147results about How to "Suppress pulsation" patented technology

A plurality of convex portions are located inside of a virtual circumferential surface. Each convex portion connects an adjacent pair of circumferential portions with each other. Each convex portion is an arcuate curve bulging radially outward. Each convex portion defines a minimum radius. A difference between a radius R and the minimum radius is a depth Dh. Dhr=Dh×25.5 / R. A range of an angular width A in relation to circumferential portion and a range of the depth Dh are set by the following expression,(5.6×Dhr+11.3)°×6 / p≦A<35°×6 / p andA<[360 / p−2×arccos]°  (1)Therefore, decrease in torque is prevented. Torque pulsation is suppressed.

A fluid pulse damper having increased dynamic range and sensitivity, being especially useful in suppressing pulsations in the fuel supply rail of an internal combustion engine. The damper is a longitudinal gas-filled plastic pillow having walls formed by opposed flexible short sides and opposed flexible long sides, and includes at least one internal self-contact element, and preferably a plurality of such elements. As the short sides flex, the elements make contact internally, shifting the damper into a different compression regime and extending the pressure / response over an increased range of pressures. A feature of some embodiments is that the inner surface within the contact elements is shifted into tension after the elements make contact, thereby stiffening the damper and increasing the damper's resistance to further deformation. The damper is formed of a plastic such as ultra-high molecular weight polyethylenes, high flow polyetherimides, or tubing grade polyphthalamides.

Disclosed is a double reciprocation pump wherein a pump operation is always stable, and pulsation is dampened. A pair of spaces are formed in the inside of a case member (2) in the axial direction of the case member (2). Each of movable partition members (3) is disposed so as be deformable in each of the pair of spaces in the axial direction of each space, so that each space is divided into a pump chamber (5) and an operation chamber (6) in the axial direction of each space. Coupling shafts (11) couple the movable partition members (3) via extendable members (14) so that the movable members (3) can extend in the axial direction thereof. Valve mechanisms (27) introduce a working fluid to the operation chambers (6), and discharge the working fluid from the operation chambers (6). A controller (25) switches the valve mechanisms (27) so that a distance of an overlapped portion in which a compression stroke of one pump chamber (5) and a compression stroke of the other pump chamber (5) are partially overlapped to each other, is formed, on the basis of the output of a displacement sensor (23) which continuously detects the displacement of each of the pair of movable partition members (3).

The invention relates to an electric excitation permanent magnet switch, a reluctance motor for the electric excitation permanent magnet switch and an electric excitation method. In the electric excitation permanent magnet switch, two magnetic poles of a permanent magnet are respectively connected with both ends of an iron core on which magnet exciting coils are wound by two soft magnets; and salient poles are arranged on the soft magnets. In the reluctance motor, the switch is used as basic components of a stator and a rotor, and the two magnetic salient poles of each component are arranged in an axial direction; the salient poles of the stator component and the rotor component are arranged oppositely, and air gaps are reserved between the salient poles; and the magnet exciting coils of the stator component and the rotor component at the axial symmetrical position are connected in series or in parallel and then are used as a phase line respectively to be connected to an excitation control power supply. The invention also provides a combination motor formed by connecting motor monomers by using a shaft in a rotary and dislocation mode and a method for the simultaneous diphase electric excitation of the stator component. The switch and the motor save energy, and have low magnetic loss and high magnetic efficiency; and the combination motor with the diphase electric excitation realizes the subdivision of stepper angles, and improves running stability, control accuracy and output power.

A settling grid separator apparatus and method of use which provides deep dehydration of high flow rate sludge in an environmentally friendly and energy efficient manner. The apparatus and method comprise and utilize an efficient mixing of the sludge with a flocculating agent or polymer solution, and sludge flow quieting techniques to reduce disturbances and promote flocculation of clustered solids. Free surface liquid rejection, a series of traps, and pressurized filtering utilize gravimetric, hydrometric, and densimetric techniques to separate liquid from suspended solids. Gravitational forces are utilized throughout the apparatus and method to promote separation of higher density solids from the lower density liquid carrier. Upon separation, solids with a minimal liquid content are controllably discharged for proper disposal or recycling.

A heat storage device that includes a first heat storage material and a second heat storage material, both of which accumulate heat by heat exchange with a heat afferent medium, and a changeover device that selectively either performs or intercepts heat storage by the second heat storage material. Accordingly, if the absorption of heat by the first heat storage material has decreased, the changeover device changes flow of the second heat storage material so that heat may be extracted from the heat afferent medium by the second heat storage medium. Thus, when the heat afferent medium is a refrigerant, it is possible to supercool the refrigerant thereof. Furthermore, since heat is extracted from the heat afferent medium and is accumulated, accordingly it is possible to anticipate effective utilization thereof.

Two magnetic poles of a permanent magnet of a permanent magnet switch and the two ends of an iron core wound with an excitation coil are connected to each other with the soft magnet having a salient pole. A motor uses the switch as the basic component of the stator and rotor, with two magnetic salient poles of each component being arranged axially, wherein the salient pole of the stator component and that of the rotor component are arranged in an opposite manner with an air gap, the excitation coil of the stator component and the rotor component at the symmetric axis position is taken as a phase line to access an excitation control power supply after serial connection or parallel connection. Electric excitation is carried out on the combined motor formed by shaft connection and rotation dislocation among single motors and the stator component in a bi-phase way simultaneously.

An AC driving signal of a frequency in the vicinity of the resonance frequency of a piezoelectric transformer is generated by a variable oscillation circuit and the waveform of the output signal of the variable oscillation circuit is shaped so as to be substantially sinusoidal by a waveform shaping circuit and the output of the waveform shaping circuit is subjected by a driving circuit to current amplification or voltage amplification so as to be amplified to a level sufficient for driving the piezoelectric transformer and the output of the driving circuit is subjected to current limitation, and then input to the piezoelectric transformer and the output signal of the transformer is applied to a cold cathode fluorescent lamp so that the cold cathode fluorescent lamp is lit and even if the impedance of the cold cathode fluorescent lamp decreases, the piezoelectric transformer cannot supply a large current.

There is provided a control apparatus for a cylinder injection internal combustion engine which suppresses fuel pulsation caused by cam phase deviation and thereby prevents internal combustion engine exhaust deterioration, so that the reliability of a high-pressure fuel system using a high-pressure fuel pump is improved. The control apparatus for a cylinder injection internal combustion engine includes a high-pressure fuel pump that raises the pressure of fuel and discharges the fuel to a fuel rail, and a fuel pressure sensor that detects a pressure of fuel stored in the fuel rail. The control apparatus controls the high-pressure fuel pump based on the fuel pressure detected by the fuel pressure sensor. The control apparatus further includes a cam phase estimation means for estimating a phase of a cam shaft of the internal combustion engine which drives the high-pressure fuel pump, and based on the phase estimation value calculated by the cam phase estimation means, corrects the amount of controlling the high-pressure fuel pump.

A sound dampening assembly adapted to engage an exhaust pipe in an automotive engine exhaust system adjacent an outlet of an internal combustion engine. The assembly includes a bottle portion having a single opening and an interior defining a predetermined amount of volume and a neck portion having a first end attached to the opening of the bottle portion and extending from the bottle portion. The neck portion is in fluid communication with the bottle portion interior and includes a second end adapted to be attached to the exhaust pipe. The neck portion has an interior defining a predetermined amount of volume and the bottle portion and the neck portion are sized to attenuate vibration at a predetermined frequency in the exhaust system.

There is provided a digital servo control unit which uses a D / A converter, which suppresses the spike-like pulsation superimposed on a current error signal inside a current control circuit, and which has control performance not lower than that in the background art even when a low-voltage and low-price power supply circuit is used. The digital servo control unit has a first-order low pass filter acting on an analog signal output by the D / A converter, and a stabilizing compensation means for compensating a phase delay caused by the first-order low pass filter. An output signal of the first-order low pass filter is input to a current control circuit as a current command signal. The first-order low pass filter is formed as a low pass filter having a cut-off frequency which is lower than a sampling frequency. The first-order low pass filter may be replaced by a notch filter having a cut-off frequency which is equal to a sampling frequency or which is equal to an integer multiple of a Nyquist frequency.

In a liquid pump for a braking system of a vehicle, one end of a piston is slidably inserted into a cylindrical space of a housing member, and a sliding ring is provided on the piston. A suction chamber is formed by an inner peripheral surface of the housing member, an outer peripheral surface of the piston and the sliding ring. An inner diameter “Dk” of the housing member is made larger than an inner diameter “Dc” of the cylindrical space. As a result, the volume of the suction chamber is increased, without making the piston smaller in its diameter.

To improve a refrigerant compressor, in particular, displacement compressor, comprising a compressor housing enclosing an outlet chamber and an outlet passage leading from the outlet chamber to an external high pressure connection, such that the pulsations in it are damped as much as possible it is suggested that a pulsation damping element be inserted into the outlet passage of the compressor housing following the outlet chamber, that the pulsation damping element have an inlet baffle which faces the outlet chamber and extends over a cross section of the outlet passage and, located opposite thereto, an outlet baffle which extends over the cross section of the outlet passage, that at least one reflection chamber be provided between the inlet baffle and the outlet baffle and that the inlet baffle and the outlet baffle each have at least one passage which faces a reflection surface on the respectively other baffle.

The object of the invention is to stably spray cutting fluid in a good mist form, when cutting fluid and air are supplied from the surrounding area and cutting fluid is sprayed in a mist form from the tip end section of a rotary cutting tool. The rotary cutter of the present invention sequentially feeds a mixture of cutting fluid and air through a supply pipe 4, first supply path b in a cover 3, second supply paths c, d in a chuck 2, a hollow center cavity (front throttle chamber d, throttle 24a, and rear throttle chamber e) in the chuck, and a third supply path g in a rotary cutting tool 1. The first supply path and second supply path are intermittently connected when the respective openings thereof face each other as the cover and chuck turn relative to each other; the second supply path sprays fluid toward the throttle; the front throttle chamber is formed such the diameter thereof expands from the second supply path; the throttle is formed such that the diameter thereof is less than the smallest diameter of the second supply path; the rear throttle chamber is formed by the rear end surface of the rotary cutting tool and the inner conical surface on the down-flow side of the throttle when that rear end surface and inner conical surface on the down-flow side come in close contact with each other; and the front throttle chamber is formed such that the capacity thereof is greater than that of the rear throttle chamber.

Fuel pipes guide fuel from a fuel tank provided in a rear area of the vehicle to a low-pressure fuel supply system and a high-pressure fuel supply system, respectively, for injecting the fuel to an engine provided in a front area of the vehicle. A branch point between the fuel pipes is arranged in the vicinity of the fuel tank to secure a long pipe length between the low-pressure fuel supply system and the high-pressure fuel supply system. This can suppress variation in fuel pressure at the low-pressure fuel supply system attributable to the fuel that is discharged from the high-pressure fuel pump within the high-pressure fuel supply system back to the fuel pipe.

A commanded negative-sequence current is added to a commanded current so as to suppress double-frequency pulsation on the DC side. The commanded negative-sequence current is found from three values (i.e., the detected value of positive-sequence voltage vector on the power-supply side, the detected value of negative-sequence voltage vector, and a commanded positive-sequence current). Thus, the pulsations which occur on the DC side of a semiconductor power converter and which have a frequency double the power-supply frequency are suppressed even when the AC power supply is at fault while assuring stability of the current control system, thus permitting stable and continuous operation.

A vibration damping device which can improve a vibration damping performance of a damper having a chamber holding a rolling member. The vibration damping device is applied to a power transmission unit having an input side rotary member that transmits a power to an elastic member and an output rotary member that is rotated by the power transmitted from the elastic member. In order to damp vibrations of the output rotary member, the vibration damping device is comprised of a holding chamber rotated integrally with the input side rotary member and a rolling member held in the holding chamber in a manner to rotate in a same direction as the output side rotary member while being allowed to rotate relatively therewith.

A gas compressor has a cylinder chamber provided with discharge holes. Openings are in communication with the discharge holes, respectively. Discharge passages having the same length are connected with the openings, respectively. The ends of the discharge passages are connected with a common passage. During operation of the cylinder chamber, discharge valves cause the expelled gas to produce pulsations on the upstream side of the two openings. The pulsations are shifted in phase by a half wavelength. Noise due to the pulsations is reduced, because the pulsations of the expelled gas cancel out each other when the gas flows through the common passage.

A method of improving scavenging operation of a two-stroke internal combustion engine. The exhaust pressure of the engine is analyzed to determine if there is a pulsation frequency. Acoustic modeling is used to design an absorber. An appropriately designed side branch absorber may be attached to the exhaust manifold.

The invention discloses a control method for a permanent magnet brushless direct current motor. The method comprises the steps as follows: storage kinetic energy of a rotor is designed and regulated as outer loop control; output average power of direct current power supply is designed and regulated as inner loop control; the permanent magnet brushless direct current motor is controlled by a modulation mode of an energy hysteresis loop; meanwhile, addition of a complicated observer and an extra hardware detection sensor is avoided; stable energy transmission is realized; and pulsation of output torque is suppressed. The method disclosed by the invention has the characteristics of being simple, practical, convenient to control, fast in dynamic response and good in system stability.

A zero-cross detecting unit (30) monitors an AC voltage detected by a voltage sensor (32), generates a zero-cross point signal when the AC voltage strides across zero volt, and sends the signal to a controller (7). A rotational speed setting unit (12) of the controller (7) sets a command for a rotational speed that will become the target of a synchronous motor (1). A rotational speed correction factor data table (17) has stored therein correction factor data for target rotational speeds. A correction factor data extracting unit (16) extracts correction factor data corresponding to the elapsed time of the zero-cross point signal that was generated from the rotational speed correction factor data table by the zero-cross detecting unit (30), and outputs the correction factor data to a correction rotational speed generating unit (18). The correction rotational speed generating unit (18) corrects the rotational speed set by the rotational speed setting unit (12), according to the extracted correction factor data, and outputs the corrected rotational speed to a sine wave data creating unit (14).

The invention discloses an internally-engaged gear pump applicable to high pressure and large flow. The internally-engaged gear pump is composed of a pump shell, a first double-tooth ring, a second double-tooth ring, a first gear shaft, a second gear shaft, a radial compensation device, a sliding bearing, a side plate and the like, wherein the first double-tooth ring and the second double-tooth ring are symmetrically arranged in the pump body, and outer teeth of the first double-tooth ring and the second double-tooth ring are engaged to form a first gear pair; the first gear shaft and the first double-tooth ring are engaged to form a second gear pair; and the second gear shaft and the second double-tooth ring are engaged to form a third gear pair. A single input shaft is used for driving the gear pairs to rotate by grades and the distribution of moment on the shaft is reasonable; and the radial unbalance force on each grade of gear pair is small and the anti-pressure ability of the pump under a high pressure working condition is improved. Oil in the pump is pressurized by the plurality of grades of gear pairs so that the output pressure and the flow of the oil are effectively improved; and meanwhile, the two paths of oil on the outlet of the pump are overlapped so that the flow and the pressure pulse of the pump are remarkably reduced and the requirements of a high-precision hydraulic system can be met.