US3443528A

US3443528A - Dampened railway truck

Info

Publication number: US3443528A
Application number: US657450A
Authority: US
Inventors: Johannes Martin Lipsius; Eugen Spehr
Original assignee: Rheinstahl Henschel AG
Current assignee: Rheinstahl Henschel AG
Priority date: 1965-02-26
Filing date: 1967-06-12
Publication date: 1969-05-13
Anticipated expiration: 1986-05-13
Also published as: AT278897B; JPS4841281B1

Description

May 13, 1969 Filed June 12 1967 J- M. .LIPSIUS ET AL DAMPENED RAILWAY TRUCK Sheet v of 7 III INVENTORS g JOHANNES MARTIN LIPSIUS P L EUGEN SEHR ATTORNEY May 13, 1969 J;M.:L| Ps|us 'ETAL 3,443,52

DAMPENED RAILWAY 'TRUCK Filed June 12, 1967 Sheet 2 of 7 FIG. 30 a 2 a I FIG. 3d

. FIG. 38

I t i 2 4 5 7 mvsnrons .loumm'ss mm uPsms EUGEN SPEHR BY a.u

ATT EY y 13, 1 J. M. |..|P s| us ET AL- DAMPENED RAILWAY TRUCK Filed June 12, 1967 FIGB FIG]

May 13, 1969 Ps u ET AL 3,443,528

DAMPEN ED RAILWAY TRUCK Filed June 12'. 1967 Sheet 4 of 7 1:2" L; z |n r L FIG.|4 6 5 I 5 May 13, 1969 1 J. M. LIPSIU S E AL 3,443,528

7 I DAMPENED RAILWAY TRUCK Filed June 12, 1967 -5 FIGIZ 2 Sheet 5 of '7 May 13, 19 69 J. LIPSIUS ET AL 3,443,528

DAMPENED RXiLwAY TRUCK Filed June 12. 1967 Sheet 6 of? all!!! v Fl(3.l9 H020 v F7 33 r| 2 km 3| J ISO 3 i j I 39 May 13, 1969 Sheet Filed June 12, 1967 FIG. 23

United States Patent 3,443,528 DAMPENED RAILWAY TRUCK Johannes Martin Lipsius, Kassel, and Eugen Spehr, Kassel- Harleshausen, Germany, assiguors to Rheinstahl Henschel A.G., Kassel, Germany, a corporation of Germany Continuation-impart of application Ser. No. 470,464, July 8, 1965. This application June 12, 1967, Ser. No. 657,450 Claims priority, application Germany, Feb. 26, 1965,

Int. (:1. B611? /10, 5/20, 5/12 U.S. Cl. 105171 11 Claims ABSTRACT OF THE DISCLOSURE This application is a continuation-in-part of our copending application Ser. No. 470,464, filed July 8, 1965, now abandoned.

Railway vehicles, particularly those having trucks, are frequently equipped with transverse spring systems in order to elastically absorb lateral shocks and the transverse movements caused by the sinusoidal path or course of the axles so that the starting forces between the wheels and the rails are reduced. A vehicle which is equipped with a transverse spring suspension system is a system capable of vibrating in the transverse direction. The frequency of the vibration excited by the sinusoidal path increases with increasing traveling speed so that resonance with the natural oscillation frequency of the vehicle spring system may occur at certain speeds.

In order to maintain the transverse vibration or oscillation amplitudes as small as possible over the entire traveling speed range, it is advisable to select the natural transverse frequency to be as low as possible, for example, 1 cycle per second. The resonance will then occur at a relatively low traveling speed, whereas at higher traveling speeds, i.e., in the overcritical range, the excited oscillation amplitudes are smaller than the excitation amplitudes, insofar as the higher exciting frequency caused by the greater traveling speed amounts to more than 1.4 times the natural oscillation frequency. With a further increase in the excitation frequencies, the amplitudes of the excited oscillations become progressively smaller. However, if a vehicle maintains a speed, over a prolonged period of time, at which there will be resonance between the excitation frequency and the natural oscillation frequency, a significant build-up of the oscillation amplitudes will occur. Outside of the resonance range, these oscillation amplitudes may additionally be minimized by dampers having a constant damping force, for example friction dampers, but in the resonance range, this damping elfect is possible only by means of a damping action which is dependent upon the speed of the oscillations. With the increasing damping action, the resonance amplitudes of the excited oscillations become smaller and, when the spring action is completely blocked by the damping action, they diminsh to the magnitude of the excitation amplitudes. This, however, will produce the disadvantage that the wheel flanges run up against the running or inner 3,443,528 Patented May 13, 1969 edges of the rails in too hard a manner and, thus, will result in an increased wear and tear, as well as undesirably high shock or impact forces in the entire vehicle.

Above the resonance range, on the other hand, i.e., at a ratio of the excitation frequency to the natural oscillation frequency of more than 1.4:1, the damping action will have an unfavorable effect so that the oscillation amplitudes will be increased until, in the border-line case of blocking of the spring suspension system, the entity of the excitation amplitude will equally arise. In order to permit a complete utilization of the favorable properties of an undamped spring suspension system in the overcritical range, the damping action accordingly must not be too large unless the damper is provided with a device for disconnecting it or for reducing the damping effect. In exchange therefor, oscillation amplitudes must be accepted, in the resonance range or below, which are considerably greater than the excitation amplitudes.

The construction of the present invention utilizes the advantages of an undamped oscillation in the overcritical range as well as an effective damping action in the resonance range and below in a manner such that optimum running properties of the vehicle are obtained insofar as the transverse vibrations or oscillations are concerned. The transverse oscillation amplitudes in the resonance range should become as small as possible while, however, the smoothness -or elasticity of the transverse spring suspension action simultaneously must not be impaired, so that hard impacts are eliminated when the wheel flanges run up or start against the running or inner edges of the rails.

In the construction of the present invention, one, or more than one, transverse oscillation damper is mounted outside of the vertical transverse central plane of the truck, for example at a terminal cross bearer member of the truck frame, in a manner such that during the sinusoidal path or course of the truck, there will be a phase shift between the damper movement and the trans verse spring movement. The transverse oscillation damper may be mounted adjacent the end of the vehicle or adjacent the center of the vehicle or at both ends of the truck with one damper being disconnected, depending upon the direction of travel. For purposes of damping with an oscillation speed-dependent damping force, hydraulic, pneumatic or electric dampers may be employed, the latter being in the form of an eddy-current brake, for example.

In order to fully utilize the advantages of the overcritical vehicle movement or course at a higher excitation frequency, the damper should be controllable fin depend ence upon the frequency and should be disconnected in the border-line case. The frequency-dependent damping effect also may be automatically achieved by a series or consecutive connection of transverse oscillation dampers and additional springs.

It is known that in railway vehicles equipped with trucks, the truck axles execute a sinusoidal movement similarly as do those in freely rolling individual axles, and both truck axles also travel generally in tandem on the same sinusoidal wave path. Consequently, the truck frame also executes rotary movements in addition to the transverse movements. Due to the provision of a damper between the truck and the vehicle frame, for example a bridge carrier member, outside of the vertical transverse central plane of the truck, a phase shift between the transverse spring movement and the damping movement is effected. This has the result that the transverse oscillations of the vehicle body are damped in the resonance r'ange sufliciently that the amplitudes of the excited oscillations become smaller than the excitation amplitudes.

Both the rotary movement of the truck and the transverse movement thereof are influenced as a result of the damping action, which is phase-shifted with regard to the spring movement. This produces a directive force which constantly seeks to guide the truck within the central position within the rails and, thus, stabilizes the movement or course of the truck and simultaneously reduces the excitation amplitudes. By simultaneously reducing the ratio of the amplitude of the excited oscillation 'to the excitation amplitude, considerably improved moving or running properties are obtained in the resonance range.

The invention will be further illustrated by reference to the accompanying drawings in which FIGURE 1 is a bottom schematic view of one half of a truck-equipped railway vehicle in which one of the trucks is shown.

FIGURE 2 is a graph in which the ratio of the oscillation amplitude to the excitation amplitude is plotted over the excitation frequency.

FIGURE 3a shows a first position illustrating the principle of the phase shift between the spring movement and the damper movement in a transverse direction, the spring suspension system having just attained the non-deflected central position while the damper has attained a greater deflection due to rotary movement of the truck,

FIGURE 3b illustrated a further position wherein there is an increase in the transverse spring deflection and increased deflection of the damper.

FIGURE 30 illustrates a further position wherein the damper deflection is decreasing while the spring deflection has just attained its maximum value,

FIGURE 3d illustrates a further position wherein the deflection of the damper has been further reduced while the spring deflection still has a certain value,

FIGURE 3e shows a further position wherein the spring deflection is zero and the damper has a negative deflection.

FIGURE 4 is a fragmentary view in elevation of a portion of a truck and a vehicle body,

FIGURE 5 is a fragmentary top view of a portion of the truck and vehicle body of FIGURE 4,

FIGURE 6 is a fragmentary view in elevation of a portion of the truck of FIGURE 4 showing the spring suspension,

FIGURE 7 is a fragmentary view of the truck frame of FIGURE 4 showing the knife-edge suspension,

FIGURE 8 is an end view of the suspension shown in FIGURE 7,

FIGURE 9 is a sectional view taken on line CC of FIGURE 10,

FIGURE 10 is a top view of a three-axle truck,

FIGURE 11 is a sectional view taken on line AA of FIGURE 9,

FIGURE 12 is a schematic view of a railway vehicle showing dampers mounted toward the ends thereof,

FIGURE 13 is a schematic view of a railway vehicle showing dampers mounted toward the center thereof,

FIGURE 14 is a schematic view of a railway vehicle showing dampers mounted in front of and behind the transverse central plane of the trucks,

FIGURE 15 is a view in elevation showing a damper connection to a truck,

FIGURE 16 is a sectional view of the connection shown in FIGURE 15,

FIGURE 17 is a schematic view of switch means employed to reverse traveling direction,

FIGURE 18 illustrates a hydraulic damper,

FIGURE 19 illustrates a pneumatic damper,

FIGURE 20 illustrates an electrical damper,

FIGURE 21 illustrates a damper in the form of an eddy-current brake,

FIGURE 22 shows a construction whereby frequencydependent damping is effected by means of a series connection with an additional spring,

FIGURE 23 shows another construction whereby frequency-dependent damping is effected by means of a series connection with an additional spring, and

FIGURE 24 shows still another construction whereby frequency-dependent damping is effected by means of a series connection with an additional spring.

Referring to FIGURE 1, a bridge carrier member 1 of a railway vehicle has a truck 2 mounted thereunder, the truck having the wheel sets 3 and being mounted on a laterally movable rotary pin 6. The transverse springs 4 serve to absorb lateral impacts. In order to provide for a phase shift between the rotary movement and the translatory transverse movement during the sinusoidal path of the truck 2, a transverse oscillation damper 5 is mounted outside of the vertical transverse central plane of the truck 2 so that a phase shift will exist between the damping movement and the transverse spring movement.

Referring to FIGURE 2, the vertical line I indicates the position of the natural frequency of the undamped oscillation whereas the vertical line II indicates 1.4 times the amount of the natural frequency. The symbol a is the amplitude ratio of the undamped oscillation; b is the amplitude ratio of an equal-phase or cophasally damped oscillation with a damping factor of 0.3; c is the amplitude ratio of an oscillation with a phase-shifted damping, as obtained in accordance with the construction of the present invention; and the horizontal line d shows the value of the excitation amplitude and, respectively, the value or amount of the oscillation amplitude when the spring action is blocked.

It is apparent from the curve 0, illustrating the phaseshifting damping, that the oscillation amplitudes are considerably reduced by the construction of the present invention.

FIGURE 3 illustrates the principle of the phase shift between the spring movement and the damper movement in the transverse direction. The schematically shown portion of the vehicle body 1 moves in the traveling direction, indicated by the arrow, and the truck 2 with the wheel sets 3 travels on the sinusoidal track 7. The vehicle body executes only minor transverse movements which have been disregarded in the illustration. In FIGURE 3a. the transverse spring action or spring suspension system 4, being positioned in the center of the truck, has just attained the non-deflected central position thereof whereas the damper 5, being mounted outside of the transverse central plane, already has attained a greater deflection due to the rotary movement of the truck. FIGURE 3b illustrates the increase in the transverse spring path 4 and the increased deflection of the damper 5. In FIGURE 3c, the damper deflection already is decreasing again whereas the spring deflection has just attained the maximum value thereof. In FIGURE 3d, the deflection of the damper 5 has been reduced to zero whereas the spring deflection 4 still has a certain value. In FIGUR'E 3e, the zero position of the spring deflection has been reached once more whereas the damper already has a negative deflection.

In this traveling direction, the damper movement precedes or leads the spring movement, i.e., it is phaseshifted with respect to the spring movement. The transverse oscillations of the vehicle body change only the extent of the deflection, but not the phase shift between the spring deflection and the damper deflection. This phase shift results in a stronger damping or suppression of the transverse vibrations between the truck and the vehicle body because the damper paths are greater than in the case where the damper is positioned within the spring plane and because the lead of the damping force, as compared to the spring force, brakes the transverse deflection of the vehicle body more rapidly.

Referring to FIGURES 4, 5, and 6, the transverse damper 5 is mounted at the end face of a truck, specifically at the end piece or head assembly 7a, 0n the bracket 8. The attachment to the bridge carrier is made at the bracket 9. The truck is provided with coil springs 10 which provide the vertical and transverse spring suspension for the rocker 11. The vehicle body is supported on the bearing pivot or pin 12.

It is not absolutely necessary that the transverse suspension system of the vehicle include coil springs but, instead, the suspension system also may be constructed as a pendulum rocker. Of decisive importance is only the low inherent frequency of the transverse oscillations. FIGURES 7 and 8 show a part of the truck frame 2, the pendulums 14, the knife-edge suspensions or bearings 14 of the pendulums 13 as well as the link suspension or mounting 15 of the suspended spring box 16 upon which the rocker springs 10 are supported.

FIGURES 9, 10, and 11 show a three-axle truck 2 and a vehicle body portion 1 mounted above it which has a transverse spring suspension system including the coil springs 10. The transverse dampers 5 are mounted outside of the transverse central plane, namely in two planes with two dampers each. This illustrates an embodiment of the invention in which the transverse damper is not connected to the end piece or head assembly of the truck, the damping force is produced by two dampers which operate on the same line of action or effective curve, and the dampers are mounted in front of and behind the vertical transverse central plane with only those dampers being operative in each case which are positioned at the front, with regard to the traveling direction.

At the bridge carrier 1, the transverse dampers 5 are mounted on the brackets 9, and, at the truck frame 2, they are mounted on the brackets 8. In this case, the transmission of the tractive force between the truck and the vehicle body is effected by means of the tie rods 17.

FIGURES 4 through 11 show embodiments of the present invention including different transverse spring suspension means, i.e., coil springs, and pendulum rockers, and different damper arrangements, i.e., at the head assembly of the truck and at the longitudinal truck carrier, as well as the production of the damping force by means of different damper coefficients on the same effective curve (1 damper and 2 dampers).

FIGURE 12 shows an arrangement of the dampers toward the ends of the vehicle. In this arrangement, the transverse vibrations over the leading truck are damped or suppressed to an increased extent.

FIGURE 13 shows an arrangement of the dampers toward the center of the vehicle. In this case, the transverse vibrations over the trailing truck are damped or suppressed to an increased extent.

FIGURE 14 shows an arrangement in which the dampers are mounted in front of and behind the transverse central plane of the trucks. The phase shifts of the damping forces in front of and behind the transverse central plane would be mutually nullified without engagement of one damper and disengagement of the other, and the resulting damping force would be as it is in the arrangement for the damping in the spring plane. On the other hand, if only the dampers are operative which are positioned at the front of the trucks, with regard to the traveling direction, the desired phase shift between the damper deflection and the spring deflection is present.

Where the dampers are of the hydraulic or pneumatic type, those mounted at the front of each truck, with regard to the traveling direction, are rendered operative and those at the rear of each truck, with regard to the traveling direction, are rendered inoperative by electromechanical means shown in FIGURES 15 and 16. The damper 5 is connected with the frame bracket 8 by means of the links 18 and can move without resistance as long as the locking pin 19 is attracted by the coil 20. When the coil 20 is deenergized, the locking pin 19 is forced into the locking bore 21 by the spring 22 so that the damper eye or lug portion 23 is now locked with respect to the bracket 8 and the damper is then operative.

Where the dampers are of the electrical type, means also is necessary for rendering those dampers operative which are positioned at the front of each truck, with regard to the traveling direction, and for rendering inoperative those dampers which are mounted at the rear of each truck, with regard to the traveling direction. This is accomplished by means of the device for reversing the traveling direction shown in FIGURE 17. When the switch 24 is actuated, it connects the current supply 25 with the

supply lines

26 or 27, depending upon the traveling direction, which lines connect to the coils of the corresponding dampers.

A transverse vibration damper of the hydraulic type is shown in FIGURE 18. A piston 28, which displaces the hydraulic fluid 29, moves in the cylinder 30. The hydraulic fluid is forced through the spring-loaded

valves

31 and 32 which, as a result of flow resistance, produces the damping force.

A pneumatic damper is shown in FIGURE 19. The piston sleeves 33 and 34 displace the enclosed gas 35 during the movement of the piston rod 36. The gas flows through the valves 37 into the opposite chambers and the damping force is produced by the flow resistance.

An electrical damper is shown in FIGURE 20 The mounting lug 38 is connected with a coil core 39 which latter is magnetically excited by the coil 40 and moves in the short-circuited secondary coil 41. The magnetic field produces a voltage in the coil 41 whereby the damping force is generated. The extent or amount of the damping force may be regulated by means of a rheostat instead of short-circuiting the coil 41.

FIGURE 21 shows a damper in the form of an eddycurrent brake. The mounting lug 42 is connected with the coil core 43 which carries the coil 44 through which current flows. The magnetic field produces eddy currents in the tube 45 during movement of the coil and the damping force is produced as a result thereof.

The frequency-dependent damping also can be effected by means of a series connection with an additional spring. This principle is illustrated in FIGURES 22 to 24. In FIGURE 22, the damper 5 is not mounted directly on the damper eye or lug portion 46 but has a rubber spring 47 positioned in the lug portion 46 and the mounting bolt 48 is positioned within the rubber spring. The mounting bolt 48 is connected with the damper bracket 8. In case of a low damper velocity, i.e., at a low frequency, primarily the damper will move whereas the spring is deformed only to a limited degree so that nearly the full damping force of the damper is produced. With increasing damper velocity and frequency, the spring is deformed more markedly and as a result, the spring assumes an increasing amount of the total movement while the amount assumed by the damper will decrease, whereby the damping effect is reduced.

In FIGURE 23, the damper 5 also is not directly mounted on the mounting bracket through the mounting stud 49, but, instead, is connected with the fame bracket 8 with the interposition of the helical spring 50.

Similarly, in FIGURE 24, the mounting stud 49 for the damper 5 has the rubber spring 51 interposed between the stud and the frame bracket 8.

It will be obvious to those skilled in the art that many modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

What is claimed is:

1. In combination, a railway truck and a vehicle frame supported thereby, a transverse spring system between said truck and vehicle frame comprising spring means operatively connected between opposite sides of said truck and said vehicle frame to receive transverse forces, said spring means having a low natural transverse frequency so that resonance occurs at relatively low traveling speeds and the spring system is overcritical at high traveling speeds, and at least one transverse oscillation damper connected between said vehicle frame and a point on said truck spaced longitudinally from said spring means and the transverse central plane of the truck, the damping force of said damper being speed dependent, whereby during a sinusoidal path of the truck, a phase shift is present between the damper movement and a transverse spring movement, and transverse oscillations are damped at low traveling speeds with a damping force which is dependent upon the speed of the oscillations.

2. A railway truck construction according to claim 1 in which the damper is mounted adjacent the end of the vehicle.

3. A railway truck construction according to claim 1 in which the damper is mounted adjacent the center of the vehicle.

4. A railway truck construction according to claim 1 including means for disconnecting the damper.

5. A railway truck construction according to claim 1 in which one damper is mounted adjacent the end of the vehicle, one damper is mounted adjacent the center of the vehicle, and including means for disconnecting one of the dampers depending upon the direction of travel.

6. A railway truck construction according to claim 1 in which the damper is hydraulic.

7. A railway truck construction according to claim 1 in which the damper is pneumatic.

8. A railway truck construction according to claim 1 in which the damper is electric.

9. A railway truck construction according to claim 7 in which the damper is an eddy-current brake.

10. Apparatus as defined in claim 1 including control means for causing the damping force of said damper to be greater at low speeds and less at high speeds.

11. Apparatus as defined in claim 10 wherein said control means comprises resilient means connected in series with said damper.

References Cited UNITED STATES PATENTS 1,113,370 10/19-14 Ostendorf 267-15 1,179,182 4/1916 Hotmann 267-15 2,040,262 5/1936 Kruckenberg et a1. 105-174 2,071,831 2/ 1937 Hanna 105-82 2,153,389 4/1939 Perkins 105-199 2,241,757 5/1941 Baade 105-192 2,349,610 5/ 1944 Brunner 188-89 2,499,087 2/11950 Bourdon 105-199 2,676,550 4/1954 Burdick 105-199 2,705,926 4/ 1955 'Burdick 105-199 2,899,911 8/1959 Lich 105-199 2,973,969 3/1961 Thall 188-88 2,988,015 6/1961 Lich 105-199 X 3,020,006 2/1962 Warren 188-88 3,240,295 3/1966 Martinek et a1. 188-88 ARTHUR L. LA POINT, Primary Examiner.

HOWARD BELT RAN, Assistant Examiner.