Showing papers on "Rotational speed published in 1992"

Self-closing fire door

Abstract: The present invention is provided with a mechanism for controlling the opening and closing of a door comprising a speed reduction means for reducing a rotational speed A high speed shaft is connected to the speed reduction means and is connectable to a means for rotating the input shaft, and a low speed output shaft is connected to the speed reduction means A governor is mounted on the input shaft for limiting the rotational speed thereof, to also regulate the rotational speed of the output shaft A brake is provided for preventing rotation of the output shaft, and a self-closing mechanism is operatively connected to the door The self-closing mechanism is adapted for storing energy when the door is opened to an open position, and a connecting means operatively connects the output shaft to the self-closing mechanism A releasing means is provided for releasing the brake to permit rotation of the output shaft under the urging of the self-closing mechanism whereby the self-closing mechanism releases the energy stored therein so as to close the door to a closed position when the brake is released by the releasing means

Control apparatus and control method for motor drive vehicle

Abstract: A control apparatus of a motor drive vehicle includes a unit for generating a target vehicle speed; a speed instruction unit for generating a target motor rotational speed of the motor based upon a preset motor control pattern in response to the target vehicle speed; a power circuit for operating the motor at the target motor rotational speed upon receipt of the target motor rotational speed; a variable transmission unit for converting a drive output from the motor into a transmission ratio for instructing a rotational speed of the drive output, and transferring the converted transmission ratio to a drive shaft of the motor drive vehicle; and a transmission ratio calculating unit for determining the transmission gear ratio based on the target vehicle speed and the target motor rotational speed thereby to instruct the determined transmission gear ratio to the variable transmission unit. A control method sets a target vehicle speed value; produces a target motor rotational speed based upon the target vehicle speed value and a preset motor control pattern; operates the motor at the target motor rotational speed; determines a transmission gear ratio based upon both of the target vehicle speed and the target motor rotational speed; and converts a rotational speed of a drive output into the transmission ratio and transfers the converted transmission ratio to a drive shaft.

Constant image quality CT scanner with variable radiation flux density

Abstract: An x-ray source (20) rotates about a fixed cylinder (16) within which a subject of non-uniform cross-section is received. Radiation from the x-ray source passes through the subject and impinges on an arc of radiation detectors (28). Because the subject is of non-uniform cross-section, the average x-ray energy fluence impinging on the detectors across the arc varies with the relative angular position of the x-ray source and the subject. In one embodiment, a motor (18) which rotates the x-ray tube relative to the subject is controlled by a digital motor control (50). The digital motor control varies the rotational speed to a preselected angular velocity indicated by a look-up table (52) at each of a multiplicity of angular positions around the subject. The angular velocity is slowed when radiation is passing through thicker portions of the subject and accelerated when passing through thinner portions of the subject such that the average x-ray energy fluence received by the radiation detectors is substantially constant regardless of the angular position of the x-ray source. In another embodiment, an x-ray tube control circuit (82) alters the tube current such that the average x-ray energy fluence received by the detectors becomes angular position independent. In this manner, the signal-to-noise ratio at each angular position is the same and structural noise is eliminated in the resultant reconstructed image.

A torsional vibration measurement system

Abstract: At the development stage of building an automobile, many power-train configurations are considered, and problems may arise when the different components are assembled. Torsional vibration, which can cause unforeseen problems, is difficult to measure when a shaft is rotating. A torsional measurement system designed so that measurements of translational and torsional motion can be taken at points along a rotating shaft is described. Extensive probe tests revealed accuracy errors of less than 1% in the rotational speed measurement, and shaft speed capabilities of at least 3400 r.p.m. The hardware selected restricts the data transfer to 1 byte per 13 mu s. For a three-channel station with 64 stripes per revolution, the maximum theoretical rotation speed at which reliable measurements can be taken is 8000 r.p.m. Results of preliminary tests showed good agreement between a commercially available torsional vibration measurement system and the prototype system. >

Drum type washing machine

Abstract: A drum type washing machine includes a drum, a brushless motor for rotating the drum, and a control device for controlling the motor. The rotational speed of the drum is controlled in the wash step so as to be varied in each period of its rotation in a range (na-nb) at least including a speed at which clothes fall down from the wall of the drum against centrifugal force. The point at which the clothes fall varies as the speed increases from na (point 35a) to nb (35b), which reduces tangling. The speed increase may be linear or otherwise. The speed control involves feedback from a position/speed Hall detector and an input may also be provided by a load volume sensor. The latter functions by detecting rotational speed for a given voltage and referring to a table of experimental data.

Advanced proof-of-rotation switch

Abstract: A HVAC system (10) employs a gas valve (20) to supply gas for combustion within a heating portion (12) of the system. An exhaust (22) removes combustion products using a motor (28) driven exhaust fan (24). An apparatus (34) controls combustion and uses a sensor (36) for sensing the rotational speed of a motor shaft (26). A switch (T1) is responsive to sensed motor speed to open and close the valve, the valve being opened only if the motor is operating within a predetermined speed range. A first speed discriminator (48A) enables of the switch to open the valve when the motor speed exceeds a first predetermined value. A second speed discriminator (48B) disables the switch to close the valve when motor speed exceeds a second and higher predetermined speed which is indicative of a blocked exhaust, or a fan blade is loose. This latter action insures that a build-up of potentially dangerous exhaust gases cannot occur.

Gas turbine engine having low cost speed reduction drive

Abstract: The cost and bulk of a speed reducing transmission required to provide low speed rotational power from a gas turbine engine is avoided by employing bearings (16, 18) jornalling a high speed shaft (12) of the engine with a power takeoff in the form of a tubular shaft (62) having bearing receiving and retaining openings (82) to act as a bearing cage for bearing elements (64, 66) disposed between inner and outer bearing races (68, 70). Upon rotation of the high speed shaft (12), the bearing elements (64, 66) will move in an epicyclic fashion thereby driving the tubular shaft (62) at a reduced rotational rate allowing it to drive loads such as a dynamoelectric machine (90) or a ducted fan (48) at rotational speeds less than the rotational speed of the high speed shaft (12).

Hydraulic control apparatus for hydraulic construction machine

Abstract: The present invention is applied to a hydraulic control apparatus for a hydraulic construction machine including; first operating means (57a,57) which is manipulated to keep the rotational speed of a prime mover (27) to an arbitrary rotational speed, second operating means (6a,6,56) which is manipulated to control the rotational speed of the prime mover (27) and is returned to an initial position of low rotational speed when the manipulating force is released, rotational speed control means (80) for controlling the rotational speed of the prime mover (27) in accordance with the first and second operating means, a variable displacement hydraulic pump (1) which is driven by the prime mover (27), a first hydraulic actuator (4) which is driven by a delivery oil from the hydraulic pump (1), a second hydraulic actuator (21) which is driven by the delivery oil of the hydraulic pump (1), a first control valve (2) which is provided between the hydraulic pump (1) and the first hydraulic actuator (4) and serves to control a pressured oil supplied to the first hydraulic actuator (4), a second control valve (20A) which is provided between the hydraulic pump (1) and the second hydraulic actuator (21) and serves to control a pressured oil supplied to the second hydraulic actuator (21), first determination means (61) for determining a first target displacement (θL) to keep the delivery pressure of the hydraulic pump (1) to a value higher than load pressure of the first and second hydraulic actuators (4,21) by a predetermined target value, second determination means (62) for determining a second target displacement (θA) by which an input torque is limited on the basis of the delivery pressure of the hydraulic pump (1), and, displacement control means (65) for controlling the displacement of the hydraulic pump (1) so that the displacement is equal to at least one of the first and second target displacements (θL,θA). The control apparatus further includes; judging means (67) for outputting a discrimination signal on the basis of a discrimination of a state where the second hydraulic actuator (21) is operated while the rotational speed of the prime mover (27) is controlled by the second operating means (6a,6,56). And when the discrimination signal is output, the displacement of the variable displacement hydraulic pump (1) is so controlled that it is equal to the second target displacement (θA) irrespective of the value of the first target displacement (θL).

Variable valve actuation control system

Abstract: In a control system for a valve actuation property variable control device which can switch over between a plurality of modes including a low speed mode for adapting at least one of an intake valve and an exhaust valve of an engine to a low speed range and a high speed mode for adapting the valve to a high speed range at least according to the rotational speed of the engine and a representative temperature of the engine, to prevent an abrupt change in the engine output by switching over valve actuating properties while the engine is being warmed up, the load condition of the engine is detected so that the transition from the low speed mode to the high speed mode may be prohibited if the representative temperature of the engine exceeds a prescribed level while a load higher than a prescribed level is being detected Thereby, the driveability of the engine is improved

Physical Property and Rotational Speed Effects on Heat Transfer in Axially Rotating Liquid/Particulate Canned Foods

Abstract: Particle surface temperatures were measured by liquid crystals that allowed unrestricted motion of the monitored particles. Liquid-particle film heat transfer coefficients (hp) were considerably higher than published values which were determined with particles attached to thermocouple wires. In general, as a result of the particle motion, hp increased with increasing rotational speed and increasing fluid viscosity. Furthermore, hp values were higher for Teflon spheres than for aluminum spheres. Results for the overall (heating medium/container wall/internal liquid) heat transfer coefficients were consistent with published observations.

Driving control apparatus for brushless motor with optimum controlled converter

Abstract: A position detector detects the position of a rotor of a brushless motor. A driving signal generator generates a driving signal at a timing corresponding to the detected position. While the driving signal is received, a driving circuit sequentially ON/OFF-operates switching elements of an inverter circuit. At this time, a rotational speed detector detects a rotational speed of the brushless motor. A rotational speed controller controls the duty of ON/OFF operations of the switching elements, performed by the driving circuit, through a chopper signal generator in accordance with the difference between a detected rotational speed and a designated rotational speed. If the detected rotational speed does not reach the designated rotational speed even when the duty becomes a preset value or more, the rotational speed controller generates a phase shift signal for advancing the phase of the driving signal from that of a driving signal in a normal operation, and supplies it to the driving signal generator. Upon this phase shift operation, in the brushless motor, a magnetic flux effectively acting from the rotor to armature windings is reduced as compared with a magnetic flux in a normal operation. Thus, the rotational speed of the brushless motor can be reliably set to a desired value without decreasing the operation efficiency.

Control apparatus for induction motor

Abstract: A control apparatus for an induction motor and an electric car propelling motor includes an inverter for supplying a driving current to the induction motor on the basis of a predetermined control signal, a rotational speed sensor for detecting a rotational speed of the induction motor, a V/f control circuit responsive to an input speed command signal for producing a control signal for the inverter, a vector control circuit for producing an inverter control signal on the basis of the speed command signal and the rotational speed signal of the rotational speed sensor, an abnormality detecting circuit for detecting abnormality of the rotational speed sensor. A change-over circuit having inputs supplied with outputs of the V/f control circuit and the vector control circuit, respectively, selects the inverter control signal from the V/f control circuit in response to detection of abnormality of the rotational speed sensor while selecting the inverter control signal supplied from the vector control circuit so long as no abnormality is detected in the rotational speed sensor.

Disc coulter operating characteristics

Abstract: Forces and kinematic behavior were measured for flat coulters having several simple geometries. The lowest draft and vertical forces occurred for thin coulters sharpened to produce cutting faces at a small slope to the flat sides of the coulter. Thick coulters having small slopes produced the greatest rotational speed relative to the forward speed. Consideration of the sliding and pushing components of cutting motion at the soil surface suggested that a large speed ratio may contribute to effective residue cutting.

Method of driving a turbine in rotation by means of a jet device

Abstract: A turbine device and a method of driving the turbine device are disclosed. The turbine device includes an admission channel, a turbine, and an injection channel. The turbine device may also include a regulator. The turbine is driven by injecting a primary fluid into the admission channel at a given velocity and simultaneously causing a secondary fluid to flow into the admission channel at a lower velocity. The primary fluid and the secondary fluid form a mixture in the admission channel, which flows toward the turbine. The velocity of the mixture is less than that of the primary fluid, while the mass flow of the mixture is approximately equal to the sum of the mass flows of the primary and secondary fluids. The regulator compares the rotational speed of the turbine to a target speed and regulates parameters associated with the turbine device if the rotational speed of the turbine and the target speed differ by more than a predetermined amount.

RAM air turbine

Abstract: The present invention relates to a ram air turbine which is preferably used in conjunction with a refueling pod on an aircraft for purposes of operating a fuel pump and/or reeling mechanism for paying in and paying out a fuel line. The turbine generally comprises a rotatable housing having a main turbine output shaft disposed therein and rigidly connect thereto. A plurality of variable pitch turbine blades extend outwardly from and are cooperatively engaged to the housing such that rotation of the turbine blades causes simultaneous rotation of the housing and output shaft. Means are provided within the housing for establishing a preset reference rotational speed for the output shaft. Additionally, a control means cooperatively engaged between the turbine blades and the reference means is provided for adjusting the pitch of the turbine blades in response to a difference in the rotational speed of the output shaft and the preset reference rotational speed. The ram air turbine further includes both electrical and mechanical braking devices for changing the pitch of the turbine blades when the rotational speed of the output shaft exceeds a pre-determined maximum.

System for indicating extent of overdrive in frictional drive arrangements

Abstract: A spiral drum freezer apparatus having a system for measuring and monitoring the "overdrive" of a rotated drum relative to a spiral belt helically wrapped around the drum in an ascending fashion. The system measures overdrive directly and continuously by obtaining a first speed measurement of the drum directly from the sprockets of a drive gear box drivingly engaging the drum. An alternative point of measurement for measuring rotational speed includes proximate the sprockets of a drum wheel driven by a belt, or sensing spaced-apart vertical outer structure members of the drum. Another point yet is on a disc-like plate. This plate is coaxially aligned and attached to the drum, and has precisionally spaced apart markings proximate a periphery where the rotational speed of the plate is directly proportional to the rotational speed of the drum. A second speed measurement is obtained by measuring the rotational speed of sprockets of a guide roller guiding the spiral belt. The second speed measurement can also be obtained by sensing evenly spaced markings on the spiral belt. A moving window averaging scheme is used to obtain a reliable and accurate measurement of the speed of the drum and the guideroller. A processor calculates overdrive and generates a readout continuously of the overdrive as a function of the first and second speed measurements.

Obtaining the Optimum Geometrical Parameters of a Refrigeration Helical Screw Compressor

Abstract: This paper presents a method for optimizing the geometrical pa.rameters of a refrigeration twin-screw compressor. The method optimizes rotor profile and discharge port position etc., by making use of two efficient computer programs; the geometrical parameter calculation program and the performance prediction program. Two new parameters; relative blow hole area and relative contact line le~th, are introduced to compare the blow hole areas and contact line len!!;ths of different rotor profiles. These new parameters, which are .determined hy profiles alone, have an important and direct influence on the performance of the compressor, so that they are suitable for used in an optimization ·process. A technique for reducing the blow hole area by manipulating its shap" in accordance with a logical proc.,dure is described. Calculation and test results arP included and discussed in the paper. INTRODUCTION Altuough many factors influence the performance of a helical screw compressor, they may he grouped into two categoriesas follows: • The operating parameters such as rotational speed, quantity of oil or liquid refrigerant injected etc .. • The geometrical parameters such as contact line length per lobe, blow hole area and discharge port position etc .. The increase of the quantity of liquid refrigerant injected always results in a slight decrease of the coefficient of performance but the use of the injection of liquid refrigerant eliminates the need for separate oil cooling. If the discharge temperature is lower than that permitted, the quantity of liquid refrigerant injected should be as small as possible. This quantity can he predicted by the computer program of the mathematical model for the working process. Increases of rotational speed and quantity of oil injected always result in a decrease of leakage through any leakage path the consequence of which is an increase in the volumet,ric efficiency. But on the other hand these increases will result in increases of fluid-dynamic losses, fluid and mechanical friction losses etc., so as to increase the energy consumption. For the rotational speed and quantity of oil injected there exist optimum values, between which there is a relationship. So far these optimum values have been ol>taiued from tests or experience only, since there are no reliable theories of fluid-dynamics and fridion yet, which can he used to develop a mathematical model to predict the increase of energy cons urn ption. The purpose of the procedure for the optimization of the geometrical parameters is to combine the smallest blow hole area, with the shortest contact line length per lobe and the correct discharge port position suitable for a given discharge pressure. This can be achived by the use of test results and two computer programs: • The geometrical calculation program. • The program simulating the working process. For a give~ wrap angle and screw pitch, the blow hole area and contact line length per lobe are totally decided by the end profiles of the male and female rotors. The purposes of optimizing the

Apparatus for detecting misfire in multicylinder internal combustion engines

Abstract: An apparatus for detecting occurrence of misfire in a multicylinder internal combustion engine detects a rotational speed of the engine in each expansion stroke of each cylinder, calculates a change of the engine rotational speed fluctuation quantity in accordance with a value of the detected rotational speed, and sets a misfire determination value for each cylinder based upon a determination result of the engine operating condition. Misfire determination is made for each cylinder based upon the misfire determination value for each cylinder and the change of the rotational speed fluctuation quantity, thereby elevating the accuracy of detecting occurrence of misfire in each cylinder.

A Three-Dimensional Analysis of Particle Deposition for the Modified Chemical Vapor Deposition (MCVD) Process

Abstract: A study has been mode of the deposition of particles that occurs during the modified chemical vapor deposition (MCVD) process. The three-dimensional conservation equations of mass, momentum, and energy have been solved numerically for forced flow, including the effects of buoyancy and variable properties in a heated, rotating tube. The motion of the particles that are formed is determined from the combined effects resulting from thermophoresis and the forced and secondary flows. The effects of torch speed, rotational speed, inlet flow rate, tube radius, and maximum surface temperature on deposition are studied. IN a horizontal tube, buoyancy results in circumferentially nonuniform temperature and velocity fields and particle deposition. The effect of tube rotation greatly reduces the nonuniformity of particle deposition in the circumferential direction. The process is chemical-reaction limited at larger flow rates and particle-transport limited at smaller flow rates. The vertical tube geometry has also been studied because its symmetric configuration results in uniform particle deposition in the circumferential direction. The 'upward' flow condition results in a large overall deposition efficiency, but this is also accompanied by a large 'tapered entry length'.

Motor control system

Abstract: A motor control system is disclosed which includes an encoder for generating pulses in proportion to the rotational amount of the motor. A speed instructing unit provides a speed instruction for the desired rotational speed of the motor. A speed control unit calculates (1) the actual rotational speed of the motor based on the pulse signal from the encoder and (2) a voltage to be applied to the motor and outputs a PWM signal which represents the actual motor speed. The PWM signal is identical with the voltage to be applied to the motor. This arrangement ensures that the motor speed will follow the speed instruction. A driver unit supplies electric power to the motor by amplifying the PWM signal. The speed of the motor is controlled by (i) adding the PWM signal which has been calculated by the speed control unit with a compensation value depending upon the rotational speed of the motor or alternatively (ii) adding the PWM signal which has been calculated by the speed control unit with a first compensation value when the motor is servo-locked and adding the PWM signal which has been calculated by the speed control unit with a second compensation value depending upon the rotational speed of the motor when the motor is rotated. This achieves nonlinearity compensation for the motor and motor control without causing oscillations when the motor is servo-locked and is stopped and without causing a time lag with respect to a speed instruction when the motor is started-up.

Method and device for non-falsifiable detection of the rotational speed of a vehicle wheel

Abstract: The rotational speed of a part which is coupled to the drive and rotates when the vehicle moves is detected by a sensor (28) from whose signals a clock signal is formed and fed to a memory (27) whose content can be transmitted by a transmitter (13, 14) to an interrogation device. The rotational speed is determined with the aid of acceleration quantities which depend on the rotational position of the rotating part and cannot be manipulated, and the supply (10) of the transmitter is performed from outside the vehicle. The said acceleration quantities are preferably formed by the gravitational acceleration and/or by the centrifugal acceleration. Application to recording distance travelled or other events such as, for example, speed violations and the like. The device is secure against manipulation and falsification.

Coriolis Effect on the Vibration of a Cantilever Plate With Time-Varying Rotating Speed

Abstract: A method for investigating the Corilois effect on the vibration of a cantilever plate rotating at a time-varying speed is presented in this paper. Due to this time-dependent speed, parametric instability occurs in the system. Furthermore, owing to the existence of the Coriolis force, the system equation is transformed, by a special modal analysis procedure, into independent sets of first-order simultaneous differential equations. This set of simultaneous differential equations is solved by the method of multiple scales, yielding the system response and the expressions for the boundaries of the unstable regions. Finally, the Coriolis effect on the changes in the boundaries of the unstable regions is investigated numerically.

System and method for ratiometrically processing sensed speed and vibration signals for a non-uniformly rotating body

Abstract: A digital ratiometric tracking filter provides superior measurement of the magnitude and phase of vibration of a rotating body, at uniform or non-uniform rotational speed. The sensed speed and vibration signals are concurrently processed and subsequently combined to produce the absolute magnitude and relative phase measurements. The concurrent processing of the sensed signals assures that any system-introduced errors are found in both signals and can be uniformly eliminated by the ratiometric processing thereof.

Device for detecting misfire of internal combustion engine

Abstract: In a device for judging of misfire of an internal combustion engine from a variation of crankshaft rotational speed during combustion stroke of each cylinders, a measurement period for measurement of crankshaft rotational speed at a cylinder is set by counting a predetermined number of first signals indicative of a predetermined rotational angle of a crankshaft firstly on the basis of a second signal indicative of a reference position of a camshaft and secondly and onward on the basis of the first signals used for setting the previous measurement section.

Device for recognising the angular position of a rotating part

Abstract: A device for recognizing the angular position of a rotating part is described in which the rotating part is a pick-up disc (14) provided with a multiplicity of regular angle marks (11) and a distinguishable reference mark (12), which is formed, for example, by two missing angle marks (11). The number of angle marks is (n-2), where n is a number which is divisible by as many numbers as possible corresponding to different numbers of cylinders and, for example, is 36. The voltage sequence generated in the sensor (15) is analyzed in the control unit (19), unambiguous cylinder recognition being obtained after the recognition of the reference mark (12) by comparison with a camshaft signal. The analysis of the voltage sequence also supplies the rotational speed and flanks, which can be predetermined, of the pulse sequence used for ignition and/or injection control.

Liquid distribution system

Abstract: A liquid distributor having a pair of variable displacement pumps driven by a single electric motor, the rotation speed of which is determined by a voltage from a controller in response to a predetermined ground speed and application rate which mixes a chemical with water in a desired proportion and delivers a solution to be directed into an open furrow just prior to the furrow being covered with dirt.

Driving device for vehicle

Abstract: PROBLEM TO BE SOLVED: To obtain a driving device for vehicles capable of amplifying and transmitting output torque of a rotary electric machine to driving wheels and performing regenerative braking while suppressing the overspeed of the rotary electric machine in a high vehicle speed range. SOLUTION: The driving device includes: the rotary electric machine MG; an input member I drive-connected to the rotary electric machine MG; an output member O; and a differential gear device DG having at least three rotating elements E1-E3 in order of rotational speed. The input member I is selectively drive-connected to the first rotating element E1 via a first one-way clutch F1 that restrains the input member I from relatively rotating in the positive direction to the first rotating element E1 and selectively drive-connected to the second rotating element E2 via a second one-way clutch F2 that restrains the input member I from relatively rotating in the negative direction to the second rotating element E2. The output member O is drive-connected to an intermediate rotating element EM located between the first rotating element E1 and the third rotating element E3 in order of the rotational speed and the third rotating element E3 is fixed to a non-rotating member. COPYRIGHT: (C)2011,JPO&INPIT

Bearing apparatus for a driven shaft of an automobile having a rotational speed detector

Abstract: A bearing apparatus is provided for a driven shaft of an automobile. It includes a rotational speed detector for detecting a rotational speed of a wheel of the automobile by detecting the rotational speed of a circular detected member which has a plurality of projections provided at even intervals in the circumferential direction. The detected member is fixed to one end of a driven shaft. The other end of the driven shaft includes a flange for mounting of a wheel. The shaft is part of an inside member which is rotatably supported by an outside member fixed to a chassis through a plurality of rolling elements. Detected speed is sent to an antilock brake system through a connector. The rotational speed detector, a cover fit to the outside member to enclose at least those parts of the rotational speed detector and detected member which are in opposition, and the connector are embedded in a resin block by a plastic molding technique such that they have a fixed relationship to each other so as to provide an assembly of unitary construction.