The present disclosure provides a bearing assembly, a rotor assembly and a draught fan. The bearing assembly has a shaft sleeve and a shaft extending through the shaft sleeve. An inner wall of the shaft sleeve is provided with two grooves in a circumferential direction. The shaft is provided with two channels corresponding to the two grooves respectively. The channels and the grooves form two raceways. Multiple rolling bodies are disposed between the shaft and the shaft sleeve and movable in the raceways. The shaft sleeve has an outer diameter of 13 mm, and a portion of the shaft extending within the shaft sleeve has a diameter of 5 mm.

The present disclosure relates to the technical field of low-temperature pumps, in particular to a permanent magnet leakage-free low-temperature pump. The permanent magnet leakage-free low-temperature pump comprises a pump body, wherein a pump impeller is arranged in the pump body, the pump impeller and a permanent magnet motor are of a coaxial structure, no coupler device is arranged between the pump impeller and the permanent magnet motor, a motor barrel is arranged in the pump body and connected with an external power source through a wiring device to work, a first flange plate is arranged at the position, located at the front end, of the outer wall of the pump body, and a second flange plate is arranged at the position, located at the rear end, of the outer wall of the pump body.

An exhaust turbocharger has a housing, in which a shaft is mounted by bearings, which carries a turbine wheel, on the one hand, and a compressor wheel, on the other hand. An electric machine has a rotor and a stator. The rotor is secured on the shaft for conjoint rotation therewith and the stator surrounds the rotor radially on the outside. A sleeve, which supports the rotor radially and axially, is arranged between the stator and the rotor. The sleeve has at least one fluid duct, by way of which a cooling fluid can be guided toward the bearings of the shaft.

An exhaust turbocharger has a housing, in which a shaft is mounted by bearings, which carries a turbine wheel, on the one hand, and a compressor wheel, on the other hand. An electric machine has a rotor and a stator. The rotor is secured on the shaft for conjoint rotation therewith and the stator surrounds the rotor radially on the outside. A sleeve, which supports the rotor radially and axially, is arranged between the stator and the rotor. The sleeve has at least one fluid duct, by way of which a cooling fluid can be guided toward the bearings of the shaft.

A bearing structure includes a drive shaft that extends in a horizontal direction, a touchdown bearing, and a bearing housing. The drive shaft is supported by a magnetic bearing. The touchdown bearing includes a rolling member interposed between an outer ring and an inner ring. The bearing housing supports the touchdown bearing from an outer periphery. At least one of an outer peripheral surface of the drive shaft, an inner peripheral surface of the inner ring, an outer peripheral surface of the outer ring, and an inner peripheral surface of the bearing housing includes a recess in a region overlapping the rolling member in a bearing radial direction.

A bearing structure includes a drive shaft that extends in a horizontal direction, a touchdown bearing, and a bearing housing. The drive shaft is supported by a magnetic bearing. The touchdown bearing includes a rolling member interposed between an outer ring and an inner ring. The bearing housing supports the touchdown bearing from an outer periphery. At least one of an outer peripheral surface of the drive shaft, an inner peripheral surface of the inner ring, an outer peripheral surface of the outer ring, and an inner peripheral surface of the bearing housing includes a recess in a region overlapping the rolling member in a bearing radial direction.

Damping devices, turbomachines, and methods of damping vibration are provided. For example, a damping device for damping vibration of a shaft rotatable about an axis of rotation is provided. The damping device defines radial and axial directions. The damping device comprises a bearing, a housing, and a damper element. The housing and damper element define a cavity therebetween for receipt of a damping fluid. The cavity has a length along the axial direction that is curved away from the axis of rotation. As another example, a turbomachine comprising a shaft rotatable about an axis of rotation includes a damping device positioned annularly about the shaft. The damping device comprises a housing and a damper element defining a cavity therebetween for receipt of a damping fluid that has a curved shape. The cavity is curved in a plane extending along the radial and axial directions and including the axis of rotation.

A levering device includes a coupling block, a gripper, an operating rod, and a constraint sleeve. The coupling block includes a coupling chamber, two guide slots in communication with the coupling chamber, an extension rod, and an axial hole axially cut through the extension rod in communication with the coupling chamber. The operating rod being axially movably inserted through the axial hole into a bearing chamber of a housing of a motor-driven water lifting device to stop against respective one end of a wheel axle of the motor-driven water lifting device. The gripper is attachable to the two guide slots of the coupling block and includes two gripper blocks and two claw bars respectively connected to the gripper blocks. The constraint sleeve is sleeved onto the coupling block to stop the two claw bars in the respective the guide slots.

A centrifugal pump includes a pump body that defines a partition between a rotor chamber and a pump chamber, a motor case that forms the rotor chamber together with the pump body, a pump cover that forms the pump chamber together with the pump body, and a bearing that rotatably supports a rotor shaft of a rotor with respect to the pump body. The pump body includes a boss part that projects from a partition wall toward the rotor chamber and rotatably supports the bearing. A projection part projects from a lateral section of the boss part. The projection part has an inclined surface section inclined radially inward toward the leading end side of the boss part. The boss part has a connection hole that extends from the rotor chamber to the pump chamber. A rotor chamber side opening end portion of the connection hole opens to the inclined surface section.

A bearing structure includes a drive shaft that extends in a horizontal direction, a touchdown bearing, and a bearing housing. The drive shaft is supported by a magnetic bearing. The touchdown bearing includes a rolling member interposed between an outer ring and an inner ring. The bearing housing supports the touchdown bearing from an outer periphery. At least one of an outer peripheral surface of the drive shaft, an inner peripheral surface of the inner ring, an outer peripheral surface of the outer ring, and an inner peripheral surface of the bearing housing includes a recess in a region overlapping the rolling member in a bearing radial direction.