46results about How to "Low critical speed" patented technology

A magnetically-levitated blood pump with an optimization method that enables miniaturization and supercritical operation. The blood pump includes an optimized annular blood gap that increases blood flow and also provides a reduction in bearing stiffness among the permanent magnet bearings. Sensors are configured and placed optimally to provide space savings for the motor and magnet sections of the blood pump. Rotor mass is increased by providing permanent magnet placement deep within the rotor enabled by a draw rod configuration.

An improvement for a turbine generator or pump having main bearings separated by a span of shaft and a thrust equalizing mechanism adjacent one of said main bearings, the improvement comprising a stationary length compensator interposed between the thrust equalizing mechanism and its adjacent main bearing to reduce the span between said main bearings. Preferably the length compensator is composed of material that shrinks less than the shaft of the generator, and the height of the length compensator, i.e., the compensating dimension, is selected according to desired thrust equalizing mechanism operating parameters over a temperature range.

The invention discloses a manufacturing method for a high-density cold spraying metal sedimentary body based on mixed powder and belongs to the technical field of material engineering. The method includes the following steps that firstly, conventional atomized metal powder and ionized metal powder or hydroxyl metal powder are mechanically mixed to manufacture the mixed powder, wherein the conventional atomized metal powder and the ionized metal powder or the hydroxyl metal powder adopt the same metal components; and secondly, the surface of a base body or the surface of a workpiece to be sprayed is pretreated, the mixed powder serves as spraying powder, a coating or a blocky material is deposited through a cold spraying method. By the adoption of the method, the characteristic that the deposition efficiency of the electrolyzed / hydroxyl metal powder is high is maintained, the defects that the electrolyzed / hydroxyl metal powder is pool in fluidity and prone to blocking a spray gun are overcome, pores in the deposited electrolyzed / hydroxyl metal powder are closed through the strong tamping effect generated by impact of conventional atomized powder, and the completely-dense metal sedimentary body is obtained.

The invention provides a self-suction type efficient stirring device. The self-suction type efficient stirring device consists of necessary stirring driving parts such as a speed reducing motor, a hollow stirring shaft, an upper auxiliary stirring paddle, a self-suction type stirring paddle and a lower auxiliary stirring paddle, wherein the self-suction type stirring paddle is a reducing pipe type stirrer; the transverse radius of a stirring pipe is gradually decreased outwards along the circumferential direction; the stirring pipe is of an all-directional porous structure; gas outlets are formed in an outlet and the back liquid level side of the stirring pipe; the upper auxiliary stirring paddle and the lower auxiliary stirring paddle are different types of axial flow type stirring paddles. The self-suction type efficient stirring device has the advantages that the gas suction critical rotation speed is low, the gas suction speed rate is high, the bubble size is small; gas is uniformly mixed with liquid and solid phases; the contact area between heterogeneous phases is large; mass transfer coefficients are high; a solid-phase medium can be effectively prevented from being settled; the reaction speed rate and the yield are increased.

A non-thrust-disc radial and axial integrated permanent magnet biased magnetic bearing comprises a permanent magnet body, a magnetic conducting ring, a radial stator core, radial coils, a rotor core, an annular magnetic pole, an axial stator core, axial coils, a thread ring and a rotating shaft, wherein the permanent magnet is used for providing a biased magnetic field; biased magnetic flux and axial control magnetic flux are transferred through the annular magnetic pole; an annular air gap which is longer than a radial air gap is formed between the annular magnetic pole and the thread ring; the magnetic bearing generates force in a differential manner through four magnetic poles of a radial stator; the magnetic bearing is free of a thrust disc and generates force through the end surface of the thread ring; the thread ring is used for compressing the rotor core. An existing radial and axial integrated magnetic bearing axially generates forces through the thrust disc, thus the outside diameter of a rotor, the linear velocity and the ventilation losses are increased, and the mechanical safety margin and critical speed of rotation of the rotor are reduced. The non-thrust-disc radial and axial integrated permanent magnet biased magnetic bearing can solve the shortage of the existing radial and axial integrated magnetic bearing which axially generates force through the thrust disc; the non-thrust-disc radial and axial integrated permanent magnet biased magnetic bearing has the advantages of reducing the losses, and improving the mechanical safety margin and critical speed of rotation of the rotor.

The invention provides a fan bearing supporting cone wall, which is a hollow rotary thin-walled part with a large end and a small end. The stress concentration part is formed at the position where the shrinkage turns to gradual expansion, and the stress concentration part is set as a fuse part to deal with the FBO event. The present invention also provides a fan rotor support system comprising the fan bearing support cone wall. The fan bearing support cone wall described above can provide an alternative to this fusing design using thinned sections.

The invention discloses an active load reducing device for a sudden load of an aero-engine tester. According to the device, a pneumatic chuck is fixed on the upper surface of a chuck support; a working sleeve at one end of a variable stiffness elastic support is arranged in the inner surface of the pneumatic chuck; a flange at the other end of the variable stiffness elastic support is connected with a simulation tester; a three-jaw chuck at one end face of the pneumatic chuck is in a clamping state when the three-jaw chuck is powered on and is in a release state when the three-jaw chuck is powered off; and the variable rigidity elastic support is clamped by adjusting the distance between chuck jaws. The device disclosed by the invention has the beneficial effects that by utilizing the variable stiffness elastic support, the support stiffness is adaptively changed and the critical rotation speed of a rotor system is significantly changed, thereby reducing an impact load of a blade flying off the rotor system and providing experimental support for the safety design of the rotor system when a sudden imbalance occurs; and the device has the characteristics of low cost, good repeatability and implementation convenience.

The invention discloses an inverse system decoupling controller of a five-degree-of-freedom bearingless synchronous reluctance motor. In the inverse system decoupling controller, a linear closed-loop controller, an alpha-th-order inverse system and a composite controlled object are connected in series successively; the composite controlled object consists of three extended hysteresis current controlled PWM inverters, a switching power amplifier and the five-degree-of-freedom bearingless synchronous reluctance motor; the alpha-th-order inverse system and the composite controlled object constitute a pseudo linear system; the five-degree-of-freedom bearingless synchronous reluctance motor consists of a three-degree-of-freedom active magnetic bearing and a two-degree-of-freedom bearingless synchronous reluctance motor which share one rotor; the rotor is provided with a plurality of eddy-current sensors; and the linear closed-loop controller consists of a rotary speed controller, four radial position controllers and an axial position controller. The controller disclosed by the invention has compact structure; and by adopting the invention, the radial suspension force, axial suspension force, motor radial suspension force and electromagnetic torque of the magnetic bearing can be controlled independently and the control performance of the entire system can be effectively increased.