Showing papers on "Rotational speed published in 1971"

Variable speed drive mechanisms

Abstract: A variable speed drive mechanism is disclosed wherein a rotatable drive member imparts movement to a driven member through a cage containing a series of rotary elements sandwiched between the two members, at least one of which is resiliently flexible. The elements engage a circular track comprising grooves of concave cross-sectional configuration disposed on the members. The grooves are of slightly larger diameter than the elements so that on flexing one of the members the effective radius of contact between the elements and the groove walls may be varied and the rotational speed imparted to the other member varied accordingly. A single directional variable speed unit is thus provided. In another unit two sets of rotary elements of the aforesaid kind are linked in back to back relationship with their cages interconnected to provide a variable speed unit with a greater speed range which passes through zero and is reversible. These units not only require fewer components than the conventional comparable unit, but the components are also relatively simple and cheap to manufacture.

Constant speed controlling device for a direct current motor

Abstract: An improved DC motor is provided with an external reference (frequency signal) oscillator, means for detecting the angular position of a rotor of the motor including magnets, and control means which is adapted to flow the exciting current to the field or driving windings of the motor in synchronism with either the output signals from said reference oscillator and said detecting means, and to interrupt the exciting or driving current in response to the other signal, whereby the motor functions as a DC motor until its rotational speed reaches a predetermined speed to provide the starting torque, but functions as a synchronous motor which rotates in synchronism with the signals from said reference oscillator after the speed of the motor has reached said predetermined speed.

Electronic fuel consumption meter

Abstract: Electric signals, corresponding to two or more engine operating parameters, such as rotational speed of the engine drive shaft and the setting of the throttle valve or a rotational speed and the pressure in the intake manifold or the pressure in the intake manifold and the setting of the throttle valve, are obtained by transducers, these signals being fed to an evaluating circuit that produces an electric output that is conducted to a meter that reads fuel consumption in unit distance, or unit time, travelled.

Digital read out indicator for vehicles

Abstract: Apparatus disposed in a vehicle for providing a digital read out indicator for displaying vehicular speed or engine revolutions comprising a mechanical shaft rotated at a speed corresponding to the vehicular speed or engine revolutions, means responsive to the shaft rotation to produce an electrical pulse train at a recurrence frequency proportional to the shaft rotational speed, and digital display means responsive to said pulse train to produce the desired display.

Method of balancing very small rotating objects using air jet acceleration

Abstract: A system of balancing extremely small rotating devices is described. The device to be balanced is mounted on its own axes and rotated at a high rotational speed driven by an air blast. By this means only the device being balanced is rotated and the mass of fixtures need not be considered. The amount of imbalance is measured and a laser beam is used to remove a portion of the rotating device to reduce the imbalance.

Gas turbine engine fuel control

Abstract: A variable orifice system that is responsive to compressor inlet pressure and temperature, compressor discharge pressure and rotational speed of a gas-turbine engine is incorporated into a hydraulic circuit that includes a zero gradient pump driven at a speed proportional to the speed of the engine. The resulting system provides control of fuel rate for starting, steady running, acceleration and deceleration under varying altitudes and flight speeds.

Control circuit for controlling a fuel injecting system

Abstract: A control arrangement in internal combustion engines for controlling a group of electromagnetically actuated injection valves simultaneously. A monostable multivibrator provides pulses synchronously with the rotational speed of the engine for the purpose of determining the opening duration of the injection valves as a function of at least one operating parameter, particularly the intake manifold pressure. A first electronic circuit operable only when the throttle valve is closed, inhibits the pulses when the engine is above an upper limit, and switches the pulses back on when the engine speed is below a lower limit which is above the idling speed. A second electronic circuit which is operable at all positions of the throttle, serves to switch off the pulses when the engine speed is above a maximum value, and then switches the pulses back on when the speed drops below this maximum value.

Methods of detecting rotation speed

Abstract: Apparatus, preferably fluidic, for providing a control signal indicative of any deviation of the speed of movement of a jet engine or other moving object from a desired speed, comprising a code disc rotated at a speed proportional to the speed of rotation of the jet engine, logic means which cyclically samples the tracks on the code disc at equal time intervals and produces an output signal if the difference between two successive samples is more than a predetermined amount, and integration means which receives and integrates said output signals to provide said control signal. The control signal may be applied to a valve controlling the supply of fuel to the engine so as to govern the engine speed.

Electronic governor for fuel-injection type internal combustion engines

Abstract: An electronic governor for fuel-injection type internal combustion engines, in which the number of component parts is minimized, the time constant is enlarged in the output voltage integrating circuit in order to eliminate the possibility of ''''hunting'''' phenomenon and thus to secure a stable state under the low-speed running condition of the engine, the speed regulation, that is, the rate of change in fuel regulating rod position for changes in the rotational speed of the engine is therefore expanded for the low-speed range, and a signal arising from the displacement of the fuel regulating rod is applied, as in positive feedback, to the rotational speed setting circuit in order to narrow the expanded speed regulation, so that a small speed regulation comes into play, under the high-speed running condition of the engine.

Spin testing apparatus for turbine-type flow meters

Abstract: An apparatus for measuring a performance-indicating parameter in a fluid flow turbine meter spin test in which the turbine meter rotor and other operative rotatable parts of the turbine meter are selectively accelerated and then allowed to coast so that the rate of the rotor rotational speed is dependent upon accuracyimpairing mechanical friction which resists rotation of the turbine meter rotor. The measured performance-indicating parameter is comparable with a reference parameter to determine if an increase has occurred in the mechanical friction which is developed by the operative meter parts under test. The measured performance indicating parameter may be the time required by the coasting turbine meter rotor to decay from one pre-selected speed to a lower pre-selected speed, or it may be the change in decaying rotor speed that occurs in a pre-selected time period.

Preliminary tests of a high speed vertical axis windmill model

Abstract: This report discusses a fixed-pitch vertical axis windmill that combines the inherent simplicity of this type of machine with a high aerodynamic efficiency and a high relative velocity. A three-bladed rotor was selected as the basic design, having constant chord symmetric airfoil blades configured in a catenary curve such that the rotor diameter is equal to the rotor height. In wind tunnel tests using a 30 inch scale model, it was found that once this rotor was given a very low rotational speed, it picked up speed and ran at a rotor tip velocity/wind speed ratio greater than 1. The number of blades was varied in the testing. A maximum power coefficient of 0.67 was achieved at 17 ft/s wind speed at a tip speed/wind speed ratio of 7.25 for a 2-bladed rotor. Increasing the number of blades above 3 did not result in higher power. The rotor could operate in gusts which double the mean wind velocity. Examination of Reynolds number effects, and taking into account the scale of the model, it was concluded that a full-scale windmill could run at lower velocity ratios than those predicted by the model tests, and that it could self-start under no-load conditions if the cut-in rpm are at least half the rpm for maximum power at the prevailing wind speed. Preliminary estimates show that a 15 ft diameter windmill of this design, designed to operate with a safety factor of 2.5 up to a maximum wind speed of 60 ft/s, would weigh ca 150 lb and could be marketed for ca $60.00, excluding the driven unit, if sufficient quantities were produced to make tooling costs negligible. Similarly, a 30 ft windmill would weigh ca 1000 lb and cost ca $400.00. 2 refs., 6 figs.

Rotational speed sensor

Abstract: A rotational speed sensor for producing a d.c. level output signal proportional to shaft speed is disclosed having a light responsive unit (phototransistor) which is masked from a light source by a pair of slotted discs. One disc defines windows and revolves directly with the shaft and the other defines shades for the windows and is mounted to be rotated by a centrifugal force mechanism mounted to revolve directly with the shaft. By means of a cam surface and groove, the second disc is caused to move relative to the first disc to unshade the window progressively as rotational speed increases. The light responsive unit is preferably of the self-integrating (long time constant) type to time average its output and produce the d.c. signal directly.

Dc motor servosystem

Abstract: In order to control the phase and speed of a DC motor, particularly employed for driving the rotary magnetic heads of a video tape recorder, the output of a signal generator having a frequency corresponding to the rotational speed of the motor is fed through a demodulation circuit to a clamping circuit, and the rotational speed of the motor is controlled in accordance with variations in an output level resulting from the slicing of the output of the clamping circuit at a reference level. Simultaneously, the rotational position of the DC motor is detected and compared with an external reference signal, for example, the synchronizing signal of a television signal, and the clamp level of the clamping circuit is controlled by the output resulting from the comparison, thereby to drive the motor in synchronism with the external reference signal.

Synchronizing installation for change-speed transmissions

Abstract: A synchronization installation for shiftable change-speed transmissions, especially for motor vehicles, in which an electronic synchronization control unit adjustable by means of a preselector is provided that is equipped with rotational speedmeasuring devices for the transmission members to be shifted and with devices for increasing or decreasing the rotational speed of the transmission elements to be shifted, and which is connected with shifting clutches by way of shifting devices that are actuated in case of rotational speed equality.

Rotation of a Glow Discharge in a Homopolar Device

Abstract: The rotation of a glow discharge in the homopolar geometry has been studied experimentally. In helium the motion of the discharge is independent of the current level and is attributed to ion drift with the neutrals stationary. In argon at low currents the rotational speed is proportional to the current and the discharge acts like a magnetohydrodynamic pump. At higher pressure in argon the discharge contracts and the rotational speed increases by nearly an order of magnitude.

Variable speed transmission with proportional inverse torque reduction

Abstract: Transmission apparatus in which the input shaft may drive the output shaft at the same rotational speed or may drive the output shaft at an increased speed with proportional inverse torque reduction. The apparatus includes input and output shafts connected together by a unidirectional stop device and a gearing arrangement so that the speed of the output shaft may be increased with proportional inverse torque reduction when the input shaft is driving in one direction and having apparatus for preventing free wheeling when the output shaft becomes the driver.

Process and circuit arrangement for the discrimination of mutual revolutional speeds of a plurality of revolving members

Abstract: The invention relates to a rotational speed descriminator determining occasional speed differences among several rotating members, such as automotive front and rear wheels. The main feature resides in the detection of two or more speedresponsive pulse signals of a first signal series as measured between two successive pulse signals belonging to a second series of speed responsive pulse signals.

Optical Current Meter Use in Southern California

Abstract: The optical current meter is a stroboscopic device with which an operator may visually follow and gage the velocity of particles moving on the water surface. From early prototypes the meter has evolved to a field usable instrument with a low power telescope, an oscillating mirror in the line of sight of the telescope, a variable-speed battery-powered motor, and a tachometer which indicates the rotational speed of the mirror. Surface velocities are computed knowing the distance to the water surface and the angular speed of the oscillating mirror. Surface velocities must be corrected by an appropriate coefficient to represent the mean velocity in the vertical. The optical current meter will find its principal use in measurements of discharge under conditions that preclude use of conventional stream-gaging equipment.

Means and method for numerically displaying the timing of ignition or other repetitive events

Abstract: A digital ignition analyzer which calibrates the output frequency of a pulse generator with respect to the rotational speed of an engine, and then uses a counter to count the pulses from the generator during the time between ignition in a selected cylinder and a reference time. The count displayed on the counter gives a direct digital reading of the rotational angle between the reference point and the point of ignition.

Tape fast feed control apparatus for endless magnetic tape cartridge player

Abstract: A tape fast feed control apparatus for an endless magnetic tape cartridge player, which comprises a motor driven tape feeding means, the motor being adapted to selectively control its rotational speed so as to normally feed the tape at low speed or fast feed it at high speed, a switch for changing rotation of the motor from low speed to high speed, and a changing means for change-over operation of the switch, the changing means being arranged to normally maintain the switch in a first position where the motor is rotated at low speed, the changing means including an operating member and adapted to change over the switch to a second position where the motor is rotated at high speed in response to manual operation of the operating member, the changing means being further adapted to change over the switch from the second position to the first position after the period proportional to a number of operations of the operating member, whereby the tape is fast fed by the period as designated by a number of operations of the operating member.

Method and device for determining the speed of a member

Abstract: A method and apparatus for controlling the rotational speed of a roller. The actual speed of the roller which is compared with a set speed in order to determine the deviation or error, is derived by means of a pulse disc which bears a plurality of pulse producing fields. The time interval which is required for each pulse flank to pass successively beyond two detectors is measured, and the inverse value of said interval instantly indicates the actual roller speed so that at each angular position of the roller, the roller speed may be exactly controlled.

Protective overspeed torque coupling

Abstract: A rotatable coupling adapted to transmit torque between a driving unit and a driven unit such as a centrifugal pump including a first member adapted to rotate with a second member, a linkage mechanism such as meshing gears or dogs normally locking the first member from rotation with respect to the second member and a release mechanism responsive to rotational speed of the coupling which will release the linkage mechanism at a predetermined rotational speed over normal speed and permit free rotation of the first member with respect to the second member.

Installation for flame starter devices

Abstract: An arrangement for a flame starter installation in aircompressing internal combustion engine, which includes an electric switch that permits the continued operation of the flame starter installation after the starting operation of the engine only when the engine rotational speed does not drop below a predetermined engine rotational speed.

Steady-state temperature distribution within a Brayton rotating unit operating in a power conversion system using helium-xenon gas

Abstract: The Brayton rotating unit (BRU), consisting of a turbine, an alternator, and a compressor, was tested as part of a Brayton cycle power conversion system over a side range of steady state operating conditions. The working fluid in the system was a mixture of helium-xenon gases. Turbine inlet temperature was varied from 1200 to 1600 F, compressor inlet temperature from 60 to 120 F, compressor discharge pressure from 20 to 45 psia, rotative speed from 32 400 to 39 600 rpm, and alternator liquid-coolant flow rate from 0.01 to 0.27 pound per second. Test results indicated that the BRU internal temperatures were highly sensitive to alternator coolant flow below the design value of 0.12 pound per second but much less so at higher values. The armature winding temperature was not influenced significantly by turbine inlet temperature, but was sensitive, up to 20 F per kVA alternator output, to varying alternator output. When only the rotational speed was changed (+ or - 10% of rated value), the BRU internal temperatures varied directly with the speed.

Improvements in or relating to gyroscopic apparatus

Abstract: 1,244,519 Positioning by ultrasonic field HARVEST QUEEN MILL & ELEVATOR CO 23 July, 1969, No 37124/69 Heading F2A [Also in Division G1] An inertial reference gyroscope comprises a hollow spherical piezo-electric body 10 containing liquid helium for partially supporting a spherical reference element 11 therein, the body 10 being energized to establish an ultrasonic wave field to position the reference element 11 within the body 10 and to rotate the element about a spin axis, rotational motion of the support 9 for the body 10 relative to the reference element 11 being sensed by optical pick-off units 19, 20 The reference element 11 comprises a quartz reflector shell 12, a sound absorbing shell 13 and a buoyant shell 14 enclosing a hollow cavity 18 connected to the outside of the element by capillary holes 17 The shells 13, 14 may be of spun quartz The body 10 is excited by use of an ultrasonic frequency electrical source and this creates standing waves in the liquid helium to support and position the reference element 11 Diffraction discs 15, 16 are mounted in the reflector shell 12 at diametrically opposed positions and at an angle of 45 degrees to the diameter for producing a rotational torque on the element 11 and causing it to spin about an axis defined by the capillaries 17 A servo loop is provided to control the rotational speed of the element 11 and to maintain a constant speed A cryostat unit is also provided to maintain the temperature of the gyroscope at a cryogenic temperature suitable for the liquid helium within the body 10

Method for supplying rotational speed signals

Abstract: A method by which even if a plurality of devices requiring information in terms of the rotational speed of an engine or a wheel are installed in the same automobile, only one rotational speed detector for each phenomenon is employed to operate a plurality of devices requiring information in terms of the engine or wheel revolutions.

Analytical and Experimental Studies of Two-Dimensional Flows in a Radial Bladed Impeller

Abstract: The current state of a research program to study flows in radial turbomachines at both on- and off-design conditions is described. Numerical solutions of the flow within a rotating impeller are described based on potential theory using a direct method of solution instead of by relaxation. The experimental apparatus comprising a rotating cascade rig is described. The rig consisted essentially of a rotor mounted horizontally in an open circular water tank. An external pipe system enabled the water to be circulated for either radial inflow or radial outflow. The rotor speed could be varied up to 300 rpm. A variety of perspex shrouded rotor geometries up to a maximum diameter of 3 ft 6 in could be tested. Flow visualization by means of polystyrene particles could be observed by a camera mounted above the rotor on its axis and driven at the same angular speed. A 12-channel electronic flash unit enabled the particle velocity and directions to be photographed. As an alternative to the flow visualization system, a bank of manometers, could be mounted above the rotor and driven at the same rotational speed, i.e., with no relative movement. Static pressure measurements could be taken on the blade faces and within the rotor passages. A comparison is made of the experimental and analytical results obtained for one straight vaned, constant area rotor.Copyright © 1971 by ASME

Electric machine of large diameter and low rotational speed having a liquid-cooled rotor

Abstract: In an electric machine of large diameter and low speed of rotation, cooling liquid is fed to the rotor via standing, open chambers. The edges of the open chambers rest against the plane end face of a rotating manifold having check valves, providing a seal.

Simple air turbine for high speed opticaI applications

Abstract: A simply constructed air-turbine air-bearing motor is described which is used to rotate dye-doped plastic through a laser beam at speeds up to 28 000 cm s-1. The turbine has excellent speed stability (5 parts in 105) for use in this and other high speed optical applications in the rotation speed range from 104 to 2 × 105 rev min-l.