WO1999024734A1

WO1999024734A1 - Torsion damper

Info

Publication number: WO1999024734A1
Application number: PCT/US1998/024521
Authority: WO
Inventors: Bruce A. Skaggs
Original assignee: Rockford Powertrain, Inc.
Priority date: 1997-11-07
Filing date: 1998-11-03
Publication date: 1999-05-20
Also published as: AU1415699A

Abstract

A torsion damper disposable between an engine and a drivetrain of a vehicle for allowing the torque generated by the engine to be transmitted to the drivetrain while tuning output torque fluctuations. The torsion damper (10) includes a drive plate (12) connected to and rotated by the engine, a retaining plate (14) connected to the drive plate so that the drive plate and retaining plate rotate together, and a driven plate (16), mounted between the drive plate and the retaining plate and and angularly displaceable with respect to the drive plate and the retaining plate, connected to the drivetrain. A frist friction plate (18a) is provided between the drive plate and the driven plate and a second friction plate (18b) is provided between the retaining plate and the driven plate. The first and second friction plates are identical and include an enlarged frictional surface and a plurality of laterally extending flanges (58). The enlarged frictional surfaces allow the friction plates to be frictionally driven by the drive and retaining plates, respectively, and the flanges, which engage with corresponding windows (44) in the driven plate, allow the friction plates to mechanically drive the driven plate. First and second identical biasing springs (56) are associated with each of the friction plates for enhancing the frictional engagement and an energy storage element (46) is operatively disposed between the drive and retaining plates and the driven plate for tuning the output torque fluctuations when slippage occurs in the frictional engagement.

Description

TORSION DAMPER

FIELD OF THE INVENTION

This invention relates generally to transmission systems and, more

particularly, relates to a torsion damper for use in a torque transmission system

BACKGROUND OF THE INVENTION

Torsion dampers of the type under consideration are used in torque

transmission systems for tuning output torque fluctuations of an engine Current

torsion dampers are typically constructed to include a drive plate, a retaining plate,

and a driven plate The retaining plate is rigidly connected to the dπve plate

which, in turn, is connected to a flywheel associated with the vehicle engine The

flywheel functions to cause the retaining plate and the drive plate to rotate

together The driven plate, mounted between the retaining plate and the drive

plate, is connected to a vehicle dπvetrain A first drive assembly lies between the

drive plate and the driven plate and a second dπve assembly lies between the

retaining plate and the driven plate for use in fπctionally transmitting the engine

torque from the drive and retaining plates to the driven plate During moments of

engine torque fluctuations, slippage may occur between the drive and retaining

plates and the dπve assemblies, and, therefore, the driven plate, which results in

the compression of springs mounted between the dπve and retaining plates and

the driven plate The spπngs function to tune the noted torque fluctuations

TJ S Patent No 4,626,226 entitled "Torque Fluctuation Damper" to

Ka_jikawa et al , which issued on December 2, 1986, for example, discloses a

torsion damper having a first dπve assembly comprising two friction plates and a second drive assembly comprising a friction plate and a disc spring The first

drive assembly makes frictional contact with the drive plate and with an

intermediate plate in positive engagement with the dπven plate while the second

dπve plate makes frictional engagement with both the retaining plate and the

driven plate By way of further example, U S Patent No 5,558,579 entitled

"Torsional Damper Having A Resiliency Coupled Damper Element And A

Fπction Generating Device Mounted Within A Padded Window Of The Damper

Element" to Tsuchiya et al , which issued on September 24, 1996, discloses the

use of frictional blocks which function as the first and second drive elements

Unfortunately, while these examples of torsion dampers work for their

intended purpose, they are relatively costly to manufacture and repair owing to the

numerous different parts required in their construction and their complex

arrangement Furthermore, the use of numerous components which are subjected

to frictional forces also tends to undesirably decrease the relative durability of

these devices Another disadvantage is that the relatively small fπctional surfaces

associated with the frictional blocks, when used in the construction of torsion

dampers, undesirably tends to make the torsion dampers less consistent in their

operation

SUMMARY OF THE INVENTION

From the foregoing, it is evident that a need exists in the art for a torsion

damper which overcomes the deficiencies above-noted Accordingly, the present

invention is directed to an improved torsion damper which generally includes a

dπve plate connected to and rotated by the engine, a retaining plate connected to and simultaneously rotated with the drive plate, and a driven plate mounted

between the drive plate and the retaining plate and angularly displaceable with

respect to the drive plate and the retaining plate. The dπve plate is connected to

the dπvetrain A first friction plate is provided between the drive plate and the

driven plate and a second friction plate is provided between the retaining plate

and the driven plate The first and second friction plates are identical in

construction and include an enlarged frictional surface and a plurality of laterally

extending flanges. The enlarged frictional surfaces allow the friction plates to be

fπctionally driven by the dπve and retaining plates, respectively, and the flanges,

which engage corresponding windows in the driven plate, allow the fπction plates

to mechanically dπve the dπven plate First and second identical biasing springs

are associated with each of the friction plates for enhancing the frictional

engagement. An energy storage element is operatively disposed between_the

dπve and retaining plates and the driven plate for tuning the output torque

fluctuations when a slip occurs in the frictional engagement

In this manner, as will become apparent from the descπption that follows,

the present invention has, among other advantages, the advantages of providing a

torsion damper which, minimizes the number of parts which must be specifically

manufactured for use in its construction resulting in a device which is relatively

less costly to manufacture, includes components which are especially adapted for

ease in construction and/or removal resulting in a device which is relatively easier

and less costly to manufacture and/or repair; reduces the number of components

which are subjected to frictional wear resulting in a device which is relatively more durable, includes components which are configured to enhance frictional

engagement resulting in a device which is relatively more reliable in its operation,

and minimizes the losses in the rotational power transmitted between the vehicle

engine and the dπvetrain by providing a torsion damper which is more accurately

designed to respond to a predetermined amount of torque fluctuations

A better understanding of the objects, advantages, features, properties and

relationships of the invention will be obtained from the following detailed

descπption and the accompanying drawings which set forth illustrative

embodiments and which are indicative of the various ways in which the principles

of the invention may be employed

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention, reference may be made to

preferred embodiments shown in the following drawings in which

Figure 1 is a front elevational view of a first embodiment of a torsion

damper constructed in accordance with the present invention,

Figure 2 is a cross-sectional, side elevational view of the torsion damper

taken along line 2-2 of Fig 1,

Figure 3 is an exploded, isometric v ew of the torsion damper of Fig 1,

Figure 4 is a close up, partially cut away view of an area of the torsion

damper of Fig 1,

Figure 5 is a front elevational view of a second embodiment of a torsion

damper constructed in accordance with the present invention, and Figure 6 is a cross sectional view of the torsion damper of taken along line

6-6 of Figure 5.

DETAILED DESCRIPTION

Referring now to the figures, wherein like reference numerals refer to like

elements, there is illustrated in Figs. 1-4 a first embodiment of a torsion damper

10 constructed in accordance with the present invention. As discussed, the

torsion damper 10 is adapted to be disposed between an engine and a drivetrain of

a vehicle (not shown) for the purpose of allowing the torque generated by the

engine to be transmitted to the drivetrain while tuning output torque fluctuations.

Generally, the torsion damper 10 includes a substantially planar drive plate 12

which is adapted to be connected to and rotated by the engine, a substantially

planar retaining plate 14 which is rigidly and coaxially connected to the drive

plate 12 for simultaneous rotation with the drive plate 12, and a substantially

planar driven plate 16 which is coaxially mounted between the drive plate 12 and

the retaining plate 14 and which is adapted to be connected to the vehicle

drivetrain. Additionally, the torsion damper 10 includes first and second

substantially planar friction plates 18a, 18b which are coaxially disposed between

the drive plate 12 and the driven plate 16 and the retaining plate 14 and the driven

plate 16, respectively. During the operation of the torsion damper 10, which will

be described in greater detail hereinafter, the friction plates 18a, 18b are used to

transmit the rotation imposed upon the drive plate 12, and, therefore, the retaining

plate 14, to the driven plate 16. The dπve plate 12 may be rotated by a flywheel associated with the

engine. More specifically, in the illustrated embodiments of the invention, the

drive plate 12 is attached to the flywheel utilizing fasteners (not shown) which are

sized to engage a first plurality of apertures 22 disposed around the periphery of

the drive plate 12. The drive plate 12 further includes a second plurality of

apertures 24, disposed within the circumference created by the first plurality of

apertures 22, which are arranged to align with a plurality of apertures 26 disposed

around the periphery of the retaining plate 14. A like number of fasteners 28,

such as bolts or the like, are passed through the apertures 24, 26 for coupling the

drive plate 12 and the retaining plate 14 Additionally, a plurality of spacers 30,

through which the fasteners 28 pass, are disposed between the drive plate 12 and

the retaining plate 14. In this manner, the spaced attachment of the drive plate 12

and the retaining plate 14 serves as a housing to enclose various other

components of the torsion damper 10.

The driven plate 16, which is disposed between the drive plate 12 and the

retaining plate 14, includes a centrally formed, splined hub portion 32 for splined

connection to the vehicle drivetrain. As illustrated in Figs. 2 and 3, the hub

portion 32 is sized and arranged to pass through centrally disposed apertures 34,

36 in the drive plate 12 and the retaining plate 14, respectively. A pair of

retaining rings 38, which are adapted to engage the hub portion 32 to the outer

surfaces of the drive plate 12 and the retaining plate 14, may be used to maintain

the desired arrangement of the components. Additionally, in order to

accommodate the spacers 30, the driven plate 16 has a series of peripheral recesses 40 which are dimensioned in the direction of rotation of the driven plate

16 to be slightly greater than the diameter of the spacers 30 In this manner, the

dπven plate 16 is angularly displaceable relative to the drive plate 12 and

retaining plate 14 within the limits determined by the opposed edges of the

recesses 40

The drive plate 12 and retaining plate 14 are further formed with a

plurality of generally rectangular shaped windows 42a, 42b which are arranged to

register with a plurality of similarly shaped windows 44 formed in the driven plate

16 Within each of the registered windows 42a, 42b and 44 is disposed an energy

storage element 46, for example, in the form of coil spπngs 48, 50 Positioned

adjacent to each of the windows 42a, 42b is a pair of oppositely disposed,

outwardly extending, generally arcuate shaped flanges 52 The flanges 52

cooperate to form a housing around each of the windows 42a, 42b for retaining

the energy storage element 46 Each energy storage element 46, which is sized

and arranged to abut the opposed edges of the registered windows 42a, 42b and

44, functions to oppose the angular displacement between the drive plate

12/retaιnιng plate 14 and the dπven plate 16 In the illustrated embodiment, by

way of example, at least one of the coil springs 48, 50 is sized and arranged to

abut the opposed edges of the registered windows 42a, 42b and 44

The pair of identical fπction plates 18a, 18b, which are disposed between

the drive and retaining plates 12, 14 and dπven plate 16, are adapted to

fπctionally engage the drive and retaining plates 12, 14 and mechanically engage

the dπven plate 16 More specifically, each of the friction plates 18 has a frictional surface 54 which functions to provide the frictional engagement with

the inteπor wall of the plate 12, 14 As illustrated in Figs 1 and 2, it is preferred

that at least one of the drive plate 12 and the retaining plate 14 be provided with

slight recesses for accommodating the fπction plate(s) 18 for ease in assembly In

a preferred embodiment of the invention, the frictional surface 54 of each of the

friction plates 18a,18b is provided with an enlarged surface area of at least eleven

square inches which results from the frictional surface 54 having an outer

diameter dl of approximately four and one-half inches (which diameter is

approximately one-third of the approximately fourteen inch outer diameter

provided to the retaining plate 14) and an inner diameter d2 of approximately two

and one-half inches This enlarged, frictional surface area has the advantage of

enhancing the frictional engagement between the friction plates 18a, 18b and the

dπve and retaining plates 12, 14, respectively In other embodiments, the

frictional surface 54 may be dimensioned to provide at least 10 square inches of

frictional surface area

The frictional engagement between the components is further enhanced by

biasing the friction plates 18 into engagement with the appropπate plate 12, 14 by

means of a pair of identical disc springs 56 which are also coaxially aligned with

the drive plate 12 about the hub 32 Each of the spπngs 56 is preferably sized and

arranged between its associated friction plate 18a, 18b and the driven plate 16

such that the outer portion 56a of the springs 56 engages the associated fπction

plate 18 while the inner portion 56b of the spπngs 56 engages the driven plate 16

proximate to the hub 32 during assembly In this manner, a substantially even pressure is applied to the fπction plates 18a, 18b resulting m a relative increase of

the effective frictional contact between the friction plates 18a, 18b and its

corresponding driving member while minimizing the potential for uneven

fπctional wear during operation

To provide the mechanical engagement between the friction plates 18a,

18b, and the driven plate 16, the friction plates 18a, 18b are further provided with

a plurality of flanges 58 which extend laterally inward from the peπphery of the

fπction plates 18a, 18b The flanges 58 are adapted to engage the windows 44

formed within the dπven plate 16 More specifically, as illustrated in Figs 2 and

4, each of the windows 44 is provided with a radially, inward extending, generally

rectangular extension 44a within which the corresponding flanges 58 of both

friction plates 18a, 18b are accommodated Specifically, the flanges 58 cooperate

with opposed edges of the extensions 44a for providing a means for the friction

plates 18a, 18b to dπve the dπven plate 16 during operation The mechanical

engagement between the friction plates 18a, 18b and the dπven plate 16 also

encloses the spπngs 56 so that the spπngs 56 move with the fπction plates 18a,

18b and the driven plate 16 In this manner, wear which may result from the

relative movement between the fπction plates 18a, 18b, and the spπngs 56 and/or

between the driven plate 16 and the springs 56 during the operation of the device

is minimized

During the operation of the torsion damper 10, the drive plate 12 and

retaining plate 14 fπctionally transmit the output torque of the engine to the

friction plates 18a, 18b which, in turn, mechanically transmit the engine torque to the driven plate 16 In response to fluctuations in the engine output torque, the

frictional surfaces 54 of the friction plates 18a, 18b will slip over the associated

surfaces of the dπve plate 12 and the retainer plate 14 resulting in the relative

angular displacement between the dπve plate 12 and the retainer plate 14 with

respect to the dπven plate 16 In response to slippage, the energy storage element

46 will undergo compression to tune the engine output torque fluctuations It is to

be noted that the mechanical linkage of the friction plates 18a, 18b to the dπven

plate 16 functions to reduce the number of surfaces which may slip relative to one

another which, in turn, allows the torsion damper 10 to be more accurately

designed to respond to a predetermined amount of torque fluctuation In this

manner, losses in the rotational power transmitted between the vehicle engine and

the drivetrain, which often result when engine torque fluctuation are over-tuned or

under-tuned, may be minimized Additionally, it will be appreciated that the

enlarged surface areas of the friction plates 18a, 18b also function to more

efficiently dissipate the heat generated as a result of this slippage which further

functions to prolong the life of the components of the torsion damper 10

In a further embodiment of the invention, illustrated in Figs 5 and 6, the

components of the torsion damper remain the same except that the hub portion 32'

of the driven ring 16 is adapted for splined engagement with a yoke 70 which is,

m turn, adapted to be connected to a universal joint associated with a remotely

mounted transmission As such, it will be appreciated that the torsion damper 10

may be easily modified for different applications without requiring an extensive

amount of retooling In particular, the hub portion 32' is sized such that an interior surface 72 of the yoke 70 engages with the exterior surface of the

retaining ring 14. Additionally, a further retaining ring 74 is provided which

engages the yoke 70 and the outer surface of the hub portion 32'. In this manner,

engagement between the retaining ring 74 and the hub portion 32' in cooperation

with the engagement between the yoke 70 and exterior surface of the retaining

plate 14 provides a means to maintain the desired arrangement of the components.

The universal joint is attachable to the yoke 70 by using fasteners which are

adapted to mate with apertures 74 formed in the yoke 70. As the components of

this embodiment of the torsion damper remain relatively unchanged with respect

to the embodiment illustrated in Figs. 1-4, it will be understood that both

illustrated embodiments function the same and, accordingly, the operation of this

embodiment will not be described in greater detail herein.

While specific embodiments of the invention have been described- in

detail, it will be appreciated by those of skill in the art that various modifications

and alternatives to those details could be developed in light of the overall

teachings of the disclosure. Accordingly, the particular arrangements disclosed

are meant to be illustrative only and not limiting as to the scope of the invention

which is to be given the full breadth of the appended claims and any equivalent

thereof.

Claims

What is claimed is:

1. A torsion damper disposable between an engine and a drivetrain of

a vehicle for allowing the torque generated by the engine to be transmitted to the

drivetrain while tuning output torque fluctuations, the torsion damper comprising:

a drive plate adapted to be connected to and rotated by the engine;

a retaining plate connected to the drive plate so that the retaining plate and

the drive plate are rotatable together;

a driven plate, mounted between the drive plate and the retaining plate and

angularly displaceable with respect to the drive plate and the retaining plate,

adapted to be connected to the drivetrain;

a first friction plate and biasing spring assembly, disposed between the

drive plate and the driven plate, adapted to be frictionally driven by the drive plate

and mechanically drive the driven plate;

a second friction plate and biasing spring assembly, identical to the first

friction plate and biasing sp╧Çng assembly and disposed between the driven plate

and the retaining plate, adapted to be frictionally driven by the retaining plate and

mechanically drive the driven plate; and

an energy storage element, operatively disposed between the drive and

retaining plates and the driven plate, for tuning the output torque fluctuations

when slippage occurs between the first and second friction plate and biasing

spring assemblies and the drive and retainer plates, respectively.

2 The torsion damper of claim 1, wherein the first and second friction

plate and biasing spring assemblies both comprise a single friction plate and a

single disc sp╧Çng

3 The torsion damper of claim 1, wherein the first and second friction

plate and biasing sp╧Çng assemblies both comp╧Çse a f╧Çction plate having a

plurality of extending flanges and the driven plate has a plurality of windows,

each window adapted to accept one of the plurality of flanges from each of the

f╧Çction plates thereby providing a means for the first and second friction plate and

biasing spring assemblies to mechanically drive the driven plate

4 The torsion damper of claim 3, further comp╧Çsing a plurality of

energy storage elements operatively disposed between the drive and retaining

plates and wherein each of the plurality of windows are further adapted to accept

a corresponding energy storage element

5 The torsion damper of claim 1, wherein each of the energy storage

elements comp╧Çses first and second coil springs

6 The torsion damper of claim 1, wherein the drive plate has a recess

for generally accommodating the first friction plate and biasing spring assembly

7 The torsion damper of claim 6, wherein the retainer plate has a

recess for generally accommodating the second friction plate and biasing spring

assembly

8 The torsion damper of claim 1 , wherein the driven plate comprises

a splined hub portion for splined connection to the d╧Çvetrain

9 The torsion damper of claim 8, further comprising first and second

retaining rings wherein the first retaining ╧Çng is adapted to be mounted over the

hub portion and engage an outer surface of the d╧Çve plate and the second

retaining ring is adapted to be mounted over the hub portion and engage an outer

surface of the retaining plate

10 The torsion damper of claim 1, wherein the drive plate, the

retaining plate, the driven plate, and the first and second friction plate and biasing

spring assemblies are all coaxially arranged with respect to one another

11 The torsion damper of claim 1, wherein the first and second friction

plate and biasing spring assemblies each comprise a single friction plate having

an enlarged frictional surface

12 The torsion damper of claim 11, wherein each of the enlarged

f╧Çctional surfaces has an outer diameter which is approximately one-third of the

outer diameter provided to the retaining ╧Çng

13 The torsion damper of claim 11, wherein each of the enlarged

frictional surfaces has an area of at least 11 square inches

14 The torsion damper of claim 1, wherein the first and second friction

plate and biasing spring assemblies both have an enlarged frictional surface of at

least 1 1 square inches

15 A torsion damper disposable between an engine and a drivetrain of

drivetrain while tuning output torque fluctuations, the torsion damper comp╧Çsing a drive plate adapted to be connected to and rotated by the engine;

a retaining plate connected to the drive plate so that the retaining plate and

the drive plate rotate together;

a driven plate, mounted between the drive plate and the retaining plate and

angularly displaceable with respect to the drive plate and the retaining plate,

adapted to be connected to the drivetrain;

a first friction plate, disposed between the drive plate and the driven plate,

having a first plurality of laterally extending flanges wherein the first friction plate

is adapted to be frictionally driven by the drive plate and the first plurality of

flanges are adapted to engage with and mechanically drive the driven plate;

a second friction plate, disposed between the retaining plate and the driven

plate, having a second plurality of laterally extending flanges wherein the second

friction plate is adapted to be frictionally driven by the retaining plate and the

second plurality of flanges are adapted to engage with and mechanically drive the

driven plate;

a first biasing spring, trapped between the first friction plate and the driven

plate, for urging the first friction plate into frictional engagement with the drive

plate;

a second biasing spring, trapped between the second friction plate and the

driven plate, for urging the second friction plate into frictional engagement with

the retaining plate; and

an energy storage element, operatively disposed between the drive and

retaining plates and the driven plate, for tuning the output torque fluctuations when slippage occurs between the first and second friction plates and the drive

and retainer plates, respectively.

16. The torsion damper of claim 15, wherein the driven plate has a

plurality of windows each adapted to accommodate a corresponding one of the

plurality of flanges from both the first and second plurality of flanges.

17. The torsion damper of claim 16, further comprising a plurality of

energy storage elements operatively disposed between the drive and retaining

a corresponding one of the plurality of energy storage elements.

18. A torsion damper disposable between an engine and a drivetrain of

a drive plate having a recess formed therein adapted to be connected to

and rotated by the engine;

a retaining plate having a recess formed therein connected to the drive

plate so that the retaining plate and the drive plate rotate together;

a driven plate, mounted between the drive plate and the retaining plate and

angularly displaceable with respect to the drive plate and the retaining plate,

adapted to be connected to the drivetrain;

a first f╧Çction plate, disposed between the drive plate and the driven plate,

having a friction surface with an outer diameter which is approximately one-third

of the outer diameter provided to the retaining plate adapted to frictionally engage the recess formed in the drive plate and be driven thereby, and wherein the first

friction plate is further adapted to mechanically drive the driven plate;

a second friction plate, identical to the first friction plate and disposed

between the retaining plate and the driven plate, having a friction surface with an

outer diameter which is approximately one-third of the outer diameter provided to

the retaining plate adapted to frictionally engage the recess formed in the retaining

plate and be driven thereby, and wherein the second friction plate is further

adapted to mechanically drive the driven plate;

a first biasing spring, trapped between the first friction plate and the driven

plate, for urging the first friction plate into frictional engagement with the recess

formed in the drive plate;

a second biasing spring, identical to the first biasing spring and disposed

between the second friction plate and the driven plate, for urging the second

friction plate into frictional engagement with the recess formed in the retaining

plate; and

an energy storage element, operatively disposed between the drive and

when slippage occurs between the first and second friction plates and the drive

and retainer plates, respectively.

19. The torsion damper as recited in claim 18, wherein the friction

surfaces of the first and second friction plates each has an area of approximately

11 square inches.

20. A torsion damper disposable between an engine of a vehicle and a

remotely positioned transmission for allowing the torque generated by the engine

to be transmitted to the transmission while tuning output torque fluctuations, the

torsion damper comprising:

a drive plate adapted to be connected to and rotated by the engine;

a retaining plate connected to the drive plate so that the retaining plate and

the drive plate rotate together;

a driven plate mounted between the drive plate and the retaining plate and

angularly displaceable with respect to the drive plate and the retaining plate;

a yoke connectable to the transmission and adapted to be driven by the

driven plate;

a first friction plate and biasing spring assembly, disposed between the

and mechanically drive the driven plate;

a second friction plate and biasing spring assembly, identical to the first

friction plate and biasing spring assembly and disposed between the driven plate

mechanically drive the driven plate; and

an energy storage element, operatively disposed between the drive and

when a slippage occurs between the first and second friction plate and biasing

spring assemblies and the drive and retainer plates, respectively.

21. The torsion damper of claim 20, wherein an inner face of the yoke

engages an outer face of the retaining plate.

22. The torsion damper of claim 21, wherein the yoke is adapted for

splined connection with the hub portion.

23. The torsion damper of claim 22, wherein the yoke is sized to

extend beyond an end of the hub portion and the damper further comprises a

retaining ring adapted to be mounted over the yoke and engage an end surface of

the hub portion.