US2588018A - Reactor assembly - Google Patents

Description

March 4, 1952 c'. F. LAUENSTEIN REACTOR ASSEMBLY 3 Sheets-Sheet 1 Filed March 14, 1950 INVENTOR. A 'a/'Me/m imm@ March 4, 1952 c. F. LAUENSTEIN REACTOR ASSEMBLY 3 Sheets-Sheet 2 Filed March 14, 1950 'r Q4 lf3 INVENTOR.

/A/i vm Malfh 4, 1952 c. F. LAuENsTElN 2,588,018

REACTOR ASSEMBLY Filed March 14, 1950 3 Sheets-Sheet 5 .f^"= Tl-40 @1 -Jig T A TTOIP//EV Patented Mar. 4, 1952 UNITED STATES PATENT OFFICE REACTGR ASSEMBLY Carl F. Lauenstein, Indianapolis, Ind., assignor to Link-Belt Company, a corporation of Illinois Application March 14, 1950, Serial No. 149,530

This invention relates to new and useful improvements in reactor assemblies, and deals more particularly with such assemblies for oscillating machinery.

One type of reactor assembly used for oscillating machinery utilizes torsion bars to impart a reaction torque to the oscillating mass. The torsion bars for such an assembly may be of a variety of cross-sectional shapes, but in many respects, square bars are to be preferred.

Some of the advantages of square torsion bars are the availability of the stock from which th'el7 are cut, and 'the ease with which they may be processed for use as torsion bars. Further, as compared with round torsion bars, the square bars are much more easily clamped against rctation relative to the parts of the assembly to which they are connected.

The principal disadvantage in the use of square torsion bars is their susceptibility to fatigue failure. It has been found that the fatigue strength of a square torsion bar subjected to continuously repeated cycles of stress variation is relatively low. It has also been found that fatigue failure is most likely to occur in a plane that is normal to the axis of the torsion bar at the point where the torsion bar enters the fitted opening in a clamping or connecting meinber.

It is the primary object of this invention to provide a reactor assembly incorporating a reactor element having a greatly increased fatigue strength.

A further object of the invention is to provide a torsion bar capable of withstanding a much greater number of stress cycles at a given load.

A further object of the invention is to provide a torsion bar that is so modied structurally at its critical stress regions as to materially increase the fatigue strength of the bar.

A still further object of the invention is to provide a square torsion bar having modified crosssections at the regions where fatigue failure is most likely to occur to thereby increase the fatgue strength of the bar.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a top plan view of a reactor assembly embodying the invention,

Figure 2A is a perspective view, partly broken 9 Claims. (C1. 267-1) 2 away, of a torsion bar of the type illustrated in Fig. 1;

Figure 3 is a transverse sectional view of a torsion bar taken on line 3 3 of Fig. 2,

Figure 4 is a perspective view of one of the bushings illustrated in Fig. l,

Figure 5 is an 'end elevational view, partly inl section, of the reactor assembly illustrated in Fig- 1J Figure 6 is a vertical sectional view taken on line 6-6 of Fig. 1,

Figure 7 is a detail sectional view showing the arrangement of the bushing and set screws in a modied embodiment of the invention,

Figure 8 is a lside elevational View of the reactor assembly illustrated in Fig. 1, and

Figure 9 is a sectional view taken on line 9 9 of Fig. 5.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of the invention, and first particularly referring to Figs. l, 5, 6, 8 and 9, reference characters I0 and II designate two duplicate housings the construction of each of which will be disclosed by specically referring to only one.

The housing I0 is provided with a suitable base I2 having openings I3 for receiving the bolts I4 or the like to connectl the housing to the supporting oor. Two axially parallel, cylindrical openings I5 and I6 extend through the housing Ill. The tapped holes I1 extend from the upper surface of the housing to the opening I5, and the tapped holes I8 extend from the upper surface of the housing to the opening I6. The locations of the tapped holes I8 with respect to their associated opening I6 may be varied, as illustrated in Fig. 7, to modify the function of the housing as will be further explained in a later paragraph.

The opening I5 receives a tightly tted tubular bushing I 9 which extends slightly beyond the inner face 20 and the outer face 2| of the housing. The bushing I 9 is held in place in the opening I5 by the set screws 22 whichV are threaded into the tapped holes I l.

The opening I6 loosely receives a cylindrical bushing 23 which is provided with a square opening 24 extending axially therethrough. The inner end portion of the bushing 23 extends beyond the inner face 20 of the housing l0 and is enlarged to form a hub 25. A slot 26, see Figs. l, 4 and 6, diametrically divides the hub 25 and extends for a short distance into the body of the bushing 23 to provide a clamping portion 24a in. the Opening' 24. The hub 25 is provided with openings 21 normal to the slot 28 and on each side of the clamping portion 24a. These openings 21 receive the bolts 28 which may be tightened to reduce the cross-sectional area of the opening 24.

The cylindrical body of the bushing 23 is provided with an exterior plane area 29 which should be substantially normal to the tapped holes I8 when the bushing is positioned in its opening I6. Set screws 30 are threaded into the tapped holes |8 to contact the area 23. Further tightening of the set screws 30 will cause the bushing 23 to rotate in its associated housing I in a clockwise or counter-clockwise direction depending upon the location of the tapped holes I8 relative to the openings I6 as illustrated in Figs. 5 and 7.

The supporting arms 3| are each provided with a cylindrical projection 32 extending from one side at the lower end portion thereof. A square opening 33 extends axially through the projection 32 and the arm 3|. The clamping portion 33a of the opening 33 in and adjacent to the supporting arm 3| is of slightly smaller dimensions than the remainder of the opening. The lower end portion of the arm and its projection 32 are divided through the clamping portion 33a of the opening 33 by the cutaway 34. A bolt 35 connects the separated extremities at the lower end portion of the arm 3| so that tightening of the bolt reduces the cross-sectional area of the clamping portion 33a of the opening 33.

The cylindrical projection 32 of each supporting arm 3| is iitted into the tubular bushing I9 of its associated housing I0 or and extends inwardly through the bushing to the inner end por.. tion thereof. The supporting arms 3| are thereby pivotally mounted on the housings ID and II with the openings 33 in transverse alinement with the similarly formed openings 24 in the cylindrical bushings 23.

The upper end portion of each arm 3| is provided with a cylindrical opening 36 for mounting a tubular bushing 31. A bracket 38 is pivotally connected to each arm 3| by a bolt 39 extending through the alined openings on each side of the bracket and through the bushing 31.

As illustrated in Figs. 5, 6 and 8, the brackets 38 are suitably connected to a conveyor trough 40. It is to be understood, however, that other types of oscillating bodies may be connected to the brackets 38 without modifying the function hereafter described.

Torsion bars 4|, square in cross-section, are each mounted with one end portion fitted into the opening 33 and the other end portion tted into i;

the opening 24 of oppositely arranged arms 3| and bushings 23. Each bushing 23, is therefore, connected to an arm 3| through a torsion bar 4|. The bolts 35 and 28 are tightened to clamp the torsion bars 4| to their associated arms 3| and bushings 23.

Referring now to Figs. 2, 3 and 9, for a detail discussion of one of the torsion bars 4| and its associated arm 3| and bushing 23, it is noted that relative rotation between the arm and bushing will impart a twist to the unsupported middle portion A of the bar. This twisting of the torsion bar 4| is resisted by torsional stresses set up in the middle portion A. The clamped end portions B and C of the bar, however, cannot be twisted and are subjected primarily to compressive stresses. The resultant stress patterns created in the transverse regions D and E of the torsion bar that are located at and adjacent to the inside margins of the clamping portion` 3,6@-

4 of the arm and 24a of the bushing are such that fatigue failures usually occur at these regions. It is for the purpose of increasing the fatigue strength of these two critical regions D and E that the torsion bars 4| are structurally modied in the following manner.

All of the edges of the torsion bar 4| are machined to form a circumferentially alined row of notches 42 at each of the critical regions D and E. Consideration of Fig. 3 shows that the square cross-section of the torsion bar 4| is changed by the notches 42 to a substantially circular crosssection. In other words, the bottom of each notch 42 is arcuately formed both longitudinally and crcumferentially, the longitudinal curvature of the bottom surface being concave and the circumferential curvature being convex.

The notches 42 at the critical region D are so located that their mid-points register radially with the inner edge of the clamping portion 83a of the opening 33. The notches 42 at the critical region E are so located that the opening 24a in the hub 25 will receive approximately one-half of the notched portion of the bar. It is to be understood that the exact locations of the notches 42 are important to the extent that the notches should be partially but not entirely included within the clamped portions B and C 0f the bar.

It is noted that the notches 42 do not reduce the strength of the torsion bar 4| under a static torsional load. This is due to the fact that torsional stresses are directly proportional to their distance from the axis of the torsion member. The longitudinal centerline of each side face of the square torsion bar 4| represents the shortest radial distance from the axis of the bar, and this distance determines the maximum allowable static torsional load which the bar will withstand.

It will be seen by again referring to Fig. 3 that the bottoms of the notches 42 are located at a slightly greater distance from the longitudinal axis of the torsion bar 4| than are the centers of the side faces. It will be seen, therefore, that the strength of the torsion bar 4| under a static' load is not reduced by the provision of the notches 42.

It has been determined by the testing of notched torsion bars, under dynamic loading conditions, that the notches do beneficially affect the stress patterns at the critical regions D and E with the result that the fatigue strength of the bar is greatly increased.

It is to be understood that the forms of this invention herewith shown and described are to be taken as preferred examples of the same, and that various changes in the shape, size, and ar rangement of parts may be resorted t0 without departing from the spirit of the invention or L the scope of the subjoined claims.

Having thus described the invention, I claim:

1. A device of the type described, comprising housing means, a bushing adjustably mounted in said housing means, an arm mounted on said housing means for pivotal movement relative thereto, said bushing and said arm each having an opening therethrough in axial alinement with the opening through the other, and a torsion bar of rectangular cross-section having longitudinally spaced portions clamped in said axially alined openings for frequently repeated twisting of its intermediate portion by the pivotal movement of said arm, said bar having stress relieving notches in all of its edges at, the inner margins of said clamped portions.

2. A device of the type described, comprising housing means, a bushing adjustably mounted A in said housing means, an arm mounted on said housing means for pivotal movement relative thereto, said bushing and said arm each having an opening therethrough in axial alinement with the opening through the other, and a torsion bar of rectangular cross-section having longitudinally spaced portions clamped in said axially alined openings for frequently repeated twisting of its intermediate portion by the pivotal movement of said arm, said bar having circumferentially alined stress relieving notches in all of its edges at the inner margins of said clamped portions.

3. A device of the type described, comprising housing means, a bushing adjustably mounted in said housing means, an arm mounted on said housing means for pivotal movement relative thereto, said bushing and said arm each having an opening therethrough in axial alinement with the opening through the other, and a torsion bar of rectangular cross-section having longitudinally spaced portions clamped in said axially alined openings for frequently repeated twisting of its intermediate portion by the pivotal movement of said arm, said bar having all of its edges notched at the inner margins of said clamped portions, each of said notches being longitudinally concavely curved and transversely convexly curved.

4. A device of the type described, comprising a torsion bar of rectangular cross-section subjected, when in use, to frequently repeated twisting of an intermediate portion thereof, said bar having stress relieving notches in all of its edges at each of the two outer limits of said intermediate portion to provide modified cross-sections at said limits, a bushing clamped tol said bar outwardly of one of said limits to prevent rotary movement of the bar, and an arm clamped to said bar outwardly of the other of said limits for applying the twist to said bar.

5. A device of the type described, comprising a torsion bar of rectangular cross-section subjected, when in use, to frequently repeated twisting of an intermediate portion thereof, said bar having all of its edges notched at each of the two outer limits of said intermediate portion, each of said notches being longitudinally concavely curved and transversely convexly curved, a bushing clamped to said bar outwardly of one of said limits to prevent rotary movement of the bar, and an arm clamped to said bar outwardly of the other of said limits for applying the twist to said bar.

6. A device of the type described, comprising a torsion bar of rectangular cross-section having longitudinally spaced clamping portions and subjected, when in use, to frequently repeated twisting of the portion of said bar intermediate its clamping portions, said bar having stress relieving notches in all of its edges at each of the two outer limits of said intermediate portion to provide modified cross-sections at said limits.

7. A device of the type described, comprising a torsion bar of rectangular cross-section having longitudinally spaced clamping portions and subjected, when in use, to frequently repeated twisting of th-e portion of said bar intermediate its clamping portions, said bar having circumferentially alined stress relieving notches in all of its edges at each of the two outer limits of-said intermediate portion to provide modified crosssections at said limits.

8. A device of the type described, comprising a torsion bar of rectangular cross-section having longitudinally spaced clamping portions and subjected, when in use, to frequently repeated twisting of the portion of said bar intermediate its clamping portions, said bar having longitudinally concavely curved stress relieving notches in all of its edges at each of the two outer limits of said intermediate portion.

9. A device of the type described, comprising a torsion bar of rectangular cross-section having longitudinally spaced clamping portions and subjected, when in use, to frequently repeated twistingof the portion of said bar intermediate its clamping portions, said bar having stress relieving notches in all of its edges at each of the two outer limits of said intermediate portion, each of said notches being longitudinally concavely curved and transversely convexly curved.

CARL F. LAUENSTEIN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS

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