GB2415755A

GB2415755A - A clutch made up of a planetary gear train and a disc, pad and calliper arrangement.

Info

Publication number: GB2415755A
Application number: GB0414591A
Authority: GB
Inventors: Arthur Mckenzie
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-06-30
Filing date: 2004-06-30
Publication date: 2006-01-04
Also published as: GB0414591D0

Abstract

A clutch mechanism 10 has an planetary gear train 12 having a ring gear 14 connected to an input shaft 16, planet gears 18 mounted to a planet carrier 20 and a central sun gear 26 inside which is mounted an output shaft 24 connected to the planet carrier 20. The mechanism 10 also has a set of callipers holding friction pads 32 which clamp a disc 34 attached to the sun gear 26. The calliper and disc 34 arrangement, can be spaced from the planetary gear train 12, which allows ease of access to the friction pads 32 when they need to be replaced. In one embodiment, when the calliper grips the disc 34, the sun gear 26 is prevented from rotating so that when the input shaft 16 is rotated the output shaft 24 is also rotated. When the calliper 32 is released, the sun gear 26 is allowed to rotate and so rotation of the input shaft 16 does not rotate the output shaft 24. Alternative embodiments are disclosed whereby different parts of the planetary gear train are attached to the input shaft, output shafts and the disc and calliper arrangement, so that different clutching effects are produces. The planetary gear train may take the form of a differential.

Description

24 1 5755 7; ;!I-Li or A:= preset nven'._cr -el__-s, c_i-n inecha--.m.

En -- cor..-enticr.a c u_cn -.ecnrism, a c utch span; acts or a pressure la'= JO se' eat vely c amp c cent he Dime to fl'/whee,. Friction liners are normcl'y pow deaf between the 'essu--e plate and the cer.tre plate and between. the flyable and the pressure plate.

TV Typically, the friction liners are the components of a clutch assembly that suffer the most wear and so tend to need replaced. However, the friction liners are so embedded in the surrounding mechanical assembly that their replacement is a very 'abour intensive, and therefore expensive, Job.

In accordance with the invention, therefore, a clutch mechanism is provided haling one or more clamping members, for example callipers, arranged to selectively clamp a coupling member, for example a wheel, dse or plate, in order to engage or disengage the clutch mechanism. An inspection plate or hatch may be provided adjacent the clamping members to facilitate their inspection or replacement. Advantageously, the clamping members are located outside of the main clutch housing or outside the gearbox. It is found that clutch mechanisms embodying the invention can reduce the amount of time taken co replace fr ction liners, or the like, from days to hours.

Ail =e--^ e,r a- t-. ,enir Or.-e_ _ .cr--r _= r- -l _ Bed =se.c i _ se C-'2 en;/ -^i;pl:nc a d ''ie siar _.- manse." 5cn _raf; and means for c^upl he the -tear assembly _o a _ clamping member, where- In, the gear assembl, selectively transmits rccaticnGl movement from the drive shaft to the transmission shaft depending on whether or not the -ramping member clamps the coupling means.

1C In preferred embodiments, when unclamped, the coupling means is rotatable axially, conveniently about the rotational axis of the transmission shaft. When clamped, the coupling means is prevented from rotating axially. Depending on whether or not the coupling means can rotate axially, r:ne or more other components of the gear assembly is caused either.o rotate axially or to revolve about the rotational axis of the transmission shaft.

The coupling means preferably includes a sleeve-like component that extends from the gear assembly in a direction generally parallel with the rotational axis of the transmission shaft and may be located around part of the transmission shaft. The coupling means may also include a coupling member, e.g. a plate or disc, which is disposed generally perpendicularly to said sleeve-like component and which may be connected directly Lo the sleeve-like component or may be coupled thereto 'oy means of, for examp e, a chain, belt or gear. Advantageously, the coupling member is located on the sleeve-like member d-star the gear assembly.

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^ .- _.c n. e.T. is _-e-- err= , _-rard _- a-- On ^e _- -- -,_.

n pre-r-- embcciments, cn.^ Hear svs-_m comprises an ep cycl c or planetary gear system. In one such embodiment, the sleeve-like cmponenl may comprise a sun gear and said one or more other components of the gear assembly may comprise a respective planet gear.

Alternatively, the sleeve-iike component may prov de a respective axle for the or each planet gear, the sun gear being carried by, or coupled to, the transmission shaft.

The invention enables the clamping member to be located l5 remotely with respect to, for example, a gearbox or transmission system. This allows the clamping member to be readily replaced without having to dismantle complex mechanical assemblies.

Furlher advantageous aspects of the invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention and with reference to the accompanying drawings in which: Figure i presents a side sectional view of a first embodiment of a clutch mechanism according to the invention;

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_ e__n= - -2e as_ _:na --or a._':. ' rrlL _ _ _ _ {- I_ _' . I _ _ _, .. .. L _ I. - _ _ '_ _! _ _ '_. 1 1_ Her_.= "icure 3 presents a Bite sectior.a' view of a third embodiment o' a clutch mechanism according 'G the invention.

Referring now to Figure 1, a clutch mechanism embodying Q He irver.ti^n is 'ndicated generally as 10. The clutch comprises an epicyclic, or planetary, gear assembly 12 including a ring gear Or annulus 14 which is connected to the drive shaft 16 of a power source (not shown), typically an engine. The gear assembly 22 Further includes a plural)'! of planet gears 18 in the form or gear wheels 18 carried by a carrier plate 20.

By way of example, there may be three planet gears 18 (only two shown) circumferential' y spaced apart around the carrier p Late 2Q. Each,clanet gear 18 is rotatably mounted on a respective shaft 22 provided on the carrier pi ate 20. The gear ring 14 and planet gears 18 may be housed within a housing 19.

A transmission shaft 24 s connected to the carrier p' ate 20 and extends therefrom in a direction generally parallel with the planet gear shafts 22. The other end of the transmission shaft is usual' y connected or coupled to a gearbox (not shown). The carrier plate 20 is rota-ably mounded on the ring gear 14 so chat the a c--r A'' '0 _r' Me - e_^ 1' ---, -- -

C _. A _ S. sun rear 2, T.]h' On is -up'' -al y sleeve-: ._ or generally cyi nd.rcal, - coupled to _he planet ce-rs 18 and is rctatan e about the same lcnaitdinal ax s bit which the carrier plate 20 and r' :-5 gear 14 may rotate. As may be seen from Figure 1, the sun gear 26 fits around, or encases, a poetics of the transmission 19 shaft '4 but may rotate independently hereof...DTD: In the illustrated embodiment, the drive shaft 16, ring gear 14, carrier plate 20, transmission shaft 24 and sun gear 25 are axially rotatable about a common lo lor.aitudinal axis, the planet gears 18 being axially rotatable about a respect axis that is generally parallel to said common axis. Bushings 21 are provided to reduce friction at various regions where relative rotation of components occurs.

The internal surface 28 of the ring gear 14 and the external surface 30 of the planet gears 18 each comprise teeth or cogs (not illus'-ated) by which the ring sear 14 and planet gears 18 may inter-engage and by which rota tonal movement of the ring gear 14 may impart rotas anal movement to the planet gears 18 or to the carrier plate -0, as is described in more detail below.

The clutch mechanism 10 further includes a se' of clamping pads, or callipers 32 arranged to clamp a 6 - cc:c2_g merge- -vn-_., i-, -our- ; omrr--=s _ ^--a-s - i---- Or.i-c _4. The.u_ irk- -_-t_ _ 1 s conne___d Or;-cu-2cd _ One sun ce_r =6 =_r -:ota_icr -.kerev Ad. In figure i, One coupling peat 34 s connected directly to the sun -tear 26 although, '.n alternative emccdiments (rot shown) the plate 34 gal/ be coupled Lo che sun gear 26 by means of, for example, z chain, belt or gear. The callipers 32 typically carry diction liners, or burn pads (not shown! for clamp ng the plate 34.

The pads 32 are operable between a non-clamping state (as illustrated) in which they do non engage the coupling plate 34, and a clamping state in which they clamp the coupling plate thereby preventing it, and therefore the sun gear 26, from rotating.

In use, in an engaged mode of operation, the pads 32 clamp the coupling plate 34 thereby preventing the sun gear 26 from rotating. Rotation of the drive shaft 16 causes the ring gear 14 to rotate. Rotation of the ring gear 14 causes the planet gears 18 to revolve around the circumference of the sun gear 26 (the planet gears 18 are prevented from rotating about their respective axis 22 because the sun gear 26 is unable to rotate). The revolution of the planet gears 18 causes the carrier plate 20, and therefore the transmission shaft, to rotate about its axis. Hence, rotation of the drive shaft 16 is imparted to the transmission 39 shaft 24.

_ ' -e=c=c. Ache ' ce-__ic' ;-r,'-- Baby ccr^spcrd, roe _Xcmp' , GO _ _ 2'U_C: ed-1 _::5 de-^--c-', the Cads 2 -- ens_ r.c -up_-ng ace 34 ElereLy 1 oiv-l.c the sun sear -6 to rotate. .o.=t'r.

of the do ve shaft 16 causes the ring gear 14 co rotate. Rotation of the ring gear l4 causes the planet gears is to rotate about their respective axis 22 (because the sun gear 26 is free to rotate about fits axis). As a result, the carrier plate 20, and therefore the transmission shaft, do not rotate.

Hence, rotation or the drive shaft 16 is not imparted to the transmission shaft 24.

Because the clamping pads 32 are coupled to the rest of = the clutch mechanism 10 via the coupling plate 34, they may be physically remote from the rest of the clutch mechanism 1C. Hence, the whole clutch mechanism 10 (and any surrounding mechanisms) do not need to be d smantled to replace the pads 32. Rather, the pads 32 2Q may readily be replaced in a relatively short space o' time via, for example, an inspection hatch (not shown).

Figure 2 illustrates an alternative embodiment of the inversion. The embodiment of Figure 2 is generally similar to the embodiment of Figure 1 and like numerals are used to indicate like parts. Figure 2 shows a clutch mechanism 110, a drive shaft 116, a planetary gear assembly 112 (including ring gear 114 and planet sears 118), a transmission shaft 124, a coupling member 134 and clamping pads 132.

A- .c-sm-ss a. sad, _- m__^c _ He --:. Bear :3 -end -s -.--.-- - Ecu i s _:--. !e r -^ m.--::r sea _ ^1 __-r-s -the sir. e^r l-- a.. s r Alec _e a '-;e there_,. The -_rr -r '2" or the F are- g=_rs 118 is rocatab e w-th respect Lo the t_ansm-ssion snaf 124 ar.c -s coup Ed to the pads 132 by means of the ccuplng plate]34.

In use, when the pads '32 engage with the coupling 0 place 174, tne carrier 120 is prevented from rotating _cout its axis. As a result, rotas-on of the ring gear 114 causes the planet gears 118 to rotate about their respective axis (or axle) 122. This in turn causes the sun gear 126, and therefore the transmission shaft 124, to rotate axially. Hence, rotation of the drive shaft 1-6 is imparted to the transmission shaft 124.

When the pads 132 release the coupling plate 134, the carrier 120 is free to rotate axially. As a result, rotation OF the ring gear 1'4 causes the plane gears 118 to revolve around the circumference of she sun gear 126. Hence, rotation of the drive shaft 116 is rot imparted to the transmission shaft 124.

Elqure 3 illustrates an alternative embodiment of the iTlVenCiGn. m' he embodiment of Figure 3 is generally similar to the embodiment of Figures 1 and 2 and like numerals are used to indicate like parts. Figure 3 shows a clutch mechanism 210, a drive shaft 216, a gear assembly 212, a transmission shaft 224, a coupling member 234 and clamping pads 232.

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r- gear assemb_i 2 2 _^mp-__e- e_s 2 2 rc ^ _^r:ed by he r_rsm:ss_sn sea _ _24 On r_sec-_-- -x es 2. The antes 242 are gere-= By perrerd-cu at -a the longitudinal axi 5 of the.rarsmssor shaft _24 so chat the gears, or gea.vAeels 240, are rotatable about: their axles 242 and a-bout an axi 3 that is generally perpendicular 'Ni' h the axis about which the transmission shaft may rotate. Each gear 240 is seated in a track 2a4 formed in a second coupling plate 246 chat is connected to the drive shaft 216, and in a track 248 formed in a sleeve-like coupling member 250.

The coupling member 20 is coupled to the pads 232 via the first coupling plate 234.

In use, when the cads 232 engage with the coupling plate 234, the oupling member 250 is prevented from rotating about its axis. As a result, rotation of the second coupling plate 246 causes the gears 240 to rotate about their respective axles 242. Hence, rotation of the drive shaft 216 is not imparted to the transmission shaft 224.

When the pads 232 release the coupling plate 234, the coupling member 250 is free to rotate axially. As a result, rotation of the second coupling plate 246 causes the transmission shaft 224 to rotate about its axis (because the gears 240 do not rotate about their respective axis 242). Hence, rotation of the drive shaft 216 is imparted to the transmission shaft 224.

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e -7er'. cr s.-c' 1irn-. ec o tre -TicccLments -esc_^ec: here or- _r.T.-_ e mcc_-__c -ear- ea w talcum c:;ep=.- fig arch. Ace sacce of -.-e n-e.r;tcn.

Claims

I A clutch Mechanism that breaks Transmissions between a driven force and driving force allowing that driving force to be re-engaged gradually controlled by means of a clamping member (calliper) burning members (Pads) and a disc Burning members being able to be replace from out side of the mechanism or a distance away from the clutch Mechanism.
2 A clutch as claimed in claim I that is controlled by remote calliper holds a disc by means of pads that presses against a disc thus bring it to a stop position in turn engaging the transmission through the mechanism.
3 A clutch as claimed in claim I or 2 where the calliper is acting directly upon the unit an inspection hatch allows excess to burning members for convenient replacement.
4 A clutch as claimed in claim 2 or 3 a chain belt or gears creates remote operation distancing the calliper away from the mechanism.

A clutch as claimed in any proceeding which is made from metal, plastic material or a combination ofthat material.