Gm Global Technolgoy Operations, Inc.

Other

Delco Electronics Corporation

The University of Mississippi

Andrzej M Pawlak

David W Graber

Takeshi Shirai

Jeffery Alan Zuraski

Dennis C Eckhardt

Chi Hung Leung

Bryan L Faist

James W Babineau

David B Young

Thaddeus Schroeder

William C Lin

Thomas Arthur Perry

Edward D Klomp

John Robert Bradley

Scott E Weiss

Stephen F De Nagel

Maged Radamis

Donald L Richardson

Alan H Green

A magnetically latching solenoid apparatus is characterized by a non-magnetic armature carrying a permanent magnet having poles aligned with the throw axis of the device. The poles of the magnet are substantially aligned with corresponding pole pieces and define respective variable air gaps therebetween. The apparatus assumes one of two bistable magnetically latched states according to the one of the air gaps across which the magnetic attractive force exceeds the magnetic attractive force across the other of the air gaps. Single or dual winding coils temporally excitable unidirectionally or bidirectionally and, in the case of dual winding coils mutually exclusively or contemporaneously, to cause the latch state to change.

Magnetically latching solenoid apparatus

A low-energy, long-life, magnetic latching apparatus includes a permanent magnet, an electro-magnet and a bi-stable armature. The magnetization axes of the permanent magnet and the electromagnet are substantially parallel to maximize respective flux coupling. Back-iron is located immediately adjacent the permanent magnet opposite the electro-magnet such that the permanent magnet is intermediate the back-iron and electro-magnet. The armature is arranged to minimize any air-gap between the armature and permanent magnet occasioned by the pivotal movement thereof. The back-iron provides for an increased permanent magnet working point and parallel flux path for electro-magnetic flux.

Magnetic latching relay

Telescopic pen shaped magnetic multi-purpose screw driver

Position of a rotatable automotive part is sensed with a trio of magnetic field intensity sensors disposed adjacent a ring that rotates with the automotive part, the ring comprising alternating permanent magnet sections with at least one localized magnetic field depression corresponding to a synchronization position of the part wherein the sensors are spaced along the direction of ring rotation so that the relative phase between the output signals of a first pair of the sensors as indicated by the relative output signal magnitude indicates incremental displacement of the part, and so that a significant difference in magnitude between the output signal of a second pair of the sensors indicates the synchronization position.

Three sensor rotational position and displacement detection apparatus

A variable reluctance rotation sensor comprising a flux member having a ferromagnetic pole piece formed of a cylindrical center portion interposed between a first and second end portion. Each of the end portions have a respective surface which contains elongated teeth, similarly separated by slots as teeth on the periphery of a toothed wheel. The cylindrical center portion is positioned with respect to the toothed wheel such that the toothed surfaces of the first and second end portions are positioned adjacent the periphery of the toothed wheel comprising the teeth and slots, the magnetic flux member and toothed wheel defining an air gap. The sensor further comprises permanent magnets which establish main flux loops traversing the air gap, and leakage flux loops linking an electrical coil wound about the cylindrical center portion. As the toothed wheel is rotated, the magnitude of the main flux loops vary in relation to the varying air gap. The leakage flux loops, in turn, vary in relation to the varying main flux loops, the varying leakage flux loops being linked to the electrical coil and resulting in a sinusoidal output voltage signal proportional to the varying leakage flux loops. Each cycle of the output signal corresponds to a predetermined incremental angular rotation of the toothed wheel.

Variable reluctance rotation sensor with leakage magnetic flux sensing

A rotary encoder capable of detecting angular rotation of a rotating shaft, and identifying its neutral position without the need for multiple encoder wheels. A magnetoresistive sensor is positioned adjacent the periphery of a single multipole magnet ring attached to a steering wheel shaft. The magnet ring comprises alternating N-pole and S-pole magnetic regions along its periphery, the surface of one of the regions containing a demagnetized portion. The sensor produces a sinusoidal signal as the shaft is rotated, responsive to the passage of the magnetic regions, with a period equal to the passage of two successive magnetic regions adjacent the sensor. The angular position of the shaft which aligns the demagnetized portion adjacent the sensor corresponds to the shaft's neutral position. Aligning of the demagnetized portion adjacent the sensor causes a voltage irregularity within the sensor's otherwise sinusoidal output signal, which is detected by a signal processing circuit.

Rotary encoder with neutral position

An integral variable reluctance sensor and bearing grease seal assembly (sensor assembly) has at least one magnet and an annular wire coil secured at the interior of a housing which seals an annular space between a dynamic inner race and a static outer race. The sensor assembly is characterized by a relatively large flux change and resulting large peak to peak periodic output due to exploitation of the outer race and housing as high permeance flux paths in the sensor magnetic circuit and an additive arrangement of plural magnets. Sensor output signal strength is variable in step with the number of magnets and output variations due to air gap variations are minimized by symmetrical distribution of the same. The sensor assembly is further characterized by a single dynamic seal and no moving parts.

Variable reluctance integral bearing sensor

A solenoid actuated valve assembly has first and second valve members, first and second valve seats, a solenoid coil, a first armature effective when the coil is energized with a positive current to permit displacement of the first valve member from the first valve seat, and a second armature effective when the coil is energized with a negative current to displace the second valve member from the second valve seat. The first valve member engages the first valve seat when the coil is energized with a negative current, and the second valve member engages the second valve seat when the coil is energized with a positive current.

Solenoid actuated valve assembly

A means is provided for improving the magnetic permeability of a magnetic circuit within a variable reluctance sensor having off-set, permanent magnets by appropriately annealing the magnetic flux member. The annealing process includes heating the machined magnetic flux member in a vacuum to a temperature and for a duration sufficient to austenitize the magnetic steel so that full carbide solution is obtained, for example about 1300.degree. F. to about 1550.degree. F. for a duration of about 15 to 30 minutes. The magnetic flux member is then appropriately cooled in the vacuum so as to prevent the formation of martensite. The magnetic circuit, incorporating the annealed magnetic flux member, exhibited improved magnetic permeability, and the sensor signal was increased by as much as about 60 percent during operation. The method of this invention enhances the overall effectiveness of the sensor, particularly when sensing low rotational speeds such as when employed within automotive anti-lock braking or traction control systems.

Variable reluctance sensor with offset magnets having improved magnetic

A power steering unit has an electromagnetic mechanism controlled by a computer-based controller for varying the steering effort in accordance with vehicle speed. The same controller is used to adjust the steering effort in accordance with a calibration value to obtain steering effort uniformity. The calibration value is obtained by applying a force to a vehicle wheel and measuring the resulting torque on the steering wheel (or vice versa) and comparing the resulting force to a standard. Any deviation from the standard is stored in the controller as a correction factor. Alternatively, the characteristics of the steering gear and the power steering pump are measured and encoded on the unit when manufactured and the encoded values are read after assembly in a vehicle and used to calculate the correction factor which is then stored in the controller.

Method of calibrating power steering for uniform vehicle-to-vehicle

A unidirectional flow heart valve includes a passageway having an inlet side and an outlet side. A disk occluder is disposed within the passageway. The disk occluder has a closed position wherein the disk occluder occludes fluid flow through the passageway and an open position wherein the disk occluder permits fluid flow through the passageway. A fulcrum causes the disk occluder to pivot off center between the open and closed positions. An electromagnetic control mechanism forces the disk occluder to remain closed when energized until a predetermined net pressure is reached against the disk occluder. When the electromagnetic control mechanism is either selectively deenergized or the force on the occluder disk is greater than the holding force of the electromagnetic control mechanism, the disk occluder is released from the closed position to pivot on the fulcrum in response to fluid pressure.

Electromagnetically controlled heart valve

A hydraulic power steering system having conventional relatively rotatable spool and valve body elements for flow regulation, and an integral electromagnetic mechanism which effectively varies the centering force between the spool and valve body to adjust the level of steering assist provided for a given operator steering input. The electromagnetic mechanism includes a rotary magnetic circuit and a stationary magnetic circuit. The rotary magnetic circuit comprises a pair of radially displaced magnetic pole pieces which rotate with the input shaft and a permanent magnet ring element which is disposed between the pole pieces and which rotates with the pinion shaft. The stationary magnetic circuit includes an annular exciting coil disposed in proximity to the rotary magnetic circuit. The exciting coil is energized so as to vary the valve body/spool centering force, and hence the driver steering effort, with vehicle speed.

Electromagnetic control apparatus for varying the driver steering effort

A drive system for artificial hearts and left-ventricular assist devices. The drive system includes one or more implantable pumps driven by external electromagnets. Each pump preferably includes an armature made of a permanent magnet material having a magnetic energy product of at least about 30.times.10.sup.6 Gauss Oersted, and coercivity of at least about 10 kOe. In one embodiment of the invention, a pair of pumps are provided, with each being coupled to a respective ventricle of an artificial heart. In a second embodiment, a pair of pumps is connected to a single left-ventricular assist device. Each pump is mounted to the pelvic bone in the vicinity of the iliac crest. Fluid communication between the pump and its associated ventricle or left-ventricular assist device is provided by a length of flexible tubing extending subcutaneously up from the pump. Means are provided to enable periodic reversal of internal system leakage, and to enable replenishment of fluid lost from the system. Each electromagnet may be operated and powered by a plurality of rechargeable batteries and a PWM-type controller with a DC/DC converter. The electromagnets, batteries, and controller may be supported on a belt or girdle to provide a portable system, or alternatively may be mounted in a stationary support.

Drive system for artificial hearts and left-ventricular assist devices

A hydraulically assisted power steering system subject to variance in steering effort due to temperature change is compensated to give consistent response at all temperatures. A hydraulic control valve is coupled to an electromagnetic device which controls the steering effort as a function of energization current. The current is adjusted in accordance with temperature to compensate for temperature changes. A microcomputer controller stores empirical data relating to the effect of temperature on steering effort and calculates the current adjustment necessary for any measured system temperature. In one embodiment, the temperature is not measured directly but is derived from the deviation of energization current from the theoretical desired current, which deviation is a function of temperature. The effect of voltage variations is also compensated for.

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Troy, MI, United States of America

Andrzej M Pawlak