Lebow Products - fedtec.com.tw

1 Lebow ProductsFull Line Catalog15th Edition, 2006 LOAD, FORCE, REACTION torque ,ROTARY T ORQUE, WIRELESS TELEMETRY T ORQUE, INSTRUMENTATION1 INDEXORDER TOLL FREE (800) 848-6564 INDEXCORPORATE PROFILE ..2 FORCE MEASUREMENT ..3 TRANSDUCER DESIGN ..3 TRANSDUCER CONSIDERATIONS ..7 torque SENSORSA Discussion ..13 Selector ..22 Slip Ring ..24 Automobile Wheel ..28 Sprocket/Pulley ..29 Socket Wrench ..30 Rotary Transformer ..32 Non-Contact/Amplified Output ..36 High-Accuracy Rotary Transformer ..38 Digital Telemetry Dynamometer ..42 Reaction ..44 Steering Effort Sensor ..54 Thrust ..55 Slip Ring Shaft Assemblies ..56 LOAD CELLSA Discussion ..58 Selector ..60 General Purpose.

2 62 General Purpose: Stainless Steel ..65 General Purpose: Calibration Standard ..69 General Purpose: Precision ..71 Fatigue Resistant ..75 Compression ..83 Harsh Environment ..87 Automotive ..89X-Y Force Sensor ..91 Hollow ..92 Bolt Force Sensor ..94 Small Diameter ..96 Overload Protectors/Accessories ..98 Junction Boxes/Accessories ..99 Extraneous Load Coefficients ..110 INSTRUMENTSAC Carrier Strain Gage Conditioner Indicator ..100 Strain Gage Transducer Indicator ..102 Process Monitor and Controller ..103 Signal Conditioners ..104 Signal Gage Conditioner Module ..106On-Board Amplifier Module ..107 Portable Strain Gage Bridge Substitution Box.

3 108 Load Cell Tester ..109 GLOSSARY OF TERMS ..111 ORDERING INFORMATIONAND SERVICES ..114 TERMS AND CONDITIONS ..115 MODEL NUMBER INDEX ..116682 CORPORATE PROFILEVISIT OUR WEB SITE: DYNAMIC FORCEIN MEASUREMENTSOLUTIONSL ebow Products is a company whose beginning dates to 1955. Then it was Milton M. Lebow ,professor of Mechanical Engineering, who began the legacy by serving the automotive the years Lebow has undergone many changes, upgrading facilities and personnel, but theconstant within is Lebow s driving energy in the pursuit of measurement in its fifth decade, Lebow Products advances force and torque solutions with new productsto satisfy the ever-evolving demands of technology.

4 Lebow has expanded service capability, servingdiverse markets including government and military, aerospace, education and research, agriculture,industrial and s accumulated experience includes an 8,000-sensor design library and extensive line oftorque and load cells, when combined with a reputation for rapid solutions, presents an innovativeand reliable CALIBRATIONSTANDARDS SPOKENGLOBALLYG lobalization means greater need for standardization, and Lebow Products has certifications andaccreditations to satisfy worldwide applications. Lebow Products are tested and certified to meetpublished specifications using a calibration system conforming to A2LA certification ISO guide 25 and ANSI/NCSL Z540 American National Standards for calibration from theAmerican National Standards Institute.

5 This calibration system ensures that all force measurementcertification is traceable back to NIST. Lebow torque Sensors and Load Cells consist of specially designedstructures which perform in a predictable and repeatablemannerwhen a force is applied. This force is translated into a signal voltageby the resistance change of strain gages which are applied to thetransducer structure. The change in resistance indicates the degreeof deformation and, in turn, the load on the strain gages are connected in a 4 arm (Wheatstone Bridge)configuration, which acts as an adding and subtracting electricalnetwork and allows compensation for temperature effects as wellas cancellation of signals caused by extraneous fixed excitation voltage is applied between Aand Dof the force applied to the structure unbalances the Wheatstone Bridge,causing an output voltage to appear between Band C.

6 This voltageis proportional to the applied load. When the shaft of a torque sensoris rotating, means must be provided to transfer the signal voltagefrom the rotational element to a stationary surface. This can beaccomplished through the use of slip rings and rotary Products follow, where possible, the transducer wiringstandard of Western Regional Strain Gage committee as revised May1960. That code, for most Lebow load cells and torque sensors, is:AXIS DEFINITIONL ebow Products comply with the Axis and Sense Definitions ofNAS-938 (National Aerospace Standard-Machine Axis and Motion)nomenclature and recommendations of the Western Regional StrainGage committee. For wheel sensors, ASTM specification F-376-73has been axes are defined in terms of a Right Handed orthogonalcoordinate system as shown below :A + sign indicates force or torque direction which produces a + signalvoltage and generally defines a tensile force direction or clockwise(CW) principal axis of a transducer will normally be the Zaxis.

7 The Zaxis will also normally be an axis of radial symmetry or axis ofrotation. In the event there is no clearly defined axis, the followingpreference system will be used: Z, X, following illustrations show the recommended axis and sensenomenclature for various transducers supplied by Lebow :NOTE: Consider hub mounting surface as fixed, and wheel mountingsurface as loading surface to determine DESIGNTORQUE SENSORSSTRUCTUREST orque transducers with solid circular shafts and with gages at 45 tothe centerline have been in use for years. Though well known, thisstructure is not generally used by Lebow where precision is impor-tant. The solid shaft is not recommended for capacities below 500lb.

8 In. as the shaft has inadequate bending strength and too muchflexibility to provide good frequency circular shaft construction permits increased bending strength;for example, a hollow shaft designed for 1,000 lb. in. will have abending strength 50% higher than a solid bar with the sametorsional level. However, the hollow circular shaft suffers some of theFORCE MEASUREMENTTRANSDUCTIONBACDR1R2R4R3eoute in+ + + +Fz+Fy+FxMxMyMzIn-lineTorque Table Load CellWheel Sensor+ Fz+ Fx+ Fy+ Mz+ Fz+ Fx+ Fy+ Mz+ Fz+ FyMz+ FxC VehicleLMx+ Fx+ FzMzTractive or Tangential ForceNormal Radial ForceMy+ FyLateralMxOver Turning MomentMzRolling Resistance MomentMyAligning TorqueC of RotationL3 FORCE MEASUREMENT/TRANSDUCER DESIGNORDER TOLL FREE (800) 848-6564684 TRANSDUCER DESIGNVISIT OUR WEB SITE: drawbacks as the solid circular shaft and, therefore, is not ingeneral use at Lebow .

9 Another structure of interest is the cruciform which will produce highstress or strain values at low values of torque . The cruciform hasgood bending strength but is difficult to predict because of the filleteffect on torsional stress and Lebow , the cruciform was modified by drilling a hole throughits center section creating the hollow cruciformstructure extensivelyused by Lebow for low capacity torque transducers. The hollowcruciform eliminates the fillet effect of the cruciform and producesthe 4 bar torsion frame. The bars in this case are subjected to a combination of torsion and bending when twisted. The stressesproduced by a torque input can be accurately predicted, thustorsional sensitivity with good strength to external bending square section used by Lebow for high-capacity transducershas several advantages over its circular counterpart for torquemeasurements.

10 One of these is the ease with which gages can beplaced on the shaft. Another is the increased bending strengthwhen compared to a round following are drawings showing, in general, structures in use astorque SHEAR STRESSA ssume there is a shaft which consists of an infinite numberof thin slices. Each slice is rigid and joined to its adjacent slice by anelastic fibre AB. As torque is applied, each slice will attempt to slippast its adjacent slice. The elastic fibre joining them becomesdeformed enough to create a resisting torque Tr, which balances theapplied torque T. This deformation is transmitted over the length Lof the shaft. The elastic fibre is thus twisted into a helix ACthroughan angle.