63results about How to "Improve high-speed stability" patented technology

The invention provides a brand new permanent magnet synchronous motor control method. A control system applied by the method comprises a torque command input unit, a torque-current lookup unit, a cross decoupling regulation unit, a space vector pulse width modulation unit, an inverter unit, a weak magnetic regulation unit and a permanent magnet synchronous motor unit, wherein the torque-current lookup unit performs analysis according to the output result of current weak magnetic regulation and a torque command and acquires an AC-DC shaft current command through lookup, and the lookup manner is irrelevant to the rotating speed so as to improve the convenience and the accuracy of torque lookup; meanwhile, the cross decoupling regulation unit performs cross PI (Proportional-Integral) regulation on the difference between the AC-DC shaft current command and actual current feedback so as to reduce the influence of cross coupling of the motor per se at high speed and improve the high-speed stability of the motor; and the weak magnetic regulation unit calculates the amplitude of voltage vector according to the current AC-DC shaft voltage reference command, performs PI regulation on the amplitude and the maximum available voltage vector amplitude in the current busbar voltage and automatically outputs a weak magnetic reference current command to conveniently enlarge the motor speed regulation range.

A pneumatic vehicle tire of the radial type with a tread strip, which has a width defined as the tread width TW, which represents its maximal width in the ground contact area in the case of mounted, loaded and inflated tires, where, when viewed in cross section, the outer contour of the tread strip has at least three different radii over its width TW, of which the first radius TR₁ extends over an area encompassing the zenith of the tire, while an adjoining area on both sides of this area has a radius TR₂, which is smaller than the radius TR₁, and while on each side of this area an adjoining area has a radius TRA, which is smaller than the radius TR₁ of the area encompassing the zenith of the tire. In each case, the edges of the tread strip defined by the tread width TW run in an area with a fourth radius, a shoulder radius provided in the transition area to the sidewalls of the tire. The radius TRA is determined according to the equation 0.05 TR₁≦TRA≦0.65 TR₁. The radius TR₂ can be either less than or greater than the radius TRA, where, for the case TR₂≦TRA, the radius TR₂ is determined according to the equation 0.05 TR₁≦TR₂≦0.6 TR₁, and, for the case TR₂≧TRA, the radius TR₂ is determined according to the equation 0.1 TR₁≦TR₂≦0.95 TR₁.

A pneumatic tire for a front wheel of a motorcycle comprises a pair of bead cores, a radial carcass toroidally extending between the pair of bead portions, a belt disposed on a radially outer surface of the carcass, and a tread portion disposed thereon, wherein the carcass is comprised of at least one carcass ply containing organic fiber cords, and the belt is a spiral belt layer formed by spirally winding a continuous rubberized cord or a continuous ribbon-shaped body containing plural cords therein in a widthwise direction of the tire, and the tread portion has a two-layer structure comprised of a cap rubber layer and a base rubber layer in at least a central region in the widthwise direction of the tire, or a reinforcing layer is disposed inside an innermost carcass ply or on an inner surface of an innerliner, or the bead core is a helically wound laminate of a single steel wire having a polygonal shape at a section of the bead core in the radial direction.

A system is configured to mitigate hydroplaning of a vehicle having an adjustable aerodynamic-aid element configured to generate a selectable downforce on the vehicle body in response to a movement of ambient airflow relative thereto. The system includes a mechanism for varying a position of the adjustable aerodynamic-aid element relative to the body to regulate the downforce and sensor(s) configured to detect a vehicle dynamic parameter indicative of hydroplaning of the vehicle. The system additionally includes an electronic controller in communication with the sensor(s) and programmed to regulate the mechanism. The controller is configured to determine a target position for the adjustable aerodynamic-aid element in response to signal(s) from the sensor(s). The controller is also configured to set the adjustable aerodynamic-aid element to the target position via the mechanism to regulate the downforce on the vehicle body and mitigate the hydroplaning of the vehicle.

The invention discloses an automobile spoiler with the adjustable height. The automobile spoiler comprises an automobile tail base and a spoiler body. A fixing base is arranged above the left portion of the automobile tail base and fixed to the automobile tail base. A hinge shaft is arranged on the fixing base. An automobile speed inductor is arranged in the automobile tail base. A line bank is arranged above the right portion of the automobile speed inductor. A cushion base is arranged above the right portion of the automobile tail base and fixed to the automobile tail base. A hydraulic stand column is arranged in the cushion base and fixed to the cushion base. The hydraulic stand column is provided with a hydraulic rod. The spoiler body is located above the automobile tail base. The left lower end of the spoiler body is hinged to the fixing base. A hinging base is arranged in the spoiler body and hinged to the hydraulic rod. The automobile spoiler with the adjustable height is simple in structure, the height is convenient to adjust, installing is convenient, the anti-impact strength and the bending strength of the spoiler body of the automobile spoiler are large, and the heat resistance of the spoiler body of the automobile spoiler is high.

The invention discloses an electric automobile carrying a wind power generation system.The electric automobile comprises an automobile body, a chassis and wheels.A storage battery, a wind turbine generator system and an airway system are arranged above the chassis.The airway system comprises an airway lower plate part installed above the chassis of the electric automobile, an airway upper plate part located above the airway lower plate part, and side plate parts connected with the two ends of the airway upper plate part and the two ends of the airway lower plate parts in the width direction.A containing cavity with openings in the two ends in the length direction is formed by the airway upper plate part, the airway lower plate part and the side plate parts together.The opening in one end of the containing cavity is an air inlet, and the opening in the other end of the containing cavity is an air outlet.An airway is formed between the air inlet and the air outlet.The sectional area of at least one part, in the direction in which the air inlet extends to the air outlet, of the airway tends to decrease.Due to the adoption of the technical scheme, the inner space of the automobile body can be reasonably used, and caught wind can be efficiently used in channels.

A semiconductor memory device is composed of a plurality of banks each including a plurality of sub-arrays arranged in rows and columns; global I/O lines shared by the plurality of banks; local I/O lines disposed for every a number of sub-arrays within each of the plurality of banks; I/O switch control circuits responsive to respective I/O switch timing signals for establishing connections between the global I/O lines and the local I/O lines within each of the plurality of banks; and a timing control circuit. The timing control circuit controls the I/O switch timing signals that each I/O switch timing signal remains activated until associated one of the plurality of banks gets out of a row active state after once the each I/O switch timing signal is activated.

The invention discloses a tilting pad supporting bearing for an acceleration gear box, and belongs to the technical field of bearing design. A bearing shell, a tilting pad, a pad back limiting screw,an oil spraying screw, a seal end cover A, a seal end cover B, end cover fastening screws, pad end face limiting screws, temperature measuring wire clamps, wire clamp fastening screws and a flange areincluded. The seal end cover A and the seal end cover B are arranged at the two ends of the bearing shell. The tilting pad is arranged in the bearing shell. The oil spraying screw and the pad back limiting screw are arranged on the side wall of the bearing shell correspondingly. The end cover fastening screws are arranged on the seal end cover A and the seal end cover B correspondingly. The pad end face limiting screws are arranged between the seal end cover A and the tilting pad and between the seal end cover B and the tilting pad. The flange, the temperature measuring wire clamps and the wire clamp fastening screws are arranged on the seal end cover B. The bearing is reasonable in structure design, convenient to machine, install and maintain, low in power consumption, safe, reliable andlong in service life.

A reaming bit designed to operate with low torque fluctuation when driven with a turbine at speeds in the order of 300-600 RPM and above features a profile that is arcuate from the gauge dimension to the nose area or alternatively has a blunt straight taper section but with a ratio of profile length (PL) to bit size (BS) of under 0.75. The blades extend into a concave cone and the cutting structure continues along the blades towards the center. The blades have a step near the gauge section to increase the exposure of the blade cutting structure. An array of protrusions are disposed parallel to and behind the cutting structure to increase high speed stability and adjacent the blade step transition to protect outer casing on run in.

The invention discloses a steam turbine tilting pad supporting thrust combined bearing, and belongs to the field of bearing design. The steam turbine tilting pad supporting thrust combined bearing comprises a supporting bearing, thrust bearings and adjusting base plates. The supporting bearing is of a tilting pad structure. The thrust bearings are of a Kingsbury type improved structure with an oilspraying structure. The two thrust bearings are arranged at the two ends of the supporting bearing respectively. The two adjusting base plates are arranged between the supporting bearing and the thrust bearings respectively. The steam turbine tilting pad supporting thrust combined bearing is of a split structure and is provided with an oil inlet structure, the installation structure is good in stability, the machining difficulty is low, a tilting pad can be cooled, friction power consumption is small, vibration is gentle and regular, and the steam turbine tilting pad supporting thrust combined bearing is very suitable for being used for high-speed running equipment such as a steam turbine.

The invention provides a liquid-magnetic composite bearing structure for a reusable rocket turbine pump. An annular bearing bush body is arranged on an inner ring of a bearing pedestal and is axiallyconnected and fixed to a turbine pump shell. An even number of sector-shaped bush blocks are distributed at equal intervals in the circumferential direction and installed on the inner surface of the bearing bush body through elastic oblique fulcrums, oblique bushes are formed, and each oblique bush is internally and symmetrically provided with a pair of superconducting blocks in an embedded mannerin the circumferential direction. The position, corresponding to a liquid-magnetic composite bearing, on a turbine pump rotating shaft is sleeved with a permanent magnet ring. According to the liquid-magnetic composite bearing, dynamic pressure liquid film force and superconductive magnetic force are used for carrying out synergistic bearing on a turbine pump shafting, low-speed suspension and high-speed deloading are achieved through superconductive magnetic force, a high-speed main bearing force field is formed through the dynamic liquid film force, the problem that at the starting and stopping stages of an ordinary liquid film bearing, friction abrasion is serious is solved, and the liquid-magnetic composite bearing structure has value for developing a next generation of long-service life and high-reliability shafting supporting technology for the reusable rocket turbine pump.

A sheet discharged from a sheet discharging portion arranged at a distance from a sheet stacking portion, to a stacking portion, is conveyed along the sheet stacking portion while the sheet edge on an upstream side in a sheet discharging direction is held. A shifting unit arranged downstream of the sheet stacking portion in the sheet discharging direction shifts the discharged sheet from the sheet discharging portion toward the downstream side in the sheet discharging direction while a pressing member presses the sheet to the sheet stacking portion.

A reaming bit designed to operate with low torque fluctuation when driven with a turbine at speeds in the order of 300-600 RPM and above features a profile that is arcuate from the gauge dimension to the nose area or alternatively has a blunt straight taper section but with a ratio of profile length (PL) to bit size (BS) of under 0.75. The blades extend into a concave cone and the cutting structure continues along the blades towards the center. The blades have a step near the gauge section to increase the exposure of the blade cutting structure. An array of protrusions are disposed parallel to and behind the cutting structure to increase high speed stability and adjacent the blade step transition to protect outer casing on run in.

The invention discloses a method for adjusting the damping factor of a CoFeB film through changing the growth sequence of MgO/CoFeB/Ta. The structure is better in perpendicular anisotropy and is goodin adjustability of the damping factor, so the material is a key material which can be used for generating an MRAM (Magnetic Random Access Memory) device. The magnetron sputtering is used for growinga Ta/CoFeB/MgO superthin film and an MgO/CoFeB/Ta superthin film, and a TRMOKE (Time Resolved Magneto-Optical Kerr Effect) is used for testing the damping factor of the material. The damping factor alpha of Ta/CoFeB/MgO is 0.017, and the damping factor of MgO/CoFeB/Ta is 0.027. Because the change of the damping factor is big, the material is very suitable for the increase of the reading and writing speed of the MRAM. The structure of a sample in the invention sequentially consists of a substrate, a buffering layer, a magnetic layer, and a coverage layer. The repetition frequency of femtosecondpulse laser is 1000Hz, the pulse width is 50fs, and the pumping power density is 3.54mJ/cm2.

A pneumatic tire excellent in high speed stability and turning ability is provided. In a band of a tire, a center portion located in an axial center has a helically wound structure in which a first band body including a first cord is wound. A shoulder portion located on an axial outside of the center portion has a meshed structure formed by a second band body including a second cord. The shoulder portion includes a plurality of first portions, a plurality of second portions and a plurality of third portions. Each first portion is inclined and extends from an axially inner end of the shoulder portion to an axially outer end of the shoulder portion. Each second portion is inclined in an opposite direction from the first portion and extends from the axially inner end of the shoulder portion to the axially outer end of the shoulder portion.

The present invention provides a control method for controlling an ink jet head. The inkjet head includes an ejection port substrate having ejection ports for ejection of the droplets, ejection electrodes respectively being located in a position corresponding to each of the ejection ports, and a guard electrode formed in the ejection port substrate. The control method includes the steps of: applying a drive voltage to each of the ejection electrodes in accordance with a drawing signal; and applying an AC bias voltage to the guard electrode, the AC bias voltage having the same frequency as the drive voltage applied to each of the ejection electrodes and alternately repeating a first voltage and a second voltage being lower than the first voltage.

A cord of a band of a tire has a single-stranded structure in which steel filaments are stranded, and the number of the filaments is not less than three and not greater than six. In a cross-section of the cord, when φ represents a diameter of a smallest circle that surrounds cross-sections of the filaments, and ψ represents a diameter of each filament, a gap is formed between the filaments such that the diameter φ is not less than three times the diameter ψ and not greater than six times the diameter ψ in the case of the number of the filaments being three or four. An initial elongation of the cord is not less than 0.1% and not greater than 1.5%.

An optical disk drive apparatus includes a cylindrical space forming unit that forms a cylindrical space. In the cylindrical space, an optical disk is located such that an upper surface, a lower surface and an edge of an outer circumference of an optical disk face inner surfaces of the cylindrical space forming unit with a predetermined distance.