clutch device has an electromagnet fixed to a rotating shaft. The electromagnet is energized to activate a valve member formed of a plate spring and an armature and provided to a drive disk or a sealed housing to externally control opening and closing an oil circulating flow passage (oil supply port). The valve member is structured so that the armature attached to the plate spring of the valve member is divided into a plurality of pieces in the direction from the base end side to the oscillating end side of the plate spring to provide a plurality of bend points of the plate spring.

Abstract: A viscous clutch includes an input member, an output member, a working chamber, a reservoir to hold a supply of a shear fluid, an outlet, a return bore, an accumulator, and a first wall having an arcuate segment. The reservoir is connected to the working chamber by a fluid circuit, along which the outlet passes the shear fluid from the reservoir to the working chamber and the return bore returns the shear fluid pumped out of the working chamber to the accumulator. The accumulator is arranged in series with the reservoir in the fluid circuit. The first wall is positioned within the reservoir to separate a first portion from a second portion.

Abstract: A viscous clutch includes a shaft, a rotor attached to the shaft, a housing located adjacent to the rotor, a working chamber defined between the rotor and the housing, a reservoir used to store a shear fluid, a valve assembly, an electromagnetic coil, and a flux insert in the housing. Selective introduction of the shear fluid to the working chamber facilitates selective torque transmission between the rotor and the housing. The valve assembly regulates flow of the shear fluid between the reservoir and the working chamber, and includes an armature. Selective energization of the electromagnetic coil governs actuation of the valve assembly. A flux circuit is provided that extends from the electromagnetic coil to the armature and back to the electromagnetic coil. The flux circuit passes through the flux insert and through the shaft, and the flux circuit crosses a radial air gap between the flux insert and the armature.

Abstract: A fan and an electronic device are provided. An opening is provided on a sidewall of a housing of the fan, a baffle is arranged at the opening and to cover a part of the opening. When an impeller of the fan rotates in a first direction, a first end of the baffle is fixed and a second end of the baffle moves towards the inside of the housing, or in the case that the impeller rotates in the first direction, the baffle protrudes towards the inside of the housing to form a protrusion. In the case that the impeller rotates in a second direction, the second end of the baffle moves towards the outside of the housing, or in the case that the impeller rotates in the second direction, the baffle protrudes towards the outside of the housing to form a protrusion.

Abstract: Provided is a highly reactive fluid fan clutch device excellent in reaction speed of fan rotation to a control signal even with a weak centrifugal force during low fan rotation. The device of an external control type includes: an annular oil reserving chamber provided in a case that is supported by a rotary shaft having a drive disk fixed thereto; and a valve member for opening and closing an oil circulating flow passage hole of the annular oil reserving chamber by an electromagnet, wherein an effective oil contact area at a torque transmission gap formed between a drive side and a driven side is increased and decreased to control rotation torque transmission from the drive side to the driven side, and an inner wall eccentric to an outer wall of the annular oil reserving chamber is provided in the annular oil reserving chamber.

Abstract: A viscous clutch includes a rotor, a housing member, a working chamber located between the housing member and the rotor, a reservoir to hold viscous fluid that is configured to rotate with the rotor, a return bore in fluid communication between the working chamber and the reservoir, a first passage from the reservoir to the working chamber, a second passage from the reservoir to the working chamber, and a valve. The second passage is spaced from the first passage, and can extend substantially radially through the rotor. The valve is configured to selectively regulate flow of the viscous fluid through the first passage, and the second passage is unobstructed such that the viscous fluid can pass from the reservoir to the working chamber regardless of the operational state of the valve. Viscous fluid present in the working chamber rotationally couples the rotor and the housing member.

Abstract: An external control type fan clutch device has a sealed housing with a torque transmission chamber incorporating a drive disk therein. The drive disk has an oil reserving chamber. The sealed housing is supported on a rotary shaft with the drive disk fixed thereto. A valve member (armature) controls opening and closing of an oil circulating flow passage hole provided on a side wall of the oil reserving chamber. The valve member has magnetism and is actuated by an electromagnet supported on the rotary shaft for opening or closing the oil circulating flow passage hole. A ring-like magnetic body is disposed between the electromagnet and the rotary shaft for efficiently transmitting a magnetic flux of the electromagnet to the armature of the valve member. The external control type fan clutch device achieves size reduction, weight reduction and power saving.

Abstract: Disclosed is an electrically controlled silicon oil fan clutch rotary valve device. The valve device is based on a magnetic mandrel, including a Y-shaped element, a driven disc, a driving disc, and a guide disc intercombined, which achieves control over flow of silicon oil by controlling rotation of a valve, and achieves precise control over positions by resetting through a reset torsion spring and using outer teeth and inner teeth of the driving disc and the driven disc as well as a stop device. In the present invention, the valve may be controlled to be stable at an appropriate position through the size of the current of the coil, so as to achieve a stepless speed and achieve a purpose of precisely controlling the clutch.

Abstract: Provided is a highly reactive fluid fan coupling device utilizing the non-Newtonian fluid characteristics of oil, thereby obtaining an excellent reaction rate of fan rotation using a control signal. In the fan coupling device, where the interior of a sealed housing supported on a rotary shaft with a drive disk secured thereto is partitioned in an oil reservoir chamber and a torque transmission chamber placing the drive disk thereinto by a partition plate; drive torque is transmitted to a driven side by oil supplied to the torque transmission chamber; and opening and closing of a flow path of oil is controlled by a valve member actuated by an electromagnet, wherein a mechanism to scrape out the oil in the oil reservoir chamber utilizing the non-Newtonian fluid characteristics of oil is provided on the drive disk so as to be opposed to an oil supply adjusting hole of the partition plate.

Abstract: A rotating mechanism driving apparatus is disclosed that includes a frictional transmission configured to output torque via a viscous fluid, the torque being input from the motor; an input shaft rotational amount detecting part configured to detect a rotational amount of an input shaft of the frictional transmission; an output shaft rotational amount detecting part configured to detect a rotational amount of an output shaft of the frictional transmission; an input torque detecting part configured to detect input torque of the frictional transmission; a slip amount calculating part configured to calculate a slip amount between the input shaft and the output shaft; and abnormal state determining part configured to determine abnormal state of a rotating mechanism connected to the output shaft of the frictional transmission based on the input torque and to determine an abnormal state of the frictional transmission based on the slip amount.

Abstract: A viscous clutch (30; 30?) includes a stationary journal bracket (32; 32?) defining a mounting shaft (32-1; 32-1?), an output member (34; 34?) rotatably supported on the mounting shaft about an axis (A), an input member (34; 34?) rotatably supported on the mounting shaft about the axis, and a working chamber (50; 50?) defined between the input member and the output member to selectively transmit torque there between when a shear fluid is present. The mounting shaft extends axially through the viscous clutch from a front face (62; 62?) of the viscous clutch to a rear face (56; 56?) of the viscous clutch, with the rear face defining a mounting surface for mounting the viscous clutch at a mounting location. The front and rear faces are located at opposite sides of the viscous clutch and face in opposite directions.

Abstract: A valve assembly for a viscous clutch includes an orifice plate defining a bore to allow the passage of a fluid through the orifice plate, a reed valve secured relative to the orifice plate, an armature comprising a magnetic flux-conducting material, an anchor spring secured to the armature, and a stiffening plate. The reed valve includes a tongue configured to selectively cover the bore of the orifice plate, and a first pivot location along the tongue. A second pivot location is defined along the anchor spring at an edge of the stiffening plate. The first and second pivot locations are spaced from each other. The armature is configured to selectively apply a force to the reed valve to pivot at least a portion of the tongue about the first pivot location.

Abstract: A liquid friction clutch (1) having a housing (2, 3), a clutch disc (4) rotatable relative to the housing (2, 3) and which is rotatably arranged on an end (5) of a shaft (6) which is mounted centrally within the housing (2, 3), which shaft (6) bears on its other end (8) a driveable active element (7). A working chamber (9) is positioned between the housing (2, 3) and the clutch disk (4). A storage chamber (10) is provided for the clutch fluid. A supply duct (11) leads from the storage chamber (10) to the working chamber (9). A stationary clutch part (13) relative to which the housing (2, 3) is rotatable, wherein a rotatably mounted pump element (14) is provided which, with the housing (2, 3), defines a shear gap (12).

Abstract: Hydraulic fan drive system with sensor feed-back. A sensor positioned in the central shaft of the fan drive assembly provides speed feedback signals and eliminates the need for routing the sensor wires.

Abstract: An engagement system (10) for a fluid-coupling device (9) may include a first engagement member (31) and a second engagement member (15) that is in operation with the first engagement member (31). A working chamber (33) is disposed between and at least partially defined by the first engagement member (31) and the second engagement member (15). The working chamber (33) has an inlet port (118) and an outlet port (120). A fluid reservoir (35) is fluidically-coupled to the working chamber (33). A scavenge valve (11) is coupled between the working chamber (33) and the fluid reservoir (35) and adjusts the fluid flow through the outlet port (120). An engagement system (10) for a fluid-coupling device (9) may in addition to or alternatively include a working chamber (33) that includes a working chamber inlet port (118) that is along an outer perimeter (126) of the first engagement member (31).

Abstract: The invention relates to a fan drive device (1) for driving at least one fan impeller (2), comprising at least one first drivable coolable housing element (9, 10) with at least one output disc (13) which can be connected to the at least one drivable coolable housing element (9, 10) in such a way as to be capable of transmitting torque by fluid friction, wherein at least one fluid can be admitted to at least one torque-transmitting space, and the mass flow of said fluid can be regulated by means of a valve element (30), wherein the valve element (30) can be actuated by at least one actuator (26, 27), and at least a section of the actuator (26, 27) is arranged in at least one retaining element (33) for fastening to a motor unit.

Abstract: A speed monitoring system (6) for a fluid-coupling device (10) includes a hub (44) and a ring magnet (220). The hub (44) rotates at a first speed that is proportional to an input clutch speed of a fluidically engageable input member. The ring magnet (220) rotates at a second speed that is proportional to an output clutch speed of a fluidically engageable output member. A magnetic sensor (232) generates a differential speed signal of the ring magnet (220) relative to the first speed. A controller (54) generates an actual speed signal indicative of the second speed in response to said differential speed signal.

Abstract: A viscous fan drive with a front-mounted fan and electrical actuation without a tethered harness. The mechanical package includes an inverted viscous clutch, a drive pulley and a split electromagnetic actuator with the electrical portion mounted to a stationary mounting member. An axially moveable valve member controls the flow of viscous fluid.

Abstract: A viscous shear fan drive mechanism for a cooling fan. A moveable valve disk is provided which controls the quantity of fluid in the operating chamber. An electronic actuation system activates piston and shaft members which move the valve disk against the bias of a return spring to open the fill holes, allow fluid communication between the reservoir and working chambers, and allow rotation of the cooling fan. Without activation of the electronic actuation system, the flow of fluid to the working chamber is prevented. A non-magnetic or insulating bushing member adjacent the piston and shaft members prevents the system from sticking in the actuation condition when power is eliminated.

Abstract: A viscous fan drive with a front-mounted fan and electrical actuation without a tethered harness. The mechanical package includes an inverted viscous clutch, a drive pulley and a split electromagnetic actuator with the electrical portion mounted to a stationary mounting member. An axially moveable valve member controls the flow of viscous fluid.

Abstract: A valve assembly for a viscous clutch includes an orifice plate defining a bore to allow the passage of a fluid through the orifice plate, a reed valve secured relative to the orifice plate, an armature comprising a magnetic flux-conducting material, an anchor spring secured to the armature, and a stiffening plate. The reed valve includes a tongue configured to selectively cover the bore of the orifice plate, and a first pivot location along the tongue. A second pivot location is defined along the anchor spring at an edge of the stiffening plate. The first and second pivot locations are spaced from each other. The armature is configured to selectively apply a force to the reed valve to pivot at least a portion of the tongue about the first pivot location.

Abstract: A viscous fan drive with a front-mounted fan and electrical actuation without a tethered harness. The mechanical package includes an inverted viscous clutch, a drive pulley and a split electromagnetic actuator with the electrical portion mounted to a stationary mounting member. An axially moveable valve member controls the flow of viscous fluid.

Abstract: In a frictional engagement apparatus that includes a clutch drum, separator plates, a clutch hub, and friction plates, a plurality of concave portions that dip inward in the plate thickness direction and a plurality of convex portions that protrude outward in the plate thickness direction are formed on an edge of the separator plates and/or a an edge of the friction plates, with each convex portion being arranged between two adjacent concave portions. Ridge lines of the concave portions and the convex portions pass through positions away from a center point of the separator plates and/or the friction plates.

Abstract: A viscous fan drive with a front-mounted fan and electrical actuation without a tethered harness. The mechanical package includes an inverted viscous clutch, a drive pulley, a split electromagnetic actuator with the electrical portion mounted to a stationary mounting member. Enhanced cooling can be provided with breather openings in the pulley, breather slots in the body member, and fins in the reservoir.

Abstract: The invention provides a control method of an external control type fan clutch able to improve engine performance, fuel cost and cooling performance of a capacitor of an air conditioner (A/C) and restrain fan noises due to associative rotation. Namely, in the external control type fan clutch device constructed so as to control the opening and closing of a supply adjusting hole of oil by a valve member operated by an electromagnet, the opening and closing of the supply adjusting hole of the oil is on-off-controlled with the temperature of a cooling liquid of a radiator, a fan rotating speed, the temperature of transmission oil, a vehicle speed, an engine rotating speed, the pressure of a compressor of the air conditioner, etc. as parameters.

Abstract: An electromagnetically actuated viscous clutch assembly includes a rotor arranged relative to an axis of rotation, an electromagnetic coil for generating magnetic flux, a housing positioned adjacent to the rotor to create a fluid working chamber therebetween with the housing and the rotor being selectively rotatable relative to one another, an insert extending through the housing and configured to conduct magnetic flux from the electromagnetic coil along a flux path, a valve assembly electromagnetically linked to the insert along the flux path for selectively controlling fluid flow into the working chamber to selectively engage the rotor and the housing, and a plurality of recesses defined in a portion of the housing located at an interior of the flux path to reduce eddy currents.

Abstract: A viscous fan drive with a front-mounted fan and electrical actuation without a tethered harness. The mechanical package includes an inverted viscous clutch, a drive pulley and a split electromagnetic actuator with the electrical portion mounted to a stationary mounting member. An axially moveable valve member controls the flow of viscous fluid.

Abstract: A viscous fan drive with a front-mounted fan and electrical actuation without a tethered harness. The mechanical package includes an inverted viscous clutch, a drive pulley and a split electromagnetic actuator with the electrical portion mounted to a stationary mounting member. An axially moveable valve member controls the flow of viscous fluid.

Abstract: A viscous fan drive having improved pumping efficiency from removing fluid from a fluid operating chamber to a fluid reservoir chamber is achieved by providing a wiper element that is located within the radial clearance between the clutch and the housing that effectively seals leakage paths leading (upstream) and trailing the wiper. The wiper element includes a radial tang that is positioned within a corresponding slot of the cover wall. The wiper element also has a pair of spaced apart arms extending from the radial tang portion each having a radial outer surface that has a similar radius as the cover wall and a radial inner surface has a similar radius as the clutch. The wiper element also preferably includes details designed to seal the radial inner surface to the outer periphery of the clutch during fan drive operation and a locating detail to aid in assembly.

Abstract: A fluid friction clutch with improved fluid pumping system. A scraping member is provided adjacent the clutch plate and has a duct which communicates with the reservoir chamber.

Abstract: A viscous clutch assembly (100) includes a rotor (104), a selectively rotatable member (102) surrounding the rotor and defining a working chamber (114) therebetween, a first opening (126A) defined through the rotor (104) between front and rear sides of the rotor (104) and in fluid communication with the working chamber (114) at both the front and rear sides of the rotor (104), a reservoir (112) supported by the rotor (104) and having a second opening (138), a valve assembly (106) supported by the rotor (106) having a cover plate (140) for selectively covering the second opening (138), and a channel (128,130) defined in the rotor (104) between the first opening (126A) and an area adjacent to the second opening (138). The channel (128,130) is in fluid communication with the first opening (126A).

Abstract: A viscous clutch assembly (100) includes a rotational input structure (110), a rotor (104) attached to the rotational input structure (110), a selectively rotatable member (102) surrounding the rotor (104) and rotatably supported by the rotational input structure (110), an electromagnetic coil (108) positioned relative to a driven side of the rotor (104), a valve assembly (106) supported by the rotor (104), and a magnetic flux circuit for controlling the valve assembly (106) with magnetic flux generated by the electromagnetic coil (108). The valve assembly (106) includes a cover plate (140) for regulating flow of a shear fluid. The rotational input structure (110) comprises a material capable of conducting magnetic flux. The magnetic flux circuit is configured to include no more than four air gaps (G1-G4).

Abstract: A controllable drive (1) suitable for a motor vehicle coolant pump (2) comprises a rotatably mounted shaft (5), a driven member (7) which is rotationally fixedly mounted on the shaft (5), a driving member (9) which is mounted so as to be rotatable relative to the shaft (5), and a coupling region (7/8) which is arranged between the driving and driven members (9, 7) and holds a viscous fluid. At least one first flow path and at least one second flow path connect a fluid reservoir to the coupling region (7/8), and an actuation device (11a, 11b, 12, 13, 14) changes at least one passage opening of at least one flow path. A coupling housing (8, 8a, 8b) is connected to the driving member (9), and the actuator (14) is arranged within the coupling housing (8, 8a, 8b).

Abstract: A viscous fan drive with a front-mounted fan and electrical actuation without a tethered harness. The mechanical package includes an inverted viscous clutch, a drive pulley and a split electromagnetic actuator with the electrical portion mounted to a stationary mounting member. An integrated slip speed sensor is provided in order to determine the output speed.

Abstract: A viscous fan drive with a front-mounted fan and electrical actuation without a tethered harness. The mechanical package includes an inverted viscous clutch, a drive pulley, a split electromagnetic actuator with the electrical portion mounted to a stationary mounting member, and anti-drainback check valve.

Abstract: A viscous friction clutch for driving a cooling fan in a motor vehicle is disclosed, wherein the viscous friction clutch comprises a driving disk and a housing, a supply chamber and a working chamber, a device for supplying shear fluid from the supply chamber to the working chamber and a device for returning the shear fluid from the working chamber to the supply chamber.

Abstract: A valve assembly (106) for an electromagnetically actuated viscous clutch (100) includes a cover plate (140) defining a seating portion configured to selectively cover an opening (138) from a reservoir (112), a flexible mounting plate (142), and an armature (144) that is movable in response to applied magnetic flux to move the cover plate (140) relative to the opening (138) from the reservoir (112). The armature (144) includes a base portion (146) connected to the cover plate (140) and the mounting plate (142), and a finger (148) extending from the base portion (146). The finger (148) and the base portion (146) define a path for conducting magnetic flux.

Abstract: A viscous clutch assembly (100) includes a rotational input structure (110), a rotor (104) attached to the rotational input structure (110), a selectively rotatable member (102) surrounding the rotor (104) and rotatably supported by the rotational input structure (110), an electromagnetic coil (108) positioned relative to a driven side of the rotor (104), a valve assembly (106) supported by the rotor (104), and a magnetic flux circuit for controlling the valve assembly (106) with magnetic flux generated by the electromagnetic coil (108). The valve assembly (106) includes a cover plate (140) for regulating flow of a shear fluid. The rotational input structure (110) comprises a material capable of conducting magnetic flux. The magnetic flux circuit is configured to include no more than four air gaps (G1-G4).

Abstract: A speed monitoring system (6) for a fluid-coupling device (10) includes a hub (44) and a ring magnet (220). The hub (44) rotates at a first speed that is proportional to an input clutch speed of a fluidically engageable input member. The ring magnet (220) rotates at a second speed that is proportional to an output clutch speed of a fluidically engageable output member. A magnetic sensor (232) generates a differential speed signal of the ring magnet (220) relative to the first speed. A controller (54) generates an actual speed signal indicative of the second speed in response to said differential speed signal.

Abstract: A viscous fan drive having improved pumping efficiency from removing fluid from a fluid operating chamber to a fluid reservoir chamber is achieved by providing a wiper element that is located within the radial clearance between the clutch and the housing that effectively seals leakage paths leading (upstream) and trailing the wiper. The wiper element includes a radial tang that is positioned within a corresponding slot of the cover wall. The wiper element also has a pair of spaced apart arms extending from the radial tang portion each having a radial outer surface that has a similar radius as the cover wall and a radial inner surface has a similar radius as the clutch. The wiper element also preferably includes details designed to seal the radial inner surface to the outer periphery of the clutch during fan drive operation and a locating detail to aid in assembly.

Abstract: A system for controlling the engagement and disengagement of a viscous type coupling is accomplished by controlling the relative positioning of a spring loaded valve arm relative to a fluid port through the use of an electrically-activated, temperature-sensitive member, such as a NiTi wire. The characteristics of shape memory alloy materials are such that they are hard above a predetermined temperature, but soft and ductile below a predetermined temperature. When engagement or disengagement of the coupling is desired, electrical current is introduced through the member, therein heating it above a predetermined temperature to harden it. This hardening causes the valve arm to either move to either cover or uncover a fluid port, depending upon the design arrangement of the valve arm relative to the fluid port. A controller coupled to a plurality of engine operating sensors and a power source controls the electrical activation as a function of a desired operating condition.

Abstract: A viscous fan drive in which the output drive to the fan is controlled by the movement of viscous fluid from a fluid reservoir and into the operating and working chamber of the coupling during normal operation. The input-coupling assembly and cover member are formed with a unique combination of continuous and non-continuous radially extending lands and grooves designed to distribute the viscous fluid in a continuous film throughout the shear zone so as to maximize output fan speed at a given input speed. An armature-venting feature is designed to simplify the opening and closing of the valve disk in an electronic version of the viscous fan drive depending upon the desired operating condition.

Abstract: In a method for controlling an external control type fan coupling device 3, arithmetic processing to determine the rotation speed of fan 4 with a quick acceleration detection signal used as a parameter is carried out at a high frequency than that in arithmetic processing to determine the rotation speed of fan 4 using signals other than the quick acceleration detection signal as a parameter.

Abstract: An external-control-type fan coupling device is provided and has no restriction on the layout or positional relationship of an electromagnetic coil and a valve element of the device. As a result, the casing and the valve structure of the device can be simplified. Additionally, the design prevents leaking of oil and leaking of magnetism without adversely affecting performance.

Abstract: A viscous fluid clutch for controlling the rotation of an engine cooling fan has a dividing disk separating a storage chamber from a working chamber. The dividing disk includes an opening having a geometry that defines a drain-back path to the working chamber regardless of the angular orientation of the clutch.

Abstract: The present invention is directed toward incorporating a single actuation unit to actuate two or more couplings. The clutch actuation arrangement has a first coupling (36) connected to a first valve (32), a second coupling (38) connected to a second valve (34), and an actuator (24) operably connected to the first valve (32) and the second valve (34). The first valve (32) and the second valve (34) control fluid flow to the first coupling (36) and the second coupling (38). The clutch actuation arrangement also includes an elongated cylinder (31) operably connected to the first valve (32) and second valve (34). A piston (30) is slidably disposed in the elongated cylinder (31), wherein the piston (30) controls the amount of pressure presented to the first and second valves (32,34).

Abstract: A valve assembly (106) for an electromagnetically actuated viscous clutch (100) includes a cover plate (140) defining a seating portion configured to selectively cover an opening (138) from a reservoir (112), a flexible mounting plate (142), and an armature (144) that is movable in response to applied magnetic flux to move the cover plate (140) relative to the opening (138) from the reservoir (112). The armature (144) includes a base portion (146) connected to the cover plate (140) and the mounting plate (142), and a finger (148) extending from the base portion (146). The finger (148) and the base portion (146) define a path for conducting magnetic flux.

Abstract: An engine mounted fan clutch is disclosed that utilizes an actuator including two shape memory alloy actuation wires to engage and disengage a valve arm and ultimately the fan. The actuator also includes a controller and a position sensor to accurately determine the position of a valve arm. The fan clutch is part of a control system that continuously monitors the engine parameters and makes adjustments to keep the engine temperature within an acceptable range.

Abstract: An external-control-type fan coupling device is provided and has no restriction on the layout or positional relationship of an electromagnetic coil and a valve element of the device. As a result, the casing and the valve structure of the device can be simplified. Additionally, the design prevents leaking of oil and leaking of magnetism without adversely affecting performance.