Abstract:
A system for mounting an engine to a frame in a manner to permit measurement of its torque by a transducer which is isolated from loads induced by installation misalignments, frame deflections and acceleration induced forces. One embodiment of the system is compatible with widely used automotive resilient elastic engine mounts without engine or frame modifications.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to an improved system for mounting an engine to a frame in a manner to measure torque while accommodating frame misalignment and flexure due to working loads. More particularly, it relates to such a system which is insensitive to most movement-induced acceleration forces. In this context, the engine is a rigid assembly including the motor and/or transmission and/or differential gear box that generates the driving torque so as, for example, to move a vehicle.  
       BACKGROUND OF THE INVENTION  
       [0002]     It is common to mount a reciprocating engine with resilient mounting assemblies to isolate the frame from engine vibration. Another not often mentioned benefit of resilient mounting is the accommodation of manufacturing tolerances when mating two relatively rigid assemblies such as an engine and automobile frame. Furthermore, resilient mounting accommodates flexure of the frame caused by the engine working torque and vehicle dynamics. Vehicle dynamics includes stresses and strains caused by movement over uneven road surfaces, acceleration forces to increase velocity, braking forces to slow the vehicle, and forces generated when going around corners.  
         [0003]     E. B. Etchells in U.S. Pat. No. 2,953,336 teaches the common three point resilient mounting of an engine transmission assembly into an automobile frame. This patent includes discussion of the nodal positioning of the engine mounts to minimize vibrations while controlling engine torque and accommodating road induced vibrations. This system incorporates a single resilient mounting at the rear of the engine assembly and a pair of transversely spaced resilient mounts at the front of the engine. The nodal point is a place of minimum vibration. Positioning of the front engine mounts as close as is practical to the percussion points of the engine assembly reduces road induced loads on the rear mount and allows the rear mount to be soft and compliant.  
         [0004]     The mounting system of Etchells is widely utilized and there exist improvement patents such as Fehlberg, U.S. Pat. No. 3,731,896, that demonstrates continued applicability. Fehlberg teaches the need for mechanical limits to retain the engine transmission assembly to the frame when the strength limits of resilient elastic elements are exceeded.  
         [0005]     R. E. Krueger, in U.S. Pat. No. 3,146,986, discusses the need for torque measurement in automobiles, boats and small airplanes. The embodiment shown includes hydraulic sensing means for measuring torque, and is mounted parallel to a resilient elastic engine mount in an automobile.  
         [0006]     The engine in an automobile is heavy, generates significant torque and must be firmly attached to the frame to resist road dynamics. These considerations require that the resilient elastic mount be of sufficient stiffness to prohibit excessive engine movements. Mounting a sensor in parallel to the resilient mount induces measurement error caused by frame deflection, thermal expansion or contraction of the elastic element and temperature induced elastic stiffness changes. The zero adjusting unit provided in the Krueger apparatus can only be effective if all conditions are static after adjustment and during the time measurements are taken. Repeatability and accuracy are affected when measurements are taken in parallel to the engine retention components of the engine mount.  
         [0007]     G. L. Malchow, in U.S. Pat. No. 3,903,738, discloses a torque-sensing device that replaces one of the engine mounts in an engine installation as depicted in Etchells. Malchow removes one of the resilient mounts and replaces it with a strain gage-equipped pivotal yoke assembly. In this configuration, the engine is restrained from rotational movement by a force couple applied on one side by the elastic engine mount and on the other side by the strain gage-equipped pivotal yoke assembly. The configuration of the yoke assembly of the strain gage equipped engine mount makes determination of the length of moment arm and the magnitude of restraining force a complex geometrical problem. Malchow avoids these issues by calibrating the apparatus “where weights were suspended from a torque arm which was connected to the transmission out put shaft.” 
         [0008]     The stability of the complex geometry that determines torque arm length affects calibration and repeatability of the torque measurement. The location of the restraining force through the resilient elastic mount is subject to movement-induced creep or sag. Resilient elastic supports undergo creep and sag over time due to thermal and long term loading. Also, frame flexure due to road induced loads can cause lateral displacements between the frame mounting points of the front engine mounts, changing the inclination of the yoke, and significantly altering the calibration of torque measurement.  
         [0009]     The yoke assembly does not restrain the engine from movement due to acceleration loads caused by braking or acceleration. These loads are restrained by the resilient engine mount on the side opposite the yoke assembly and the compliant mount on the transmission. Aside from potential safety issues, the resilient engine mounts will allow movement that may result in damage to the yoke assembly and/or inaccurate torque measurement.  
         [0010]     A three point mounting system, with a sensor at one of the mounting points, has an effective pivotal axis through the other two mounting points. The center of gravity of the engine mass is significantly displaced both vertically and laterally from the pivotal axis of the engine, thereby departing from the teachings of Etchells regarding the importance of nodal positioning of the mounts.  
         [0011]     Even when vehicle velocity and engine torque are constant, the lateral or sideways displacement of the center of gravity with respect to the pivotal axis allows vertical accelerations of the vehicle, such as those caused by movement while traveling over bumps in the road, to create forces that result in false torque measurements.  
         [0012]     Similarly, even when vehicle velocity and engine torque are constant, vertical displacement of the center of gravity from the pivotal axis allows cornering accelerations caused by the vehicle going around turns to create forces that result in false torque measurements.  
         [0013]     Also, even if engine torque is constant, combined vertical and lateral displacement of the center of gravity from the pivotal axis along with an inclined pivotal axis allows longitudinal accelerations resulting in vehicle velocity changes to create forces that result in false torque measurements.  
       SUMMARY OF THE INVENTION  
       [0014]     Accordingly, it is a principal object of the present invention to provide an improved system for mounting an engine to a frame in a manner to measure engine torque while isolating the measurement from loads induced by installation misalignments and frame deflections as well as acceleration induced forces.  
         [0015]     Another object is to provide a mounting system which is compatible with previously installed resilient engine mounts, without engine or frame modifications.  
         [0016]     A further object is to provide such a system wherein torque is sensed by a transducer which has the ability to sense torque in only one or in both directions.  
         [0017]     These and other objects are accomplished in accordance with illustrated embodiments of the invention wherein the system includes: first and second bearings, each connectable to the frame and engine to form a pivotal axis about which the engine is free to rotate relative to the frame, wherein, in accordance with the objects of the invention, the pivotal axis passes near the center of gravity of the engine and is aligned other than orthogonally to the axis of the engine output shaft. More particularly, the system also includes a load sensing transducer which includes parts connectable to the frame and the engine for resisting and measuring rotational forces between the engine and the frame about the pivotal axis.  
         [0018]     In one embodiment of the invention, the first and second bearings are connectable to portions of the frame and engine and are in axial alignment to receive shaft portions on the pivotal axis displaced from one another about the engine.  
         [0019]     In other embodiments, one of the bearings comprises bearing segments, with each segment having a first part guidably moveable with respect to a second part, forming an instantaneous pivotal center on the pivotal axis. The other bearing preferably comprises a compliant engine mount. For reasons which will be apparent from the description to follow, the pivotal axis extends through or near the center of gravity of the engine. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     These and other objects of the present invention are accomplished as described in the following description and drawings in which:  
         [0021]      FIG. 1  is a side view of an engine mounted on a frame in accordance with one embodiment of the invention.  
         [0022]      FIG. 1 ( a ) is a top view of the engine and frame shown in  FIG. 1 , as seen from  1 ( a )- 1 ( a ) of  FIG. 1 .  
         [0023]      FIG. 1 ( b ) is a rear view of the engine shown in  FIG. 1 , as seen from  1 ( b )- 1 ( b ) of  FIG. 1 .  
         [0024]      FIG. 1 ( c ) is a sectional view of the engine shown in  FIG. 1 , as seen along  1 ( c )- 1 ( c ) of  FIG. 1 .  
         [0025]      FIG. 1 ( d ) is an enlarged detail view of a portion of  FIG. 1 , as shown thereupon.  
         [0026]      FIG. 2  is a side view of an engine mounted in accordance with another embodiment of the invention.  
         [0027]      FIG. 2 ( a ) is a rear view of the engine shown in  FIG. 2 , as seen from  2 ( a )- 2 ( a ) of  FIG. 2 .  
         [0028]      FIG. 2 ( b ) is a cross-sectional view of the engine and frame shown in  FIG. 2 , taken along the line  2 ( b )- 2 ( b ) of  FIG. 2 , and broken away to show the rear bearing.  
         [0029]      FIG. 3  is an enlarged rear view of a bearing segment shown in  FIG. 2 ( a ).  
         [0030]      FIG. 3 ( a ) is a view of the bearing segment shown in  FIG. 3 , as seen along the line  3 ( a )- 3 ( a ) of  FIG. 3 .  
         [0031]      FIG. 3 ( b ) is a cross-sectional view of the bearing segment shown in  FIG. 3 , as seen along the line  3 ( b )- 3 ( b ) of  FIG. 3 .  
         [0032]      FIG. 3 ( c ) is a cross-sectional view of the bearing segment shown in  FIG. 3 , as seen along the line  3 ( c )- 3 ( c ) of  FIG. 3 .  
         [0033]      FIG. 3 ( d ) is a cross-sectional view of the bearing segment shown in  FIG. 3 ( a ), as seen along the line  3 ( d )- 3 ( d ) of  FIG. 3 ( a ).  
         [0034]      FIG. 3 ( e ) is an exploded view showing the parts comprising the bearing segment shown in  FIG. 3 .  
         [0035]      FIG. 4  is an enlarged rear view of a bearing segment shown in  FIG. 2 ( a ).  
         [0036]      FIG. 4 ( a ) is a view of the bearing segment shown in  FIG. 4 , as seen along the line  4 ( a )- 4 ( a ) of  FIG. 4 .  
         [0037]      FIG. 4 ( b ) is a cross-sectional view of the bearing segment shown in  FIG. 4 , as seen along the line  4 ( b )- 4 ( b ) of  FIG. 4 .  
         [0038]      FIG. 4 ( c ) is a cross-sectional view of the bearing segment shown in  FIG. 4 , as seen along the line  4 ( c )- 4 ( c ) of  FIG. 4 .  
         [0039]      FIG. 4 ( d ) is a cross-sectional view of the bearing segment shown in  FIG. 4 ( a ), as seen along the line  4 ( d )- 4 ( d ) of  FIG. 4 ( a ).  
         [0040]      FIG. 5  is a side view of an engine mounted on a frame in accordance with a further embodiment of the invention.  
         [0041]      FIG. 5 ( a ) is a rear view of the engine and frame shown in  FIG. 5 .  
         [0042]      FIG. 5 ( b ) is an enlarged cross-sectional view of the engine and frame shown in  FIG. 5 , as seen along the line  5 ( b )- 5 ( b ) of  FIG. 5  and broken away to show the rear bearing.  
         [0043]      FIG. 6  is an expanded rear view of a bearing segment shown in  FIG. 5 ( a ).  
         [0044]      FIG. 6 ( a ) is a cross-sectional view of the bearing segment shown in  FIG. 6 , as seen along the line  6 ( a )- 6 ( a ) of  FIG. 6 .  
         [0045]      FIG. 6 ( b ) is a cross-sectional view of the bearing segment shown in  FIG. 6 , as seen along the line  6 ( b )- 6 ( b ) of  FIG. 6 .  
         [0046]      FIG. 6 ( c ) is a cross-sectional view of the bearing segment shown in  FIG. 6 , as seen along the line  6 ( c )- 6 ( c ) of  FIG. 6 .  
         [0047]      FIG. 6 ( d ) is a cross-sectional view of the bearing segment shown in  FIG. 6 ( a ), as seen along the line  6 ( d )- 6 ( d ) of  FIG. 6 ( a ).  
         [0048]      FIG. 7  is a side elevation view of an engine mounted in accordance with a further embodiment of the invention.  
         [0049]      FIG. 7 ( a ) is an enlarged rear view of the engine shown in  FIG. 7 , as seen along  7 ( a )- 7 ( a ) of  FIG. 7 .  
         [0050]      FIG. 7 ( b ) is a cross-sectional view of the engine shown in  FIG. 7 , as seen along the line  7 ( b )- 7 ( b ) of  FIG. 7 , and broken away in part to show the rear bearing.  
         [0051]      FIG. 8  is an enlarged rear view of a bearing segment shown in  FIG. 7 ( a ).  
         [0052]      FIG. 8 ( a ) is a cross-sectional view of the bearing segment shown in  FIG. 8 , as seen along the line  8 ( a )- 8 ( a ) of  FIG. 8 .  
         [0053]      FIG. 8 ( b ) is a cross-sectional view of the bearing segment shown in  FIG. 8 , as seen along the line  8 ( b )- 8 ( b ) of  FIG. 8 .  
         [0054]      FIG. 8 ( c ) is a cross-sectional view of the bearing segment shown in  FIG. 8 , as seen along the line  8 ( c )- 8 ( c ) of  FIG. 8 .  
         [0055]      FIG. 8 ( d ) is a cross-sectional view of the bearing segment shown in  FIG. 8 ( a ), as seen along the line  8 ( d )- 8 ( d ) of  FIG. 8 ( a ).  
         [0056]      FIG. 8 ( e ) is an exploded view showing the parts comprising the bearing segment shown in  FIG. 8 .  
         [0057]      FIG. 9  is a rear view of a bearing segment shown in  FIG. 7 ( a )  
         [0058]      FIG. 9 ( a ) is a cross-sectional view of the bearing segment shown in  FIG. 9 , as seen along the line  9 ( a )- 9 ( a ) of  FIG. 9 .  
         [0059]      FIG. 9 ( b ) is a cross-sectional view of the bearing segment shown in  FIG. 9 , as seen along the line  9 ( b )- 9 ( b ) of  FIG. 9 .  
         [0060]      FIG. 9 ( c ) is a cross-sectional view of the bearing segment shown in  FIG. 9 , as seen along the line  9 ( c )- 9 ( c ) of  FIG. 9 .  
         [0061]      FIG. 9 ( d ) is a cross-sectional view of the bearing segment shown in  FIG. 9 ( a ), as seen along the line  9 ( d )- 9 ( d ) of  FIG. 9 ( a ). 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0062]     A first embodiment of the invention is shown in  FIGS. 1 and 1 ( a ). An engine  1  generally consists of internal combustion motor  2  and transmission assembly  3  as might be installed in any common automobile. The engine  1  is secured to the automobile frame  8  (partially shown) by bearings  4  and  5 , which receive rigid extensions  6  and  6   a  of the engine  1 , and which are pillow block bearings as are commonly known to the art, as, for example, Model No. G1105KRAB, manufactured by Torrington Company, a division of Ingersoll-Rand. Bolts  7  fasten the bearings  4  and  5  to the automobile frame  8 . Bearings  4  and  5  are fitted to rigid extensions  6  and  6 ( a ) of the engine. Stop collar  10  is located on shaft extension  6 ( a ) to prevent fore and aft movement of the engine  1  in relation to the frame  8 .  
         [0063]     Bearings  4  and  5  form a pivotal axis  9  about which the mass of the engine may rotate. As will be discussed more fully below, pivotal axis  9  passes through or near the center of gravity CG of the engine  1 . A lug  11  projects outwardly from the engine  1 , and a load-sensing transducer  12  is connected between lug  11  and the automobile frame  8 , as shown, for example, in U.S. Pat. No. 3,903,738, for measuring tension generated by the engine and transmitted to its output shaft  13 .  
         [0064]     Thus, it can be seen that the engine  1  is securely attached to the frame in that bearings  4  and  5 , and stop collar  10  provide vertical, lateral and longitudinal support of the engine mass and define pivotal axis  9 . Torque generated by the engine  1  and transmitted to the output shaft  13 , creates a reaction torque that is restrained by the load-sensing transducer  12  and lug  11 .  
         [0065]     Load-sensing transducer  12  may be any suitable type known to the art, such as Model DSM Series transducers manufactured by Transducer Techniques of Rio Nedo, Temecula, Ca. The transducer  12  may be positioned in any convenient location radially displaced from the pivotal axis of the engine  1 , as long as its axis of sensitivity, x on  FIG. 1 , is so oriented as to measure the torque. Since the transducer  12  does not form a part of, and is in fact independent of, the means by which the engine is retained to the frame, it may be easily repaired or replaced.  
         [0066]     Thus, for example, the angle beta, which is the angle between the axis of rotation of the engine output shaft  13  and the pivotal axis  9 , projected onto and measured on a mutually parallel plane to both the pivotal axis  9  and axis of rotation of the output shaft  13 , can have any value other than ninety degrees. If angle beta had a value of ninety degrees, the bearings  4  and  5  would resist the reaction torque created as a result of engine torque transmitted by the output shaft  13  and the load-sensing transducer  12  would not sense a load in proportion to the engine torque.  
         [0067]     The axis of sensitivity x is defined as the axis of the resultant force vector acting on the point of contact on the engine measured by load sensing transducer  12 , and cannot share any plane with the pivotal axis. If x did share a plane with the pivotal axis, the load-sensing transducer  12  would not sense a load in proportion to the engine torque.  
         [0068]     As mentioned previously, the center of gravity CG of the engine  1  is on or near pivotal axis  9 . When the center of gravity CG is positioned exactly on pivotal axis  9 , all engine retention loads except torque are provided by the bearings  4  and  5 , and stop collar  10 , so that the load on the load-sensing transducer  12  is purely a function of engine torque.  
         [0069]     If the center of gravity CG is displaced laterally of the pivotal axis  9 , a static torque will be measured by the load-sensing transducer  12  proportional to the weight of the engine  1  and the lateral displacement of the center of gravity CG from pivotal axis  9 . This static load could be removed by zero offset calibration of the load-sensing transducer  12 . However, if the automobile is moving and passes over bumps in the road or is traveling uphill or downhill, acceleration-induced forces will be generated. These forces are dynamic, not easily cancelled and thus would represent errors in engine torque measurement.  
         [0070]     As shown in  FIG. 1 , pivotal axis  9  extends at an angle to the horizontal. This angle is a result of typical automobile configuration of low output shafts on the transmission and heavy engines with elevated centers of gravity. This angle is common even in front wheel drive automobiles with transversely mounted engines. The lateral displacement of the CG as discussed above would also result in acceleration induced loads on the load-sensing transducer  12  during braking and speed increases. These forces also are dynamic, not easily cancelled, and thus would also represent errors in engine torque measurement. Similarly, if the CG was vertically displaced from axis  9 , the load-sensing transducer  12  would experience dynamic loads induced by cornering acceleration.  
         [0071]     Although the engine torque measurement will be most accurate if pivotal axis  9  passes directly through the CG as shown in  FIGS. 1 and 1 ( a ), the present invention contemplates that pivotal axis  9  passes sufficiently near the CG as to accomplish the accuracy required in torque measurement and the acceleration envelope in which the vehicle will operate while taking measurements. Thus, a family sedan driven on smooth freeways rarely experiences more than one tenth of gravity acceleration and if the torque information is used to determine transmission shift points, perhaps 10% measurement accuracy is adequate. However, a race car running on a rough dirt oval track will be subjected to one times the acceleration of gravity and will probably require 1% measurement accuracy to better tune the engine.  
         [0072]     By way of example: 
 
 F=W×A/ 32.2  fps   2  
 
 Where: 
    F=force in pounds     A=acceleration in feet per second squared     W=engine weight in pounds 
 
 Lm=T  %× Tm ×12/( F× 100) 
 
 Where: 
    Lm=length of mislocation in inches     T %=percentage of torque measurement accuracy     Tm=torque output of the motor in pound feet     F=force in pounds    
 
         [0080]     For the purposes of these examples, assume that the engine of both the family sedan and the race car is a 350 cubic inch motor and transmission weighing 750 pounds. The motor has a maximum torque output of 350 pound feet. In the case of the family sedan, F=750 lb×3.22 fps 2 /32.2 fps 2 =75 lb. For a desired torque measurement accuracy of 10%, Lm=10%×350 lb-ft×12/(75 lb×100)=5.6 inches. Therefore, in order to achieve a 10% torque measurement accuracy in the family sedan which experiences a one tenth of one gravity cornering acceleration, pivotal axis  9  must pass within 5.6 inches of the engine CG.  
         [0081]     In the case of the race car, F=750 lb×32.2 fps 2 /32.2 fps 2 =750 lb. For a desired torque measurement accuracy of 1%, Lm=1%×350 lb-ft×12/(750 lb×100)=0.056 inches. Therefore, in order to achieve a 1% torque measurement accuracy in the race car which experiences one gravity cornering acceleration, pivotal axis  9  must pass within 0.056 inches of the engine CG.  
         [0082]     The examples discussed above are, of course, intended only as examples, and should not be understood as limiting the invention, and there are many different vehicles operated under different conditions in which the invention disclosed herein could be adapted with minor variations by a person of ordinary skill in the art. To determine an acceptable location of the pivotal axis relative to the engine CG, the specific application should be considered together with the calculations. For instance, a drag race car only races in straight lines on smooth surfaces and would not require accurate location of the pivotal axis relative to the CG to eliminate cornering acceleration forces.  
         [0083]     Quite often, the pivotal axis is near enough to the CG when the CG is within the volume defined by the conical shaped space formed by the center of one bearing and the circle defined by the surfaces of relative motion of the other bearing.  
         [0084]     In the following alternate embodiment of the invention, the engine restraints are compatible with a three point mounting system similar to that disclosed in Etchells, U.S. Pat. No. 2,953,336. Thus, as will be discussed in greater detail below, bearing  5  of  FIG. 1  becomes a compliant rubber mount, while bearing  4  of  FIG. 1  becomes segmented and compatible with the standard pair of forward engine mounts well known in the art. Together, the two bearings, one being segmented, constrain the engine from movement with respect to the vehicle frame, except for the small amount of rotation about a pivotal axis which enables torque measurement.  
         [0085]     Thus, as shown in FIGS.  2 ,  2 ( a ), and  2 ( b ), another embodiment of the invention comprises an engine  14  including internal combustion motor  15  and transmission assembly  16  as might be installed in any common automobile. As will be explained, the engine mounting system according to this embodiment of the invention provides the same separation of engine retention forces from torque force measurement as provided by the previously described embodiment shown in  FIGS. 1 and 1 ( a ), but has the further advantage of being compatible with the three point engine mounting systems widely used by many automobile manufacturers.  
         [0086]     As in the first embodiment, pivotal axis  17  passes through or at least near the center of gravity CG of the engine  14 . Near the transmission output shaft  18  is a compliant rubber engine mount  19  as in U.S. Pat. No. 2,953,336, which acts as a bearing in that it positions one end of the pivotal axis  17 , in much the same way as the pillow block forming bearing  5  defined one end of the pivotal axis  9  in the previously-discussed embodiment. As will be explained below, bearing segments  21  and  22 , securely attach engine  14  to the vehicle frame  23 , as best shown in  FIG. 2 ( b ).  
         [0087]     Referring to FIGS.  3 ,  3 ( a ), and  3 ( e ), bearing segment  21  comprises an engine component  21 ( a ) attached to the engine  14  by bolts  26 . Bearing segment  21  further comprises a frame component  21 ( b ) attached to the automobile frame  23  by bolt  24 . Engine component  21 ( a ) has an elongated upper track  28  formed with inner track surface  31  and outer track surface  30 . Inner track surface  31  and outer track surface  30  are parallel to each other. Pin  28 ( a ), passing through the upper track  28 , is rotationally mounted within the frame component  21 ( b ) by means of roller bearings  28 ( b ) and  28 ( c ). Similarly, engine component  21 ( a ) has an elongated lower track  29  formed with inner track surface  31 ( a ) and outer track surface  30 ( a ). Inner track surface  31 ( a ) and outer track surface  30 ( a ) are parallel to each other. Pin  29 ( a ), passing through the lower track  29 , is rotationally mounted within the frame component  21 ( b ) with roller bearings  29 ( b ) and  29 ( c ), the pin and track thus forming surfaces of relative rotation, as above described.  
         [0088]     Pin  28 ( a ) is retained within the frame component  21 ( b ) by disk  28 ( d ), disk  28 ( e ), bearing  28 ( f ), bearing  28 ( g ), screw  40 , screw  41 , screw  42 , and screw  43 . Similarly, pin  29 ( a ) is retained within the frame component  21 ( b ) by disk  29 ( d ), disk  29 ( e ), bearing  29 ( f ), bearing  29 ( g ), screw  40 ( a ), screw  41 ( a ), screw  42 ( a ), and screw  43 ( a ).  
         [0089]     Load sensor  48  is retained within bore  47  formed in the frame component  21 ( b ) by snap ring  49  and snap ring  50 . Pin  51  is press fitted within load sensor  48  and closely fitted within slot  52  of the frame component  21 ( b ) to assure angular alignment of the sensor  48  with the frame component  21 ( b ). The load sensor  48  has a reduced intermediate diameter  53  with a bump  54 . The load sensor  48  is equipped with strain gages  55  connected by wire  56  for remote electrical measurement of transducer signals resulting from loads applied to the bump  54 . The stop screw  57  threadedly engages the frame component  21 ( b ) and is locked in place by nut  58  with a small gap  59  between the stop screw  57  and the engine component  21 ( a ). In any case, the load sensor may be replaced for repair without disturbing retention of the engine to the frame.  
         [0090]     Shaft  60  is closely fitted to engine component  21 ( a ) within bore  61  on one end and supported on the other end by ring  62  which is closely fitted in bore  63  of the engine component  21 ( a ). The plate  64  is threadedly secured by screw  65  and screw  66  to the engine component  21 ( a ) and retains the shaft  60  within engine component  21 ( a ). The tire  67 , which rides radially on needle bearings  68  and rides axially on thrust bearing  69  and thrust bearing  70 , is fixed longitudinally and free to rotate within engine component  21 ( a ) about shaft  60 . The bore  63  and the outer diameter of the tire  67  exceed the width of the engine component  21 ( a ) in the middle section  71  in vicinity of the tire  67 . Thus, the tire  67  is exposed for rolling engagement with the frame component  21 ( b ) on surface  72  and surface  73  and will prevent the engine component  21 ( a ) from rubbing on frame component  21 ( b ) when loads are applied along the pivotal axis  17 .  
         [0091]     Referring to FIGS.  3 ( d ),  3 ( e ), and  2 ( b ), it can be seen that the engine component  21 ( a ) is free to roll on pin  28 ( a ) and pin  29 ( a ) along the track surface  31  and track surface  31 ( a ) about a pivotal point  20  located on the pivotal axis  17 . Pivotal point  20  is located at the intersection of lines of projection  74  and  75 . Line of projection  74  extends from the center of pin  28 ( a ) through the contact point of pin  28 ( a ) on track surface  31 , in a plane perpendicular to the pivotal axis  17 . Similarly, line of projection  75  extends from the center of the pin  29 ( a ) through the contact point of pin  29 ( a ) on track surface  31 ( a ), in a plane perpendicular to the pivotal axis  17 .  
         [0092]     The range of rotational motion of the engine  14  is limited to the small gap  59  between engine component  21 ( a ) and stop screw  57 . Arcuate motion of the engine component  21 ( a ) is limited in one direction by the load sensor  48 , mounted in the bore  47  of the frame component  21 ( b ) which is attached to the frame  23  with bolt  24 . The force of the engine component  21 ( a ), as a result of torque reaction to engine  14  torque delivered to the output shaft  18 , bearing on the bump  54  on the load sensor  48 , deflects the load sensor  48  causing a detectable change in output of the load sensor  48  proportional to engine  14  torque. Arcuate motion, caused by opposite engine torque from that described above, of the engine component  21 ( a ) is limited by the stop screw  57  threadedly engaged in the frame component  21 ( b ) which is attached to the frame  23  with bolt  24 . This motion will not load the load sensor  48  or create a detectable change in output. Thus, it will be understood that the transducer includes parts connected by engine and frame components  21 ( a ) and  21 ( b ) to the engine and frame, respectively.  
         [0093]      FIG. 4  is an enlarged view of the bearing segment  22  shown in  FIG. 2 ( a ) with section lines to define the cross-sectional view of FIGS.  4 ( a ),  4 ( b ), and  4 ( c ).  FIG. 4 ( d ) is a cross-sectional view of bearing segment  22  taken along the section lines defined in  FIG. 4 ( a ). Referring to  FIGS. 4 and 2 ( a ), bearing segment  22  comprises a engine component  22 ( a ) attached to the engine  14  by bolts  27 . Bearing segment  22  further comprises a frame component  22 ( b ) attached to the automobile frame  23  by bolt  25 .  
         [0094]     Referring to FIGS.  4 ( b ),  4 ( d ), and  2 ( b ), engine component  22 ( a ) has an elongated upper track  34  formed with inner track surface  36  and outer track surface  37 . Inner track surface  36  and outer track surface  37  are parallel to each other. Passing through the upper track  34  is pin  34 ( a ) rotationally mounted within the frame component  22 ( b ) by  7  means of roller bearings  34 ( b ) and  34 ( c ). Similarly, the engine component  22 ( a ) has an elongated lower track  35  formed with inner track surface  36 ( a ) and outer track surface  37 ( a ). Inner track surface  36 ( a ) and outer track surface  37 ( a ) are parallel to each other. Passing through the lower track  35  is pin  35 ( a ) rotationally mounted within the frame component  22 ( b ) with roller bearings  35 ( b ) and  35 ( c ).  
         [0095]     Referring to  FIGS. 4 and 4 ( b ), pin  34 ( a ) is retained within the frame component  22 ( b ) by disk  34 ( d ), disk  34 ( e ), bearing  34 ( f ), bearing  34 ( g ), screw  76 , screw  77 , screw  78 , and screw  79 . Similarly, pin  35 ( a ) is retained within the frame component  22 ( b ) by disk  35 ( d ), disk  35 ( e ), bearing  35 ( f ), bearing  35 ( g ), screw  80 , screw  81 , screw  82  and screw  83 .  
         [0096]     Referring to  FIGS. 2, 4 ,  4 ( b ), and  4 ( d ), shaft  84  is closely fitted to engine component  22 ( a ) within bore  85  on one end and supported on the other end by ring  86  which is closely fitted in bore  87  of the engine component  22 ( a ). The plate  88  is threadedly secured by screw  89  and screw  90  to the engine component  22 ( a ) and retains the shaft  84  within engine component  22 ( a ). The tire  91  riding radially on needle bearings  92  and riding axially on thrust bearing  93  and thrust bearing  94  is fixed longitudinally and free to rotate within engine segment  22 ( a ) about shaft  84 . The bore  87  and the outer diameter of the tire  91  exceed the width of the engine component  22 ( a ) in the middle section  97  in vicinity of the tire  91 . Thus, the tire  91  is exposed for rolling engagement with the frame component  22 ( b ) on surface  93 ( a ) and surface  94 ( a ) and will prevent the engine component  22 ( a ) from rubbing on frame component  22 ( b ) when loads are applied along the pivotal axis  17 .  
         [0097]     Referring to FIGS.  4 ( d ) and  2 ( b ), and from the above discussion, it is apparent that the engine component  22 ( a ) is free to roll on pin  34 ( a ) and pin  35 ( a ) along the track surfaces  36  and  36 ( a ) about a pivotal point  20  located on pivotal axis  17 . Pivotal point  20  is located at the intersection of lines of projection  95  and  96 . Line of projection  95  extends from the center of pin  34 ( a ) through the contact point of pin  34 ( a ) on track surface  36 , in a plane perpendicular to the pivotal axis  17 . Similarly, line of projection  96  extends from the center of the pin  35 ( a ) through the contact point of pin  35 ( a ) on track surface  36 ( a ), in a plane perpendicular to the pivotal axis  17 . The relative upward and downward motion between the engine component  22 ( a ) and the frame component  22 ( b ) is limited within the bearing segment  21  as discussed above.  
         [0098]     More particularly, as shown in  FIG. 2 ( b ), bearing segments  21  and  22  are located on the circle indicated at “C”, and allow the engine  14  to undergo a limited range of rotational movement about the pivotal axis  17 . Thus, as previously described, it can be seen that the CG lies within the cone containing the center of the surfaces of relative motion of the compliant engine mount  19  and the circle “C”. Viewed in this way, it is seen that the bearing segments  21  and  22  effectively replace bearing  4  of the first embodiment shown in  FIG. 1 .  
         [0099]     FIGS.  5 ,  5 ( a ), and  5 ( b ) disclose a further embodiment of the invention. An engine  175  comprises an internal combustion motor  176  and transmission  177  assembly as might be installed in any common automobile. The engine mounting system according to this embodiment of the invention provides the same separation of engine retention forces from torque force measurement as provided by the previously described embodiments, and is compatible with the three point engine mounting systems widely used by many automobile manufacturers.  
         [0100]      FIG. 5  is a side view of the engine  175  having a pivotal axis  178  passing through or near the center of gravity CG of the engine  175 . Near the transmission output shaft  179  is a compliant rubber mount  180  which positions one end of the pivotal axis  178 , in much the same way as bearing  5  defined one end of the pivotal axis  9  in the first embodiment discussed herein. Bearing segments  100  and  181 , as will be explained below, securely attach engine  175  to the vehicle frame  123 , shown in FIGS.  5 ( a ) and  5 ( b ), and define the location of pivotal point  182  on the pivotal axis  178  as shown in  FIG. 5 ( b ).  
         [0101]     Bearing segment  181  is constructed in the same manner as bearing segment  22  described in detail above and shown in FIGS.  4 ,  4 ( a ),  4 ( b ),  4 ( c ), and  4 ( d ).  
         [0102]     Bearing segment  100  shown in FIGS.  6 ,  6 ( a ),  6 ( b ),  6 ( c ), and  6 ( d ), is an enlarged view of bearing segment  100  shown in  FIG. 5 ,  FIG. 5 ( a ) and  FIG. 5 ( b ). Bearing segment  100  is capable of measuring engine torque for acceleration and torque of engine braking.  
         [0103]     Referring to  FIG. 6 , bearing segment  100  has a engine component  100 ( a ) attached to the engine  175  by bolts  126  and a frame component  100 ( b ) attached to the frame  123  by bolt  124 . As can be seen in FIGS.  6 ( b ) and  6 ( d ), the motor component  100 ( a ) has an elongated upper track  128  formed with inner track surface  131  and outer track surface  130 . Inner track surface  131  and outer track surface  130  are parallel to each other. Passing through the upper track  128  is pin  128 ( a ) rotationally mounted within the frame component  100 ( b ) with roller bearings  128 ( b ) and  128 ( c ). Similarly, the engine component  100 ( a ) has an elongated lower track  129  formed with inner track surface  131 ( a ) and outer track surface  130 ( a ). Inner track surface  131 ( a ) and outer track surface  130 ( a ) are parallel to each other. Passing through the lower track  129  is pin  129 ( a ) rotationally mounted within the frame component  100 ( b ) with roller bearings  129 ( b ) and  129 ( c ).  
         [0104]     Referring to  FIGS. 6 and 6 ( b ), pin  128 ( a ) is retained within the frame component  100 ( b ) by disk  128 ( d ), disk  128 ( e ), bearing  128 ( f ), bearing  128 ( g ), screw  140 , screw  141 , screw  142  and screw  143 . Similarly, pin  129 ( a ) is retained within the frame component  100 ( b ) by disk  129 ( d ), disk  129 ( e ), bearing  129 ( f ), bearing  129 ( g ), screw  140 ( a ), screw  141 ( a ), screw  142 ( a ) and screw  143 ( a ).  
         [0105]     Referring to FIGS.  6 ,  6 ( a ),  6 ( b ),  6 ( c ), and  6 ( d ), load sensor  148  is retained within bore  147  formed in the frame component  100 ( b ) by snap ring  149  and snap ring  150 . Pin  151  is press fitted within load sensor  148  and closely fitted within slot  152  of the frame component  100 ( b ) to assure angular alignment of the sensor  148  with the frame component  100 ( b ). The load sensor  148  has a reduced diameter  153  and reduced diameter  153 ( a ) with a bump  154  and bump  154 ( a ). The load sensor  148  is equipped with strain gages  155  connected by wire  156  for remote electrical measurement of transducer signals resulting from loads applied to either bump  154  or bump  154 ( a ). There is a small gap  159  between engine component  100 ( a ) and bump  154  on the load sensor  148 .  
         [0106]     Referring to  FIGS. 5, 6 ,  6 ( b ), and  6 ( d ), shaft  160  is closely fitted to engine component  100 ( a ) within bore  161  on one end and supported on the other end by ring  162  which is closely fitted in bore  163  of the engine component  100 ( a ). The plate  164  is threadedly secured by screw  165  and screw  166  to the engine component  100 ( a ) and retains the shaft  160  within engine component  100 ( a ). The tire  167  riding radially on needle bearings  168  and riding axially on thrust bearing  169  and thrust bearing  170  is fixed longitudinally and free to rotate within engine segment  100 ( a ) about shaft  160 . The bore  163  and the outer diameter of the tire  167  exceed the width of the engine component  100 ( a ) in the middle section  171  in vicinity of the tire  167 . Thus, the tire  167  is exposed for rolling engagement with the frame component  100 ( b ) on surface  172  and surface  173  and will prevent the engine component  100 ( a ) from rubbing on frame component  100 ( b ) when load is applied along the pivotal axis  178 .  
         [0107]     Referring to FIGS.  6 ( d ),  6 ( b ) and the above discussion, it can be seen that the engine component  100 ( a ) is free to roll on pin  128 ( a ) and pin  129 ( a ) along the track surfaces  131  and  131 ( a ) as described above in connection with bearing segment  21 . The rolling distance is limited to the small gap  159 . Arcuate motion of the engine component  100 ( a ) is limited by the load sensor  148 , mounted in the bore  147  of the frame component  100 ( b ) which is attached to the frame  123  with bolt  124 . The force of the engine component  100 ( a ), as a result of torque reaction to engine  175  torque delivered to the output shaft  179 , bearing on the bump  154  on the load sensor  148 , deflects the load sensor  148  causing a detectable change in output of the load sensor  148  proportional to engine  175  torque. Arcuate motion in the opposite direction of the engine component  100 ( a ) is also limited by the load sensor  148 , mounted in the bore  147  of the frame component  100 ( b ), which is attached to the frame  123  with bolt  124 . This force of the engine component  100 ( a ), as a result of engine  175  braking torque delivered to the output shaft  179 , bearing on the bump  154 ( a ) on the load sensor  148 , deflects the load sensor  148  causing a detectable negative change in output of the load sensor  148  proportional to engine  175  torque.  
         [0108]     More particularly, as shown in  FIG. 5 ( b ), bearing segments  100  and  181  are located on the circle indicated at “C” and allow the engine  175  to undergo a limited range of rotational movement about the pivotal axis  178 . In this embodiment, it can be seen that the CG lies within the cone containing the center of the surfaces of relative motion of the compliant engine mount  180  and the circle “C”. Again it is seen that bearing segments  100  and  181  effectively replace bearing  4  in  FIG. 1 .  
         [0109]     FIGS.  7 ,  7 ( a ), and  7 ( b ) disclose still another embodiment of the invention, wherein an engine  200  comprises an internal combustion motor  201  and transmission  202  assembly as might be installed in any common automobile. The engine mounting system according to this embodiment of the invention provides the same separation of engine retention forces from torque force measurement as provided by the previously described embodiments. As mentioned above, this embodiment is also compatible with the three point engine mounting systems widely used by many automobile manufacturers.  
         [0110]     Referring to  FIG. 7 ( a ), a rear view is shown of an engine  200 , attached to an automobile frame  203 . Bearing segment  204  is attached to the engine  200  by bolts  205  and bolt  206 , and to the frame  203  by bolt  207  and bolt  208 . Bearing segment  209  is attached to the engine  200  by bolts  210  and bolt  211 , and to the frame  203  by bolt  212  and bolt  213 .  
         [0111]     This embodiment of the invention is similar to the prior embodiment discussed above, except that a different and simplified construction of the bearing segments is possible due to the plurality of bolts connecting each of the two bearing segments to the automobile frame. This embodiment is an adaptation that is compatible with three point mounting systems where attachment to the frame is more secure than the single bolt disclosed by Etchells in U.S. Pat. No. 2,953,336.  
         [0112]      FIG. 7  is a side view of an engine  200  having a pivotal axis  214  passing through or near the center of gravity CG of the engine  200 . Near the transmission output shaft  215  is a compliant rubber mount  216  which acts as a bearing to position one end of the pivotal axis  214 , in much the same way as bearing  5  defined one end of the pivotal axis  9  in the first embodiment discussed herein. Bearing segments  209  and  204 , as will be explained below, securely attach engine  200  to the vehicle frame  203 , shown in FIGS.  7 ( a ) and  7 ( b ), and define the location of pivotal point  217  on the pivotal axis  214 , as shown in  FIG. 7 ( b ).  
         [0113]     Referring to FIGS.  8 ,  8 ( a ),  8 ( b ),  8 ( c ),  8 ( d ),  8 ( e ),  7 ( a ), and  7 ( b ), bearing segment  209  comprises an engine component  209 ( a ) attached to the engine  200  by bolt  210 , bolt  210 ( a ), and bolt  211 . Bearing segment  209  further comprises a frame component  209 ( b ) attached to the automobile frame  203  by bolt  212 , bolt  212 ( a ), bolt  213 , and bolt  213 ( a ).  
         [0114]     Referring to FIGS.  8 ( c ),  8 ( b ),  8 ( d ),  8 ( e ), and  7 ( b ), engine component  209 ( a ) has a track  218  formed by first track surface  219  and second track surface  220 . First track surface  219  and second track surface  220  are parallel to each other. Within track  218  is a track roller assembly  222  comprising a tire  222 ( a ), needle bearings  222 ( b ), inner race  222 ( c ), washer  222 ( d ) and washer  222 ( e ).  
         [0115]     Referring to FIGS.  8 ,  8 ( b ),  8 ( d ),  8 ( e ), and  7 ( b ), the track roller assembly  222  is secured to the frame component  209 ( b ) by pin  221  pressed into bore  223 . Frame component  209 ( b ) has a track  224  formed by first track surface  225  and second track surface  226 . First track surface  225  and second track surface  226  are parallel to each other. Within track  224  is a track roller assembly  227  composed of a tire  227 ( a ), needle bearings  227 ( b ), inner race  227 ( c ), washer  227 ( d ) and washer  227 ( e ). Track roller assemblies  222  and  227  may be commercially available units such as airframe needle roller bearing No. 8812022Y manufactured by the Torrington Company.  
         [0116]     Referring to FIGS.  8 ,  8 ( a ),  8 ( b ),  8 ( d ),  8 ( e ), and  7 ( b ), the track roller assembly  227  is secured to the engine component  209 ( a ) by bolt  211  passing through the bore  228  in the engine component  209 ( a ) through the washer  243  and through the track roller assembly  227  and into threaded engagement with the engine  200 .  
         [0117]     Load sensor  229  is retained within bore  230  formed in the frame component  209 ( b ) by snap ring  231  and snap ring  232 . Pin  233  is press fitted within load sensor  229  and closely fitted within slot  234  of the frame component  209 ( b ) to assure angular alignment of the load sensor  229  with the frame component  209 ( b ). The load sensor  229  has a reduced intermediate diameter  235  with a bump  236 . The load sensor  229  is equipped with strain gages  237  connected by wire  238  for remote electrical measurement of transducer signals resulting from loads applied to the bump  236 . The stop screw  239  is threadedly engaged to the frame component  209 ( b ) and locked in place by nut  240  with a small gap  241  between the stop screw  239  and the engine component  209 ( a ).  
         [0118]     Thus, the tire  227 ( a ) is exposed for rolling engagement with the frame component  209 ( b ) on track surface  226  and track surface  225  and will prevent the engine component  209 ( a ) from rubbing on frame component  209 ( b ) when loads are applied along the pivotal axis  214 .  
         [0119]     The engine component  209 ( a ) is free to roll on track roller assembly  222  along the track surface  219  or track surface  220  depending on gravity or vehicle dynamics. First projection line  242  extends from the center of pin  221  through the contact point of track roller assembly  222  on track surface  219 . The significance of first projection line  242  will be explained below. The rolling distance is limited to the small gap  241 .  
         [0120]     Arcuate motion of the engine component  209 ( a ) is limited by the load sensor  229 , mounted in the bore  230  of the frame component  209 ( b ) which is attached to the frame  203  with bolt  212 , bolt  212 ( a ), bolt  213 , and bolt  213 ( a ). The force of the engine component  209 ( a ), as a result of torque reaction to engine  200  torque delivered to the output shaft  215 , bearing on the bump  236  on the load sensor  229 , deflects the load sensor  229  causing a detectable change in output of the load sensor  229  proportional to engine torque. Arcuate motion, caused by opposite engine torque from that described above, of the engine component  209 ( a ) is limited by the stop screw  239  threadedly engaged in the frame component  209 ( b ) which is attached to the frame  203  with bolt  212 , bolt  212 ( a ), bolt  213  and bolt  213 ( a ). This motion will not load the load sensor  229  or create a detectable change in output.  
         [0121]      FIG. 9  is an enlarged view of bearing segment  204  shown in  FIG. 7 ( a ) with section lines to define the cross-sectional views of FIGS.  9 ( a ),  9 ( b ), and  9 ( c ).  FIG. 9 ( d ) is a cross-sectional view of bearing segment  204  taken along the section lines defined in  FIG. 9 ( a ).  
         [0122]     Referring to FIGS.  9 ,  9 ( a ),  9 ( b ),  9 ( c ),  9 ( d ),  7 ( a ), and  7 ( b ), bearing segment  204  comprises an engine component  204 ( a ) attached to the engine  200  by bolt  205 , bolt  205 ( a ), and bolt  206 . Bearing segment  204  further comprises a frame component  204 ( b ) attached to the frame  203  by bolt  207 , bolt  207 ( a ), bolt  208 , and bolt  208 ( a ). The engine component  204 ( a ) has a track  318  formed by first track surface  319  and second track surface  320 . First track surface  319  and second track surface  320  are parallel to each other. Within track  318  is a track roller assembly  322  composed of a tire  322 ( a ), needle bearings  322 ( b ), inner race  322 ( c ), washer  322 ( d ) and washer  322 ( e ). The track roller assembly  322  is secured to the frame component  204 ( b ) by pin  321  pressed into bore  323 .  
         [0123]     The frame component  204 ( b ) comprises a track  324  formed by first track surface  325  and second track surface  326 . First track surface  325  and second track surface  326  are parallel to each other. Within track  324  is a track roller assembly  327  composed of a tire  327 ( a ), needle bearings  327 ( b ), inner race  327 ( c ), washer  327 ( d ) and washer  327 ( e ). Track roller assemblies  322  and  327  may be commercially available units such as airframe needle roller bearing No. 8NBL2022YJ manufactured by the Torrington Company, aforementioned.  
         [0124]     Referring to FIGS.  9 ,  9 ( a ),  9 ( b ),  9 ( d ), and  7 ( b ), the track roller assembly  327  is secured to the engine component  204 ( a ) by bolt  206  passing through the bore  328  in the engine component  204 ( a ) and through the track roller assembly  327  and into threaded engagement with the engine  200 .  
         [0125]     Referring to FIGS.  7 ,  7 ( a ),  7 ( b ),  9 ,  9 ( a ),  9 ( b ),  9 ( d ), tire  327  is exposed for rolling engagement with the frame component  204 ( b ) on first track surface  326  and second track surface  325  and will prevent the engine component  204 ( a ) from rubbing on frame component  204 ( b ) when loads are applied along the pivotal axis  214 .  
         [0126]     Engine component  204 ( a ) is free to roll on track roller assembly  322  along the first track surface  319  or second track surface  320  depending on gravity or vehicle dynamics. The rolling distance is limited in one direction to the small gap  241  previously described in connection with first bearing segment  209 . Motion of the engine component  204 ( a ) is limited in the other direction by the load sensor  229  previously described in connection with bearing segment  209 .  
         [0127]     Second projection line  342  extends from the center of pin  321  through the contact point of track roller assembly  322  on track surface  319 . The intersection of second projection line  342  with the previously described first projection line  242  locates a pivotal point  217  that along with the compliant rubber mount  216  defines the pivotal axis  214 .  
         [0128]     More particularly, as shown in  FIG. 7 ( b ), bearing segments  209  and  204  are located on the circle indicated at “C” and allow the engine  200  to undergo a limited range of rotational movement about pivotal axis  214 . In this embodiment, it can be seen that the CG lies within the cone containing the center of the surfaces of relative motion of the compliant engine mount  216  and the circle “C”. Again it is seen that the bearing segments  209  and  204  effectively replace bearing  4  of the first embodiment shown in  FIG. 1 .  
         [0129]     Various basics of the invention have been explained herein. Details for the implementation thereof can be added by those with ordinary skill in the art. Various combinations and permutations of all elements or applications can be created and presented. All can be done to optimize performance in a specific application. Those skilled in the art will readily appreciate such variations hereof without departing from the spirit and scope of the present invention.