GB2228062A

GB2228062A - Flywheel assembly

Info

Publication number: GB2228062A
Application number: GB9003127A
Authority: GB
Inventors: Hirotaka Fukushima
Original assignee: Daikin Manufacturing Co Ltd
Current assignee: Exedy Corp
Priority date: 1986-01-30
Filing date: 1990-02-12
Publication date: 1990-08-15
Anticipated expiration: 2007-01-26
Also published as: GB9003127D0; GB2228061B; GB9003126D0; GB2228062B; GB2228061A

Description

1 JSS080290 This inventlorl relates to a flywheel assembly which

absc---!-s a vi-l,-- at-4on of an inputted power.

In F i g. 3 which is a schematic strUcturaldiagram of a c=ventional clutCh. disc, 10 is an encine input side and 12 is an output side from which a power is t=ansmitted to a t=ansm,.ission, for examnle. A f-4--st-stace torsion 14a, a seccnd-staae tcrslon spring 14b and a third stace tcrsic= smr-4.,ic 14c are -nter::osed between th.e inpuz s44.de 10 and the our-zu-. side 12, and t-orsion anale plays -14d & 14e are pr--vided to the seccnd-stage torsion smr-.;=c 14b and the thi-rd-stage torsion spring 14c. a fi=st-stage hvszeres.is to=:-ue generat4 =g mechani_cm 16a, a second-szaaa hysteresis torque generating mechanism 16b and a th-4=d-s--ace hysteresis torque generating mechanism 16c are intermosed therebezween in the same manner, and plays 16d & 16e are provided to the secc-ndstage hysteresis torque generat-4ng mechanism 16b and the third-stage hysteresis torque generating mechanism 16c, respec=ively.

1 1 i i 1 i JSS080290 !"- the above-mentioned conventional embodiment, a t=sion characteristic changes f=cm a fIrst-stage characteristic KdL and a fi_rst-stage hysteresis character- istic MU which are both generated by the f.4rst-stace smr-4ng 14a together wit.h. the first-stage hysteresi_s torque generating mechanism 16a., to a third-stace torsicr.

c.liarac=er-4s-L--4c Kd3 and a third-stage hysteresis character- 1 1 1 1 1 1 istic which are bor-b. generated by thi-d-staae torsion SDrina 14c tcaether with the. third-stage hysteresis torque cerieraz--.-,g mec-;.,an-4sm 16c, with. an increase in a torsion a1 nale as shown by Fig. 4.

However, this characteristic 1 1 1 has th.e following disadvantage.

Nameiv, it is desired to set the fst-stage torsion 1-3 Kd_ --c small values as a countermeasure acainst noises such 1 as ce-== c generated a t=ansmission in its neuz=-=' mosJ-:.---4on and gear chazte=-4--as generated from the -k=ans=-=sion and a differential gear in their driving posi- t -4 cr.. On the conz=ary, however, it is necessary to sez e =.: --=sz-stace tors' on cliaracze=ist.; c Kdl J_ - cnaracter!3t-4c Kd:3 to large values as a counter- measure against low frequency vibrations.

1 1 Accc 4 r,44=gly, the torsion charac-er4st4c of FiC3.

is to ba ses up separately ac--ord:nc to. a characteristia- i 1 i i i JSS080290 reau-4----d to each vehicle. Further, since a level of for noise and vibration control of clutch becomes increasingly higher in recent years, it sometimes --equ-4--ea to realize a characteristic which. can never be dealt with 3 by the convenzional, structure, such as the case that the confl--ct--ng countermeasures against the noise and the low frequency are required simultaneously as mentioned above- Therefore, such technologies have been develczed that vibrations: from encine are positively absorbed even by the 10 flywheel.

13 There have been pr.;or arts, for examnle, that an auxflywheel 26a and a damper 26b are interposed in series between a conventlonall clutch. disc 20 & f lywheel -9 222 and a crank shaft 24 as shown by Fig. 5, and the aux-4-lia=:,., -.0- "vwhee-". 26a is installed in parallel with the f llywheel 22 throuch a torsion spring as shown by Fig. 6.

With reca--d to this kind of flvwhee-l assembly, also the a=licant of the present invention has developed and am=1-4--d a flywhee-11 assembly as shown in Fig. 7 for a cateaz, which includes a first flywheel 104 fastened to an encine crank shaft- 100 and engaged and disengaged by a clutch disc 102, a second flywheel 106 installed concentrically with the first flywheel and set tc a snec-4--,f-4-od mass, 3 a dammer mechanism 108 resiliently coupling the both flywheels, and a f=- 4cli4on damping mechanism 112 which t_ransmits an output from the second flywheel 106 to a spline hub 110 of the clutch disc 102 and damps its vibration only when said clutch disc 102 contacts with the first flywheel 104. (Japanese Patent Application. No. 6(-442-Q8, United. States Patent Amolication No. 836,365, West German Patent Application No. 36 07 398.9, French Patent Application No. 8603211, Korean Patent Application No. 86/1451).

Incidentally, it is desired to further imurove this prior art- of the present applicant.

in the f-4--st place, for examcle, an inertial damcer sez a snec-4-.':ied mass may be equipped to a propeller shaft -Jn or-"er to damn a torsional vibration of a so-called d=-4ve-zransm.,ssiori system from an engine output shaft. to a dr-"7e-,i wheel of automobile. T.h.e applicant of the presenz invention gets to invent this invention -..while i--tending. to damn the torsional vibration of the drivetransmission system by the use of a flywheel- assembly in 2Cplace of' the inertial dammer.

In the second place, a facing 116 of the friction. damning mechanism 112 is connected to a. bolt 118 of the second flywhee-t 106 side in said conventional embodiment, so that i i 1 i i i i i i 1 1 i i i 1 i i i it be=mes necessary to for-n a hole 120 an the fi=st fly wheel 104 and a working range of the damr,4nc mec.li anism 112 is also liziitted to within an area of the hole 120.

3 Further, in case when a power of a stater motor is in=utze,- from a ring gear 122 of the fIrst flywheel 104 at the,.--4me of starting the encine, the power is transmitted thrcuch the da=er'mechanism 108 to a crank shaLt; so that it is necessary to determine a spring characteristic of the io da=er mechanism 108 in acCordance with a load of the stater motor to cause a small decree of freedom of desian.

Mo r e a v er friction SM1ine hub 1.10 IZ.1.e -:-=c-4ng 11-6 a of in the third place, a ccnec disc spring 114 darr=inc mechanism 112 -'s -4nszalled on the and a connect-4.,la plate 1 13 which c=nects to the smline hub 110 is prcv-4ded, so that the clutch, disc 102 beccmes cc-nr)licated in said c=ventional embodiment. Fu::.:.termcre, the fac-4na 116 -LS also fixed to the bolt 118 of the second flywheel LO 6 side, so that the flvwheel assembIv and the clutCh disc 102 are recui.-ed to be co=leteiv disassembled when the worn-out facing 116 is replaced with new one and the renlace=ent work becomes difficult.

1 1 1 1 A general object of the present invention is tz- further imr)-cve the flywheel assembly in many aspects, in which i i the flvwheel is divided into two blocks and the friction damming mechanism absorbing vibration is installed.

A detailed object of the invention is to provide a 9l,iwhee-'. assembly which can damp a torsional vibration of a dr --:ve-t--ansm.,s s ion svs-%P-.m by ut--liz-4ng a part of a fly- wheel mass.

1 1 i 1 Another detailed object of the invention is to provide a asserrably which effectively absorbs the v-4b--at--;cn enc:4ne and at the same time simplIfies the st--uc-..ire clutchl disc, and requires only an easy maintenance.

further detailed ob-ect of the invention. is to pro- J i vide a flvwheel assembly which. enlarges a wor.k.zc rance of th.e friction damming mechanism and at the same time eases a design of the damper mechanism.

A still further detailed object of the invention is i to prcv--;de a flywheel assembly which effectively absorbs the vibration from engine and at the same time si=lifies the sz=ucture of the clutch disc, and reauires onIv an easv 1 1 i maintenance.

JSS080290 - 7 - With these objects in view the present invention provides a flywheel assembly including a first flywheel fastened to an engine crank shaft and engaged and disengaged by a clutch disc, a second flywheel supported concentrically with the first flywheel, a damper mechanism resiliently connecting the both flywheels, and a friction damping mechanism which transmits an output from the second flywheel to a spline hub of the clutch disc and damps a vibration only when said clutch disc contacts with the first flywheel, the second flywheel being set to a specified mass which is determined in relation to a drive transmission's inertial mass; characterised by that a friction member of the friction damping mechanism is fastened to a clutch plate of the clutch disc, the clutch plate and a sub-plate are clamped by a connecting pin to the spline hub, an annular plate connected to a clutch facing provided on a radially outer peripheral part of the clutch disc is installed between the clutch plate and the sub-plate in a circumferentially rotatable manner, a torsion spring is interposed between the annular plate, the clutch plate and the sub-plate, and spring member of the friction damping mechanism is connected to said second flywheel.

The flywheel assembly accomplishes the abovementioned objects while connecting the friction damping mechanism to a part of the clutch disc.

1 i JSS080290 Brief Description of the Drawings

Fig. 1 is a vertical sectional partial view of a clutch applied with a third embodiment of the invention.

Fig. 2 is an enlarged view of the clutch disc of Fig. 1.

Fig. 2a is an essential vertical sectional view showing an alternate example of the third embodiment.

Fig. 3 is a structural skelton diagram showing a conventional embodiment.

Fig. 4 is a graph showing a torsion characteristic of the conventional embodiment of Fig. 3.

Figs. 5 & 6 are structural skelton diagrams showing further prior art embodiments.

Fig. 7 is a vertical sectional view showing a further prior art i i i i i 1 1 1 1 i i JSS080290 - 9 A preferred embodiment of the invention is a flywheel assembly including a first flywheel fastened to an engine crank shaft and enaaaed and disengaged by a clutch disc, a second flywheel supported concentrically with the f irst f lywheel and set to a specif -4ed mass, a damwer mechanism which connects the both f Ivwheels..esir-Jent-ly, and a friction damning mechanism which t=ansnii.i-,,s an output from the second flywheel to a sm.L-,ne hub of the clutch disc and damns a torsional vibration of the dx.-4ve--t--ansmission system only when said clutch disc contacts with the first flywheel; c.;-.aracter-'--ed by that a friction member of the fric4.--'--n da=ing mechanism is fastened to a clutch plate of the clutch disc, this clutch plate and a sub-clate are fixed to the splIne hub by a connecting pin, an annular plate consecutive to a facing provided at a rad-Jally outer peripheral part of the clutch disc is installed between the clutch plate and the sub-plate.L.=eely slidingly in a c-4=--umiere=t-4al direction, a torsion spring is interposed between the annular plate, the clutch plate and the sub-plate, and a spring member for the f-riction damning mechanism-is connected to said second flywheel.

JSS080290 Th e above-mentioned flywheel third embodiment functions as follows:

assembly of the The spring mem.ner is installed at the second flywheel side and the f----ct-4on member is fastened to the clutch plate of the clutch disc, so that the mem.ner ccnnec4.--4na the friction member to the clutch disc becomes unnecessary. When the friction member is worn out, the friction member is to be "rem-laced to gether with the clutch disc.

A clutch according to claim 1 W-11-1 be described hereunder with reference to Fig. 1.

in Ficj. 1, 30 is an enaine, crank shaft. A 'L irst --vwhee-", is f ixed to a rear end of the crank sha-."

by a bolt 31a. A facina 35a of the clutch disc 34 13 -'s adapted to contact with an annular surface 33a of L-he first flywheel 32. A clutch cover 35b is -aszened to a rear end face of the first flywheel 32, and a pressure plate 35e is held to the clutch cover 35b throuah a wire rinc 35c and a diaphragm spring 35d.

The first flywheel 32 is form.ed into an approx-4 mately disc-like shame, and a second flywheel- 36 is installed at a front of the first flywheel 32 ratatably and concentrically wit.1.1 the first flywheel 32.

1 1 i 1 i 1 i 1 1 i 1 i i i i i JSS080 2 9 0 The second flywheel 36 is formed into an approxirnately annular shape having a flange 37a at its inner peripheral part and set to a specifled mass adacted to an inertial mass of the dr-4ve-t.-ansmission system such as a transmission (not shown) etc. connected to a rear stage of the clutch.

A torsion spring 38 (damper mechanism) is commresS.41.vely installed between an outer per4pheral par- of the second flywheel 36 and the first flywheel 32 to resiliently connect the first flywheel 32 to the second f lvwheel 3 6.

A spring constant of the torsion spring 38 is so determined that a resonance point 39a of a character- j'9 -- - revresen-4na a relat4on between a value 13 e27/el and an engine rotation N is generated at a rotation region lower thah' an idle r--zat-4cn 1, supposing that a chance in angular velocity of: the first flywheel is el and a chance in velocitv of the clutch disc spline hub 35f is 92.

2 Accordingly, at a- normal rotation region higher t.han the idle rotation 1, the value 1e2/ell decreases with an. increase in the rotation and the change in 1 i JSS080290 1 i 1 i i angular velocity e2 of the clut=h disc spline hub c= a rotational fluctuation of the transmission etc.

is practically very small.

1 i A friction damming mechanism 140 is interposed between said second flywheel 36 and the spline hub 35f of the clutch disc 34, and the friction damming mec-a- nism 140 is adapted to damn vibrations which are transm-,zted to the first flywheel 32 when the facing 35a c--,-,zacts with the pressure surface 33a of the. fIrst ic f17wheel 32.

1 i The friction damming mechanism 140 is composed c.= a bolt 142, a retainina rina 144, a coned disc member), a facing 148 a.0=-;ct4on plate and an intermediate 52. etc. A threaded part- 142a of the bolt screwed in a fiance 37a of the second flywheel 6, and the bolt 142 pierces a hole 33c ofthe first 0..

---wheel 32.

The retain;ng r4na 144 fastened, for exa=lel by a small screw etc. fits onto a rear end 9 0 L_ face of the bolt 142.

The retaining ring 144 is fcr:ned into an approximately annul ar shame extendina in the c-4=cum=erent-4al di=ection of the first flywheel 32 and sec-nd flvwheel 36, and notches 144b are formed i i 1 i i i i JSS080290 io 1:,- at plural places of an outer peripheral flange 144a of the retaining ring 144 with equal distances legz therebetween in its c-,--c,",mferent-,al di- -ect-4on.

A claw 152a which is provided integrally on an outer peripheral face of said intermediate plate 152, in the notch 144b and the intermediate plate 152 is connected to the retaining ring 144 through the notc.'^. 144b and the claw 152a freely slidingly in their axial d----ect--on.

The coned disc spring 146 is interposed between the retaining rinc 144 and the intermediate plate 152, and the coned disc spring 146 urges the intermediate L-"a-.e 152 backward i. e. toward the f-.--st flywheel j2.

The coned disc spring 146 is also formed into the an.nular shame extendina in the c e rent -4 al direc t.:_n of the fl-rst flywheel 32 and the second &flywheel 36.

The facina 148 is disposed at opposite side to a pressure surface 152b of the intermediate plate 152, and the facing 148 is fastened to a clutch plate 160 of the clutch disc 34, which will be described later in details, by means of such as banding.

The clutch disc 34 is formed as shown by Fig. 2. The clutch plate 160 is formed into an approximately JSS080290 d-4-cc-l-'ke shape, and holes.160a are at four places, for exarmle, in the c-4l-c,I,Mferen.lal direction.

A sub-plate 162 is in'stalled opposite to the clutch plate 160 with a specified distance left therebetween, and a hole 162a is formed on the sub-plate 162, too.

Th.e clutch plate 160 and the sub-plate 162 are fixed tc a flange 166 of the spline hub 35f at their radially inner peripheries by a connecting pin 164. The c=necting pin 164 is disposed at eight places, for lo exanw-le, with equal distances left therebetween in the c rent ial direction.

164a, small-dia. parts 164b A large-d4a. part a n, d flanaes 164c are farmed on the c=necting pin 164, and the small-dia. mart 164b at a right side of cure f its in and is f astened by "sk.-.ak-Jna" to a hole 166a of the. flancre 166 and a hole 162b of the sub p!-=te 162. Further, the small-dia. part 164b at a le-ft side of the connecting pin 164 is fixed to the hole 160b of the clutch plate 160 in the same manner.

An approximately annular first bush 168, an annular plate 170 and a second bush 172 are interposed in this order between the flance 166 and the clutch p, ate 160. The annular plate 170 connects to said 1 1 1 i i i i i i i 1 1 1 i i 1 JSS080290 - is - 3a throuch a cushion-ing plate 1711 at a -ad4al outer perpheral part. In an c--d.4na--y c 1. u t ch disc, the annular plate 170 is a member corresponding to the flange of the sp-line hub and is installed freely slidingly in relation to the clutch plate 160 and "he sub-clate 162 within a spec-4-1-4ed torsion angle as described later in details.

A hole 170a is made on the annular plate 170, and a torsion s-m--4ng 1714 (coil spring) is c-.-mressi10 veiv installed in the hole 170a, 160a, & 162a. Fur.ther, circular slotted holes 168b, 170b & 172b throuch which the large-dia. part 164a of the connect;nz pin 164 passes are made on inn er merimner-=-, marzs cf' the f-'--st bush 168, the annular Pl_.ze -1-70 and the 13 second bush 1-12. These circular slotted hcles 168b, 170b & 172b are form.ed into c-4--c,-llar shares over the torsion anale rance of said annular plate 170, so that the annular plate 170 can slide freely in the c---cumferent-4al direction within the rance of the circular slotted holes 168b, 170b & 172b.

The first bush 168 and the second bush 172 are bcnded to the annular plate 170 at bonding sur-faces 17S, and a left side end f'ace of the second bush 172 JSS080290 is a slding contac- J. f ace 1.72a. A secticn of the 0--st bush 168 is bent in an approximately L-shame, 1 and its inner per-4zh&ral surface 168a slidingly con- 1 i i 1 tacts with a sliding contact face 176 of the splIne hub 3 5f.

The clutch disc 34 and the second flywheel 36 are dis- i posed in parallel at a rear-szage of the first flywheel A torsion spring 35a is equipped in parallel with a hysteresis generat4ng mecha h_ - nism 35h to the C.utch disc 34. The torsion spring 38 and the fac- 148 fo= aenerating a hysteresis tor-que are install- led in series with t.he secona --vwhee-l 36.

1 i 1 1 1 Function will be described hereunder. in the Clutch enaasina state where the facing 35a is pressed c.-, the annular surface 33a of the first flywheel 32 i by the pressure plate 35e, a spring force of the diap- k_ - - i i i 1 hragm s-jr4ng 35d urges the clutch disc 34 to slide on a splJne shaft of a transmission (not shown) toward t.;-.e f=st flywheel 32, and the f=-4c,--4cn plate 1-150 -resses on the facing 148.

In this instance, the c=led disc spring 146 defor=s itself due to a pressing i i i i 1 17 JSS080290 force from the friction plate 1-150 and the friction plate 1H and the fac4ng 148 are always pressed tocether by a constant pressure, so that a friction force generated between the facing 148 and the friction plate 150 is always kent constant.

In the above cluttch engaging state, the engine -ted power inputted in the first flywheel 32 is transmit through two paths: a path through the clutch. disc 34 and a path through the second flywheel 36, the facing jo 148 and the friction mlate 1-50 to the transmission.

Accordingly, concerning a to-rque (averace toraue fluctuatina torwue) transmitted from the ena-,ne to t.-.-- transmission, the fluctuar-ina is absorbed -v the facina 148 and the second -'-"-iwhee-l 36 sumcc-zed resil and by th.e torsion s==---ng -38, and only the average torque is transmitted through the clutch disc 34 to the transmission, so that Che enaine ::ozat'cna-l fluctuation and the to----ue fluctuation can be removed approximately cc=le-tely.

As compared with a clutch disc 102 illustrated n Fig. 7,. the facing 148 is only fastened to the clutch mlate 160 so that a structure of the clutch disc 34 is very simple.

- 18 JSS080290 Moreover, when the ent4re clutch disc 34 is replaced due to worn-out of the facings 35a & 148 after a long period of use,' the f acing 148 is also replaced together with the clutch disc 34. Therefore, all consuming parts of the friction damping mechanism 140 are installed at the clutch disc 34 side so that the f----st flvwheel 32 side and the second flywheel 36 side are not reaui-- ed to be disassembled.

I",m I---- As described above, in the flywheel assembly of embodiment, the facing 148 (friction member) C.P the friction damming mechanism 140 is fastened to clutch plate 160 of- the clutch. disc 34, this c.utch. plate 160 and the sub-clats 162 are to the sniine hub 35f by the connecting pin 164, the an.nular plate 170 consecut4ve to the fac4na 148 zrov4d ed at the radially outer peripheral part of 'the clut=h disc 34 is installed between the clutch plate 160 and the sub-olate 162 freelv slidinalv in the circumferen ti-al direction, the torsion spring 174 is interposed between the annular plate 170, the clutch plate 160 and the sub-plate 162, and the coned disc member) for the f=-4ct-4--n damcinc mechanism 140 is c=nected to said second flvwheel 36.

sp-ring 146 i 1 i i 1 i i v i 1 i 1 JSS080290 Therefo--e, the connecting plate 120 of Fig. 13 can be eliminated and the structure of the clutch disc 34 can be simplified.

Further, when the ent-'---- clutch disc 34 is re placed due to wo,-,-,.-out of the facings 35a & 148 after a long period of use, the facing 148 is also replaced tocether with the clutch disc 34. Theref are, all cc,-.sum-4na parts of the friction darming mechanism 140 are installed at the clutch disc 34 side so that the first flywheel 32 side and the second flywheel 36 side are not tc be disassembled and its maintenance becomes The f--=sz bush 168 and the second bush 172 are norr.ecessar--!v ccns-L-=- .:czed as shown by Fig. 2, but may be an intea--ally mc-1ded arzicle 180 made of a material s.j.c.l.,. as plastic ez--., for examnle, havinz a-low f=icz:.cn ccefficient, which is molded integrally with an nner per- 4mheral par= of the annular plate 170.

Further, the flange 166 is not necessarily be disposed :2o ar- the inner peripheral parts of the clutch plate 160 and the sub-plar-e 16Z, but may be disposed at their outer perlpheral parts. In this instance, the C facing 148 is to be bonded to the inner peripheral part of the clutch p late 160.

JSS080290

Claims

CLAIMS 1. A flywheel assembly including a first flywheel fastened to an

engine crank shaft and engaged and disengaged by a clutch disc, a second flywheel supported concentrically with the first flywheel, a damper mechanism resiliently connecting the both flywheels, and a friction damping mechanism which transmits an output from the second flywheel to a spline hub of the clutch disc and damps a vibration only when said clutch disc contacts with the first flywheel, the second flywheel being set to a specified mass which is determined in relation to a drive transmission's inertial mass; characterised by that a friction member of the friction damping mechanism is fastened to a clutch plate of the clutch disc, the clutch plate and a sub-plate are clamped by a connecting pin to the spline hub, an annular plate connected to a clutch facing provided on a radially outer peripheral part of the clutch disc is installed between the clutch plate and the sub-plate in a circumferentially rotatable manner, a torsion spring is interposed between the annular plate, the clutch plate and the sub-plate, and spring member of the friction damping mechanism is connected to said second flywheel.
2. A flywheel assembly as set forth in claim 1, in which the connecting pin is composed of a large-dia. part, small-dia. parts and flanges, and the small-dia.

k 1 1 i i 1 1 1 1 1 4 JSS080290 - 21 parts at both sides are fastened to the clutch plate, the sub-plate and a flange of the spline hub.
3. A flywheel assembly as set forth in claim 1 in which an annular plate is sandwiched between the clutchplate and the sub-plate of the clutch disc through bushes on its both sides, and circular slotted holes for passing a large-dia. part of the connecting pin are made on the annular plate and the two bushes.
4. A flywheel assembly as claimed in claim 3 in which a section of one of the bushes is bent into an approximately L-shape and its inner peripheral surface contacts slidingly with a sliding contact surface of the spline hub.
5. A flywheel assembly substantially as hereinbefore described with reference to and as illustrated in Figs. 1, 2 and 2a of the accompanying drawings.

Published 1990 at The Patent office. State House. 66 71 High Holborn. London WC1 R 4TP-F=ther copies maybe obtained from The FatentOfficeSales Branch, St Mary Cray. Orpington. Kent BR5 3RD Printed by Multiplex techniques ltd. St Mary Cray. Kent. Con. 187