GB2096237A - Isolation of auxiliary-device drive belt from torsional vibrations of an I.C. engine - Google Patents

Isolation of auxiliary-device drive belt from torsional vibrations of an I.C. engine Download PDF

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Publication number
GB2096237A
GB2096237A GB8205967A GB8205967A GB2096237A GB 2096237 A GB2096237 A GB 2096237A GB 8205967 A GB8205967 A GB 8205967A GB 8205967 A GB8205967 A GB 8205967A GB 2096237 A GB2096237 A GB 2096237A
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GB
United Kingdom
Prior art keywords
belt
pulley
drive shaft
drive
torsional vibrations
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB8205967A
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GB2096237B (en
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Wallace Murray Corp
Original Assignee
Wallace Murray Corp
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Publication date
Application filed by Wallace Murray Corp filed Critical Wallace Murray Corp
Publication of GB2096237A publication Critical patent/GB2096237A/en
Application granted granted Critical
Publication of GB2096237B publication Critical patent/GB2096237B/en
Expired legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
    • F16F15/10—Suppression of vibrations in rotating systems by making use of members moving with the system
    • F16F15/16—Suppression of vibrations in rotating systems by making use of members moving with the system using a fluid or pasty material
    • F16F15/167—Suppression of vibrations in rotating systems by making use of members moving with the system using a fluid or pasty material having an inertia member, e.g. ring
    • F16F15/173—Suppression of vibrations in rotating systems by making use of members moving with the system using a fluid or pasty material having an inertia member, e.g. ring provided within a closed housing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D35/00—Fluid clutches in which the clutching is predominantly obtained by fluid adhesion
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
    • F16H55/32—Friction members
    • F16H55/36—Pulleys
    • F16H2055/366—Pulleys with means providing resilience or vibration damping

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Devices For Conveying Motion By Means Of Endless Flexible Members (AREA)
  • Pulleys (AREA)

Abstract

A fluid-shear pulley (10) coupled to the engine crankshaft (12) operates on the principle of fluid-shear transmission of torque through liquid in the chamber (32) for the purpose of isolating torsional vibrations in the hub (14) of the pulley from the outermost, belt-driving portion (20) of the pulley. The fluid-shear pulley (10) thus serves to isolate torsional vibrations in the crankshaft (12) from the driving belt. This isolation of vibrations precludes attainment of resonant modes of vibration in the driving belt, thereby extending the life of the driving belt and making possible the use of a lighter and smaller driving belt. The belt (34), Fig. 2 (not shown). drives an alternator (36), a power steering pump (38) and a power brake pump (40). <IMAGE>

Description

SPECIFICATION Isolation of auxiliary-device drive belt from torsional vibrations of l.C. engine The present invention relates to the transmission of rotary power from the crankshaft or drive shaft of an internal combustion engine to various auxiliary power-consuming devices associated with the engine by means of a belt and pulley power-transmitting arrangement or system.
More particularly the invention relates to the isolation of the auxiliary-device drive belt from torsional vibrations present in the engine drive shaft.
Modern passenger cars as well as industrial/commercial vehicles usually require an alternator or generator driven from the engine crankshaft. The generator is necessary to supply electrical power for operating headlights, recharging the battery, supplying power to a radio, etc. Further, many passenger vehicles and very nearly all industrial vehicles of any size are equipped with power steering and power brakes.
These latter auxiliary power-consuming devices usually include a rotary pump, with the power required to operate them being derived from the engine crankshaft. It is customary to drive such auxiliary power-consuming devices by means of several belts, the belts being driven by one or more pulleys attached to the engine crankshaft or drive shaft.
It is known in the internal combustion engine art that torsional vibrations are continuously generated in the crankshaft by virtue of the inherent mode of operation and mechanical characteristics of an internal combustion engine. It is also known that the attainment of dangerously high resonant modes of such torsional vibrations may be inhibited or prevented by, for example, the placing of a torsional vibration damper on the crankshaft. However, such dampers do not eliminate torsional vibrations, they merely preclude the build-up of such vibrations, in certain resonant modes, to high magnitudes which could in some circumstances lead to failure of the crankshaft. Such vibrations are, oftentimes referred to as resonant vibrations.In addition to these (resonant) vibrations there exist other vibrations, these latter being of relatively high amplitude (50 double amplitude) and relatively low frequencies, such as those present at low and at engine idling speeds. These latter (slow) vibrations are inherent in six cylinder engines as 3rd order vibrations and in eight cylinder engines as 4th order vibrations.
Because torsional vibrations are always present, it is clear that a drive pulley attached to the drive shaft will also be subject to torsional vibrations, namely, the pulley will also exhibit torsional vibrations in a back and forth manner while it is turning unidirectionally with the crankshaft. With the tendency of automotive designers to employ a single belt to drive the auxiliary power devices (as opposed to the prior practice of employing a plurality of belts) the total length of the drive belt is accordingly extended.
While the number of drive belts from the driveshaft drive pulley to the driven auxiliary devices is diminished, thus saving expense, such new design procedures carry with them certain disadvantages.
One particularly noticeable disadvantage is present. Namely, the belt is more susceptible to wear due to the attainment of oscillations, in turn derived from the torsional vibrations of the crankshaft to which the pulley is attached. The socalled slow vibrations are particularly troublesome in this respect. With a conventional pulley, the periphery of the pulley will obviously transmit oscillations to the belt which passes around and is driven by it. These oscillations, particularly with longer drive belts, some of which are termed Poly-V belts, can in certain circumstances result in the attainment of undesirably high vibration amplitudes. In turn, large amplitude vibrations of the drive belt may result in shorter belt life, improper contact between the drive belt and its driven auxiliary devices, and in some cases the belt may be thrown completely off the pulleys.
According to one aspect of the present invention, there is provided in an installation including an internal combustion engine and at least one auxiliary device, a pulley and belt system for transmitting power from the drive shaft of the internal combustion engine to the said at least one auxiliary device, said drive shaft during engine operation possessing torsional vibrations as it unidirectionally rotates, and the belt and pulley system comprising a drive pulley mounted on the engine drive shaft, at least one driven pulley for driving the said at least one auxiliary device, and a belt engaged around said pulleys, the drive pulley being of the fluid shear type wherein a fluid coupling is provided between a pulley hub portion which is rigidly coupled to the engine drive shaft, and a radially-outermost pulley portion which is engaged by the belt, the fluid coupling serving to at least partially isolate the belt from torsional vibrations of the drive shaft to thereby lessen the occurrence of large amplitude vibrations in the belt arising from said torsional vibrations.
According to another aspect of the present invention, there is provided a method of isolating an auxiliary-device drive belt from torsional vibrations present in the drive shaft of an internal combustion engine, said belt engaging around a drive pulley carried by the drive shaft and at least one driven pulley attached to an associated driven auxiliary device, the method comprising the step of using as the drive pulley a pulley having a fluid coupling between a hub portion thereof which is connected to the drive shaft and a radially outermost, belt-engaging portion, whereby torsional vibrations in the drive shaft are isolated from the belt driven by it, to thereby lessen the occurrence of large amplitude vibrations in the belt and non-uniform rotation of auxiliary power devices, due to torsional vibrations in the drive shaft.
The use of a fluid-shear type pulley as the belt drive pulley inhibits the attainment of undesirably high belt vibrations, caused by both resonant vibrations and by slow vibrations both in a transverse mode and in a longitudinal mode.
The construction and functioning of fluid-shear type pulleys is already known. However, the use of this type of pulley to isolate an auxiliary-device drive belt from torsional vibrations in the drive shaft of an internal combustion engine has not previously been proposed.
An embodiment of the invention will now be particularly described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a cross-sectional view of part of a crankshaft-mounted drive pulley of a belt and pulley system used to transmit power from the crankshaft of an internal combustion engine to auxiliary power-consuming devices; and Figure 2 is a schematic perspective view illustrating the belt and pulley system, incorporating the Figure 1 pulley, in combination with the crankshaft of an internal combustion engine and auxiliary power-consuming device driven from the engine via the belt and pulley system.
Referring now to Figure 1 of the drawing, the numeral 10 denotes generally a fluid-shear drive pulley which is fast for rotation with the crankshaft or drive shaft 12 of an internal combustion engine.
The shaft 12 passes through the centre of a hub portion 14 of the pulley, the hub portion being optionally provided with one or more angularly spaced apertures 1 6 to facilitate attachment of the crankshaft 12 to the hub portion 14. Such attachment is not illustrated for purposes of clarity. The axial location of the pulley along the shaft is not material to the practice of the present invention. The numeral 1 8 denotes an angularly continuous and radially extending rib or web member integrally attached to hub portion 14, the radially outermost portion of the former carrying an angularly continuous ring member or portion 17.The numeral 20 denotes the radially outermost portion or rim of the pulley, the surface of the rim being (optionally) provided with a plurality of angularly continuous grooves to facilitate frictional contact between the outermost pulley surface and a drive belt (not illustrated in Figure 1). The numeral 22 denotes a first side cover while the numeral 24 denotes a second side cover. These side covers are each angularly continuous. The numerals 26 and 28 each schematically denote a seal or seal bearing, the function of which is to permit relative rotation between the side cover members 22 and 24 which carry rim portion 20, and the hub portion 14 which carries the members 18 and 1 7. Such seal bearings are well known so-called shelf items, and any of a great variety of constructions of such seal bearings may be selected.The numeral 30 denotes an O-ring which may either be square or round in transverse cross-section, the O-rings serving to establish a fluid seal between the outer periphery of the rim portion 20 of the pulley and the radially outermost flanges of the side covers 22 and 24. The numeral 32 denotes an angularly continuous cavity between the exterior of ring-like members 1 8 and 17 and the interior surfaces of the side covers 22, 24, seal bearings 26 and 28 and rim portion 20. At its time of manufacture, the pulley 10 is provided with a viscous shear liquid which occupies and fills the annular cavity 32.
It will be understood that constructions of fluid shear pulleys themselves are already known, as shown for example in U.S. Patents 2,977,819 to Fujita, 3,498,431 to Sutaruk, and 3,910, 391 to Detty.
In operation, with a belt (not illustrated in Figure 1) running around a part of the circumference of the pulley 10 at rim portion 20 thereof, the crankshaft 1 2 transmits torque to the hub portion 1 4 by virtue of the rigid connection therebetween. All of the torsional vibrations of the shaft 12 are accordingly present in the motion of hub portion 14 during rotation. These motions are accordingly also present in the annular web 1 8 and the ring member 1 7. By virtue of fluid shear coupling, an action well understood by workers in the automotive arts, the unidirectional rotary motion of the hub portion 14 is transmitted to the rim portion 20 and associated covers 22 and 24 of the pulley.However, because of the fluid shear connection between the ring members 1 7 and 1 8 and the outermost rim portion 20 of the pulley 10, the relatively large back and forth twistings which represent the (slow) torsional vibrations of the crankshaft 12 are hardly transmitted at all to beltdriving rim portion 20. Thus, during operation, the side covers 22 and 24 together with pulley rim portion 20 rotate relative to ring members 1 7 and 18, this relative rotation being made possible by the presence of the rotary seal or seal bearing members 26 and 28 which also maintain the shear fluid in the annular cavity 32.
Referring now to Figure 2 of the drawing, the Figure 1 pulley is illustrated in combination with auxiliary power-consuming devices often found in modern internal combustion engines. The numeral 34 denotes a drive belt (typically a V-belt) driven by the pulley 10. The belt 10 is arranged to drive a first belt-driven auxiliary device such as an alternator 36, a second auxiliary device such as a power steering pump 38, and a third auxiliary device such as a power brake pump 40. It will be understood that the number and location of such auxiliary power-consuming devices relative to the pulley 10 may be varied.
From a consideration of Figures 1 and 2, the reader will now be in a position to comprehend that torsional vibrations of the crankshaft 1 2 as it is undergoing unidirectional motion, while transmitted to the hub 14 portion of the pulley 10 will be only very slightly transmitted, if at all, to pulley rim portion 20 and hence will effectively be absent from the drive belt 34. This lack of back and forth twistings of the periphery or rim portion 20 of pulley 10 will result in a reduced probability of build-up of undesirably high modes in the belt 34 of both transverse and longitudinal vibrations.
In turn, this will result in longer belt life and also a more uniform operation of the auxiliary powerconsuming devices 36, 38 and 40.

Claims (4)

1. In an installation including an internal combustion engine and at least one driven auxiliary device, a pulley and belt system for transmitting power from the drive shaft of the internal combustion engine to the said at least one auxiliary device, said drive shaft during engine operation possessing torsional vibrations as it unidirectionally rotates, and the belt and pulley system comprising a drive pulley mounted on the engine drive shaft, at least one driven pulley for driving the said at least one auxiliary device, and a belt engaged around said pulleys, the drive pulley being of the fluid shear type wherein a fluid coupling is provided between a pulley hub portion which is rigidly coupled to the engine drive shaft, and a radially-outermost pulley portion which is engaged by the belt, the fluid coupling serving to at least partially isolate the belt from torsional vibrations of the drive shaft to thereby lessen the occurrence of large amplitude vibrations in the belt arising from said torsional vibrations.
2. A method of isolating an auxiliary-device drive belt from torsional vibrations present in the drive shaft of an internal combustion engine, said belt engaging around a drive pulley carried by the drive shaft and at least one driven pulley attached to an associated driven auxiliary device, the method comprising the step of using as the drive pulley a pulley having a fluid coupling between a hub portion thereof which is connected to the drive shaft and a radially outermost, belt-engaging portion, whereby torsional vibrations in the drive shaft are isolated from the belt driven by it, to thereby lessen the occurrence of large amplitude vibrations in the belt and non-uniform rotation of auxiliary power devices, due to torsional vibrations in the drive shaft.
3. An internal combustion engine with a pulley and belt system for transmitting power to auxiliary power-consuming devices, said system being substantially as hereinbefore described with reference to the accompanying drawing.
4. A method of isolating an auxiliary-device drive belt from torsionai vibrations present in the drive shaft of an internal combustion engine, said method being substantially as hereinbefore described with reference to the accompanying drawing.
GB8205967A 1981-04-08 1982-03-01 Isolations of auxiliary-device belt from torsional vibratins of an i c engine Expired GB2096237B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US25220781A 1981-04-08 1981-04-08

Publications (2)

Publication Number Publication Date
GB2096237A true GB2096237A (en) 1982-10-13
GB2096237B GB2096237B (en) 1985-05-30

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ID=22955051

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GB8205967A Expired GB2096237B (en) 1981-04-08 1982-03-01 Isolations of auxiliary-device belt from torsional vibratins of an i c engine

Country Status (9)

Country Link
JP (1) JPS57167560A (en)
BR (1) BR8200250A (en)
CA (1) CA1181261A (en)
DE (1) DE3148602A1 (en)
ES (1) ES8300977A1 (en)
FR (1) FR2503819A1 (en)
GB (1) GB2096237B (en)
IN (1) IN156104B (en)
SE (1) SE8107037L (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3610415A1 (en) * 1985-03-29 1986-10-02 Bando Kagaku K.K., Kobe BELT DRIVE DEVICE AND METHOD
DE10012233A1 (en) * 2000-03-14 2001-09-20 Schaeffler Waelzlager Ohg Automotive pulley drive wheel with friction slip clutch and helical spring on a hub
DE10012232A1 (en) * 2000-03-14 2001-10-11 Schaeffler Waelzlager Ohg Belt pulley for internal combustion engines is mounted on hub with interposition of friction clutch having displaceable friction bush defining ring chamber containing coil compression spring
EP1452763A2 (en) * 2003-02-28 2004-09-01 Peugeot Citroen Automobiles Decoupling pulley and internal combustion engine equipped with such a pulley

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4227260A1 (en) * 1992-07-24 1994-01-27 Metzeler Gimetall Ag Vibration damper for engine crankshafts - has housing forming belt pulley for V=belts for secondary drives and acting as slip clutch to dampen torsion vibrations and protect belt.
DE19710965C1 (en) * 1997-03-17 1998-09-10 Univ Magdeburg Tech Device for reduction of vibrations in tractive drives
DE19929417C1 (en) * 1999-06-26 2000-10-19 Bayerische Motoren Werke Ag Reciprocating piston internal combustion motor has counterbalance shafts with viscosity rotary oscillation dampers geared to the crankshaft to drive ancillary and auxiliary assemblies at the motor without oscillations

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1484029A (en) * 1965-05-27 1967-09-13
GB1312941A (en) * 1970-04-16 1973-04-11 Holset Engineering Co Torsional vibration damper
GB1346052A (en) * 1971-04-19 1974-02-06 Powder Couplings Ltd Vibration dampers

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3610415A1 (en) * 1985-03-29 1986-10-02 Bando Kagaku K.K., Kobe BELT DRIVE DEVICE AND METHOD
US4725259A (en) * 1985-03-29 1988-02-16 Bando Kagaku Kabushiki Kaisha Belt drive method and apparatus
DE10012233A1 (en) * 2000-03-14 2001-09-20 Schaeffler Waelzlager Ohg Automotive pulley drive wheel with friction slip clutch and helical spring on a hub
DE10012232A1 (en) * 2000-03-14 2001-10-11 Schaeffler Waelzlager Ohg Belt pulley for internal combustion engines is mounted on hub with interposition of friction clutch having displaceable friction bush defining ring chamber containing coil compression spring
EP1452763A2 (en) * 2003-02-28 2004-09-01 Peugeot Citroen Automobiles Decoupling pulley and internal combustion engine equipped with such a pulley
FR2851805A1 (en) * 2003-02-28 2004-09-03 Peugeot Citroen Automobiles Sa DECOUPLING PULLEY AND INTERNAL COMBUSTION ENGINE HAVING SUCH A PULLEY
EP1452763A3 (en) * 2003-02-28 2005-11-16 Peugeot Citroen Automobiles Decoupling pulley and internal combustion engine equipped with such a pulley

Also Published As

Publication number Publication date
FR2503819A1 (en) 1982-10-15
IN156104B (en) 1985-05-11
BR8200250A (en) 1982-11-23
GB2096237B (en) 1985-05-30
DE3148602A1 (en) 1982-10-28
ES508411A0 (en) 1982-11-01
SE8107037L (en) 1982-10-09
JPS57167560A (en) 1982-10-15
ES8300977A1 (en) 1982-11-01
CA1181261A (en) 1985-01-22

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PCNP Patent ceased through non-payment of renewal fee