Showing papers on "Rotational speed published in 1974"
TL;DR: In this article, the authors describe a combined theoretical and experimental investigation into the heat transfer from a disk rotating close to a stator with a radial outflow of coolant, and obtain mean Nusselt numbers for the free disk, the disk rotating very close to an unshrouded stator, and for the stator itself.
Abstract: This paper describes a combined theoretical and experimental investigation into the heat transfer from a disk rotating close to a stator with a radial outflow of coolant. Experimental results are obtained from a 762 mm diameter disk, rotating up to 4000 rev/min at axial clearances from 2 to 230 mm from a stator of the same diameter, with coolant flow rates up to 0.7 kg/s. Mean Nusselt numbers are presented for the free disk, the disk rotating close to an unshrouded stator with no coolant outflow, the disk rotating close to a shrouded and unshrouded stator with coolant outflow, and for the unshrouded stator itself. Numerical solutions of the turbulent boundary layer equations are in satisfactory agreement with the experimentally determined mean Nusselt numbers for the air-cooled disk over a wide range of conditions. At large ratios of mass flow rate/rotational speed the mean Nusselt numbers for the air-cooled disk are independent of rotation, and both the numerical solutions and experimental results become asymptotic to an approximate solution of the boundary layer equations.
56 citations
TL;DR: In this paper, a rotating valve was used to measure the combustion response of solid propellants to small amplitude pressure oscillations in a small rocket motor by varying the area of a secondary exhaust nozzle in a periodic manner.
Abstract: A study has been conducted to evaluate the rotating valve method of measuring the combustion response of solid propellants to small amplitude pressure oscillations. The method is based on producing pressure oscillations in a small rocket motor by varying the area of a secondary exhaust nozzle in a periodic manner. This is accomplished by using a rotating valve as the secondary orifice. The valve apparatus operates concurrently with a primary nozzle which controls the steady-state pressure. The frequency of the oscillations is determined by the rotational speed of the valve. A theoretical analysis was conducted to relate the combustion response function to measurable ballistic properties of the combustion chamber. Assuming that the combustion chamber is small in comparison to the acoustic wavelength, the combustion response function can be calculated from the amplitude of the oscillating pressure and the phase angle between the oscillating pressure and oscillating nozzle area. Cold flow tests were conducted using nitrogen and helium to test the validity of the analysis. Excellent agreement was found between the measured and predicted amplitudes and phase angles. Combustion tests then were conducted using two aluminized propellant formulations and three nonaluminized formulations. There was excellent agreement between the T-burner and rotating valve tests conducted on the same batch of propellant. For two nonaluminized propellants, the comparisons were based on different batches of propellant. Differences in combustion response and variations in burning rate and characteristic exhaust velocity were observed for these two formulations. It was concluded that the rotating valve method is a valid substitute for the T-burner. Substantial reductions in the cost of characterizing propellants also were obtained using this new approach.
51 citations
Patent•
26 Jul 1974TL;DR: In this article, an installation for automatic shifting of change-speed transmissions, especially for motor vehicles, in which actuating devices are provided for the engagement and disengagement of the speeds, which are controllable by way of control means by at least two influencing magnitudes, particularly output rotational speed and torque.
Abstract: An installation for the automatic shifting of change-speed transmissions, especially for motor vehicles, in which actuating devices are provided for the engagement and disengagement of the speeds, which are controllable by way of control means by at least two influencing magnitudes, particularly output rotational speed and torque; an electronic control unit having a programmed, constant-value memory device is provided, in which is stored at least one set of output rotational speed limit values coordinated to the individual speeds and torque steps, while at least the influencing magnitudes of torque and engaged speed are adapted to be applied to the electronic control unit by way of corresponding inputs; and output of the constant value memory device is operatively connected with a rotational speed comparison unit, in which the output rotational speed limit values given out by the constant-value memory device are adapted to be compared with the prevailing output rotational speed, whereby in this rotational speed comparison unit shifting-up or shifting-down signals are adapted to be released, when exceeding or falling below the limit values; these shifting-up or shifting-down signals are then applied to the actuating devices.
45 citations
TL;DR: In this article, the Navier-Stokes equations for both the stationary and the freely rotating case were solved numerically for values of the Reynolds number R in the range from 0.047 to 70.
Abstract: The two-dimensional steady flow of an incompressible viscous fluid past a circular cylinder, placed symmetrically in a simple shear field, has been studied for both the stationary and the freely rotating case by solving numerically the Navier-Stokes equations for values of the Reynolds number R in the range from 0.047 to 70. At R = 0.047, the results obtained are in substantial agreement with the analytic small-R perturbation solution given by Robertson and Acrivos (1970). Inertia effects were found, however, to play a significant role even at R = 1, and hence the calculated flow pattern for R greater than or equal to 1 differs significantly from that of the creeping-flow solution. Specifically, for the freely rotating case, the region of closed streamlines decreases rapidly in extent with increasing R, two symmetrically placed wakes are formed on either side of the cylinder, and the dimensionless rotational speed of the freely suspended cylinder decreases as the reciprocal of the square root of R.
44 citations
Patent•
16 Jul 1974
TL;DR: In this article, a digital acceleration detecting system for rotating bodies comprising a first counter for counting the number of pulse signals corresponding to the rotational speed of a rotating body, a second counter for calculating the pulse signals later than the first counter, and a control circuit for generating an output signal correspond to the difference between the counts of the first and second counters.
Abstract: There is provided a digital acceleration detecting system for rotating bodies comprising a first counter for counting the number of pulse signals corresponding to the rotational speed of a rotating body, a second counter for counting the number of the pulse signals later than the first counter, and a control circuit for generating an output signal corresponding to the difference between the counts of the first and second counters.
34 citations
Patent•
31 May 1974TL;DR: In this article, a sensor consisting of fluidic elements is used to detect the vehicle speed from the pressure in the control fluid supplied to the operational circuit, depending on the rotational speed of vehicle wheels.
Abstract: The sensor comprises an operational circuit consisting of fluidic elements The detecting sensor causes variation in the pressure of a control fluid supplied to the operational circuit The variation of pressure, depending on the rotational speed of vehicle wheels, serves to detect the vehicle speed from the pressure in the control fluid
20 citations
TL;DR: In this article, the imploded metallic liner used in axial flux compression experiments can be stabilized by linear rotation and the cost of field compression efficiency is calculated in terms of the stabilization cost.
Abstract: Taylor instability of the imploded metallic liner used in axial flux compression experiments can be stabilized by linear rotation. One can either remove the instability or limit its amplitude by choosing the rotation speed. The cost (in field compression efficiency) of stabilization is calculated.
19 citations
TL;DR: The behavior of Taylor cells in a polyacrylamide solution contained between rotating cylinders is described in this article, where the cell aspect ratio changes from about 1 to 4 as rotational speed increases.
Abstract: The behavior of Taylor cells in a polyacrylamide solution contained between rotating cylinders is described. As the rotational speed increases, the cell aspect ratio changes from about 1 to 4. Hysteresis of the 4‐cell configuration is observed.
15 citations
Patent•
07 Mar 1974TL;DR: In this paper, a circuit is disclosed for monitoring the velocity of a rotating member and determining when its speed is below a predetermined value, and the circuit arrangement is designed to compare the rotational speed of the member with an asynchronous AC line frequency.
Abstract: A circuit is disclosed for monitoring the velocity of a rotating member and determining when its speed is below a predetermined value. The circuit arrangement is designed to compare the rotational speed of the member with an asynchronous AC line frequency. Signals produced by the circuitry are utilized for control purposes.
15 citations
Patent•
25 Apr 1974
TL;DR: A fluid pressure control system for automatic fluid transmissions includes a fluid pressure source, fluid pressure regulating valve for regulating the fluid from the source to a particular line pressure, and a plurality of frictional engaging devices, adapted to be actuated by the line pressure through means of a manual shift valve, for attaining a particular gear ratio within the gear train of the transmission as discussed by the authors.
Abstract: A fluid pressure control system for automatic fluid transmissions includes a fluid pressure source, a fluid pressure regulating valve for regulating the fluid from the source to a particular line pressure, and a plurality of frictional engaging devices, adapted to be actuated by the line pressure through means of a manual shift valve, for attaining a particular gear ratio within the gear train of the transmission which are interposed between the input and output shafts. A governor valve generates a governor pressure in response to the rotational speed of the input shaft, a throttle valve generates a throttle pressure in response to the engine throttle valve, and a shift valve selectively actuates the frictional engaging devices in response to the governor and throttle pressures.
14 citations
Patent•
26 Jun 1974
TL;DR: In this paper, the rotational speed of an engine was estimated by using electrical pulses produced with rotating parts of the engine, including the use of a number of series of transducers or pickups producing numbers of asynchronous pulses.
Abstract: A method and apparatus for determining the rotational speed of an engine, using electrical pulses produced with revolving parts of the engine, including the use of a number of series of transducers or pickups producing numbers of asynchronous pulses, different for each series during each revolution of the engine, the transducers corresponding to as many series of detection elements comprising teeth and/or bosses spaced on the periphery of corresponding revolving parts of the engine, such that if n is the number of detection elements of a largest series giving the highest pulse frequency for a corresponding transducer due to engine revolution, and q is the total number of transducers associated with another series of detection elements, then the angular location of said another series of detection elements is obtained to the nearest 360°/qn. The pulses obtained are shaped, compared with a fixed reference frequency to count the shaped pulses and then divided and converted into analog signals or properly coded signals.
Patent•
06 Jun 1974TL;DR: In this paper, the authors present a numerical control apparatus for a lathe which reads from an input medium data specifying the transverse and axial position of the cutting edge of a tool with respect to the axis of the workpiece being machined, the cutting rate for the tool, and the rate of advance of the tool.
Abstract: Numerical control apparatus for a lathe which reads from an input medium data specifying the transverse and axial position of the cutting edge of a lathe tool with respect to the axis of the workpiece being machined, the cutting rate for the tool, and the rate of advance of the tool. The apparatus includes processing means responsive to the data for generating a continuous transverse position datum for the tool and computing means controlled by the cutting rate datum and the continuous transverse position datum for controlling the rotational speed of the mandrel of the lathe.
Patent•
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TL;DR: In this article, a machine for making bags out of thermoplastics material including a rotating drum having pockets, a feed station including means for feeding material into the pockets at a predetermined rate to form loops, the rate of feed being linked to the rotational speed of the drum by a feed-back control means to ensure that the loops are of a predetermined size.
Abstract: A machine for making bags out of thermoplastics material including a rotating drum having pockets, a feed station including means for feeding material into the pockets at a predetermined rate to form loops, the rate of feed being linked to the rotational speed of the drum by a feed-back control means to ensure that the loops are of a predetermined size. The loops are welded and cut by a laser to form bags.
DSM1
TL;DR: The Model-E Spinco-Ultracentrifuge was used for phase separations in macromolecular systems at temperatures of 0 −200 °C as discussed by the authors.
Abstract: A description is given of the design, construction and application of a 0–2000 rev/min centrifuge for studying liquid-liquid phase separations in macromolecular systems at temperatures of 0–200 °C. The concentrations in the phase can be measured with the aid of the complete optical schlieren system of the Model-E Spinco-Ultracentrifuge.
Owing to the low rotational speed, sedimentation-velocity and sedimentation-diffusion equilibrium measurements can be carried out also in solutions containing macromolecules of very high molecular weight.
Patent•
24 Oct 1974TL;DR: In this article, a hydrodynamic fluid coupling and a planetary gear arrangement were used to provide two different modes of differential action for use at different vehicle speeds for coupling the engine of the vehicle to opposite drive wheels.
Abstract: A differential mechanism suitable for such purposes as coupling the engine of the vehicle to opposite drive wheels utilizes a hydrodynamic fluid coupling and a planetary gear arrangement to provide two different modes of differential action for use at different vehicle speeds. In a first mode for use at low speeds, a mechanical differential action is modified by torque regeneration through the fluid coupling to limit slip of one wheel relative to the other with the slip limiting effect being proportional to the difference of rotational speed of the two wheels. In the second or high speed mode of operation, brought about by discharging the fluid coupling, a purely mechanical differential action is realized.
Patent•
19 Dec 1974
TL;DR: In this paper, a load on the flyweight transmitted through the pilot valve to preload the thrust bearings of a speed sensor serves to prevent the fuel control for a turbine type of power plant from shifting to its emergency schedule from the starting or normal schedule or vice versa at an indeterminant speed.
Abstract: A load on the flyweight transmitted through the pilot valve to preload the thrust bearings of a speed sensor serves to prevent the fuel control for a turbine type of power plant from shifting to its emergency schedule from the starting or normal schedule or vice versa at an indeterminant speed. Thus, the preload assures that the transition from one schedule to the other always occurs at a predetermined compressor rotational speed.
Patent•
09 Dec 1974
TL;DR: In this article, the synchronizing apparatus functions to sense the difference in the relative rotational speeds of a pair of independently driven reversely rotated shafts, and to translate this difference in rotational speed into an output motion for an actuating member.
Abstract: The synchronizing apparatus functions to sense the difference in the relative rotational speeds of a pair of independently driven reversely rotated shafts, and to translate this difference in rotational speeds into an output motion for an actuating member. This output motion is utilized to adjust the rotational speed of one of the driven shafts to a predetermined function or ratio of the rotational speed of the other driven shaft. This synchronization of the rotational speeds of the pair of shafts at the predetermined speed ratio is attained when the output motion of the actuating member is reduced to zero or rendered nonexistent.
Patent•
26 Mar 1974
TL;DR: In this paper, a cylindrical layer resistor is rotated about its longitudinal axis at a predetermined rotational speed, and a pulsating laser beam is moved at a linear speed along a line parallel to the longitudinal axis of the resistor element.
Abstract: A method for adjusting the resistance of cylindrical layer resistors comprising utilization of a laser beam. The resistor is rotated about its longitudinal axis at a predetermined rotational speed. Simultaneously therewith, a pulsating laser beam is moved at a predetermined linear speed along a line parallel to the longitudinal axis of the resistor element. The resistor rotational speed is preferably an integral multiple of the linear speed of the laser beam. The impulse time (t) of the laser beam preferably lies within the range from 0.1 to 0.9 of the period time (T). The above relationships produce a resistance element of high quality and having a uniform current density preventing premature burn out of the elements.
Patent•
08 Oct 1974
TL;DR: In this article, a control device for an electric car employing a DC shunt motor, the armature of which is connected to a storage battery through a first relay contact and two series resistors shunted by second and third relay contacts, is described.
Abstract: A control device is disclosed for an electric car employing a DC shunt motor, the armature, of which, is connected to a storage battery through a first relay contact and two series resistors shunted by second and third relay contacts second and third relays are energized in turn depending upon a degree of depression of an accelerator pedal, so that an armature terminal voltage is controlled to a plurality of values which are dependent upon the degree of pedal depression, the shunt field coil is connected through a field current control circuit for continuously controlling the field current depending upon a degree of depression of the accelerator pedal. In a preferred embodiment transistors are connected in series with the relays such that transistors are controlled by threshold values of rotational speed of the armature and/or an armature current. Therefore, the energization of the relays and thus of the switching control of the armature terminal voltage is conditioned by an armature rotational speed and/or an armature current. In another preferred embodiment of the present invention, the abovementioned continuous control of the field current is conditioned by a threshold value of armature rotational speed and/or an armature current. In a further preferred embodiment, the abovementioned switching control of the armature voltage and the abovementioned continuous control of the field current are both conditioned by a threshold value of armature rotational speed and/or an armature current.
Patent•
17 Sep 1974
TL;DR: This fuel injection system for internal combustion engines includes first means for generating a DC voltage proportional to the weight flow rate of air taken into an engine, second means for producing a sawtooth voltage which is synchronized with the working cycle of the engine, and third means for comparing the output voltages of said first and second means and generating a pulse corresponding to the amount of fuel required for each engine cylinder per operating cycle of an engine as discussed by the authors.
Abstract: This fuel injection system for internal combustion engines includes first means for generating a DC voltage proportional to the weight flow rate of air taken into an engine, second means for generating a sawtooth voltage which is synchronized with the working cycle of the engine and whose slope varies with the rotational speed of the engine, third means for comparing the output voltages of said first and second means and generating a pulse corresponding to the amount of fuel required for each engine cylinder per operating cycle of the engine, and at least one electromagnetic valve operable in response to a pulse generated by said third means.
TL;DR: In this paper, a theoretical and experimental investigation of the pumping characteristics of the normal stress extruder was made, which requires only material property data and extruder dimensions and rotation speed to evaluate the main velocity field, flow rate, and pressure.
Abstract: A theoretical and experimental investigation of the pumping characteristics of the normal stress extruder was made. The theoretical model requires only material property data and extruder dimensions and rotation speed to evaluate the main velocity field, flow rate, and pressure. The flow from the extruder was measured for two viscoelastic polymer solutions and a polymer melt as a function of gap setting and angular velocity. These measurements were in reasonable agreement with the proposed model.
Patent•
22 Oct 1974TL;DR: In this paper, an X-ray diagnostic apparatus employed in radioscopy and for Xray film exposures, including an Xray tube with a rotating anode, is described, in which the transitional time during changes in operational mode is completely eliminated, and each exposure upon actuation of an exposure triggering element immediately follows the preceding radioscopic operation.
Abstract: An X-ray diagnostic apparatus employed in radioscopy and for X-ray film exposures, including an X-ray tube with a rotating anode, in which the transitional time during changes in operational mode is completely eliminated. A circuit arrangement is included in the X-ray diagnostic apparatus in which each exposure upon actuation of an exposure triggering element immediately follows the preceding radioscopic operation, and wherein a signal corresponding to the actual value of the anode rotational speed is transmitted to a power output adjusting element, the power adjusting element being programmed in conformance with the permissible cycle of the X-ray tube power output in dependence upon the anode rotational speed, and to thereby effect the setting of the X-ray tube power output associated with the respective anode rotational speed.
Patent•
24 Dec 1974
TL;DR: In this paper, a pump speed control for filling machines is proposed, in which the rotational speed of the pump is varied between its intake stroke and the discharge stroke by selectively controlling the speed of driving motor as a function of the position of the output shaft of the driving motor.
Abstract: A pump speed control for filling machines in which the rotational speed of the pump is varied between its intake stroke and the discharge stroke by selectively controlling the speed of the driving motor as a function of the rotational position of the output shaft of the driving motor.
Patent•
24 Jun 1974
TL;DR: In this article, an apparatus for suppressing the rotational fluctuation of a supply roll includes a drive source and a differential gear, which is operatively connected to the first input shaft of the differential gear and a support shaft for the supply roll via a variable speed gear.
Abstract: An apparatus for suppressing the rotational fluctuation of a supply roll includes a drive source and a differential gear. The drive source is operatively connected to the first input shaft of the differential gear and a support shaft for the supply roll is operatively connected to the second input shaft via a variable speed gear. The output shaft is joined to both a hydraulic coupling and a control for the variable speed gear. A high frequency fluctuation of the rotation of the supply roll causes a forward or reverse rotation of the output shaft of the differential gear. The hydraulic coupling acts to retard the output shaft rotation thereby causing a braking or driving force to be applied through the differential gear to the supply roll for eliminating the rotational fluctuation of the supply roll. The variable speed gear functions to keep the second input shaft of the differential gear to rotate at a fixed average speed while the average rotational speed of the supply roll continues to gradually increase as the roll diameter is reduced with the progress of the unrolling operation.
TL;DR: In this article, a study of the behavior of particulate flows near the solid boundaries is necessary to determine the effect of the presence of solid particles on the skin friction and heat transfer.
Abstract: A study of the behavior of particulate flows near the solid boundaries is necessary to determine the effect of the presence of solid particles on the skin friction and heat transfer. In the present analysis, the particles are continuously distributed throughout the flowfield and each of the two phases has its own mean properties. The particles translational velocity is generally different in magnitude and direction from that of the gas. They also have a rotational velocity which is not equal to the gas rotational speed. The particles motion, however, is basically due to the gas motion. If the rate of change of the angular momentum of the suspension in the volume V is set equal to the total moment of the surface forces about an axis in the /c-direction passing through a point 0 within this volume we obtain
Patent•
21 Jun 1974TL;DR: In this paper, a control installation for shifting back an automatically shifted planetary gear change-speed transmission in which the various speeds are adapted to be engaged by servo-devices that are actuated by a pressure medium whereby the servo device of the speed to be brought into readiness and is fully engaged only after the determination of the correct shifting point by means of at least one feeler device as a function of the latter.
Abstract: A control installation for shifting back an automatically shifted planetary gear change-speed transmission in which the various speeds are adapted to be engaged by servo-devices that are actuated by a pressure medium whereby the servo-device of the speed to be engaged is brought into readiness and is fully engaged only after the determination of the correct shifting point by means of at least one feeler device as a function of the latter; a solenoid valve is coordinated to the pressure line leading to the actuating member of the servo device and is adapted to be shifted by means of a shifting pulse into a position releasing the pressure to the actuating member of the servo-device whereby the shifting pulse is triggered by at least one rotational speed transmitter which detects the rotational speed condition of a corresponding transmission member.
Patent•
11 Mar 1974
TL;DR: A rotational speed responsive type fluid pressure signal control valve comprises a plurality of fly weights rotated by a drive shaft, a sleeve operated by the fly weights, fluid passages provided in the valve and valve bodies actuated by the sleeve so as to open and close the fluid passages, thereby getting a fluid pressure signals from the fluid passage as mentioned in this paper.
Abstract: A rotational speed responsive type fluid pressure signal control valve comprises a plurality of fly weights rotated by a drive shaft, a sleeve operated by the fly weights, fluid passages provided in the valve and valve bodies actuated by the sleeve so as to open and close the fluid passages, thereby getting a fluid pressure signal from the fluid passages.
Patent•
19 Feb 1974
TL;DR: In this paper, a rotational speed changing and transmitting device which operates by transmission of power from conical input disks to a centrally located movable idler disk to conical output disks for transmission to an output shaft is presented.
Abstract: The present invention provides a low cost, versatile rotational speed changing and transmitting device which operates by transmission of power from conical input disks to a centrally located movable idler disk to conical output disks for transmission to an output shaft, the position of the idler disk determining the output speed.
TL;DR: In this paper, a vibrating reed regulator is used to control the speed of a gas turbine driving an alternator, and the entire study of the cycle is studied analogically.
Abstract: This paper describes a vibrating reed regulator used to control the speed of a gas turbine driving an alternator The vibrating reed is excited by a pulsed jet of air at a frequency near to its resonant frequency The edge of the reed is displaced opposite a fuel pipe, therefore the center section varies as the amplitude of vibrations varies This amplitude is dependent on the frequency of excitation of the jet and is a function, through the intermediate member to the detector and the acoustic wheel, of the rotational speed of the exit shaft This regulator is connected to the gas turbine and the entire study of the cycle is studied analogically However, it must be specified that the study of this control system using a vibrating reed as speed sensor and fuel regulator is a simplified linearized analogical study The paper presents the theoretical and experimental results concerning the characteristics of the regulator and the performance in a closed loop of the studied system