Abstract: A system for measuring a formation parameter, the system including: a formation parameter test device having: a structure capable of segregating a discrete volume including a formation interface surface within a well, and a parameter sensor in operable communication with the volume; a high bandwidth communications system in operable communication with the parameter sensor; and a processing unit in operable communication with the high bandwidth communications system and disposed remotely from the parameter sensor, the processing unit configured to receive parameter data.

Abstract: Certain viscous oil reservoirs are too deep to be commercially mined but lack an adequate top seal to employ in situ recovery methods such as SAGD. Without an adequate top seal, gases from the reservoir can rise into overlying aquifers and potentially to the surface. While ice-like hydrates would not normally form above the oil reservoir during in situ recovery, an additive can be added to promote hydrate formation. In this way, a hydrate barrier can be formed to act as a top seal to contain these gases.

Abstract: A method for treating water at a water treatment facility is provided. In one aspect, the water has been circulated through a subsurface formation in a shale oil development area. The subsurface formation may comprise shale that has been spent due to pyrolysis of formation hydrocarbons. The method in one embodiment includes receiving the water at the water treatment facility, and treating the water at the water treatment facility in order to (i) substantially separate oil from the water, (ii) substantially remove organic materials from the water, (iii) substantially reduce hardness and alkalinity of the water, (iv) substantially remove dissolved inorganic solids from the water, and/or (v) substantially remove suspended solids from the water. The method may further includes delivering the water that has been treated at the water treatment facility re-injecting the treated water into the subsurface formation to continue leaching out contaminants from the spent shale.

Abstract: A method of completing a wellbore in a subsurface formation. The method principally has application to subsurface formations comprising organic-rich rock that is to be heated in situ. Heating the organic-rich rock pyrolyzes solid hydrocarbons into hydrocarbon fluids. The method includes identifying sections along the wellbore where the organic richness of formation rock within the identified zones varies over short distances. Such variance presents a risk of mechanical failure to downhole equipment. The method further includes strengthening the downhole equipment in at least one of the identified sections.

Abstract: A well bore servicing apparatus comprising a housing having a longitudinal axis and a through bore, and a movable member disposed in the housing, the movable member having a through bore and a fluid aperture therein, wherein the movable member is movable between a first stop position and a second stop position relative to the housing, wherein the fluid aperture is in fluid communication with the housing through bore and the movable member through bore to provide a fluid stream to the well bore in the first and second axially spaced stop positions.

Abstract: Systems and methods for determining at least one parameter of a fluid in a well are provided. The system has a downhole system deployable into the well, and sensor elements to measure fluid parameter(s) of the fluid in the well. Each of the sensor elements is provided with a base and sensors. The base is positionable on the coiled tubing system about the injection port. The sensors are positionable in the base. Each of the sensors are thermally isolated from each other, and are capable of operating as both a heater to heat the fluid, and as a temperature sensor for measuring a temperature of the fluid. The sensors are operatively interchangeable such that the sensors may selectively heat and measure the temperature of the fluid whereby fluid parameters of the fluid are determined.

Abstract: A process for treating a water stream produced in the recovery of heavy oil from geological formations. The process includes use of a heat exchange unit having at least one tube having a multi-layer coating. The multi-layer coating includes a melt flowable copolymer of tetrafluoroethylene adhered to the interior surface or exterior surface of the tube.

Abstract: Viscoelastic surfactant (VES) gelled aqueous fluids containing water, a VES in an amount effective to increase the viscosity of the water, and an internal breaker may be useful in removing a residual polymer from a hydraulic fracture. Optionally, a pseudo-crosslinker may be present to further improve the properties related to treatment fluid placement and polymer clean-up. A plurality of aliquots of VES gelled fluid may be injected into a subterranean formation. A stop-start interval may exist between the injection of each aliquot. The VES gelled fluid may contact at least some of the residual polymer in the hydraulic fracture, and a broken fluid is formed once the viscosity of the VES gelled fluid is reduced with the internal breaker. At least a portion of the residual polymer and a majority of the broken fluid may be removed.

Abstract: The present invention is to an internal sleeve slidably received within a tubular housing. The sleeve and outer housing have windows that selectively align. Movement of the sleeve within the housing is controlled by a ball passing through the interior of the sleeve to activate a ratchet that allows the sleeve to move a set amount under the influence of a spring. A split seat at a lower end of the housing traps after a set number of balls have passed through the housing. A number of similar tools can be used to provide openings at various points that include coordinated ratchet steps so that only one tool at a time opens for fracturing or other purposes. A reverse flow causes a ball to impinge upon the next higher ball seat and thereby opening the seat to provide a full bore flow passage through the tool.

Abstract: The riser pipe section comprises a main tube 22 and auxiliary line elements 23 arranged parallel to tube 22. The ends of the main tube comprise connectors 20a and 20b allowing longitudinal stresses to be transmitted. The ends of auxiliary line elements 23 comprise connectors 20c and 20d. Auxiliary line elements 23 consist of two parts 23a and 23b assembled by an adjustment device 23c or 30 allowing the axial length of each auxiliary line element to be adjusted.

Abstract: Apparatus for improving the safety and recovery of wells to be installed in oil wells comprising a Deep Set Well Head (DSWH), a Casing Receptacle (1), a Deep Set Tubing Hanger (DSTH) (2), Sub-Surface Safety Valves (SSSVs) (12) (13) with one or two independent Control Lines and Connection elements between the DSTH and well head.

Abstract: A plunger lift system of an oil or gas well and method of use is described. The plunger lift system includes a plunger, a sensor, a flow valve assembly, and a controller. The plunger is positioned within the tube string and travels up and down the string in response to the opening and/or closing of the flow valve assembly. The sensor is connected to the tube string and detects vibrations generated by impacts created by the plunger temporarily catching on gaps in the tube string. The sensor generates a sensor signal in response to the impacts of the plunger which are used by the controller to determine the velocity of the plunger within the tube string. If the velocity of the plunger exceeds a preselected maximum velocity, the controller selectively opens or closes the flow valve assembly to reduce the velocity of the plunger.

Abstract: A system includes a back pressure valve configured to mount in a mineral extraction system. The back pressure valve comprises a cylindrical body comprising a venting port coaxial with a longitudinal axis of the cylindrical body and a plunger disposed in the venting port, wherein the plunger comprises a stem that extends from the venting port into an adjacent cavity of the cylindrical body. A method of operating a valve, includes biasing a plunger to an open position, biasing a valve locking mechanism to a locked position in relation to a bore of a mineral extraction system, and biasing a plunger to a closed position.

Abstract: Apparatus and methods for controlling the flow of fluid, such as formation fluid, through an oilfield tubular positioned in a wellbore extending through a subterranean formation. Fluid flow is autonomously controlled in response to change in a fluid flow characteristic, such as density or viscosity. A fluid diverter is movable between an open and closed position in response to fluid density change and operable to restrict fluid flow through a valve assembly inlet. The diverter can be pivotable, rotatable or otherwise movable in response to the fluid density change. The diverter is operable to control a fluid flow ratio through two valve inlets. The fluid flow ratio is used to operate a valve member to restrict fluid flow through the valve.

Abstract: A hydraulic control system for a sub-surface safety valve has control lines in hydraulic communication with the valve. A first control line communicates hydraulic pressure to actuate the valve, while the other control line communicates hydraulic pressure to compensate for hydrostatic pressure associated with the first control line. A regulator regulates hydraulic communication between the two control lines. The regulator prevents fluid communication from the first to the balance control line as long as integrity of the second line is maintained. When the second line fails, the safety valve can fail in the open position. In this case, the regulator permits hydraulic pressure to bleed from the first line to the second line. This allows the safety valve to then fail in a closed condition and allows the second line to potentially be recharged if its integrity is regained.

Abstract: Disclosed is a torque limiter having driver mandrel and driven axially aligned mandrels, a piston movable into and out of an engaged position wherein the driver and driven mandrels are coupled together to transmit torque there between. Hydraulically locking the movable piston in an engaged position. Disengaging the hydraulic lock when during rotation when a specified torque magnitude is exceeded to allow relative rotation between the mandrels. Resetting the torque limiter by hydraulically locking the piston in the engaging position when relative rotation ceases or is reduced.

Abstract: A system and method for positioning a tool within a wellbore are described herein. The interior surface of a tubular string is provided with one or more pluralities of grooves, each defining a selected profile. A tool is lowered into the tubular string, having a blade in communication therewith. The blade includes a plurality of protruding members thereon, which define a profile complementary to at least one of the selected profiles formed by one of the pluralities of grooves. A biasing member in communication with the blade continually biases the blade toward the interior surface of the tubular string to cause the profile of the blade to engage within the corresponding complementary profile of the tubular string. Positioning a tool in this manner is especially advantageous for locating a cutting tool at a precise location to sever a tubular segment at a joint, releasing tensile forces from the joint.

Abstract: The present invention is an in-situ apparatus for generating carbon dioxide gas at an oil site for use in enhanced oil recovery (EOR). The apparatus includes a steam generator adapted to boil and superheat water to generate a source of superheated steam, as well as a source of essentially pure oxygen. The apparatus also includes a steam reformer adapted to react a carbonaceous material with the superheated steam and the pure oxygen, in an absence of air, to generate a driver gas comprising primarily carbon dioxide gas and hydrogen gas. A separator is adapted to separate at least a portion of the carbon dioxide gas from the rest of the driver gas to generate a carbon dioxide-rich driver gas and a hydrogen-rich fuel gas. A compressor is used for compressing the carbon dioxide-rich driver gas for use in enhanced oil recovery, and the compressed carbon dioxide-rich driver gas, with substantially no oxygen, is injected to a predetermined depth in order to enhance oil recovery at the oil site.

Abstract: A fire suppression system having a foam proportioning system, a water source, and a controller. The foam proportioning system includes a foam tank having at least two types of chemical foamants, a selector valve in fluid communication with the foam tank for selecting one of the at least two types of chemical foamants, a foam pump in fluid communication with the selector valve for supplying the selected chemical foamant to a discharge unit, and a foam controller operatively connected to the foam pump and the selector valve. The water source is connected to the foam proportioning system for mixing water with the selected chemical foamant to form a fire suppression fluid. The controller is operatively connected to the foam proportioning system and includes a one-touch activation control for activating the controller. The controller is also configured to automatically output to the foam controller inputs for configuring the foam pump.

Abstract: A mobile soil aeration device including a machine frame, a drive, at least one guide arm that can be moved up and down by the drive and that is pivotably arranged on the machine frame, at least one articulated piercing tool that is coupled to the guide arm, said piercing tool can be lowered into the soil and withdrawn therefrom, a tool holder for the piercing tool, that is mounted about a first pivotable axis in the guide arm that can be displaced up and down by the drive in order to allow the piercing tool to pivot in relation to the guide arm when engaging with the soil.

Abstract: A bulldozer includes a body, a drive unit, a ripper, an operating lever, a steering lever, and a controller. The ripper is attached to a rear part of the body and performs ripping work. The operating lever is for operating the ripper. The steering lever is for controlling a travel operation by the drive unit. The controller executes a first control of pulling the ripper up out of the ground and a second control of tilting back the ripper, when it is detected that the ripping work has been ended by operation of the operating lever and the steering lever.

Abstract: A bushing is provided for mounting a pivot arm that has both a threaded portion as well as one or two smooth cylindrical portions. The threaded portion enables the pivot arm to be a laterally adjusted by rotating the bushing while the smooth portion or portions provide a bearing surface or surfaces for the pivot arm loads. This removes the load from the threads, reducing wear of both the bushing and the pivot arm, thereby reducing maintenance cost.

Abstract: A motor control device includes a target value setting unit, a measuring unit, a deviation calculating unit, a proportional control unit, an integral control unit, and a disabling unit. The deviation calculating unit calculates a deviation between a target value, set by the target value setting unit, and a measured value for rotational speed, measured by the measuring unit. The disabling unit disables proportional control, performed by the proportional control unit, when the deviation, calculated by the deviation calculating unit, is a value within a predetermined range.

Abstract: A power tool of the present teachings comprises a prime mover that drives a tool, a main switch that causes the prime mover to operate when the main switch is turned on and causes the prime mover to stop operating when the main switch is turned off, an illuminator that lights a working area of the tool, and a lighting mode selector switch for switching the lighting mode of the illuminator between a plurality of lighting modes which include a first lighting mode and a second lighting mode. When the first lighting mode is selected, the illuminator will be turned on for a first predetermined period from the point at which the main switch is turned off. When the second lighting mode is selected, the illuminator will not be turned on during the first predetermined period from the point at which the main switch is turned off.

Abstract: A pneumatic hammer mechanism is disclosed. The hammer mechanism features: a flying mass, which is movable along an impact axis; an impact surface, which limits a movement of the flying mass along the impact axis in the impact direction; an exciting piston, which limits a movement of the flying mass along the impact axis opposite from the impact direction; a pneumatic chamber between the flying mass and exciting piston; and a drive for periodically moving the exciting piston with a stroke along the impact axis. The flying mass is excited to a periodic movement between the impact surface and a minimum approach of the exciting piston. A length ratio of the maximum length of the pneumatic chamber to the stroke is selected as less than 1.55.

Abstract: The present invention provides for pulsed powered drilling apparatuses and methods. A drilling apparatus is provided comprising a bit having one or more sets of electrodes through which a pulsed voltage is passed through a mineral substrate to create a crushing or drilling action. The electrocrushing drilling process may have, but does not require, rotation of the bit. The electrocrushing drilling process is capable of excavating the hole out beyond the edges of the bit with or without the need of mechanical teeth.

Abstract: A down-the-hole assembly includes a housing having a central axis and a mechanical gear box positioned within the housing. The mechanical gear box is coupled to the housing such that rotation of the housing at a first rotational rate provides a rotary input to the mechanical gear box. A rotary cutting bit is coupled to the mechanical gear box. The mechanical gear box is configured to rotate said rotary cutting bit at a second rotational rate in response to that rotary input from the housing. The second rotational rate is greater than the first rotational rate. The mechanical gear box is also further configured to cause the rotary cutting bit to orbit about the central axis of the housing.

Abstract: Various embodiments relate to bearing assemblies configured to enable removal and replacement of superhard bearing elements, and bearing apparatuses that may utilize such bearing assemblies. The disclosed bearing assemblies may be used in a number of applications, such as downhole motors in subterranean drilling systems, directional drilling systems, roller-cone drill bits, and many other applications. In an embodiment, a bearing assembly includes a support ring and a retention ring assembled with the support ring. The bearing assembly further includes a plurality of superhard bearing elements. The retention ring and at least a number of the superhard bearing element are collectively configured to restrict displacement of the at least a number of the superhard bearing elements.

Abstract: In one aspect of the present invention, a downhole fixed bladed bit comprises a working surface comprising a plurality of blades converging at a center of the working surface and diverging towards a gauge of the bit, at least on blade comprising a cutting element comprising a superhard material bonded to a cemented metal carbide substrate at a non-planer interface, the cutting element being positioned at a positive rake angle, and the superhard material comprising a substantially conical geometry with an apex comprising a curvature.

Abstract: Embodiments of the invention relate to a polycrystalline diamond compact. In an embodiment, the polycrystalline diamond compact includes a substrate and a polycrystalline diamond table including a first polycrystalline diamond layer bonded to the substrate and at least a second polycrystalline diamond layer. At least an un-leached portion of the polycrystalline diamond table includes a plurality of diamond grains defining a plurality of interstitial regions and a metal-solvent catalyst occupying at least a portion of the plurality of interstitial regions. The plurality of diamond grains and the metal-solvent catalyst collectively exhibit a coercivity of about 115 Oe or more and a specific magnetic saturation of about 15 G·cm3/g or less. The second polycrystalline diamond layer exhibits a second average diamond grain size that is less than a first average diamond grain size of the first polycrystalline diamond layer and/or the first polycrystalline diamond layer includes a tungsten-containing material therein.

Abstract: Thermally stable diamond bonded construction comprise a diamond bonded body including a thermally stable region, comprising a plurality of diamond grains bonded together by a reaction product of the diamond grains with a reactant such as Si, and a polycrystalline diamond region, comprising intercrystalline bonded diamond and a catalyst material. The body further comprises a ceramic compound formed by reaction of an Nb, Zr, Ti, or Mo getter material with a gaseous element generated during HPHT sintering of the diamond bonded body. The diamond bonded body may comprise from 0.1 to 15 percent by weight of the ceramic compound. The diamond bonded body can be formed during a single HPHT process operated at different temperatures when the reactant has a melting temperature above the catalyst material. The construction may include a metallic substrate attached to the diamond bonded body to facilitate use as a wear or cutting element.

Abstract: Mobile robot systems and methods are provided. At least one tracked mobile robot has a first end comprising a first pair of wheels, a second end comprising a second pair of wheels, an articulated arm coaxial with the first pair of wheels, and a driven support surface surrounding the first pair of wheels and the second pair of wheels. The at least one mobile robot surmounts obstacles and performs additional maneuvers alone and in combination with at least one other mobile robot.

Abstract: A front wheel drive powered wheelchair is provided and may include a support frame, a pair of opposing drive wheels, a pair of drives, and a pair of rear wheels. The frame may include a front portion, a seat post, and two independent arms extending rearward from the front portion. Each drive wheel may be coupled to the front portion of the frame. Each drive may be mounted to the front portion of the frame and may be operatively connected to a respective drive wheel of the pair of drive wheels. Each rear wheel may be coupled to a respective independent arm of the support frame. Each independent arm may be capable of flexing independent of the other.

Abstract: The instant invention is an electric machine/tractor particularly intended for farming, gardening and landscaping and is nonpolluting and self charging. The tractor accommodates standard farm implements and can supply electrical power to remote areas. To achieve these goals, the machine is comprised of a frame and wheels which are driven independently by hydraulic motors powered by a variable volume, hydrostatic pump that is driven in line, by an electric motor that also drives a hydraulic lift pump and a power-take-off shaft through belts. The hydrostatic pump is controlled by the operator for forward and reverse motion. The electric motor is powered by batteries and the batteries can be recharged by an on-board photoelectric panel. A combination charger/inverter is located aboard the tractor to charge the batteries from any 110V A.C. power outlet or generate 110V A.C. electrical power from the tractor.

Abstract: An electrical storage device includes: a conductive battery house casing electrically connected to a chassis; a plurality of battery cells held in the battery house casing; and a control unit that comprises a circuit that manages the plurality of battery cells and is mounted on the battery house casing so that a negative terminal of the circuit and the battery house casing are electrically conducting.

Abstract: A method of operating a vehicle powertrain system where the powertrain system includes a fuel controlled engine, an electric motor, and a battery, the fuel, controlled engine and the electric motor capable of powering the powertrain system. The powertrain system is capable of operating in a plurality of operational modes. The method includes detecting a current value representative of a current flowing through a portion of the battery, calculating a first value representative of the current over a predetermined amount of time, and de-rating at least one of the plurality of operational modes in response to the calculated first value.

Abstract: Autonomous and lightweight vehicle intended to transport a city dweller combined with the use of public transportation. Formed by one motorized wheel on which the user maintains, through speed, his or her lateral balance, and longitudinal balance is ensured by automatic functioning driven by an accelerometer. The footrests and the guide supports that tightly hold the leg are retractable. Driving does not require the use of the hands. The entire device goes into a bag, e.g. a backpack, and weighs less than 4 kg.

Abstract: A wheel driving apparatus is provided. The wheel driving apparatus includes a cylindrical inner housing supported by a vehicle body via a suspension, a wheel supported by the cylindrical inner housing so that the wheel is rotatable relative to the cylindrical inner housing, a motor having a stator attached to the cylindrical inner housing and a rotor attached to the wheel. The wheel includes a main body portion and an outside portion positioned on an outer side of the vehicle body, and the rotor is attached to the main body portion.

Abstract: An electric motor includes a case, a stator disposed in an interior of the case, a rotor including a shaft disposed to be rotatable with respect to the stator, and an oil circulator to contact with oil that is accommodated or stored at the interior of the case, the oil circulator may disperse at least a portion of the oil when the rotor rotates with respect to the stator. Accordingly, outputs can be improved by restraining an increase in the temperature of components.

Abstract: A forward structure of a motor vehicle is provided that includes, but is not limited to a drive unit and a radiator arrangement for releasing the heat of the drive unit into the environment. The radiator arrangement encompasses at least two cooling unit, which are spatially separated from one another and which are arranged so as to overlap at least area by area in cross direction of the motor vehicle. An imaginary connecting line between the cooling units crosses at least one component of the drive unit.

Abstract: A vehicle includes at least one cooling circuit for cooling a fuel cell system. The cooling circuit includes at least one cooling heat exchanger, a cooling medium transportation device and a heat exchanger in a fuel cell stack of fuel cell system. Cooling heat exchanger is affected by motion-related air flow as cooling air. The cooling heat exchanger is constructed in at least two stages, which are arranged in such a way that they are serially flowed through, one after another, by motion-related airflow.

Abstract: A mounting arrangement for mounting a cooler unit to a work machine has a traveling device, a machine body frame, an engine and the cooler unit disposed adjacent the engine. The arrangement includes a support deck provided in the machine body frame for supporting the cooler unit, an attachment unit for releasably fixing the cooler unit to the machine body frame and a movement mechanism provided between the cooler unit and the support deck, the movement mechanism allowing the cooler unit to effect a translational movement to change a distance relative to the engine.

Abstract: In a mounting structure for a vehicle battery box, a battery box is supported in a suspended manner between left and right rear side frames at the rear of a vehicle with first and second cross members that are installed between the left and right rear side frames. The first cross member is fixed at a substantially front end of a rear deformation zone that is set at the left and right rear side frames. High-voltage equipment is fixed between the first and second cross members on the top surface of the right rear side frame. The battery box is electrically connected to the high-voltage equipment with a connecting member.

Abstract: An automated vehicle includes a vehicle body, a power source, one or more motors housed within the vehicle body and in operable connection with the power source, running gear in operable connection with the one or more motors for facilitating movement and supporting the vehicle body upon a surface, and an optical system. The optical system includes an optical sensor for detecting light reflected from the surface and generating an output in response to the light reflected, and one or more light sources, each light source capable of projecting light on the surface. Furthermore, the optical system is configured to regulate an amount of power supplied to the one or more motors in response to the output generated by the optical sensor.

Abstract: A control apparatus for a motor-assisted bicycle detects a pedaling torque applied to a crankshaft with a pedaling force sensor, controls a motor unit of the motor-assisted bicycle in a regenerative control process to charge a battery if the torque value of the detected pedaling torque is equal to or smaller than a predetermined level, and controls the motor unit in an assistive control process if the torque value is greater than the predetermined level. The control apparatus includes a storage unit for storing an assisted state and a regenerated state in a single event of use of the motor-assisted bicycle by a user, and a control quantity corrector for correcting a control quantity of the assistive control process and a control quantity of the regenerative control process based on the assisted state and the regenerated state which are stored in the storage unit.

Abstract: Since a stand including a plurality of supports and a top plate is built in on one side of a rear part of an upper frame of an upper rotating body as seen from an operator in a cabin, and a power storage device is installed on the top plate of this stand, the power storage device is arranged at the highest position among all the devices mounted in the upper rotating body. The power storage device is made up of a main body and a casing, and cooled down by taking cooling air into the casing.

Abstract: The present invention generally relates to hybrid power systems for vehicles. In one embodiment, the present invention relates to hybrid power systems for various types of transportation vehicles where the hybrid power systems is partially, or even totally, based on the use of at least one hydraulic system to provide supplemental, or even the primary, motion power for a hybrid vehicle. In another embodiment, the hybrid power systems of the present invention are capable of providing both motion power as well as cabin comfort heating and/or cooling.

Abstract: A sub-frame and component configuration for mounting on a motorcycle includes a body frame structure including a main frame portion; and a sub-frame portion, he sub-frame is fixedly secured to the main frame portion and is configured for receiving and securing thereon a drop seat providing a rider with a seating area that is relatively closer to the ground than the seating area of a conventional motorcycle seat. A method of mounting the sub-frame on a motorcycle includes: fixedly securing a drop seat sub-frame portion onto a main frame portion, wherein the drop seat sub-frame portion is configured for receiving and securing thereon a drop seat.

Abstract: A drive shaft damper assembly installed onto a drive shaft bearing secured to a drive shaft mounted to a vehicle. The drive shaft bearing assembly includes a bearing collar assembly securely attached to the drive shaft bearing. The drive shaft damper assembly also includes an inner damper assembly, interconnected to the bearing collar assembly, which defines an inner bushing interface, and an outer damper assembly defining an outer bushing interface. A bushing assembly is disposed in an operative engagement between the inner and outer damper assemblies, wherein each of a plurality of bushing members are individually interconnected between the inner bushing interface and the outer bushing interface via corresponding bushing fasteners, the bushing members being removable and replaceable to permit tuning of the operation of the drive shaft. A mounting mechanism is structured to securely attach the outer damper assembly to a portion of the vehicle.

Abstract: A torque detection device includes: a torsion bar that couples a first shaft to a second shaft such that the first shaft and the second shaft are rotatable relative to each other; an annular magnet that is fixed to the first shaft; a pair of magnetic yokes that are fixed to the second shaft and that are arranged to face the magnet; and Hall ICs. Each of the magnetic yokes has a plurality of lugs arranged at equal intervals in a circumferential direction, and each lug becomes narrower toward its distal end, and has a curved profile with rounded corners when viewed from a radial direction of the corresponding magnetic yoke.