Provided is a vacuum pump regarding which compression can be improved at low costs.

Included is a plurality of Siegbahn exhaust mechanisms in which a helical groove is provided to a stator disc. The Siegbahn exhaust mechanisms are provided on both faces of an upstream side and a downstream side of the stator disc. An end portion of the helical groove provided on the upstream side and a start portion of the helical groove provided on the downstream side are situated at least partially overlapping in a circumferential direction. A width of a channel of a switchback portion of the upstream side and the downstream side is equivalent or less than a depth of a channel of the Siegbahn exhaust mechanisms.

A fan shroud and a blower device are provided. The fan shroud includes a shroud wall surface and a plurality of ventilation openings. The shroud wall surface extends around a fan along a radial direction orthogonal to a rotation axis. The plurality of ventilation openings are formed through the shroud wall surface in a thickness direction of the shroud wall surface to allow passing of wind generated by a fan motor. A width of a wall surface side opening on a downstream side of the wind in the ventilation opening is smaller than a width of a lateral wall side opening on an upstream side of the wind in the ventilation opening.

Disclosed embodiments relate to a combination axial fan and LED lighting system configured to fit into the footprint of a standard ceiling tile. Disclosed embodiments further include ceiling tiles with a built-in fan and/or LED lighting. The disclosed systems may include a housing container and an axial fan. The fan has a fan cavity including air diversion mechanism to direct air from the fan cavity toward the lighting and fan components. The inventions include an airflow surface to direct air existing the fan cavity along an LED light fixture. Moreover, disclosed embodiments include one or more UV light sources which irradiate contaminants as air flows through the ceiling tile.

The present application discloses a flow guide cover and a server having the same. The flow guide cover includes an annular frame, a flow directing member, an air collecting ring, a plurality of first air guide vanes and a plurality of second air guide vanes. The flow directing member is arranged inside the annular frame and comprises a first surface and a second surface which are arranged opposite to each other, the first surface having an area greater than that of the second surface. The air collecting ring is arranged surrounding an outer periphery of the flow directing member, located between the flow directing member and the annular frame, and spaced apart from the flow directing member and the annular frame respectively. When the flow guide cover of the present application is used in conjunction with a fan, heat can be dissipated more evenly.

The present application discloses a flow guide cover and a server having the same. The flow guide cover includes an annular frame, a flow directing member, an air collecting ring, a plurality of first air guide vanes and a plurality of second air guide vanes. The flow directing member is arranged inside the annular frame and comprises a first surface and a second surface which are arranged opposite to each other, the first surface having an area greater than that of the second surface. The air collecting ring is arranged surrounding an outer periphery of the flow directing member, located between the flow directing member and the annular frame, and spaced apart from the flow directing member and the annular frame respectively. When the flow guide cover of the present application is used in conjunction with a fan, heat can be dissipated more evenly.

There is provided a radiator fan configured to introduce outside air into a radiator in front of an engine. The radiator fan includes: a propeller disposed behind the radiator; a fan motor configured to drive the propeller to rotate; and a fan shroud covering the propeller from behind. The fan shroud is formed with a plurality of hoods whose exhaust air ports are directed in any directions in a range from a lateral direction to a downward direction.

An electric motor assembly includes an electric motor, a fan assembly coupled to the electric motor and configured to rotate therewith about an axis. The bower assembly also includes a shroud coupled to the electric motor and extending about the fan assembly. The shroud includes a central hub coupled to the electric motor, an inlet ring, and a plurality of arms extending between the central hub and the inlet ring. Each arm of the plurality of arms includes a curved radial portion extending from the central hub and a planar axial portion extending from the radial portion to the inlet ring.

An extractor fan assembly for an extractor of a sugarcane harvester comprises a motor, fan blades, and a clamshell hub. The motor comprises an output that rotates about an axis of rotation. The clamshell hub comprises a base and clamp jaws. The base is coupled to the output for rotation therewith about the axis of rotation. The clamp jaws are positioned angularly about the axis of rotation. Each clamp jaw is fastened to and cooperates with the base to clamp a respective fan blade of the fan blades therebetween to position the fan blades angularly about the axis of rotation.

A two-way flow control device including: a housing defining a first opening interface and a second opening interface, a rotor having a plurality of blades, each blade controllable to be angled in a range of positive and negative blade angles to generate respective positive and negative flows between the first opening interface and the second opening interface, first stator vanes mounted to the housing between the blades and the first opening interface, each including a respective stator vane slope having a stator vane angle which are collectively positive or negative angled; second stator vanes mounted to the housing between the blades and the second opening interface, each including a respective stator vane slope having a stator vane angle which are collectively opposite angled to the stator vane angles of the first stator vanes, the second stator vanes mounted to be circumferentially offset with respect to the first stator vanes.

A cooling system includes a fan and a system component. The fan includes a plurality of fan blades and configured to rotate in a fan direction. The system component is located downstream of the fan, and includes a cutout for passing of airflow from the fan, and a bridge spanning the cutout. The bridge includes a center section and at least one arm section extending from the center section to an edge of the cutout along a curved path offset towards the fan direction.