Showing papers on "Rotational speed published in 1989"

Device with a rotationally driven surgical instrument

Abstract: The device comprises a rotationally driven surgical instrument incorporating a hand-held element having a mount rotatably installed therein for reception of interchangeable cutting and milling inserts, a driving motor for driving the mount receiving the tool inserts, a control unit for controlling the driving motor with means of setting the rotational speed and of preselecting the rotational speed range and direction of rotation as well as a digital indicator for displaying the rotational speed set up in each case. For the purpose of accessible storage of setting data, the control unit incorporates a non-volatile read-write memory for digital storage of rotational speeds, a code carrier as well as a coding/decoding arrangement.

Method and apparatus for determining characteristics of the movement of a rotating drill string including rotation speed and lateral shocks

Abstract: The invention is related to a method of determininng the instantaneous rotation speed of a drill string or a drill bit in a borehole or the lateral shocks applied to the string or bit. The centripetal acceleration of the drill string is measured at at least two opposite ends of a drill string diameter so as to obtain two centripetal acceleration signals ac1 and ac2; the signals ac1 and ac2 are combined and the instantaneous rotation speed or the lateral shocks are derived from said combined signal. The accelerometers must be of the type delivering a signal with a DC component. An important application of the invention is to transform drill string rotation speed dependent data acquired versus time with a constant sampling time increment T c separating successive data, into compensated data which would be obtained for a substantially constant drill string rotation speed S c . The compensated data are obtained either by adjusting the constant sampling time interval T c into a variable sampling time increment T v , using the measured instantaneous rotation speed S, or by selecting the data which have been acquired during periods of time during which the instantaneous rotation speed of the drill string varied within predetermined limits only.

High bypass turbofan engine having a partially geared fan drive turbine

Abstract: The present invention provides a high bypass turbofan engine configuration wherein a fan drive turbine is divided into first and second turbine sections mounted for independent rotation within the engine frame. The first, higher pressure, higher speed turbine section is coupled to the fan section drive shaft via a gear box which reduces the rotational speed of the power delivered by the higher pressure first turbine section to match the design rotational speed of the fan section. The second turbine section, having a larger diameter and lower rotational speed as compared to the first turbine section, is directly connected to the fan section and drives the fan section at the same rotational speed as that of the second turbine section. In this manner, the fan drive shaft horsepower is provided while reducing the weight and size of the necessary gearing between the fan drive turbine and the fan. The weight and size of the fan drive turbine and the booster compressor are also reduced.

Development of Rotational Speed Control Systems for a Savonius-Type Wind Turbine

Abstract: An attempt is made here to increase the output of a Savonius rotor by using a flow deflecting plate. When the deflecting plate is located at the optimum position, the rotor power increases nearly 30 percent over that when no deflecting plate is present. The rotor torque was found to become almost zero, when the plate is placed just in front of the rotor. In addition, two systems to control the rotational speed of a Savonius rotor are developed. These permit the rotor to be stopped in strong wind. Operating characteristics of the two control systems are investigated.

Power generating system

Abstract: A power generating system comprising a fluid driven rotor, a generator, and a transmission assembly for coupling the rotor to the generator. The transmission assembly is controlled by an hydraulic circuit which comprises a valve which in a first state prevents flow of operating fluid through the circuit and in a second state permits such flow, whereby in the first state torque is transmitted from the rotor to the generator with substantially zero slip, and in the second state the assembly slips so as to permit the rotational speed of the rotor to increase relative to the rotational speed of the generator and maintain a substantially constant torque at the generator.

A high-performance neutron velocity selector

Abstract: A high-performance neutron velocity selector of the helical lamella type is presented (rotational speed 28 300 rpm, overall length 300 mm). The peak transmission remains high (81%) even at high resolution (10%) and large beam divergence (60′).

A method of balancing a container which rotates about an essentially horizontal axis

Abstract: According to a method of balancing a container (10) which is rotating about an essentially horizontal axis, preferably a washing machine drum, the container is provided with cavities (15) evenly distributed along the periphery thereof and having openings (20) via which selectively liquid can be introduced in the respective cavity. A sensor (24) is provided for sensing vibrations caused by the rotation of the container and for emitting an electrical signal the magnitude of which is a measure of the magnitude of the vibrations. The container (10) is brought to rotate at a first rotational speed and the sensor signal is read. A predetermined amount of liquid is introduced in a randomly selected cavity (15) along the periphery of the drum. The sensor signal is again read and the value is compared with the preceding sensed value, wherein if the value is lower than the preceding one a new dose of the predetermined amount is introduced in the selected cavity while if the value is equal to or greater than the preceding one the predetermined amount is introduced in the immediate following cavity along the periphery. The described sequence is repeated until the sensor signal is lower than a predetermined, permissible value at which the container is brought to rotate at a second rotational speed, higher than the first one. The sequence described is repeated for different rotational speeds until the desired rotational speed has been reached and the sensor signal is lower than the predetermined value.

Mechanical-hydraulic transmission gear system and method of controlling power transmission using the system

Abstract: A mechanical-hydraulic transmission gear system for use in construction vehicles or construction equipment and a method of controlling power transmission using the system arranged such that when a prime mover is rotating at high speeds, power transmission is effected only through a mechanical transmission gear to thereby reduce the power loss due to fluid pressure substantially to zero, while when the prime mover is rotating at low speeds power transmission is effected only through a hydraulic transmission gear so as to facilitate control of the speed of the vehicle and control of changing forward running over to reversing and vice versa. The mechanical-hydraulic transmission gear system comprises a hydraulic transmission gear (10) having a hydraulic pump (11) and a hydraulic motor (13); a mechanical transmission gear (30); change-over means (26) for changing forward running of the vehicle over to reversing and vice versa; a speed control means (27); a sensor means (22) for sensing the rotational speed of output shaft (14); and control means (20) for comparing the signals transmitted by the change-over means, the speed control means and the rotational speed sensor means so as to effect control of disconnection and connection of a clutch (31) mounted on an input shaft (2) of the mechanical transmission gear and control of discharge of fluid from the pump and the motor. The method of controlling power transmission using this system includes the steps of disconnecting the clutch of the mechanical transmission so as to transmit the power from the prime mover only through the hydraulic transmission gear to the output shaft when the rotational speed of the output shaft is lower than a predetermined value; and connecting the clutch of the mechanical transmission gear so as to transmit the power only through the mechanical transmission gear to the output shaft and minimizing the power required by the hydraulic transmission gear according to a command from the control means when the rotational speed of the output shaft is higher than the predetermined value.

Method and apparatus for controlling drilling operation

Abstract: In drilling control method and apparatus for making holes through a composite workpiece (3) made of a plurality of materials (3a, 3b) having different machining properties, the workpiece (3) is first drilled at a feeding speed and a rotational speed of a drill (1) which are selected. When the drilling of the workpiece is initiated, the amounts of the feed speed and the rotational speed are detected by a feed speed sensor (5) and a rotational speed sensor (6), respectively, and thrust force applied to the drill during the drilling is also detected by a thrust sensor (8). The detected feed speed and the rotational speed of the drill (1) are compared in a comparison unit (7) with optimum values which are adapted to the detected thrust force. When the detected values of the feed speed and the rotational speed of the drill coincide substantially with the optimum values, the drilling operation is performed, while when the detected values of the speed do not coincide with the optimum values, the feed speed and rotational speed of the drill are changed to the optimum values.

Twin scroll turbine

Abstract: A radial turbine combining a twin scroll structure and a variable area nozzle structure which is suitable for use as the exhaust turbine of a turbocharger for an automotive internal combustion engine. The first scroll passage is provided with no flow control means while the second scroll passage is provided with a variable area nozzle unit so that only the first scroll passage is used with the second scroll passage substantially closed in low speed range of the engine and the variable area nozzle unit is activated only when the rotational speed of the engine is increased beyond a certain value. Alternatively, by providing a control valve in the first scroll passage, it is possible to adjust the variable area nozzle unit with the control valve kept closed in low speed range, and to open up both the variable area nozzle unit and the control valve in high speed range. In either case, the turbine is capable of finely adjusting the operating condition thereof without creating excessive back pressure at its inlet end or involving any shocks or lags over the whole speed range.

Variable speed turbo vacuum pump

Abstract: A variable speed turbo vacuum pump system (10) utilizes a motor driven compressor (12) to evacuate a gaseous medium from an enclosed space (22). The compressor (12) is a rotational type having at least one compressor wheel (40), the rotational speed of which is increased in inverse proportion to the decreasing inlet density of the gaseous medium from within the enclosed space (22).

Apparatus for controlling rotational speed of prime mover of construction machine

Abstract: A controller having an up/down (6U, 6D) switch for changing the rotational speed of a prime mover such as an engine (1), an actuator (3) such as an electric motor for driving a governor on the basis of the operation of the up/down switch so as to control the rotational speed of the prime mover. A target speed is calculated on the basis of the operation of the up/down switch, and the prime mover speed is controlled by using the calculated value. Another switch is provided to immediately shift the prime mover speed to a speed previously set as desired. This shift switch is used to control the prime mover so that the prime mover rotates at the set speed, and this speed is adjusted by operating the up/down switch.

Controlling device for non-stage transmission for vehicles

Abstract: A controlling device for controlling the transmission ratio of a non-stage transmission in a vehicle. The transmission ratio is controlled according to a forecast output power of the vehicle. The output power is forecast based on an operating condition of the vehicle, such as atmospheric pressure. The control considers various operating parameters. A comparison of a predetermined ratio of increase of engine speed or throttle opening with actual ratios of increase of engine speed or throttle opening may be made in controlling the transmission ratio. An uneven road surface is detected and a transmission ratio of the transmission is controlled accordingly to substantially eliminate hunting. An engine speed is controlled so that the engine speed may not exceed a predetermined rotational speed when the transmission gear ratio is fixed. A target engine speed or target transmission ratio is corrected in response to an output signal of a comparison device which compares an actual vehicle velocity with a set vehicle velocity during automatic fixed vehicle velocity running.

Arrangement for controlling the power transmission to at least two axles of a motor vehicle

Abstract: The arrangement controls a friction element for limiting a rotational speed compensation between the axles of a two-axle or all-wheel-driven vehicle as a function of the difference of the medium wheel speeds of both axles (longitudinal speed difference). This longitudinal speed difference is compared with two driving-speed-dependent tolerance bands, the first tolerance band being determining for positive and the second tolerance band being determining for negative longitudinal speed differences. If the values of the longitudinal speed differences are above the first or below the second tolerance band, the limiting is increased; if the values are within the tolerance bands, the instantaneous limiting is maintained; and if the values are between the tolerance bands, the limiting is reduced. This arrangement may also be expanded to include an adaptation device of the limit criteria with respect to different tread radii of the wheels and a cornering correction device.

Method of controlling idling rotational speed of internal combustion engine for vehicles equipped with air conditioning systems

Abstract: A method of controlling the idling rotational speed of an internal combustion engine for an automotive vehicle equipped with an air conditioning system having a variable capacity compressor disposed to be driven by the engine and capable of being controlled by an external control signal. A value of a capacity control signal as the external control signal for controlling the capacity of the compressor is calculated. A value of torque required for starting the compressor is calculated based upon ambient temperature and the calculated value of the capacity control signal. The engine idling rotational speed is increased in accordance with the calculated starting torque. When the ambient temperature is higher than a predetermined value, the required starting torque is calculated based only upon the ambient temperature irrespective of the calculated value of the capacity control signal, whereas when the ambient temperature is lower than the predetermined value, the required starting torque is calculated based upon both the ambient temperature and the calculated value of the capacity control signal.

Method for controlling valve operation in an internal combustion engine

Abstract: A method of controlling the operation of engine valves in an internal combustion engine, dependent on the rotational speed of the engine, involves controlling a valve operation changing mechanism (10) capable of opening and closing the engine valves selectively in a low-speed mode of operation corresponding to low-speed operation of the engine and a high-speed mode of operation corresponding to high-speed operation of the engine. The method includes the steps of determining the rotational speed (Ne of the engine at which the output torque (T) produced by the engine when the valve operation changing mechanism (10) is in the low-speed mode of operation and the output torque (T) produced by the engine when the valve operation changing mechanism is in the high-speed mode of operation are of a certain relationship to each other; and selecting a switching rotational speed for switching operation of the valve operation changing mechanism based on said determined engine rotational speed.

Traction control apparatus

Abstract: A driving wheel rotational speed and a driven wheel rotational speed are detected by corresponding wheel speed sensors to calculate a slip value DV of driving wheels. A target output torque of an engine of a vehicle is calculated on the basis of the slip value DV. A target intake air amount per a predetermined number of revolutions of the engine is set in accordance with the target torque. Opening correction of a throttle valve is performed at every control cycle time Δt on the basis of an difference between a target intake air amount per the predetermined number of revolutions of the engine and an actual intake air amount per the predetermined number of revolutions of the engine in the controller. The opening of the throttle valve is increased/decreased in accordance with the opening correction value Δθti by the motor drive circuit.

Rotating Rayleigh-Benard convection with modulation

Abstract: The author considers rotating Rayleigh-Benard convection with modulated rotation speed. Galerkin truncation under realistic, i.e. experimentally realisable, boundary conditions is carried out. The threshold of convection can be raised or lowered depending on the Prandtl number and rotation speed.

Inter-axle differential having a friction-type biasing clutch and wheel slip sensing control means therefor

Abstract: A four-wheel drive vehicle comprises an engine and a power transmission system, including a shiftable change gear transmission having a power input shaft and a differential having front and rear output shafts and a biasing clutch, for driving the front and rear vehicle wheels. The differential, with biasing clutch disengaged, allows for differences in rotational speed between the front and rear wheels. Increased speed of one output shaft as may be caused by its' associated wheels slipping, results in decreased speed of the other output shaft. Conversely, decreased speed of one output shaft as may be caused by its' associated wheels being bogged down by mud, sand or deep snow, results in increased speed of the other output shaft. The degree of differential action may be determined from the known input shaft speed, the gear ratio engaged and an output shaft speed. A control system, which includes a microprocessor, employs sensors to directly sense the speed differences between the power input shaft of the transmission and only one of the output shafts of the differential and effects temporary biasing clutch engagement in the event of excessive slippage for a predetermined interval of time. The control system also senses the selected gear range of the transmission. The microprocessor periodically samples the speed ratio between those two shafts, compensating for the gear range selected, and compares it to a preselected (adjsutable) ratio in the microprocessor memory. If the preselected ratio band is deviated from for a selected interval of time, the microprocessor effects clutch lockup for a selected interval of time so that both output shafts of the differential (and the front and rear wheels) rotate at the same speed and wheel slippage is eliminated.

Magnetic tape wind-up control method, and tape wind-up apparatus

Abstract: A magnetic tape wind-up control method comprises the steps of controlling the speed, at which a feed motor is rotated, in accordance with a signal generated by a tape movement detector, and controlling the speed, at which a wind-up motor is rotated, in accordance with a signal which represents the position of a dancing arm, which thereby controls the tension on the magnetic tape. The number of revolutions completed by the wind-up motor is detected, and the outer diameter of a roll of magnetic tape, which is being wound around a wind-up reel, is calculated from the thickness of the magnetic tape, the diameter of a core of the wind-up reel, and the number of revolutions completed by the wind-up motor. The value indicated by a tape speed command is divided by the outer diameter of the roll of the magnetic tape. A rotation speed command signal, which represents the quotient of this division, is generated, and the speed of rotation of the wind-up motor is controlled on the basis of the rotation speed command signal. Simultaneously, the tension on the magnetic tape is controlled on the basis of the position of the dancing arm.

Method and apparatus for operating a variable speed power generation system

Abstract: A method and apparatus for operating a variable speed power generation system in which the generated output of an induction generator is adjusted by controlling current in the secondary side of the induction generator. Rotation speeds of the induction generator coupled to a prime mover are detected, a secondary current command for controlling a difference between a detected rotation speed and a speed command to be zero is generated, and current in the secondary side of the induction generator is controlled on the basis of the secondary current command. In addition, the generated output of the induction generator is sequentially detected in order that a command value of the speed command is sequentially changed when a detected generated output shows a tendency to increase and, when a detected generated output shifts from an increasing tendency to a decreasing tendency, the command value of the speed command is once changed to a lower speed value and thereafter returned to a higher speed value, thereby maximizing efficiency of the variable speed power generation system and reducing costs.

Method and apparatus for low speed estimation

Abstract: A system and method determines the rotational speed of a rotating member by determining speed from signals having a frequency directly proportional to the rotational speed. The system provides for the estimation of rotational speed even if no speed signals are detected over a sampling interval.

Antiskid control device

Abstract: An antiskid device according to this invention controls the hydraulic pressure to vehicle brakes based on the rotational speed of the wheel having the smallest coefficient of friction until a standard vehicle velocity becomes less than a predetermined velocity. Further, the antiskid device controls the hydraulic pressure to the brakes based on the speed of each wheel if the standard vehicle velocity becomes less than the predetermined velocity. Accordingly, directional stabilization of the vehicle is maintained when the vehicle runs at high speed, and at low speed, the braking range for stopping the vehicle is mainimized by utilizing the braking force more efficiently.

Running control device for vehicle

Abstract: PURPOSE:To prevent the occurrence of unstable control due to a change in road surface friction, by a method wherein, based on a change in an estimated road surface load, a feedforward control amount is added to an output from a drive wheel servo control means to control a drive wheel in a manner to follow a target rotation speed CONSTITUTION:A drive wheel servo control means M4 controls an internal combustion engine M1 or an automatic speed change gear M2 so that the rotation speed of a drive wheel M3 is adjusted to a target value In this running, when the factor of friction with a road surface is changed, a relation between the number of revolutions of an engine and the rotation speed of a drive wheel through the automatic speed change gear M2 is also changed Therefore, based on a control model, from a parameter responding to the number of revolutions of an engine and the rotation speed of a drive wheel, a change in a road surface load is estimated by a road surface load estimating means M5 Based on the change, an feedforward control amount is added to an output from the drive wheel servo control means M4 by means of a road surface load change compensating means M6 This constitution enables improvement of a running feeling and safety

Optical transducer systems

Abstract: An optical transducer system for producing an optical output signal representative of the rotational speed of a rotary member, particularly a shaft of a gas turbine engine, comprises a conventional inductive speed probe positioned adjacent the shaft to sense the passing of the teeth of a toothed wheel secured to and rotatable with the shaft. The inductive sensor thus produces an AC output signal whose frequency is proportional to the rotational speed of the shaft, and this signal is used to excite electrostatically vibration of a cantilever beam micromachined in silicon. The vibrating beam is arranged in an optical path defined by one or more optical fibres, such that its vibrations modulate light directed along the optical path at a frequency which is again proportional to the rotational speed of the shaft.

Speed change control device for automatic transmission

Abstract: PURPOSE:To prevent hunting by inhibiting a down-shift alone for a predetermined time when an up-shift of a transmission is made, and by inhibiting an up-shift alone for a predetermined time when a down-shift is made. CONSTITUTION:A CPU 21 determines a gear shift in accordance with a vehicle speed detected by a rotational speed detector 13 and a throttle opening degree detected by a sensor 12, so as to control the gear shift by means of solenoids SOL1-SOL3. In this case, when a transmission 10 makes an up-shift, a down- shift is inhibited for the predetermined time, and when it makes a down-shift, an up-shift is inhibited for a predetermined time. Since only such a hunting condition that it is returned to its original speed stage after a gear shift is once made is inhibited, it is possible to set the predetermined time to be relatively long, thereby it is possible to reduce the rotational speed of gear shift and shocks upon gear shift.

Rotational speed differential responsive type control coupling

Abstract: A rotational speed differential responsive type control coupling is provided with a device for manually or automatically preventing relative rotation of a drive housing and rotor in order to prevent working oil from being heated up to an excessively high temperature.

Air-fuel ratio control device for internal combustion engine

Abstract: PURPOSE:To improve fuel consumption and to enable excellent cleaning of exhaust gas, by a method wherein a change in the fluctuation width of the rotation speed of an internal combustion engine is detected, and according to the change, the air-fuel ratio of the internal combustion engine is varied. CONSTITUTION:A detecting means M1 detects the fluctuation width of a rotation speed during non-load running of an internal combustion engine. A varying means M2 varies an air-fuel ratio so that the fluctuation width of the rotation speed is decreased. In this case, a change in the fluctuation width of the rotation speed is detected by a detecting means M3. When a change in the fluctuation width of the rotation speed is produced, based on the change, the varying means M2 is controlled by a first control means M4 so that an air-fuel ratio is brought into the lean side or the rich side. Meanwhile, when there is no change, the varying means M2 is controlled by a second control means M5 so that an air- fuel ratio is brought into the lean side. This constitution improves fuel consumption during non-load running, and cleans exhaust gas in an excellent state.

Diagnostic system for rotational speed sensors in drive train of four wheels drive vehicle having central differential device

Abstract: A diagnostic system for detecting failure of rotational speed sensors incorporated in a central differential device of a four wheels drive vehicle for the purpose of controlling a lock-up clutch in the central differential device, wherein the rotational speed sensor for an output rotational member of the central differential device is checked, when the rotational speed detected thereby is lower than the rotational speed detected by the other rotational sensor, if the rotational speed detected thereby is continually zero over a period such as 10 seconds while the output of the other rotational speed sensor is above a certain low value.