Abstract: An adjustable camshaft having at least one shaft, and having at least one cam package which has at least two different cams and/or cam contours. According to the invention, the cams and/or the cam contours of the cam packages have different widths.

Abstract: A hydraulic valve lifter apparatus including a seal at the interface of a pushrod seat and a pushrod is provided herein. In one form, the hydraulic valve lifter apparatus includes a body, a piston slidably disposed within the body including a pushrod seat for contacting a pushrod, and a seal located between the pushrod seat and the pushrod.

Abstract: A gasoline composition comprising, as an additive, one or more quaternary ammonium salt(s) (i) formed by the reaction of a compound of formula (A): and a compound formed by the reaction of a hydrocarbyl-substituted acylating agent and an amine of formula (B1) or (B2): wherein R is an optionally substituted alkyl, alkenyl, aryl or alkylaryl group; R1 is an alkyl, aryl or alkylaryl group having up to 36 carbon atoms; R2 and R3 are the same or different alkyl groups having from 1 to 36 carbon atoms; X is an alkylene group having from 1 to 20 carbon atoms; n is from 0 to 20; m is from 1 to 5; and R4 is hydrogen or a C1 to C36 alkyl group.

Abstract: A laser spark plug for an internal combustion engine, including at least one generating arrangement for at least one of guiding, shaping and generating laser radiation, further including a combustion chamber window and a housing, in which the housing has, on the opposite side of the combustion chamber window from the at least one generating arrangement, in particular at an end of the housing on the combustion chamber side, an aperture for the passage of the laser radiation that is at least one of guided, shaped and generated by the at least one generating arrangement into a combustion chamber, the aperture having on the side thereof remote from the combustion chamber window an exit cross-section of 78 mm2 or less, especially 19 mm2 or less.

Abstract: A device for starting an engine includes a starter for starting the engine and an ECU for controlling the starter. The starter includes a pinion gear structured to engage with a ring gear coupled to a crankshaft of the engine, an actuator for moving the pinion gear to an engagement position with the ring gear, and a motor for rotating the pinion gear. The ECU can individually control each of the actuator and the motor. The ECU holds such a state that the motor is stopped and the actuator is driven during a stand-by period until a reference condition is satisfied after completion of start of the engine. Thus, when the engine stopped immediately after start, the engine can quickly be re-started.

Abstract: An engine start control device includes: a control valve which adjusts a gas flow rate of a gas channel provided so as to bypass a throttle valve of an engine; a starter motor capable of driving a crankshaft of the engine; a control unit which controls an opening degree of the control valve and a current supply to the starter motor; and a latch circuit which holds a command for current control from the control unit to the starter motor, wherein the control unit performs the control so as to cause the current supply to the starter motor to start after the opening degree of the control valve reaches a target opening degree for an engine start time, and even when the control unit is reset, the latch circuit continues the current supply to the starter motor according to the command for current control that the latch circuit keeps holding.

Abstract: A starter includes a pinion gear that can be engaged with a ring gear provided around an outer circumference of a flywheel or a drive plate of an engine, an actuator for moving the pinion gear to a position of engagement with the ring gear in a driven state, a helical spline for rotating the pinion gear in a reverse direction while the pinion gear moves toward the ring gear, and a motor for rotating the pinion gear. The actuator and the motor are individually controlled. After the actuator was driven and before the motor is driven, drive of the actuator is stopped.

Abstract: An intake assembly for an internal-combustion engine includes an intake duct for each cylinder, which communicates with an airbox that includes a filtering element. Each intake duct communicates with the airbox by a respective throttle body. A monitoring channel connects the intake ducts together and is configured for perturbing in a negligible way the dynamics of the fluid inside the intake ducts. Associated to said monitoring duct are sensors for monitoring the pressure inside the monitoring duct and designed to send signals indicating the value of pressure of the fluid taken in by the engine to an electronic control unit.

Abstract: A vehicle air intake mechanism comprises an air intake duct having an inlet end opening which opens in an axial direction, and a flow-guiding member having an outer surrounding wall that defines a flow channel in fluid communication with the inlet end opening. The outer surrounding wall has first and second end portions that extend in the axial direction. The first end portion of the outer surrounding wall surrounds an inlet end portion of the air intake duct. The first axial end of the outer surrounding wall defines a first end opening that is in fluid communication with the flow channel and that opens in the axial direction. The inlet end opening is disposed between and is spaced apart from first and second axial ends of the outer surrounding wall in the axial direction.

Abstract: A starting system for an internal combustion engine automatically operates a starting feature on a carburetor associated with the engine. The starting system includes a cam with a bearing mounted on the crankshaft. The bearing is secured so that its inner race will always rotate with the crankshaft. The cam has bosses on one side and is shaped such that it includes a base and a lobe with an outer surface surrounding the cam. At least one spring-loaded pawl is mounted on the flywheel. The pawl is biased to engage a cam boss so as to cause the cam to rotate with the crankshaft during a start-up process. A spring loaded rocker arm is pivotally mounted adjacent the cam. The rocker arm has a roller assembly configured to ride on the outer surface of the cam. As the cam rotates, the roller assembly riding on the cam surface is pushed outward by the cam lobe. A throttle cable is attached at a first end to the rocker arm and at its opposite end to the starting feature on the carburetor.

Abstract: A rope-pull starting device for an internal combustion engine including a hub, rope pulley, rope and torsion damper spring. The hub configured to drivingly engage an engine when the hub is rotated in a first direction. The rope pulley interconnects with the hub by a torsion damper spring. The torsion damper spring coupled at a first end to the hub and at a second end to the rope pulley, wherein the torsion damper spring is coiled from the first end connected to the hub, toward the rope pulley, in a second direction opposite to the first direction, and whereby the rope pulley is rotated in the first direction when the rope is unwound therefrom and the torsion damper spring responsively urges the hub to rotate in the first direction.

Abstract: A balance shaft module of a V6 engine increases an engine balancing rate by improving a structure of the balance shaft module and increasing engine balancing of bank angle 70 to 90° of a V6 engine. The balance shaft module of a V6 engine includes a shaft rotating by interworking with a crank shaft of an engine, a balance shaft connected with the shaft via a gear to rotate at the same velocity and reverse direction as the crank shaft and a second balance shaft connected with the shaft via a gear to rotate in a 2X reverse direction with the crank shaft.

Abstract: A combustion chamber for an internal combustion engine, adapted to promote induction air flow. The combustion chamber has a bulge located near an intake valve head. The bulge projects away from the piston and forms that part of the combustion chamber farthest from the piston. Slope of the walls of the bulge is greater than the angle of the head of the intake valve relative to the deck of the engine block, in engines having separate cylinder heads. The bulge is curved so as to make seamless transition with the cylinder wall at that portion away of the bulge which is distant from the intake valve.

Abstract: A valve cover of a internal combustion engine is fixed on the cylinder head by a plurality of screwed joints, preferably with a circumferential gasket inserted in between. At least some of the screwed joints are provided and/or coupled in such a way with a resiliently and/or elastically flexible element (11) on a cold side (3) of the cylinder head (1), which faces away from the at least one exhaust port in the cylinder head (1) and hence faces a cold side of the engine, that the valve cover (2) lifts off from the cylinder head (1) in a defined area of the cover only in the area of said cold side (3) when there is a defined excess pressure in the crankcase.

Abstract: The present invention relates to a piston (10, 110, 210, 310) for an internal combustion engine, having a piston base body (11, 111, 211, 311) and a piston head element (12, 112, 212, 312), wherein the piston base body (11, 111, 211, 311) has a piston skirt (16) that is provided with pin bosses (18) having pin bores (17), wherein the piston head element (12, 112, 212, 312) forms at least one part of a piston head (25, 125, 225, 325), and wherein a circumferential cooling channel (26, 126, 226, 326) is provided in the piston head (25, 125, 225, 325). According to the invention, it is provided that at least one heat conduction element (27, 127, 227, 327) is disposed in the cooling channel (26, 126, 226, 326).

Abstract: A single cylinder engine includes a crankcase having a crank chamber, a crankshaft disposed in the crank chamber of the crank case and having a crank web with a side surface perpendicular to a rotating shaft of an engine, and a lubricating structure for lubricating oil to components in the engine. The lubricating structure includes an oil reservoir communicating with the crank chamber through an oil discharge port formed to the crank chamber under the crank chamber, and an oil discharge groove formed to the crankcase for discharging oil flying from the crank web into the oil reservoir, the oil discharge groove being provided in a side wall of the crankcase facing a side surface of the crank web in the crank chamber.

Abstract: In an internal combustion engine, a valve actuating mechanism actuates an intake valve member to open an intake port, and actuates an exhaust valve member to return a first part of exhaust gas with a high-temperature from a gas exhaust passage into a combustion chamber via an exhaust port. A cooling and recirculation system recirculates a second part of the exhaust gas from the gas exhaust passage into the gas intake passage via a recirculation passage while cooling the second part of the exhaust gas. This results in a stratified temperature distribution of a high-temperature mixture of first fresh air and the first part of the exhaust gas with the high temperature and a low-temperature mixture of second fresh air and the second part of the exhaust gas with a low temperature in the combustion chamber.

Abstract: A system and method for controlling an exhaust brake of a vehicle may measure rotation speed (RPM) of an engine, transmit the rotation speed of the engine to a control unit, determine an opening of a valve which opens/closes an exhaust pipe of the engine in the control unit based on the rotation speed of the engine to maintain the back pressure of exhaust gas generated by the exhaust brake to be constant, and control the valve according to the valve opening determined by the control unit.

Abstract: A linear actuator (10) includes a plastic housing (12) having an integral flange (14) for mounting the actuator. A stator assembly (16), having windings (18), is disposed in the plastic housing. A rotor assembly (20), having a permanent magnet (22), is mounted for rotation with respect to the stator assembly such that when the windings are energized, a magnetic field is generated to cause rotation of the rotor assembly. A shaft (32) is restricted from rotation and is associated with the rotor assembly such that rotation of the rotor assembly causes linear movement of the shaft. Connector structure (46) houses leads for powering the windings. The plastic housing has an annular end (48) that captures an annular surface (50) of the connector structure to couple the plastic housing to the connector structure.

Abstract: A system according to the principles of the present disclosure includes a throttle limit determination module, a throttle area adjustment module, and a throttle control module. The throttle limit determination module determines a throttle limit based on an intake cam phaser position. The throttle area adjustment module adjusts a desired throttle area based on the throttle limit when the desired throttle area is greater than the throttle limit. The throttle control module controls a throttle opening area of a throttle valve based on the desired throttle area.

Abstract: An air cutoff valve (ACV) is provided. The full open state of the flap valve is maintained using the latchet which operates as the solenoid is turned on and off, so the restart performance is significantly enhanced as the air is quickly supplied by the ACV when the engine stops abnormally irrespective of a driver's intention, and since the ACV is made from a plastic material, the assembling process of the molding formation is simplified, so the unit cost for manufactures is reduced, and the corrosion phenomenon due to moisture can be prevented, and the operation reliability can be enhanced.

Abstract: An ignition system for an internal combustion engine that utilizes a single primary coil and a single secondary coil to drive a pair of spark plugs. Current flowing in both a first direction and a second direction passes through the primary coil. The current flowing through the primary coil induces corresponding current in the secondary coil, which flows from the secondary coil to one of two spark plugs. Each spark plug is coupled to the secondary coil such that each of the two spark plugs receives current flowing only in a single direction. The current flowing through the ignition system can be from either a power source or created by the rotation of a flywheel having a series of magnet clusters.

Abstract: Combustion chamber inserts and associated methods of use and manufacture are disclosed herein. In some embodiments, a combustion chamber assembly comprises a cylinder having a cylinder wall at least partially defining a combustion chamber, an intake valve, an exhaust valve, and a piston. The intake valve has an intake valve surface exposed to the combustion chamber, the exhaust valve has an exhaust valve surface exposed to the combustion chamber, and the piston has a piston surface exposed to the combustion chamber. At least one of the cylinder wall, the intake valve surface, the exhaust valve surface, and/or the piston surface includes an insulative portion composed of a synthetic matrix characterization of crystals that is configured to retain heat in the combustion chamber that is generated from a combustion event in the combustion chamber.

Abstract: A step height is provided in an upper surface of a nozzle plate. Plural pairs of nozzle holes are provided in the nozzle plate, and thereby a liquid film is formed with fuel liquid columns injected from each pair of nozzle holes. In one nozzle hole, as the step height is placed in the vicinity of the nozzle hole, the direction of the fuel flow is changed to a direction along the surface of the step height, and a swirl flow is formed at its inlet. On the other hand, as the other nozzle hole is away from the step height, thereby a uniform inflow without swirl flow is formed. As a result, the shape of the liquid film is changed to a predetermined pattern liquid film by increase of the pressure.

Abstract: In an opposed-piston engine, two or more fuel injectors are mounted to a cylinder for direct side injection into the cylinder. The injectors are controlled so as to inject either a single fuel pulse or a plurality of fuel pulses per cycle of engine operation in order to initiate combustion during varying engine speeds and operating conditions.

Abstract: A fuel injection system includes a fuel tank configured to contain fuel, an injector fluidly connected to the fuel tank by a flow path, a pump disposed along the flow path and configured to deliver fuel to the injector, and a vapor relief passage in fluid communication with the flow path and the fuel tank. The vapor relief passage is fluidly connected to the flow path at an opening and allows vaporized fuel to return to the fuel tank from the flow path.

Abstract: A multi-fuel pre-mixed combustion system of an internal combustion engine includes a main fuel spray nozzle (2), which injects a mixed fuel of compression-ignition-suitable fuels, spark-ignition-suitable fuel, or a wide cut fuel to form a homogeneous primary pre-mixed gas. An auxiliary spray nozzle (4) injects a spark-ignition-suitable fuel to form a secondary mixed gas, which is ignited by the spark plug (3) by means of spray guiding or an ignition chamber (5), and the primary pre-mixed gas in the combustion chamber (1) is compression ignited. Consequently, the ignition point of the primary mixed gas is effectively controlled and knock is avoided, and a homogeneous pre-mixed compression ignition is achieved over the whole range of operating conditions. The combustion rate is controlled by exhaust gas recirculation or spray of water into a cylinder or intake port, and high thermal efficiency is ensured by a high expansion ratio.

Abstract: An apparatus includes a recreational vehicle genset having an engine and a generator. The apparatus includes a fuel injection system having a primary fuel reservoir, a secondary fuel reservoir, and a fill pump that receives fuel from a primary fuel reservoir and is fluidly coupled to the secondary fuel reservoir at the pump outlet. The apparatus includes a reservoir fuel indicator that provides a fuel amount signal corresponding to the fuel in the secondary fuel reservoir, and a pressure regulator that relieves pressure in the secondary fuel reservoir at a threshold relief pressure. The apparatus includes an injection pump that provides pressurized fuel from the secondary fuel reservoir to a fuel injector for the engine. The apparatus further includes a controller having a pump regulation module that interprets the fuel amount signal, and that selectively provides a fill pump operation command in response to the fuel amount signal.

Abstract: A fuel rail has a mounting portion with an aperture through which a fastener extends along a central axis. The fastener secures the fuel rail with respect to a support surface. Stacked-layer isolators are positioned on both sides of the mounting portion. Each stacked-layer isolator includes a pair of rings and an elastomer layer positioned between the rings. Each elastomer layer has a pair of opposing contact surfaces respectively contacting adjacent contact surfaces of the corresponding pair of rings. The pairs of opposing contact surfaces of the elastomer layers and the contact surfaces of the pairs of rings are oblique to the central axis.

Abstract: A flow limiter for a fuel system is provided. The flow limiter includes a self-contained portion that enables testing of the flow limiter prior to assembly into a fuel system. A housing of the flow limiter is arranged to provide reduced or no pressure differential across a wall of the housing, permitting the housing to be reduced in size and thickness and providing improved consistency of operation.

Abstract: A fuel injector cup assembly (26) includes a fuel injector cup (10) having an opening (18) to receive fuel from a fuel rail (15). An open end (27) receives an inlet of a fuel injector (10) therein such that an O-ring (16) seals with the injector cup. A mounting portion (20) extends from a body (29) of the cup and mounts the cup with respect to a cylinder head. Rotation limiting structure (26) is associated with the mounting portion such that when the cup is coupled to the cylinder head and when a first moment is created about the mounting portion causing rotation of the cup with respect to the fuel injector, the rotation limiting structure will engage at least the mounting portion of the cup and create a second moment equal and opposite to the first moment, to prevent further rotation of the cup.

Abstract: An engine includes an engine block comprising a cylinder, an intake and exhaust port, and two linearly opposing pistons reciprocatingly mounted relative to two opposing crankshafts. A pair of piston sleeves are reciprocatingly mounted in the cylinder around each piston and connected relative to their respective crankshafts. Each piston sleeve includes a slotted port in communication with either the intake or exhaust port. A pair of sleeve couplers are pivotably connected to their respective piston sleeves and eccentrically rotatable relative to their respective crankshafts. A pair of eccentric inserts include an outside circumferential surface concentrically offset from an inside circumferential surface aperture. Each inside circumferential surface aperture is pivotable about its respective crankshaft. Each outside circumferential surface is rotatable relative to its respective sleeve coupler.

Abstract: A fuel injection control system for an internal combustion engine includes a plurality of first energy storage elements each for supplying a high voltage to a fuel injection solenoid valve, boosting circuits each for boosting a battery voltage and electrically charging one of the first energy storage elements, a second energy storage element for accumulating electrical energy of the battery voltage, and a switching circuit for transferring the electrical energy between the plurality of first energy storage elements via the second energy storage element. This configuration enables the fuel injection control system for an internal combustion engine to implement stabilized supply of a fuel by obtaining within a short time the high voltage needed to operate the fuel injector both accurately and reliably, and to contribute to cost reduction by, for example, alleviating capability requirements and part performance requirements of the individual boosting circuits.

Abstract: A tank ventilation system of a motor vehicle includes a vapor filter, a first line connecting the vapor filter at a corresponding first introduction point to a suction pipe, and a second line connecting the vapor filter at a corresponding second introduction point to an environment line. The second introduction point is arranged between an air filter and a compressor of the environment line. The second line includes a Venturi nozzle configured to remove carrier flow from downstream of the compressor and upstream of the throttle valve.

Abstract: A vapor solenoid valve is connected so as to lead to a canister. A vapor line connecting port and a purge line connecting port are connected to a vapor line and a purge line, respectively. When switched on and in an open position, the vapor solenoid valve connects a canister connecting port, the vapor line connecting port and the purge connecting port to each other, and thus allows a fuel evaporative gas to flow out of and into a canister or allows air to flow from an air filter. When switched off and in a CLOSED position, the vapor solenoid valve closes the canister connecting port and connects only the vapor line connecting port and the purge line connecting port to each other, and thus inhibits the fuel evaporative gas from flowing out of and into the canister.

Abstract: In a low-pressure EGR system, a mechanical stopper limits a rotation range of a low-pressure EGR regulating valve at a limit opening degree of the low-pressure EGR regulating valve on its fully-open side and outside an EGR amount adjustment opening degree range of the low-pressure EGR regulating valve. After an engine is stopped, a failure detection unit rotates the low-pressure EGR regulating valve to its fully-open position to such an extent that rotation of a linking device is prevented by the mechanical stopper, and is configured to determine that a failure has occurred when an opening degree of the low-pressure EGR regulating valve detected by a low-pressure EGR opening sensor is different from the limit opening degree of the low-pressure EGR regulating valve.

Abstract: An engine air management system is provided for an internal combustion engine generating blowby gas in a crankcase containing engine oil and oil aerosol. The system includes combinations of two or more of an air-oil separator, an air filter, and an acoustic silencer.

Abstract: A method of improving the diffusion combustion of a compression ignition engine. Such engines have at least one cylinder, each cylinder having a compression chamber and operated with an intake phase, compression phase, expansion phase, and exhaust phase of a reciprocating piston. An antenna is placed within the combustion chamber, and is used to apply electromagnetic energy to the diffusion combustion.

Abstract: A method of improving the combustion of a spark-ignition internal combustion engine. Such engines have at least one cylinder, each cylinder having a compression chamber and operated such that an air-fuel mixture introduced into the combustion chamber is ignited to cause a combustion event. An antenna is placed within the combustion chamber, and is used to apply electromagnetic energy to the combustion.

Abstract: An ignition coil assembly and a method of assembling the ignition coil assembly including a first spool, a first coil, and a second spool. The first coil is wound around a first spool outer surface. The first spool and the first coil are disposed within a cavity of the second spool and an electrically insulating material injected into an annular space defined between a first coil outer surface and a second spool inner surface. The first spool is configured to allow a decrease of a circumference of the first spool when the first coil is wound around an outer surface of the first spool. Decreasing the circumference of the first spool increases the annular space sufficient to inject the electrically insulating material into the annular space without creating substantial voids in the electrically insulating material.

Abstract: Gyration induced acceleration of a mass is modified by inserting changes in the pathway of a mass under the influence of gyration force resulting in an acceleration to re-phase after the phase disruption.

Abstract: Archery bow arrangements described herein include an archery bow body defining opposing limb tips and rotational elements mounted at the limb tips. A bowstring and additional cable portions extend between the limb tips. A cable guard extends from the archery bow body. The cable guard includes two slider pieces which each engage one portion of the cable arrangement and which can each separately translate forward or rearward during the bow's draw and release cycle. The slider pieces can preferably translate relative to each other, yet can each form limits to the translation of the other slider. Preferably, each slider is slidable to allow the respective cable portion to remain substantially straight or imparts only a minimal forward or rearward bend angle during the bow's draw and release cycle.

Abstract: In at least one embodiment, an archery bow comprises a riser supporting a first limb and a second limb. The first limb supports a first rotatable member that defines a first axis of rotation. The second limb supports a second rotatable member that defines a second axis of rotation. The first axis of rotation and the second axis of rotation move with respect to one another as the bow is drawn from a brace condition to a drawn condition. The bow defines a reference plane that includes the first axis of rotation and the second axis of rotation, wherein a distance between a predetermined location on the riser and the reference plane is greater in the brace condition than in the drawn condition.

Abstract: Machine for launching targets (6) comprising means for storage of targets, means for delivering a target (6) from the storage means to the delivery area (13), launch area (16) remote from the delivery area (13) and connected to the delivery area (13) by a transfer ramp (12), a launch arm able to apply a launch force on a target (6) in the launch area (16), characterised in that it comprises means for inclining the transfer ramp (12). The invention is particularly suitable for use in launching targets for archery or clay pigeon shooting.

Abstract: Certain exemplary embodiments can provide a system, machine, device, manufacture, circuit, composition of matter, and/or user interface adapted for and/or resulting from, and/or a method and/or machine-readable medium storing machine-implementable instructions for, activities that can comprise and/or relate to, controlling the amount of energy delivered to a projectile from a source of compressed gas.

Abstract: A ball throwing machine can include a hopper for receiving one or more balls and a ball delivery device. The ball delivery device can be used to throw or pitch a ball from the hopper to a user of the machine. The ball delivery device can include wheels to impart speed to the ball and a direction system to control the projection angle of the ball. The direction system can control at least one of the up and down angle and the side to side angle of the ball as it is thrown, among possibly other throwing parameters. A controller may be provided for controlling operation of the ball throwing machine.

Abstract: Method, system, and apparatus are disclosed for projecting a sports object onto a playing surface based upon player position. The method and system includes monitoring player position and projecting the sports object onto a playing surface using a sports object projection apparatus based upon the monitored player position.

Abstract: A concrete saw having a geared assembly for rotating a cutting blade is described. The saw utilizes a longitudinally oriented engine for rotating the blade. Various additional features and improvements are described including a particular belt tensioner assembly, an indicator and control system for cutting blade depth, a handle adjustment and locking system, and provisions for control of blade water are described.

Abstract: Cooking and heating stove fuelled by pellet or biomass grain apt to cook and to heat water for domestic heating comprising a hearth fuelled by pellets or biomass grains, at least one plate to cook food and two heat exchangers to heat water for domestic heating wherein the cooking plate is located above the hearth fuelled by pellets or biomass grains, said two heat exchangers are positioned at the sides of the cooking plate, that on one side of said heat exchangers two inclined deflection plate are mounted that forces the combustion fumes to go up to touch the cooking plate and then to flow on the heat exchangers, the heat exchangers are two bundles with parallel pipes, on said pipes of said bundle heat exchangers at least one fixed deflection plate is located, said fixed deflection plates are perpendicular to said pipes of said bundle heat exchangers, each fixed deflection plate has a unique gateway that is positioned above or below each pipe bundle.

Abstract: A pellet furnace includes a pellet feed assembly, a conveyor assembly, a combustion blower assembly, a baffle assembly, and a control system. The pellet feed assembly includes a distribution tray having a plurality of distribution pins for spreading a mass of pellets over a desired area. The conveyor assembly includes an air distribution plenum and a plurality of grate plates for maintaining a deposited mass of pellets and receiving air from air distribution plenum to facilitate primary combustion of the mass of pellets.