The technology disclosed herein relates to a grounds maintenance vehicle. The grounds maintenance vehicle has an engine and an engine shroud defining a cooling volume around the engine. The shroud defines a shroud intake. An engine oil conduit extends from the engine and a heat exchanger is coupled to the engine oil conduit.

A screening device and a self-propelled harvester with a screening device is disclosed. The screening device includes at least one suction nozzle that has an elongated hollow body with at least one suction opening which extends sectionally in the longitudinal direction and transverse direction of the hollow body, and is connected by at least one air duct in the interior of the hollow body to a connection arranged in the hollow body for connecting to a vacuum source. The suction opening is positioned facing a screen of the screening device. The air duct has a cross-sectional shape that increases in the vertical direction toward the connection starting from an outer end of the suction nozzle. An inner contour facing the suction opening of the air duct has a contour that substantially corresponds to an airfoil.

A heat exchanger arrangement includes a heat exchanger having a front, a rear, and a side between the front and the rear, a fan arranged to direct an airflow from the front to the rear of the heat exchanger, and a screen disposed over at least the front and side of the heat exchanger and attached to a structure at or behind the rear of the heat exchanger.

A motorized working apparatus includes a housing having an air inlet, an air guide leading from the air inlet into the housing, and an air filter which is curved hood-shaped outwardly and covers the air inlet of the housing. The air filter includes a filter frame body with a filter-fabric-free air outlet face facing the air inlet of the housing and with a window frame structure protruding over the filter-fabric-free air outlet face and having at least one window region. A filter fabric occupies the at least one window region, and a fixation releasably fixes the filter frame body to the housing. The window frame structure has frame webs which delimit the at least one window region and which protrude relative to the filter fabric towards an air supply side in the at least one window region and include web side edges which run sloping at an obtuse angle relative to adjacent window planes, and/or the fixation includes a pre-fixing clamping holding arrangement and a final fixing holding arrangement which are independent of each other, and/or the window frame structure of the air filter protrudes over the filter-fabric-free air outlet face in the shape of a roof with a triangular cross-sectional form.

An estimator includes a model unit that calculates a state quantity by using an input signal and a relational expression that expresses a target model, a correction signal measurement sensor that measures a correction signal for correcting the state quantity, a correction unit that outputs a value for correcting the state quantity based on the correction signal to the model unit, and a model changing unit that changes the model unit in accordance with an oil flow related value that relates to a change of flow of cooling oil. The correction signal measurement sensor is arranged to be in contact with a metal member that includes a coil conductive wire that constitutes the stator coil, a terminal connected to the coil conductive wire, and a power line connected between the coil conductive wire and the terminal, at a point on which no cooling oil drops.

An estimator includes a model unit that calculates a state quantity by using an input signal and a relational expression that expresses a target model, a correction signal measurement sensor that measures a correction signal for correcting the state quantity, a correction unit that outputs a value for correcting the state quantity based on the correction signal to the model unit, and a model changing unit that changes the model unit in accordance with an oil flow related value that relates to a change of flow of cooling oil. The correction signal measurement sensor is arranged to be in contact with a metal member that includes a coil conductive wire that constitutes the stator coil, a terminal connected to the coil conductive wire, and a power line connected between the coil conductive wire and the terminal, at a point on which no cooling oil drops.

A multiplane fan cooling system and method is disclosed for a cooling system with first, second and intake planes; a first fan and heat exchanger on the first plane, a second fan and heat exchanger on the second plane, and a shared air cavity bounded at least partially by these three planes. Each fan pulls air into the shared air cavity through the intake plane and across its associated heat exchanger. The first fan cools the first heat exchanger, and counteracts the second fan from drawing air into the shared air cavity through the first heat exchanger. The second fan cools the second heat exchanger. The second fan can be activated to counteract the first fan from drawing air into the shared air cavity through the second heat exchanger. All the air in the shared air cavity can be available to each of the fans.

A multiplane fan cooling system and method is disclosed for a cooling system with first, second and intake planes; a first fan and heat exchanger on the first plane, a second fan and heat exchanger on the second plane, and a shared air cavity bounded at least partially by these three planes. Each fan pulls air into the shared air cavity through the intake plane and across its associated heat exchanger. The first fan cools the first heat exchanger, and counteracts the second fan from drawing air into the shared air cavity through the first heat exchanger. The second fan cools the second heat exchanger. The second fan can be activated to counteract the first fan from drawing air into the shared air cavity through the second heat exchanger. All the air in the shared air cavity can be available to each of the fans.

A noise suppression system for an air-cooled internal combustion engine is disclosed. The system may include an acoustically designed shroud forming a cavity and configured for attenuating noise produced by a cooling air fan associated with the engine. In one system, the shroud is mountable on a housing of the air fan. A pair of air inlet passages may be provided which are operable to draw ambient cooling air into the shroud to the fan. The air inlet passages are acoustically configured and tuned to attenuate noise generated by the fan. In one system, the air inlet passages may each be formed in a rear quadrant of the shroud. Various configurations of the shroud may include quarter wave resonators and/or micro-perforated panels to further attenuate fan noise.

A noise suppression system for an air-cooled internal combustion engine is disclosed. The system may include an acoustically designed shroud forming a cavity and configured for attenuating noise produced by a cooling air fan associated with the engine. In one system, the shroud is mountable on a housing of the air fan. A pair of air inlet passages may be provided which are operable to draw ambient cooling air into the shroud to the fan. The air inlet passages are acoustically configured and tuned to attenuate noise generated by the fan. In one system, the air inlet passages may each be formed in a rear quadrant of the shroud. Various configurations of the shroud may include quarter wave resonators and/or micro-perforated panels to further attenuate fan noise.