Abstract: A heat exchanger tube having an integral restricting and turbulating structure consisting of dimples formed by confronting indentations pressed into the sides of the heat exchanger tube. The dimples are comprised of indentations disposed in pairs which extend into the tube to such a depth as is necessary to significantly reduce the cross sectional area of the heat exchanger tube and provide a pair of converging, diverging flow nozzles to promote turbulence of the flue gases. The turbulence characteristics of the tube can be controlled by varying the size of the aperture of the nozzles. In certain applications, the dimples are located along the sides of the heat exchanger tube, thereby providing unobstructed drainage for liquids even when the tube is bent into a serpentine shape.

Abstract: In a high-pressure side heat exchanger for a vapor compression refrigerant cycle, a refrigerant passage is formed such that a flow area (S), a length (L), and an equivalent diameter (d) satisfy the conditional expression 0.04×e−1.8d≦S/L≦2.1×e−1.8d. The flow area (S) is obtained by dividing the product of a total cross-sectional area of the passages in one tube and the number of tubes by the path number. The length (L) is a flow distance of the refrigerant from the refrigerant inlet to the refrigerant outlet. That is, the length (L) is obtained by the product of the length of the tube and the path number. The diameter (d) is obtained by dividing the product of four and the cross-sectional area of the passage by a circumference of the passage.

Abstract: The aim of the invention is a device (100) for coolant cooling in a gas turbine (2) which, with a relatively simple construction and low plant complexity permits a particularly high degree of efficiency in using the heat produced on cooling the coolant from a gas turbine (2). Said aim is achieved, whereby a number of interconnected evaporator tubes (140, 150, 160, 170) for a flow medium, are arranged in a coolant channel (102), connected to the gas turbine (2), to form a forced throughflow steam generator. Said device (100) is preferably used in a gas and steam turbine unit (1, 1′, 1″) with a waste heat steam generator (30) on the exhaust gas side of a gas turbine (2), the heating surfaces of which are connected into the water-steam circuit (24) of a steam turbine (20). The evaporator tubes (140) of the device (100) are thus connected on the inlet side by means of a supply line (112) to the feed water train of the water-steam circuit (24) of the steam turbine (20).

Abstract: A heat exchanger (10) is provided to transfer heat between a first and second fluid flow. The heat exchanger 10 includes a flow path (20) provided in the form of one or more heat exchange tubes (40, 40A-C), and a second flow path (30) provided in the form of one or more serpentine heat exchange tubes (42, 42A-C). The tube(s) (40, 40A-C) is (are) “woven” together with the tube(s) (42, 42A-C) such that they are perpendicular to each other. The heat exchanger (10) can provide particular advantages when used as a suction line heat exchanger in a transcritical cooling system (12).

Abstract: In a brazed condenser for an air conditioner, such as a motor vehicle air conditioner, a collecting tube connected with a collector is a prefabricated as a one-piece tube which is connected by tack weld seams with the collector before brazing the collecting tube and the collector together.

Abstract: Heat exchanger with thermal inertia for a heat transfer fluid circuit, particularly of a motor vehicle The invention relates to a heat exchanger for a heat transfer fluid circuit comprising ducts for the circulation of the heat transfer fluid, which are inserted between an inlet and an outlet, and cavities which are designed to contain a heat storage fluid are situated adjacent to the cooling fluid circulation ducts and are also associated with heat-exchange surfaces able to be swept by a flow of air to be conditioned, so that the heat storage fluid is capable of exchanging heat with the air flow, if the circulation of the heat transfer fluid is stopped. Application in particular to the air-conditioning evaporators of motor vehicles.

Abstract: It is an object of the present invention to provide an inexpensive heat radiating fin having a high cooling effect. A coating metal layer consisting of a metallic material with ionization tendency larger than that of silver is stacked on a surface of a heat radiating fin main body by plating or the like to form the heat radiating fin such that the coating metal layer has a layer thickness which increases a difference between a heat capacity of the coating metal layer and a heat capacity of the air, and facilitates chemical adsorption of molecules in the air. The heat radiating fin radiates heat while being brought into contact with the air serving as a cooling fluid.

Abstract: A heat exchanger apparatus and method of manufacturing comprising: an interface layer for cooling a heat source and configured to pass fluid therethrough, the interface layer having an appropriate thermal conductivity and a manifold layer for providing fluid to the interface layer, wherein the manifold layer is configured to achieve temperature uniformity in the heat source preferably by cooling interface hot spot regions. A plurality of fluid ports are configured to the heat exchanger such as an inlet port and outlet port, whereby the fluid ports are configured vertically and horizontally. The manifold layer circulates fluid to a predetermined interface hot spot region in the interface layer, wherein the interface hot spot region is associated with the hot spot. The heat exchanger preferably includes an intermediate layer positioned between the interface and manifold layers and optimally channels fluid to the interface hot spot region.

Abstract: The performance of a double-cone device (1) is increased, not only by moving the gap or inlet openings (22) a short distance into the exit cone (47), but also by making the conicity &thgr;3 (55) of the so-formed small diffuser less than the conicity &thgr;2 (109) of the remaining part (53) of the exit cone. Double cone units (7, 60), particularly the ones with this improved diffuser, may be used in pump installations (1, 60), like well-pumps (1), where liquids must be pumped from great depths.

Abstract: A flow completion apparatus comprises a wellhead housing installed at an upper end of a well bore and a tubing spool connected over the wellhead housing. The tubing spool includes a central bore extending axially therethrough, a production outlet communicating with the central bore and an annulus passageway communicating with the tubing annulus. A tubing hanger is supported in the central bore and includes a production bore extending axially therethrough and a production passageway communicating between the production bore and the production outlet. The tubing spool comprises a workover passageway extending between the annulus passageway and a portion of the central bore located below the top of the tubing hanger. Furthermore, the tubing hanger comprises an annulus bore extending between the workover passageway and the top of the tubing hanger.

Abstract: A non-rotating cement wiper plug has an insert, with inner and outer telescoping sleeves, within a resilient outer body. The outer body has annular fins which bear against a casing wall. The inner sleeve has a tapering nose within a tapered cavity in the outer sleeve. Slots in the outer sleeve form a plurality of segments. The inner and outer sleeves are preferably of a frangible material. When the plug is pumped down and lodges against downhole float equipment, pump pressure compresses the plug, forces the inner sleeve down within the outer sleeve, forces the segments radially outward, and fractures or separates the outer sleeve segments. The outer body is forced against the casing wall so tightly that it cannot rotate in response to the forces from a rotary drill bit. Lock surfaces on the inner and outer sleeves lock them together and maintain the outer body in its forced-outwardly position.

Abstract: An expandable device, such as a sand screen, is used in a wellbore. The expandable device comprises an expandable base pipe and a filter layer that facilitates expansion of the device while maintaining filtering capability.

Abstract: A method and associated apparatus continuously optimizes reservoir, well and surface network systems by using monitoring data and downhole control devices to continuously change the position of a downhole intelligent control valve (ICV) (12) until a set of characteristics associated with the “actual” monitored data is approximately equal to, or is not significantly different than, a set of characteristics associated with “target” data that is provided by a reservoir simulator (32). A control pulse (18) having a predetermined signature is transmitted downhole thereby changing a position of the ICV. In response, a sensor (14) generates signals representing, “actual” monitoring data. A simulator (32) which models a reservoir layer provides “target” data.

Abstract: A device and method for sealing boreholes. Typically, a seismic test hole is sealed by covering a topping plug with water expansible material, such as bentonite, which seals the hole once it expands on exposure to water or moisture. The present invention provides a method and a device for sealing seismic holes, the device comprising a generally tubular water permeable sleeve filled with water expansible aggregate.

Abstract: An instrumented perforating gun and associated methods. One aspect provides a recess for placement of instruments on the perforating gun. Another aspect provides methods for perforating and completing a well in a single trip. The present invention also provides an instrumented intergun housing. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: The present invention provides an apparatus and a method for removing undesirable material from a well bore in a hydrocarbon formation with minimum damage to the formation. The apparatus comprises a concentric tubing string, said concentric tubing string further comprising an inner tube means having an inner annulus therethrough and an outer tube means forming an outer annulus between said outer tube means and said inner tube means, means for introducing into said well bore a pressurized clean out medium through one of the said inner annulus and outer annulus, and means for removing said material and clean out medium through the other of the said inner annulus and said outer annulus to the surface of said well bore. In a preferred embodiment, the introducing means comprises a discharge compressor or mud pump and the removing means comprises a suctioning compressor.

Abstract: A method of installing an internal latch profile in an existing tubular string does not require the use of a packer. In a described embodiment, a method of latch installation includes the step of deforming an interior surface of the tubular string after the tubular string is positioned in a well. In another described embodiment, a method of latch installation includes the step of cutting into the interior surface of the tubular string.

Abstract: A materials pushing or moving blade for use with heavy equipment vehicles, for example, a bulldozer or loader, and more specifically to a method and apparatus for moving snow, specifically a snow moving blade having a reinforcing gusset for strengthening the extended sidewalls of the snow moving blade.

Abstract: The invention relates to a handheld hammer drill and/or paving breaker which is at least of average weight and power class and which comprises an electric motor (23; 30), a striking tool (9) which can be actuated by the electric motor (23; 30) and a housing (2) wherein the electric motor and the striking tool are received. A handle (8) is embodied in such a way on the housing (2) that a holding position is arranged in a projection of the striking axis (6) of the striking tool (9). A rotating axis (25) of a motor shaft (26) of an electric motor is parallel to the axis of the striking axis (6), the total length (LGES) of the hammer drill and/or striking hammer (1) being small in the longitudinal direction.

Abstract: A multifunction handheld tool machine having an at least partially axially percussive tool receptacle (7), a safety coupling (8) disposed in the power line between the tool receptacle and an electrical motor (6), a hand-guided housing and an ATC safety module (1) with a rotational sensor (3) sensitive to an angular displacement. The ATC safety module (1) is connected to an axial displacement sensor (4) and, in the event of exceeding an axial limit value (13b), the binary control signal (5) is suppressed by the axial displacement.

Abstract: A duct for electrical cables comprises a plurality of filiform metal elements arranged substantially parallel to one another according to the longitudinal development of the duct. The duct of the invention comprises, for at least a portion of its length, a plurality of structural modules, which are arranged in a transverse direction with respect to said filiform elements and are set at a distance from one another in succession according to the longitudinal development of the duct. The supporting modules have a basically U-shaped body that comprises a central wall from which there project, on opposites sides with respect to one another, two side walls that are set substantially parallel to one another. On said shaped body coupling means, designed to enable connection with said filiform elements, are arranged.

Abstract: A junction box and ballast circuitry assembly including a ballast housing for attachment to the junction box. The junction box is provided with two opposed open ends, one of the ends being in alignment with a side of the ballast housing and the opposed open end being adaptable for electrical communication with a lighting fixture. The junction box is provided with brackets on opposed sides for alignment with outwardly extending tabs on opposite sides of the ballast assembly to receive a fastening bolt through the tab and an opening in the aligned bracket.

Abstract: Storage containers and storage container kits for storing electronic devices and cables/wires are disclosed. The storage container comprises a first rigid divider that is attached to said storage container and is substantially parallel to two sides of said substantially rectangular storage container, a compartment having a plurality of ventilation holes, wherein said first rigid divider forms one side of said compartment, and a plurality of electrical outlets associated with said first rigid divider. A kit is disclosed for converting a storage container into a cable and electronics storage device, comprising (a) a first rigid divider that is attachable to said storage container, (b) a plurality of electrical outlets attached or attachable to the top edge of said first rigid divider, and (c) instructions for perforating said storage container with a plurality of ventilation holes.

Abstract: A capacitor element includes an anode chip body formed by sintering valve metal powder, an anode wire projecting from an end surface of the anode chip body, and a ring member made of a water-repellent thermoplastic synthetic resin and fitted around a root portion of the anode wire connected to the anode chip body. The ring member is fitted and attached to the anode wire. The ring member adheres closely to both of the anode chip body and the anode wire without a gap by thermally melting the ring member in its fitted state around the anode wire.

Abstract: An on-the-go twist-on wire connector for enhancing the current carrying capacity of the electrical wires contained therein with the housing having a closed end and an open end with a wire engaging coil located in the closed end of the housing for bringing a plurality of wires into surface-to-surface contact to provide a direct surface-to-surface electrical path for flow of electrical energy therebetween. Located in the twist-on wire connector is a wire adhereable electrically conducting medium the adhereable electrical conducting medium is conformable around the plurality of wires as the plurality of wires are brought into surface-to-surface engagement with the conformable electrical conducting medium thereby forming an indirect current path between the ends of the plurality of wires while retaining the on-the-go ability of the twist-on wire connector to form the electrical connection solely through twisting action.

Abstract: A method making possible the production of an injection molded conductor carrying means composed of a first supporting substrate and a second supporting substrate. The first supporting substrate comprises a basically metallizeable plastic material and the second supporting substrate a basically non-metallizeable plastic material. However the plastic material of the second supporting substrate is able to be activated by a laser beam. The laser activation produces a metallization pattern on it and such pattern is connected with uncovered areas of the first supporting substrate, following which a common treatment takes place which results in an electrical conductor arrangement being produced. The invention furthermore relates to a conductor carrying means produced by the method.

Abstract: An element, such as a Printed Wired Board (PWB) or Printed Circuit Board (PCB) is provided with elongated lower-stiffness areas, which provide the element with areas obtaining a lower deformation during deformation of the element, such as during a fall thereof. Fragile or large electronic or electrical parts, such as Integrated Circuits (IC), such as Ball Grid Arrays (BGA) are positioned the lower deformation areas in order to maintain electrical connection to the element during and after the deformation of the element.

Abstract: The present invention comprises a plurality of laminating double-side circuit boards and a plurality sheets of prepreg for interlayer connection that are placed one on another. Via holes extend from the circuit on one side of each laminating double-side circuit board to the circuit on the other side thereof. Each via hole is filled with electro-conductive material to connect the circuits on both sides of the laminating double-side circuit board. The pad on a laminating double-side circuit board and the pad on another laminating double-side circuit board are laminated via a sheet of prepreg for interlayer connection so that the respective pads are opposed to each other via the through hole filled with electro-conductive material formed through the sheet of prepreg for interlayer connection. Thereby, the respective pads on the laminating double-side wiring circuit boards are electrically connected with one another.

Abstract: The present invention discloses a method of manufacturing circuit devices 10 with arbitrary external shapes, comprising the steps of: forming, on a conductive foil 30, conductive patterns 11 constituting circuit devices 10 of the same type or different types; affixing circuit elements 12 onto conductive patterns 11; molding with insulating resin 13 so as to cover circuit elements 12; and using a laser to cut insulating resin 13 at locations of the outer peripheral part of each circuit device 10 that are in accordance with a desired shape to thereby perform separation into each of circuit devices 10. Circuit devices 10 with arbitrary shapes can thus be manufactured and circuit devices that accommodate the shapes of the frames of sets can be provided.

Abstract: A printed circuit board comprises a plurality of patterned circuit layers, a plurality of insulation layers and a plurality of circuits. Each insulation layer is located between a pair of neighboring patterned circuit layers for isolating the patterned circuit layers. The insulation layer and the patterned circuit layers together form a laminated layer. The circuits are formed on the sidewalls of the printed circuit board or the interior sidewalls of a cavity or an opening within the printed circuit board for interconnecting various patterned circuit layers electrically.

Abstract: Apparatus and method for setting cement in the annulus of an oil or gas well during well completion or other similar well operations. An induction heating tool is lowered to a desired position within the well casing and power is supplied to the tool to heat the casing and the cement which has been injected in the annulus adjacent the heated well casing and the wellbore.

Abstract: A system and method provide for controlling an HDD machine to move a cutting tool along an underground path in accordance with a pre-established bore plan. Cutting tool movement is detected from above-ground. During HDD machine operation, one or more control programs are accessed. Each of the control programs can cause the HDD machine to execute a sequence of pre-defined HDD machine actions. A particular control program of the one or more control programs is executed to augment movement of a drill pipe or the cutting tool.

Abstract: Devices and methods for incorporating a gap sub assembly into a drill string to electrically isolate portions of a transmitter assembly within, for example, an MWD tool located within the drill string. The gap sub assembly incorporates upper and lower subs having an insulated interconnection. A central conductor assembly is axially disposed within the lower sub and does not extend through the length of the gap sub. The central conductor assembly is used to transmit electrical power and data across the gap sub assembly between the upper portions of the drill string and transmitter components housed within the MWD tool disposed below the gap sub assembly.

Abstract: A method is provided for gathering information on the pore pressure in an earth formation surrounding a wellbore. The method includes the initial steps of selecting at least one suitable property (e.g., porosity, drilling fluid composition, etc.) of the drilling environment (which is defined by the wellbore and the surrounding formation) and at least one NMR parameter (e.g., T2 distribution) in an NMR measurement response. The method selects a suitable property for which values over a plurality of wellbore depths can be correlated with the characteristics or behavior of the pore pressure in the earth formation. The method further includes conducting an NMR measurement at a plurality of wellbore depths, thereby generating an NMR response from the drilling environment. The measured values of the NMR parameter in the NMR response are then correlated with values of the suitable property.

Abstract: The present invention provides a method of forming a support column in soil using a reverse circulation down-the-hole hammer apparatus. The method includes drilling a hole with a reverse circulation down-the-hole hammer apparatus having a drill string with a return outlet and a down-the-hole hammer, and forming a column of mortar-like substance by pumping a mortar-like substance down the return outlet while lifting the apparatus out of the hole.

Abstract: The invention relates to a method for drilling, being carried out by a drilling apparatus, having a drilling device (1) unit (3), in the drilling head (I) of which there hole and second drilling means (5) for reaming of the center hole for the casing part (2) as well as flushing flow arrangement (6) for flushing of waste, being generated. At least during the drilling situation, the first drilling means (4) are coupled by a power transmitting and, in order to enable removal of the same from the hole, removable arrangement, such as a bayonet coupling or like, with the second drilling means (5).

Abstract: A directional casing drilling system including a casing string for rotation of a drill bit, a shaft coupled to the casing string, and a sleeve having pads that are hydraulically extensible. The sleeve may be positioned about a portion of the shaft. The invention may also include a tube connecting the sleeve to the drill collar, the tube adapted to conduct drilling fluid, and a valve system adapted to operatively conduct at least a portion of the drilling fluid to the pads whereby the pads move between an extended position and a retracted position.

Abstract: Method and apparatus for drilling a directional or horizontal wellbore in a hydrocarbon formation using concentric coiled tubing drill string having an inner coiled tubing string and an outer coiled tubing string defining an annulus there between. A bottomhole assembly comprising a directional drilling means is provided at the lower end of the concentric coiled tubing drill string for reverse circulation drilling. Directional drilling means comprises a reciprocating air hammer and a drill bit, a positive displacement motor and a reverse circulating drill bit, or a reverse circulating mud motor and a rotary drill bit, and a bent sub or housing. Drilling medium is delivered through the annulus or inner coiled tubing string for operating the directional drilling means to form the directional or horizontal wellbore. Exhaust drilling medium comprising drilling medium, drilling cuttings and hydrocarbons are removed from the wellbore by extraction through the other of the annulus or inner coiled tubing string.

Abstract: Roller cone drilling wherein the bit optimization process equalizes the downforce (axial force) for the cones (as nearly as possible, subject to other design constraints). Bit performance is significantly enhanced by equalizing downforce.

Abstract: A combinational measuring device is provided with a radiation feeder transporting objects and a measuring hopper measuring the weight of each group of objects transported by the radiation feeder. As to each measuring hopper performing introduction by a prescribed frequency, an average operation part obtains an average and standard deviation of a transport quantity every group transported by the radiation feeder. On the basis of the obtained standard deviation, a parameter operation part determines whether or not the transport quantity per group transported by the radiation feeder is dispersed.

Abstract: A balance (1) with a weighing pan (3) inside a weighing compartment (2) enclosed by a draft shield (4) has at least one thermoelectric module (16) that is arranged outside of the weighing compartment (2) and thermally connected to a stationary part of the balance (1). At least one vertical wall (8) of the draft shield (4) has a lower end portion in thermal connection with the thermoelectric module (16). The vertical wall (8) is configured in such a way that a temperature gradient develops in the vertical wall (8), wherein the temperature increases from the bottom to the top of the wall (8).

Abstract: A method and apparatus for a four-wheel drive motor vehicle provides improved cornering by disengaging drive torque to the inside rear wheel during significant steering maneuvers. The apparatus includes a primary front wheel drive motor vehicle driveline having a center differential which provides drive energy to the primary (front) driveline and secondary (rear) driveline and a rear axle assembly having a pair of normally engaged (active) clutches which provide drive energy to the respective rear wheels. A steering angle sensor detects angular displacement of the steering column or front (steering) wheels and an associated controller disengages the clutch associated with the rear wheel on the inside of the turn as determined by the steering angle sensor.

Abstract: An electric golf cart drive mechanism is constructed to include two wheels pivoted to two sides of a frame of a golf cart, and a drive axle unit configured on one side of the frame of the golf cart, the drive axle unit includes a motor base, a gear axle and a case cover, the drive axle unit is fixedly locked to the frame of the golf cart, and the gear axle is embedded into one wheel, transmission to the wheel on the gear axle is effectuated through a spiral gear driven by a motor, achieving an auxiliary pulling force on the golf cart that provides economy of effort in transporting golf equipment.

Abstract: A method of operating a hybrid electric vehicle 10 to reduce emissions. The method utilizes the vehicle's electric motor/generator 12 to generate a negative torque during cold-start conditions, effective to increase the load on the internal combustion engine 16, thereby reducing the light-off time of the catalytic converter 28. The method also reduces emissions by utilizing the vehicle's motor/generator 12 to provide a supplemental torque to engine 16 during transient events, thereby reducing the generated mass flow and amount of untreated emissions.

Abstract: A front and rear wheel drive vehicle having front and rear wheel pairs one of which is driven with an engine and the other of which is driven with an electric motor. The vehicle has a control device including a target drive-power unit which sets a target drive-power responsive to operating conditions of the vehicle and a motor-assist-mode drive-power distribution-ratio setting unit which sets a drive-power distribution-ratio between an engine drive-power and a motor drive-power according to an energy efficiency index value indicating the degree of contribution to fuel consumption based on the target drive-power and a vehicle speed.

Abstract: The invention provides a driver's cab for a work vehicle which is provided with a function of effectively transferring an external force applied to a ceiling portion to a pillar without making a structure complex, and can achieve a reinforced structure. In a driver's cab (1) in a working vehicle, the driver's cab being structured by a pipe-like member, a connection member (30 (31)) for dispersing a stress is arranged in a support pillar (11 (12)) in an opposite side particularly in the case that an external force is applied to a transverse outer side of a ceiling portion.

Abstract: The invention is a suspension system, typically for use between a cab and a truck frame, includes a strut module having a strut and an air spring, and a control module, connected to a source of pressurized air, for sensing a distance between the cab and truck frame and selectively pressurizing the air spring in response to changes in that distance. Preferably, the strut is a McPherson-type strut and the air spring encloses at least a portion of the strut to provide a compact assembly and includes a three point connection to the cab and frame to resist relative lateral movement between the cab and frame. The strut also preferably is a magnetorheological-type damper so that the control module can adjust the damping characteristics of the strut to optimize rider comfort.

Abstract: A snowmobile includes a side panel that is mounted to the snowmobile's frame about a generally vertically extending side panel axis. In a closed position, the side panel protects and encloses a lateral side of the snowmobile's engine. In an open position, the side panel facilitates easy access to the engine. The side panel includes a lower leg support that includes a knee rest, a lower front leg support, and an inner leg support. The lower leg support improves the rider's comfort and ability to actively position himself on the snowmobile. The snowmobile also includes a rewind starter operatively connected to the engine. The rewind starter is accessible through a hole formed in the side panel.

Abstract: A snowmobile is described having a frame, at least one steerable ski disposed at a forward end of the frame, and an endless drive track disposed beneath a rearward end of the frame to propel the frame. A seat is mounted on the frame, which may accommodate at least one person. A fairing is disposed behind the seat, and a storage compartment is defined interiorly to the fairing. Variations are also described.

Abstract: A housing cannot be made compact by only securing a space corresponding to a reservoir tank at the upper part of the housing, and the space at the upper part of the housing cannot be utilized if the reservoir tank is integrally provided to the upper part of the housing. An axle driving apparatus comprising a tubular reservoir tank erected on the upper surface of the upper wall surface of the housing for accommodating an HST, wherein, since the reservoir tank is thinly elongated and is freely bendable, it can be disposed in a limited space. The housing is divided into a first room and a second room with which the reservoir tank communicates. Further, a first magnet is disposed at a position where the first and second rooms are connected, and a second magnet is disposed in the proximity of an oil filter connected to a closed circuit of the HST so that impurities can be removed.