US2084080A - Engine mounting - Google Patents

Description

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ENGINE MOUNTING Filed May 20, 1955 5 Sheets-Sheet 5 Patented June 15, 1937 UNITED STATES yPMI-NT oFFlcE ENGINE MOUNTING Paul Charles Albert Marie dAubarde,

Saint-Genis-Laval, France Application May 20, 1935, Serial No. 22,481. In l) France May ,19, 1934 18 claims. (c1. 18o-s4) (Granted under the provisions oi' sec. 14, act of March 2, 1927, 357 0. G.

The mounting according to this invention is an application of the invention described in my U. S.

l Letters Patent No. 2,055,279 dated'September 22,

torque on the engine assembly. The latter tends Q5 to rotate or oscillate about a further transverse axis and the mounting must be such as to prevent it from rotating while permitting its oscillations about the corresponding natural axis.

Afirst object of this invention is therefore to so dispose a flexible connection between an engine and its support that it will substantially permit oscillation about three natural oscillationaxes, to wit, the oscillation axis corresponding to the internal periodic torquesparallel to the motor shaft or crankshaft, the oscillation axis corresponding to the internal periodic forces, and the oscillation axis corresponding to the periodic portion of the transverse driving torque.

A further object of this invention is to dispose supporting springs for the engine on its support in such a way that they will permit oscillation about the natural oscillation axeswhile maintaining the engine against the action of the average driving torque.

Another object of this invention is to provide a flexible connection which will be of a sufficiently yielding character'to accommodate variations in the position of the natural oscillation axes.

The elasticities and moments of inertia of the intermediate gearing between the motor shaft and the driving shafts are preferably so deter# mined that this gearing forms anarresting filter between the motor shaft and the driving shafts. 55, The driving torque applied to the latter shafts ls thus as steady and regular as possible and the periodic portion of thetransverse torque applied to the engine assembly is as reduced as possible.

The tendency of the engine assembly to oscillate about the corresponding transverse natural axis lis much reduced and the mounting is easier and more efficient.

The condition to be fulfilled by a torsional elastic system inserted 'in the gearing for obtaining the arresting filter operation is as follows:

2` l a a CCL-1+i) in. which:

a is the angle of twist of the torsional elastic system inserted in the gearing under the action of an average torque C on the motor shaft.

M is the moment of inertia of -a supposed ywheel which, if keyed on the engine side of the torsional elastic system, would have a. kinetic energy equal to the total kinetic energy of all the parts connected with this side of the system.

A is the moment of inertia of a supposed flywheel which, if 'keyed on the other side of the torsional elastic system, would have a kinetic energy equal to the total kinetic energy of all the parts connected withl this side of the system.

It is assumed in the relation that the two sides of the torsional elastic system rotate at the same speed.

wo is the smallest possible pulsation of the periodic torque of the engine.

In most cases, such a torsional elastic system is preferably disposed between the flywheel and the gear box.

The angular elastic reaction of the system, i. e. Y the rate of increase of the torque C with respect to the angle of twist a preferably increases-with the torque C itself.

VIn the annexed drawings:-

Fig. 1 is a side view of a mounting according to this invention applied to an engine assembly for cars or the like, the engine being `of the standardv pattern. ,Y

Fig. 2 is a plan view thereof.

Fig. 3 is an-end view;

Fig. 4 is a detailed vertical section of the abutment to an enlarged scale.

Figs. 5 to 7 show in the same manner a modified lform of mounting according to this invention.

Fig. 8 shows a modified form of connecting member.

Ans

this

' according to this-invention applied to an engine assembly for vehicles or the like, in which the engine cylinders are radially arranged in a horizontal plane.

Fig. 15 is a plan view thereof.

Fig. 16 shows a modiiled form of spring.

Fig. 17 is an end view of a torsional elastic system.

Fig. 18 is a longitudinal section thereof.

Figs. 19 to 21 show another example of such a torsional system.

Figs. 22 to 24 show modied forms thereof.

Fig. 25 is a transverse section of another torsional elastic system.

In the drawings, the engine assembly comprises an internal combustion engine I. The crankshaft axis is indicated at V--V and there is provided a gear box 2 which connects the crankshaft with the transverse shafts 3. The latter directly drive the wheels of the car (the iront wheels, for instance). They are perpendicular to the crankshaft axis V-V. 'I'he center of gravity is shown at G and F designates the line of action of the .resultant of the periodic forces.

The engine assembly is submitted to three principal different stresses:

l. The internal periodic forces which tend to oscillate the engine assembly about an axis such as o-c.

2. 'Ihe internal periodic torqueof the engine proper (torque exerted by the crankshaft on the ywheel) which tends to oscillate the engine assembly about a longitudinal axis such as X-X,

passing through G and substantially parallel to 'lhe actions of these forces and torques have been explained in my above-referred to patent application No. 666,380.

3. A transverse troque-or driving torque resulting from the torque exerted by shafts 3.. This torque is not wholly regular and comprises a periodic portion which tends to oscillate the engine assembly about a transverse axis T-T passing through G.

The mounting according to this invention is so arranged that the engine assembly is free to oscillate about its natural oscillation axes c-c, X-X and T T, notwithstanding their variations in position. l

In the arrangement according to Figs. l. 2 and 3, the engine assembly is supported by two lateral springs l .and l and it is attached to the frame 'l by means of a exible connection. The latter comprises a block 3 of rubber or the like glued between a bracket 3 ilxedto the gear box 2 and a plate 3 ilxed to the frame. l. 'I'he engine is thus free to osciilate about a variable axis intermediate between c-c and T-T owing to the yielding character of block 3. It is also free to oscillate about a longitudinal axis such as X'X. v

Springs l and l support a part of the weight of the engine. I'hey have also to resist the average driving torque exerted by shafts 3 and the eventual average torque exerted by the crankshaft on the flywheel (during accelerations).

The end of the engine remote from the connection 6-1--3-3 is provided with a limiting abutment detailed in Fig. 4. It comprises a rubber block I0 glued on a hollow finger II $0 the engine proper I by bolts I2. Block I3 is housed with play within a slightly conical box I3 fixed to the frame 1. When, under external actions (Jolts on the road, for instance) the engine tends to move vmore than normal with respect to the frame, block I0 limits the motion. The length of nger II is smallerthan the thickness of block III and therefore the contact between block I0 and box I3 is very progressive, since it begins at Il, where the rubber is unsupported.

The play of block I0 within box I3 is preferably adjustable by means of a ilexible strip IM pressed by an adjusting screw IM.

vIn the mounting according to Figs. 5, 6 and 'l the exible connection embodies a tubular block II of soft rubber arranged between a transverse hole through the engine casing and a rod Il supported by arms Il fixed to the frame. 'I'here are provided two lateral springs I3 and 23 and an axial one,|3. 'Ihere is also provided a limiting abutment lof the kind shown in Fig. 4.

This mounting is similar to the preceding one.-

Spring I3 relieves the exible connection Il-IO of the engine weight, provided. of course, the respective strengths of the springs are correctly determined with respect to distances a and b (Fig. 6).

Fig. 8 shows a modiiled type of connection in which rod I6 is located between two soft rubber blocks 2l, 22 within a stirrup 23 ilxed on the gear box 2. Abutments 24 and 23 (made of ilbre or the like) limit the vertical motions of the engine with respect to rod I3. This connection is appropriete when, as in Figs. 5 to 7. the engine is wholly supported by springs.

In the mounting according to Fig'. 9, the iiexible engine speed there is no average torque o! such axis tending to rotate t (l. e. to'overturn) the engine; there'is a mere periodic torque tending to osclllate it, which is possible by twisting strap 23. The tendency of the engine to overturn therefore only occurs during sudden accelerations and'the abutment lI-i3 limits the angle of rotation, block Il and box I3 being rectangular or square in 'cross-section.

In the mounting of Fig. 10 there is but one spring 23 and a connection 3l comprising a. soft rubber block 33 between metallic plates 3| and 32 with turned edges. Plate 3I supports the gear box 2 through two bolts 33 disposed eachside 0f block 33. Plate 32 rests on the frame 1. Two auxiliary rubber blocks 34 are disposed ,between the turned edges of plates 3I and 32 to longitudinally retain the engine.

Fig. 11 shows a similar type of connection in the free state. Under the weight of the engine the central rubber block 33 is compressed betweenplates 33 and 31. 'The auxiliary blocks 33' then are compressed and assume a rectangular shape. lin the connection according to Fig. 12, the

- edges of plates 33 and 40 are oblique: thus when the connection is loaded, the auxiliary blocks III are more highly compressed.

In the connection shown in Fig. '13, there is only provided one main rubber block 42 to support the engine weight. 'I'he auxiliary blocks of Figs. 10, 11 and 12 are replaced by a exible strap 43 attached to frame 1 and to a curved arm 44 fixed to the gear box 2. The main block 42 is itself comprised between plates 45 and 48.

Curved wings 45 and 41 limit the flexion of strap engine about an axis X-X passing through G- and parallel to the axis V--V of the crankshaft. This axis X--X is practically located in the irnmediate vicinity of the latter, the engine assembly being almost symmetrical. The transverse periodic driving torque tends to oscillate the engine about the axis T-T passing through G and parallel to the transverse driving shafts I'.

In such an engine the periodic forces are located in the plane F-F of the cylinder axes. The line of action of their resultant rotates in this plane, either in the same direction as the crankshaft or in the reverse direction, according to the. construction of the engine.

When this resultant is not balanced by special devices, it tends to oscillate the engine assembly about an axis similar to axis c-c of Figs. 1 and 2, but rotating about X-X as the resultant proper, in such a manner that the engine assembly tends to move so to speak conically about a point C (Fig. 14) which is the intersection of X--X and c-c. Of course point C varies in ing a recessed portion at the bottom of the gearbox 2. Owing to the yielding character of block 15, the engine assembly is free to oscillate about point C and also about axis T-T. The average driving torque is supported by springs 1I which prevent the engine from overturning about a transverse axis.

The limiting abutment Ill-Il is placed at the top of the engine as shown.

Fig. 16' shows a modified form of spring system comprising but one spring formed as a ilat spiral inserted within a ring 11 fixed to the engine. The inner winding is fixed to a stud 1l ,carried by the frame. Spherically curved plates 19 are provided at each side of the spring in such a way that when the latter 'is deflected in either direction the windings progressively contact a plate and are inactive, whereby the elastic reaction increases with the load. Oi' course the plates may also be supported by ring Il and cooperate with the outer windings instead of the innerones; the increase in elastic reaction is practically more rapid with this second arrangement.

In the mountings described, thesprings are preferably conical as shown. the windings being made of a dat steel strip. They have a variable elastic reaction, as explained in my patent application No. 10,075 filed-March 8, 1935. They -are so determined that the oscillating system formed by the engine on its springs operates as an arresting lter for the periodic strains at any normal engine speed.

In all these mountings the operation is greatly improved when an elastic system is interposed in the transmission of power from kthe engine to the driving shafts. It has been explained that the engine (Fig. 1) tends to oscillate about axis c-c under the action of the kinternal periodic forces and about axis T-T under the action of the periodic portion of the driving torque (exerted by -shafts 3). 'I'hese tendencies result in an oscillation about a widely variable instantaneous axis whose position is dependent on the relative amplitudes and phases of each individual oscillation. By lessening as much as possible the importance of the periodic portion of the driv- Aing torque, the tendency to oscillate about T--T is decreased and the instantaneous axis practically remains in the vicinity of c-c.

In Figs. 17 and 18 a layer 5i of soft rubber or the like is inserted between two tubular coaxial members 52 and 53 provided with registering undulations as shown. Member 52 is fixed to the flywheel 54 keyed at the end of the crankshaft 55; member 53 is fixed on the driven shaft 55. Arcuate openings 51 are provided in member 53 and they cooperate with studs 50 to limitate the twisting of the device under abnormal stresses.

In the device according to Figs. 19, 20and 21,' the elastic material is inserted between two disklike members 59 and Bilrhaving slightly undulated surfaces. i

Fig. 22 shows the same kind of device with undulations of greater depth, for transmitting higher torques.

In Fig. 23, the undulations of the disks have the same depth from the inner part to the outer periphery. A collar 55 formed at the end of the driving shaft 53 is retained by a ange 55 carried by the driven shaft 54.

In Fig. 24, the thickness of the elastic material decreases from the periphery down to the inner part.

The -device of Fig. 25 embodies two hollow shafts 51 and 58 connected by elastic strips 50 and 10.

All these devices must be determined so as to fulfill the above-described condition:

On the other hand, their elastic reaction preferably increases with the torque transmitted. Since an internal combustion engine never exerts its full torque at low speeds, the filter condition is always fulfilled notwithstanding the increase in vhardness (elastic reaction) of the coupling provided, of course, that this increase be correctly determined.

In the above examples, the angle of the power shafts with respect to the motor shaft (crankshaft) is 90. 'I'his is the most common case. When the power shafts or shaft are at an angle other than 90 with respect to the crankshaft, the axis'T-T has to be determined and the flexible connection has to be so selected and located as to permit the oscillation of the engine about such an axis.

In the above description the term "internaP as applied to the periodic torques or forces only means that these torques and forces result from parts internal to the engine proper and is.used for differentiating such forces or torques from the driving torque exerted by shafts l.

I claim:-

1. In combination a frame; an engine assembly submitted to periodic internal forces and to periodic internal torques tending to oscillate it about two varying natural oscillation axes; a motor shaft in said engine assembly; driving shafts through which a driving torque is derived from said engine assembly, said driving shafts being supported by said engine assembly at an angle with saidl motor shaft: spring means adapted to maintain said engine assembly on said frame against gravity and against the action of the average driving torque exerted by said driving shafts; and a flexible connection between said engine assembly and said frame for yieldably retaining said engine assembly with respect to the frame while permitting the engine assembly to oscillate so as to accommodate oscillatory motion of -said engine assembly about the varying natural oscillation axes resulting from said internal periodic forces, internal periodic torques and spring means, and also about an oscillation axis resulting from the action on said engine y assembly of the periodic portion of the driving torque exerted by said driving shafts; said connection being disposed substantially on the average position of the varying natural oscillation axis which is the resultant of the actions of the internal periodic torques vand of the springA means, at a position intermediate between the center of gravity of said engine assembly andthe intersection o! said last-named varying naturaly a motor shaft in said engine assembly; driving shafts through which a driving torque is derived from said engine assembly, said driving shafts being supported by-said engine assembly transversely of said motor shaft; spring means adapted to maintain said engine assembly on said frame against gravity and against the action of the average driving torque exerted by said driving shafts; and a flexible connection for yieldably retaining said engine assembly with v respect to the frame while permitting the engine assembly 'to oscillate so as to accommodate oscillatory motionof said engine assembly about the substantially longitudinal varying natural oscillation axis of said engine assembly under the action of said internal periodic torques, and also oscillatory motion about a varying substantially transverse oscillation axis which is the resultant of the actions of said periodic internal forces, of said spring means and of the periodic portion of the 'driving torqueexerted by said driving shafts; said connection, being disposed substantially on the average position of the substantially longitudinal natural voscillation axis which is the resultant of the actions of the internal periodic torques and of the spring means, at a position intermediate between the center of gravity of said engine assembly and the intersection of said last-named natural oscillation axis with the varying natural oscillation axis which is the .tion of said second-named varying natural oscilassembly about a varying natural oscillation axis substantially transverse with respect to said nrstnamed natural oscillation axis; driving shafts through which a driving torque is derived from said engine assembly, said driving shafts being supported by said engine assembly transversely of said crankshaft: sprin means adapted to maintain said engine assembly on said frame against gravity and against the action of the average driving torque exerted by said driving shafts; and a flexible connection for yieldably retaining said engine assembly with respect to said frame, said connection being disposed substantially on the average position of said rstnamed varying natural oscillation axis, at a position intermediate between the center oi' gravity of said engine assembly and the average posilation axis.

4. In a combination as claimed in claim 3, said spring means comprising two spring systems disposed at each side of said engine assembly on the other side of the center `of gravity of saidconnection; said three spring systems being so.-

determined in strength as to relieve said connection of the weight of said engine assembly.

6. In a combination as claimed in claim 3, said spring means comprising two spring systems disposed at each side of said connection, said spring systems and connection being substantially disposed in the longitudinal vertical plane passing through the center of gravity of said engine assembly, and said spring systems being determined so as to support substantially the whole weight of said engine assembly. 7. In a combination as claimed in claim 3, said spring means comprising a spring system disposed opposite to said connection with respect to the center of gravity of said engine assembly. e

8. In a combination as claimed in claim l, a limiting abutment adapted to limit the motions of said engine assembly with respect to said y frame under other actions than those of the internal periodic forces and torques and of the driving torque. y

'9, In a combination as claimed in claim l, a limiting abutment adapted limit the motions ofv said engine assembly with respect to said frame.

spring means being so disposed as to relieve said flexible connection from the weight of said engine assembly; and said flexible connection comprising a transverse rod iixed to the frame,

a stirrup xed to said engine assembly and traversed by said rod, and rubber blocks interposed between the sides of said rod and the sides of said stirrup. l 11. In a combination as claimed in claim 3, said spring means being so disposed as to relieve said flexible connection from the weight of said engine assembly; and saidexible connection com# prising a transverse rod xed to the frame, a stirrup fixed to said engine assembly and traversed by said rod, rubber blocks interposed between the sides of said rod and the sides of said stirrup, and blocks forming abutments to limit vertical motion of said rod within said stirrup.

12. In a combination as claimed in claim 3, said spring means being so determined that said ilexible connection supports a part of the weight of said engine assembly; and said flexible connection comprising a block of rubber to support the said part of the Weight of said engine assembly; andfsaid exible connection comprising a block of rubber to support the said part of the weight of said engine assembly, vertical members xed to the frame, vertical members xed to said engine assembly, and blocks of rubber interposed between said frame and engine members to yieldably limit horizontal motions of said engine assembly with respect to said frame.

13. In a combination as claimed in claim 3, said spring means being so determined that said flexible connection supports a part of the weight of tion comprising a, block of rubber to support the said part of the weight of said engine assembly, and a horizontally disposed strap to prevent horizontal motions of said engine assembly -with respect to said frame.

PAUL CHARUES ALBERT MARIE DAUBAREDE.

4said engine assembly; and said flexible connec-

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