An exhaust-gas turbocharger (1) having a turbine (2) which has a turbine housing (3) and which has an exhaust-gas control device (4, 5) arranged in the turbine housing (2); and having an actuator (12; 12) which is operatively connected to the exhaust-gas control device (4, 5) via a drive train (6), with at least one damping connecting element (8; 8.sup.I; 8.sup.II; 8.sup.III; 8.sup.IV; 8.sup.V; 8.sup.VI) arranged in the drive train (6).

An exhaust-gas turbocharger (1) having a turbine (2) which has a turbine housing (3) and which has an exhaust-gas control device (4, 5) arranged in the turbine housing (2); and having an actuator (12; 12) which is operatively connected to the exhaust-gas control device (4, 5) via a drive train (6), with at least one damping connecting element (8; 8.sup.I; 8.sup.II; 8.sup.III; 8.sup.IV; 8.sup.V; 8.sup.VI) arranged in the drive train (6).

An electric fan with a self-cleaning mode to energise rotating fan blades in alternate forward and reverse directions to create a vibration in order to shake built-up dust or dirt particles from the blades in a frequency at which the rotational direction is alternated set to a known or detected resonant frequency of the blades thereby excite resonant modes and maximise the amplitude of vibrations. The self-cleaning operation may be triggered by detection of excessive/abnormal loading on the motor. The fan may be operated in a vibration detecting mode over a range of rotational speeds to locate speeds that produce resonance, or to detect a fault with the fan. Motor reversal frequencies corresponding to resonance-inducing speeds may be used in the self-cleaning mode. The vibration detecting mode may be carried out while the at least one blade is rotated in a direction opposite to its normal operational rotational direction.

A radial compressor has at least one compressor stage. The compressor stage includes: an impeller having moving blades on a rotor side arranged in a flow channel of the compressor stage. The flow channel is bounded by a hub contour and a housing contour or cover disc contour. Each moving blade has a flow inlet edge and a flow outlet edge. In the region of the compressor stage on the hub contour of the flow channel, initially a curvature change from a first concave curvature into a convex curvature and following this a curvature change from the convex curvature into a second concave curvature is formed; and/or on the housing contour or cover disc contour of the flow channel, initially a curvature change from a first convex curvature into a concave curvature and following this a curvature change from the concave curvature into a second convex curvature is formed.

A radial compressor has at least one compressor stage. The compressor stage includes: an impeller having moving blades on a rotor side arranged in a flow channel of the compressor stage. The flow channel is bounded by a hub contour and a housing contour or cover disc contour. Each moving blade has a flow inlet edge and a flow outlet edge. In the region of the compressor stage on the hub contour of the flow channel, initially a curvature change from a first concave curvature into a convex curvature and following this a curvature change from the convex curvature into a second concave curvature is formed; and/or on the housing contour or cover disc contour of the flow channel, initially a curvature change from a first convex curvature into a concave curvature and following this a curvature change from the concave curvature into a second convex curvature is formed.

A refrigeration device or appliance has a fan assembly which is mounted in a housing with a housing front side part and a housing rear side part, and the fan assembly is secured to the housing rear side part and is held in place by the housing front side part.

A refrigeration device or appliance has a fan assembly which is mounted in a housing with a housing front side part and a housing rear side part, and the fan assembly is secured to the housing rear side part and is held in place by the housing front side part.

In an impeller for a fluid energy machine with a hub and a plurality of rotor blades which are mounted on the hub and around which a medium may flow through the fluid energy machine and which form a blade duct between two neighboring rotor blades with a blade duct length which extends in the axial direction of the impeller, wherein each rotor blade is connected to the hub via a first transition region with a first curvature and via a second transition region with a second curvature and with a straight conical blade duct bottom of the blade duct formed between the first transition region and the second transition region.

In an impeller for a fluid energy machine with a hub and a plurality of rotor blades which are mounted on the hub and around which a medium may flow through the fluid energy machine and which form a blade duct between two neighboring rotor blades with a blade duct length which extends in the axial direction of the impeller, wherein each rotor blade is connected to the hub via a first transition region with a first curvature and via a second transition region with a second curvature and with a straight conical blade duct bottom of the blade duct formed between the first transition region and the second transition region.

Example embodiments relate to a device for heating a liquid and/or warming air, including a burner device and an air conveying device. The air conveying device conveys combustion air to the burner device. The air conveying device has a carrier housing, a movable fan wheel, an air inlet, and an air outlet. The carrier housing has a conveying channel which is connected to the air inlet and the air outlet. The fan wheel is arranged so as to be rotatable about a longitudinal axis of the air conveying device and has a blade structure. The air outlet is arranged in a central area of the air conveying device and extends through the fan wheel. The invention further relates to a side channel blower.