Abstract: Methods and systems are provided for adjusting water injection at distinct locations of an engine based on a total water injection error determined from an output of an exhaust oxygen sensor. The method may include injecting water at distinct locations based on a cooling demand and a dilution demand. Further, the method may include distributing the total injection error to respective water injectors, as well as adjusting engine operating parameters, to provide desired engine cooling and dilution.

Abstract: A canister close valve device for opening or closing a passage provided between a canister, which collects evaporation gas evaporated from a fuel tank and the atmosphere may include a plunger configured to selectively move up or down through magnetization with a core inside a valve housing when a solenoid is activated, a rod configured to perform a rectilinear reciprocating movement toward or away from the passage due to the upward/downward movement of the plunger, and a diaphragm valve body, which is inserted into the plunger, is connected to the valve housing, and is configured to be deformed by the upward/downward movement of the plunger and to generate force for impeding the upward/downward movement of the plunger using a pressure difference generated between the plunger and the valve housing.

Abstract: A method of providing internal EGR to an engine having at least one dedicated EGR cylinder. The main (non dedicated) cylinders are operated with internal EGR, in addition to external EGR from the dedicated EGR cylinder. The dedicated EGR cylinder has separate valve control so that it need not be operated with internal EGR, thereby allowing it to be operated at a richer air-to-fuel ratio.

Abstract: An engine, methods and systems are provided for supercharging charge air for internal combustion engines. The engine having an intake, and a blower with at least one impeller in the intake mounted on a rotatable shaft. An EGR line opens into the intake system upstream of the at least one impeller to form a junction point. A flap, pivotable about an axis running transversely with respect to the intake air flow, has: a first position which blocks the intake by way of a front side, and which opens up the EGR line; and a second position to cover the EGR line and open intake system wherein the flap is not planar, and has, at least on the front side thereof, at least one deformation as an unevenness.

Abstract: A fuel-saving device for treating a fuel includes at least one pyroelectric element to be in contact with the fuel. The at least one pyroelectric element includes a high molecular polymer substrate and a plurality of polarized pyroelectric particles dispersed in the polymer substrate. The polarized pyroelectric particle has infrared absorption peaks at wavenumber ranging from 430 cm?1 to 980 cm?1 and from 1600 cm?1 to 2700 cm?1.

Abstract: An intake manifold made of resin includes a surge tank, a plurality of branch pipes branching off from the surge tank, an EGR gas distribution part for distributing EGR gas to each of the branch pipes, and an EGR cooler for cooling EGR gas introduced into the EGR gas distribution part. The EGR cooler and the EGR gas distribution part are made of resin and provided adjacently and integrally. The EGR cooler includes a gas passage through which EGR gas flows and a water passage through which engine cooling water flows to cool the gas passage to allow the EGR gas to pass through the EGR cooler and then flow in the EGR gas distribution part.

Abstract: A partial forced induction system is provided that has one or more combustion engine cylinders with each engine cylinder having a first and a second intake valve with individual ports. A source of forced induction in fluid communication with the one or more combustion engine cylinders and urging air into the one or more combustion engine cylinders. A naturally aspirated intake manifold path connecting to each of the first intake valves at each of said one or more engine cylinders. A forced induction intake manifold path connects the source of forced induction to each of said second intake valves at each of the one or more engine cylinders.

Abstract: A cylinder of an engine of a motorcycle is tilted frontward. A throttle unit is provided above the cylinder, and a heat shielding sheet is provided between the cylinder and the throttle unit. The throttle unit includes a fuel injection device, and the heat shielding sheet extends between the fuel injection device and the cylinder.

Abstract: Check valves, Venturi devices and engines having such check valves, define an internal cavity having a first port and a second port, a first seat and a second seat, and a translatable seal disk. The check valves have an outlet conduit extending from the second port and/or the first seat has a first annular seal bead and a second annular seal bead disposed radially inward of the first annular seal bead with a plurality of ribs extending between the first annular seal bead and the second annular seal bead within the fluid flow path of the first port. The outlet conduit defines an outlet passageway having a restrictor profile that is circular in a transverse profile, and the ribs decrease the flow area of the fluid flow path of the first port by about 10% to about 60%.

Abstract: A condensation dispersion device for a turbocharged vehicle engine includes a valve body, a movable valve, and a biasing means. The movable valve and biasing means are disposed within the valve body. The valve body defines a valve seat within the valve body, and includes an inlet and an outlet. The movable valve defines an engagement feature operatively configured to engage with the valve seat when the movable valve is in a first position. The biasing means is operatively configured to urge the movable valve to a second position when the pressure in the intake manifold is equal to or greater than atmospheric pressure.

Abstract: A sensor device is disposed in an intake passage through which intake air flows to an internal combustion engine. The sensor device includes a humidity sensor that generates a signal according to a humidity of the intake air flowing through the intake passage. A choke portion is defined in the intake passage to decrease a cross-sectional area of the intake passage. The humidity sensor is arranged on the choke portion.

Abstract: An internal combustion engine comprising: a plurality of cylinders; at least one intake manifold, which receives fresh air from the outside; a plurality of intake channels, each connecting a cylinder to the intake manifold; and an intake sound amplification device, which is provided with an amplification pipe, an insulating element sealing the amplification pipe in a tight manner, a plurality of amplification channels, each originating from a corresponding intake channel, and an amplification manifold, which, on one side, is connected to all amplification channels and, on the other side, is connected to the amplification pipe.

Abstract: A pumping unit has a fuel storage tank (2), a piston pump (6) for feeding the fuel to an internal combustion engine (3); a gear pump (7) for feeding the fuel from the storage tank (2) to the piston pump (6), and a hydraulic circuit (46) which connects together the storage tank (2) and the internal combustion engine (3), extends through a pump body (8) of the piston pump (6) so as to lubricate an actuating shaft (36) of the piston pump (6) and has a collection branch (55) for collecting the fuel leaks resulting from the lubrication of said actuating shaft (36); the collection branch (55) being connected to an intake (37a) of the gear pump (7) so as to lubricate an actuating shaft (42) of the gear pump (7) with the fuel from said collection branch (55).

Abstract: In a fuel supply device for separating raw fuel into high-octane fuel and low-octane fuel and supplying the fuel, to arrange the structural components compactly and to facilitate sealing against fuel vapor, the fuel supply device (1) includes: a raw fuel tank (2) for storing raw fuel; a separator (6) provided inside the raw fuel tank to separate the raw fuel into high-octane fuel that contains a greater amount of components with high octane numbers than the raw fuel and low-octane fuel that contains a greater amount of components with low octane numbers than the raw fuel; and a high-octane fuel tank (5) provided inside the raw fuel tank to store the high-octane fuel separated from the raw fuel by the separator.

Abstract: It is important not to form the partial bump in the collision structural part, however the fixed core and the movable core are relatively inclined due to an accumulation of tolerances and therefore even if each collision structural part of the fixed core and the movable core in formed in a flat shape, the fixed core and the movable core are contacted with not the whole of the collision structural parts but a part of the collision structural parts at the moment of the collision. In a case in which the collision structural part is formed in a ring shape or an intermittent ring shape, the fixed core and the movable core are contacted with each other at outer peripheral parts. Thus, when the fixed core and the movable core are collided with each other, a high stress is applied to the outer peripheral parts contacted first.

Abstract: A cryogenic LNG fuel system is provided that includes a tank for storing LNG and a LNG fill system including a LNG inlet passage for directing a flow of LNG into the tank. A cryogenic pump is in fluid communication with the tank and includes a pumping element at least partially immersed in the LNG for directing the LNG out of the tank and a seal. A lubricant system is provided that includes a lubricant reservoir and a lubricant inlet passage in communication with the lubricant reservoir and the LNG inlet passage. The lubricant system is adapted to introduce the lubricant into the flow of LNG in the LNG inlet passage such that at least a portion of the lubricant is entrained in the LNG in the LNG inlet passage and carried into the tank.

Abstract: A cup is in a bottomed tubular shape to receive an injector along an injector axis. A bracket is extended from a sidewall of the cup. The bracket includes at least one arm and a body. The at least one arm connects the body with the cup. The body forms a screw opening configured to receive a screw along a screw axis. The body has a pivot end on an opposite side of the screw axis from the injector axis.

Abstract: A nozzle plate to be attached to a fuel injection port of a fuel injection device has, in a nozzle plate main body, a nozzle hole through which fuel injected from the fuel injection port passes. A spray direction change element colliding with fuel spray injected from the nozzle hole and changing the travel direction of the fuel spray is integrally formed near an outlet of the nozzle hole of the nozzle plate main body. Accordingly, the travel direction of spray is determined by the spray direction change element according to the shape of the intake pipe, the position of an intake port, and the like.

Abstract: A system includes an electric machine coupled to an engine and configured to start the engine from an inactive state. A controller executes a first control algorithm while output speed of the electric machine is less than a first speed threshold, and also executes a second control algorithm while the output speed is greater than the first speed threshold and less than a second speed threshold. Additionally, the controller is programmed to execute a third control algorithm while the output speed is greater than the second speed threshold. The first control algorithm includes operating the electric machine using trapezoidal current control with pulse width modulation. The second control algorithm includes operating the electric machine using six-step voltage control with a variable phase advance angle. The third control algorithm includes operating the electric machine using six-step voltage control with a predetermined fixed phase advance angle.

Abstract: A stop-start control system for a vehicle includes a camera disposed at the vehicle and having a field of view exterior and forward of the vehicle. A control includes an image processor operable to process image data captured by the camera. Responsive to image processing of captured image data, the control determines the presence of a stopping area ahead of the vehicle and being approached by the vehicle. Responsive to determination of the presence of the stopping area ahead of the vehicle and being approached by the vehicle, and responsive to determination that the driver of the vehicle releases the accelerator pedal of the vehicle so the vehicle is coasting toward the determined stopping area, the control causes the engine to at least partially shut off.

Abstract: A method of rapid starting an internal combustion engine includes determining that the engine is stopped and detecting an engine start request. The method also includes enabling a starter assembly having a brushless electric motor including a stator and a rotor and configured to drive a pinion gear, and engaging the pinion gear with the engine flywheel. The method also includes determining a present angular position of the rotor relative to the stator configured to generate a first rotor torque. The method additionally includes applying an electrical current to the motor, in response to the determined angular position of the rotor, to turn the rotor to a predetermined starting angular position configured to provide a second torque that is greater than the first torque. Furthermore, the method includes commanding the motor to spin the rotor and thereby apply the second torque via the pinion gear to start the engine.

Abstract: An apparatus includes a dynamo-electric machine driving an engine, and a calculator calculating an increment in a crank angular acceleration of the engine every certain period from a base time after the driving of the engine by the dynamo-electric machine. The apparatus further includes a determiner determining that the engine has started by the dynamo-electric machine on a condition that the increment calculated by the calculator exceeds a standard value.

Abstract: An internal combustion engine ignition coil according to the present invention includes: a central iron core; a primary coil disposed on an outer circumference of the central iron core; a secondary coil disposed on an outer circumference of the primary coil; a side iron core disposed on an outer circumference of the secondary coil; and an insulating material sealing the central iron core, the primary coil, and the secondary coil on an inner side of the side iron core. A first layered silicate having a particle diameter less than a winding diameter of the secondary coil is present at a higher concentration in a vicinity of the secondary coil than that in a vicinity of the side iron core in the insulating material. A second layered silicate having a particle diameter greater than the winding diameter of the secondary coil is present at a higher concentration than that of the first layered silicate between the outer circumference side of the secondary coil and the side iron core.

Abstract: A method for actuating a spark plug, in which the spark plug is assigned a first ignition coil and second ignition coil.

Abstract: This method can be used for refurbishing a facility for converting hydraulic energy into electrical or mechanical energy, and vice versa. The facility includes a Francis type pump-turbine. The pump-turbine includes a runner movable about an axis, a pre-distributor, including stay vanes defining between each pair of two adjacent stay vanes a first water passage channel and a distributor, including guide vanes arranged downstream of the stay vanes in the direction of water flow feeding the pump-turbine operating in turbine mode. The guide vanes define between each pair of two adjacent guide vanes a second water passage channel. This method includes steps of reducing the height, taken parallel to the axis of rotation of the runner, of the first water passage channels and reducing the height, taken parallel to the axis of rotation of the runner, of the second water passage channels.

Abstract: This invention provides a modularized ocean energy generating device and a built-in module thereof. The built-in module includes an inner frame, at least one hydraulic generator module, at least one mounting shaft, at least one driving unit, and at least two barriers. The modularized ocean energy generating device includes an outer frame, and the inner frame is detachably disposed in the outer frame. The hydraulic generator module is disposed in the inner frame and is mounted at the at least one mounting shaft, and the at least one mounting shaft is rotatably mounted at the inner frame. The driving unit is connected to the mounting shaft to drive the mounting shaft to rotate. The barriers are disposed at the inner frame or the outer frame and located at upstream and downstream sides of the hydraulic generator module along a water flow direction, respectively.

Abstract: The invention discloses a heavy hammer type wave power generation method and device. According to the invention, under the action of wave power and gravity, a floating box enables driving sprockets and guiding sprockets to turn leftwards or rightwards along a chain, the driving sprockets turn leftwards or rightwards by means of a speed-increasing gear in a speed-increasing box and a transmission mechanism for converting bidirectional swinging to unidirectional rotation, a generator shaft always rotates in one direction to generate power. According to the invention, a wave energy collecting method is simple and easy, a large amount of wave energy can be collected, energy converting efficiency is high, the structure is simple, manufacturing costs are low, maintenance is avoided for a long time, service life is long, safety is good, a wave power generation station can be established by networking.

Abstract: A wave energy converter comprises a submerged buoyant vessel (10) that can react directly with the seabed using neutrally buoyant taut tethers (19) at depths that characterize the continental shelf. The vessel (10) is held by a taut vertical mooring line (12) of controllable length and a taut vertical upper line (17) of controllable length connected to a surface float (15). These lines (12, 17) have elastic sections, allowing the vessel (10) to follow an orbital path in response to swell from any direction. By varying the length of these lines (12, 17) the submersion of the vessel (10) can be varied dynamically according to wave height. By varying the tension of these lines (12, 17) the natural oscillation period of the vessel (10) can be varied dynamically in response to the swell period.

Abstract: A device for automatically generating energy arranged in a water tank includes a buoy sinking in a water tank. Sides of the buoy are provided with a water inlet and a water outlet, which respectively connect with a tube body and a three-way tube. The tube body and the three-way tube are respectively provided with two valves. Each valve connects with a floating ball. When the buoy sinks in the water tank, each floating ball floats to close the valves, so that the liquid within the buoy is drained from a side through hole of the three-way tube to raise the buoy to a water level of the liquid, and each floating ball looses the valves, and the liquid flows into the buoy through the water inlet, and the buoy sinks in the water tank again. The buoy endlessly floats and sinks to generate electricity.

Abstract: The TRAVELING WAVE PROPELLER, PUMP AND GENERATOR APPARATUSES, METHODS AND SYSTEMS include force or forces applied to an arc-like flexible sheet-like material to create a deformed crenated strip fin with strained-deformations. The strained-deformations take on a sinusoid-like form that express the internal energy state of the flexible sheet-like material after it has been configured into a crenated strip fin. After being incorporated into a mechanism with couplings that prevent the crenated strip fin from returning to its un-strained state, the strained-deformations persist. Actuators may be used to sequentially rotate vertebrae attached to the fins causing the travel of sinusoid-like deformations along the fins. In a fluid medium, the traveling waves of sinusoidal deformations may exert force on the fluid causing the fluid to move and/or creating thrust.

Abstract: The present disclosure is directed to a rotor blade assembly for a wind turbine. The rotor blade assembly includes a rotor blade having a blade root section and a rigid ring insert. The rotor blade has pressure and suction sides extending between leading and trailing edges. The blade root section includes an end face configured to attach the rotor blade assembly to a hub. Further, the blade root section includes a span-wise end portion defined by inner and outer circumferential components separated by a radial gap. The radial gap includes a first laminate material embedded between the inner and outer circumferential components at a first span-wise depth and a second laminate material embedded between the inner and outer circumferential components at a second span-wise depth. Thus, the rigid ring insert is disposed in the radial gap and embedded between the first and second laminate materials.

Abstract: The lengths and/or chords and/or pitches of wind turbine or propeller blades are individually established, so that a first blade can have a length/chord/pitch that is different at a given time to the length/chord/pitch of a second blade to optimize performance and/or to equalize stresses on the system.

Abstract: The present invention relates to a blade control apparatus and method for a wind power generator, and a wind power generator using the same, which includes a measurement unit configured to measure a change in electrical characteristic of a measurement section set in a conductive region having electrical conductivity. The conductive region is included in the blade for the wind power generator. Thus, the state of the blade may be easily checked without separate sensors, and the blade may be controlled in response to the state of the blade.

Abstract: A method of controlling a wind power plant having a plurality of wind power generators includes monitoring the generation state of the wind power plant, analyzing the generation quantity reduction factor of a wind power generator if that generator has a reduced generation output quantity, and individually controlling the generation output quantity of that wind power generator based on the analyzed generation quantity reduction factor so that the generation output quantity is increased.

Abstract: A method for compensating the output power of wind turbine generator set includes acquiring the average values of the first ambient temperature of environments where the wind turbine generator set is located in various periods; collecting the output power of the wind turbine generator set at the end time of various periods; compensating the set output power collected at the end time of current period according to difference value between the average value of the first ambient temperature in the current period and that in the previous period so as to guarantee the stability of the set output power if the average value of the first ambient temperature in the current period and the average value of the first ambient temperature in the previous period both are higher than a preset temperature threshold value.

Abstract: A roller bearing comprises an outer ring, an inner ring, a plurality of rollers arranged between said outer ring and said inner ring; and a plurality of retainer segments having a plurality of column parts extending in a direction along a shaft so as to form a pocket for holding said roller. A connection part extends in a circumferential direction so as to connect the plurality of column parts, and continuously lined with each other in the circumferential direction between said outer ring and said inner ring, in which a corner of a circumferential end face is chamfered. Also provided is a spacer arranged between the circumferentially arranged first retainer segment and last retainer segment, wherein a chamfered part is provided at a corner of a circumferential spacer end face of the space. The roller bearing can be used in a main shaft support structure of a wind-power generator.

Abstract: A maintenance tool and method for detaching mechanically-connected components of a drive train in a wind turbine is disclosed. The method involves positioning the maintenance tool below a hoist and hoisting only the lift assembly portion of the maintenance tool into a nacelle of a wind turbine. Connecting the lift assembly portion to a power source in the nacelle and extending at least two induction cables from an induction generator disposed on the lift assembly portion to wrap at least a portion of a component of the mechanically-connected components. Then operating the induction generator to pass alternating current through the induction cables and inductively heat the wrapped component such that thermal expansion creates a clearance between the mechanically-connected components thereby assisting in separating the mechanically-connected components.

Abstract: A miniature pump includes a cylinder, a piston module, a driving module and a wall body. The cylinder has a first end and a second end opposite to each other along a direction. The piston module is accommodated in the cylinder. The piston module has at least one pumping chamber structure protruded towards the second end, and the pumping chamber structure is able to extend or retract along the direction. The driving module is located at the second end and connected to the pumping chamber structure, configured to drive the pumping chamber structure to extend or retract along the direction. The wall body at least partially surrounds a position of the pumping chamber structure near the first end, and is located between the cylinder and the pumping chamber structure.

Abstract: A balance weight includes a main weight portion extending over a range defined by a circular-arc circumferential edge centered at a rotational shaft hole side and a pair of virtual end surfaces located on the circular-arc circumferential edge on both sides of the rotational shaft hole, a pair of extension weight portions extending from the pair of virtual end surfaces to an opposite circular-arc side of the rotational shaft hole from the circular-arc circumferential edge, the rotational shaft hole provided at the main weight portion so as to be located on a central side of the circular-arc circumferential edge, a crank shaft attachment protrusion, a crank shaft hole provided at the crank shaft attachment protrusion radially eccentrically with respect to the rotational shaft hole, and a pair of spaces formed between positions on both sides of the crank shaft attachment protrusion and the pair of extension weight portions, respectively.

Abstract: A system for supplementing the electric power needed by a pump jack electric motor, thereby reducing the electric power purchased from the local utility or power supplier. The system comprises a solar photovoltaic system, or other forms of renewable energy, and regenerated power from the electric motor or drive. The system can be both “on-grid” and “off-grid.” Battery banks and capacitor banks may be used to store energy.

Abstract: Enhanced tools and techniques are disclosed for performing post-lubrication fluid operations and other fluid maintenance operations on the fluid system of a machine. A control module may be provided for initiating post-lubrication fluid operations for regulating temperature of engine components.

Abstract: A system for monitoring a pump, while the pump operates at a worksite, is disclosed. The system includes one or more sensors, wherein each of the one or more sensors is associated with the pump and is configured to collect high frequency data associated with the pump. The system further includes a field-programmable gate array (FPGA) controller configured to receive the high frequency data from the one or more sensors and is also configured to generate low frequency data based on the high frequency data. The system further includes a low frequency controller configured to receive the low frequency data from the FPGA controller and configured to transmit the low frequency data to a monitor.

Abstract: A positive displacement pump includes a drive unit and a pump unit. The pump unit comprises at least one inline valve unit, a connecting and/or spacing device, and a pair of flanges which are connected to each other via the connecting and/or spacing device. In an operating position, the at least one inline valve unit is clamped between the pair of flanges. The at least one inline valve unit is configured to be displaced without removing the connecting and/or spacing device.

Abstract: An electric pump includes a motor unit including a stator, a rotor core disposed inside the stator and a shaft coupled to the rotor core; a first pump unit and a second pump unit which are coupled using the shaft as a coaxial axis; a first housing in which a motor housing receiving the motor unit and a pump housing including a first pump accommodating part are integrally formed, the first pump unit being inserted in the first pump accommodating part; a second housing coupled to the first housing to cover the first pump accommodating part and including a second pump accommodating part in which the second pump unit is inserted; and a cover unit coupled to the second housing to cover the second pump accommodating part.

Abstract: The invention provides a pump comprising a pump inlet, a pump outlet, at least two threaded rotors and a pressure controlled valve, the pressure controlled valve being capable of controlling re-circulation of fluid from the pump outlet to the pump inlet. The pressure controlled valve can be a control valve. The invention also provides a multiple stage pump assembly comprising at least two pumps arranged in series, wherein at least one of the pumps is the aforementioned pump.

Abstract: A compressor is provided with a fixed scroll having a spiral lap erected on a bed plate; an orbiting scroll having a spiral lap erected on a panel and forming a compression room meshed with the fixed scroll; and an orbiting bearing disposed penetrating the panel and the central part of the lap of the orbiting scroll, wherein a lap center is so shifted from a panel center out of alignment in a direction in which, within a range in which the orbiting bearing can be formed in the central part of the lap, the longer of the minimum distance between the lap winding end position of the orbiting scroll and the outer circumference of the panel and the minimum distance between the outermost circumferential part and the outer circumference of the panel in an approximately 90° direction of becomes the shortest distance.

Abstract: A motor-driven compressor includes an electric motor including a rotor, a housing, a compression unit, a drive circuit, and a controller. The controller includes a deceleration controller that performs a deceleration control, which decelerates the rotor, during a first period in response to the rotor being rotating in a direction opposite to the forward direction, and a continuation controller that performs a continuation control, which continues the rotation of the rotor, during a second period that is longer than the first period after the deceleration control is performed. A fluctuation difference of a rotational frequency of the rotor during the continuation control is less than a deceleration rotational frequency difference.

Abstract: A compressor includes a housing member having an injection passage communicating with a compression chamber, a check valve in the injection passage, and an injection pipe that supplies refrigerant to the injection passage. The check valve has a slidable valve body, and a valve supporting member that restricts movement of the valve body toward the injection pipe side when the check valve checks a flow of refrigerant. A center hole is formed in the valve body. A peripheral hole is formed in the valve supporting member and opposes a rim part of the valve body. Refrigerant passes through the peripheral and center holes and is supplied to the compression chamber. The center hole can be closed by the valve supporting member, and the peripheral hole can be closed by the rim part of the valve body when the check valve checks the flow of refrigerant.

Abstract: A pothead cable seal for electric submersible motors. An electric submersible motor pothead system including a pothead that couples a power cable to an electric submersible motor operable in well fluid, the pothead including a finger seal including a finger around each phase of the power cable and a radial flange, a compression plate that exerts a radial force on each phase from an axial load provided by the compression plate against the radial flange, a seal seat including sockets that receive each finger; a space extending between a portion of an outer diameter of each finger and a flared inner diameter of the socket of the seal seat, and a seal ring extending circumferentially around an outer diameter of each finger and tangent to the flange, the seal ring contacting the flared inner diameter of the seal seat and closing the space to the ingress of well fluid.

Abstract: A blower filter system includes a blower unit (11), an electric motor (24) for driving a blower impeller, a control unit (27) for controlling the electric motor, contacts (22, 23) for connecting to a battery pack, and a battery pack (10) with secondary cells (12) with high energy density and contacts (22, 23) for connecting to the blower unit. The blower unit (11) can be detachably coupled to the battery pack (10). The battery pack is electrically connected to the blower unit via the contacts. The battery pack (10) has protective circuits including electronic components (15, 16, 17, 18, 19, 20, 21, 31) to electrically switch off at least one of the plurality of secondary cells (12) of the battery pack if excessive currents and/or excessive temperatures occur. The battery pack (10) and the blower unit (11) are each at least partially cast in a casting compound.