Starter motor (ger. Anlasser) must not have a stiff connection with a crankshaft because the engine is too heavy for such a small motor. In case of stiff connection such a rapid rotation transfer would cause a big load for starter motor. Therefore starter motor must have its own starter clutch (ger. Anlasserkupplung) which will gradually transfer starter motor rotation onto crankshaft and the whole engine.
xv400/xv500/xv535
 |
| Yamaha xv535 Virago - starter motor and starter clutch |
How does it work?
The starter clutch (#3) is mounted on flywheel (rotor/magnet) which is fixed on the crankshaft axle (not shown on diagram). The starter motor over idler gear 1 (#1) and idler gear 2 (#8) transfers the rotation to the starter clutch (#3). Gradual transfer of rotation between idler gear 2 and starter clutch is achieved over gear's inner cylinder and three rollers inside starter clutch. At the beginning, in idle state, these three rollers do squeeze inner cylinder of idler gear 2. When starter motor starts, it gradually transfers the rotation from starter motor over idler gears in contact with rollers to starter clutch and further to crankshaft. Later when the combustion engine starts with its own rotation (flywheel and starter clutch do rotate along with crankshaft), the centrifugal force attract rollers out of center, and rollers separate from idler gear 2 inner cylinder and starter motor (starter clutch is disengaged from starter motor).Starter clutch versions
Yamaha on older Virago xv535 versions (from 1987. until 1996.) was using one model of starter clutch. In 1997. it was replaced with newer starter clutch model. This newer starter clutch model was used on DragStar xvs400 and xvs650 as well. |  |
| old flywheel gear and starter clutch - 1987-1996 flywheel gear = 22U-15517-00-00 starter clutch = 22U-15580-00-00 | new flywheel gear and starter clutch - from 1997. on flywheel gear = 4VR-15517-01-00 starter clutch = 4TR-15590-00-00 |
 |
| heavy duty starter clutch for Yamaha xv535 Virago by alternative manufacturer with 6 contact rollers (customers that bought and use this starter clutch corroborate about good experiences with it) |
xv700/xv750/xv920/xv1000/xv1100
On bigger Virago models (from xv700 to xv1100) another type of starter clutch is used (so called bendix type with helical threads - see Bendix drive).
 |
| Yamaha xv750 Virago - starter motor and its starter clutch (bendix) |
How does it work?
Although on diagram above it's not presented in sufficient detail, bendix gear (#5) does have helical outer threads and idler gear 2 (#7) has helical inner threads. When starter motor stats with rotation, it rotates starter gear (#1), idler gear 1 (#6) and bendix gear (#5). The centrifugal force over helical threads between bendix gear (starter wheel) (#5) and idler gear 2 (#7) moves idler gear 2 forward to engage over its outer teeth with gear on flywheel (not shown on diagram) and transfer the motion to flywheel (crankshaft and the whole engine). When starter motor stops with its rotation, the absence of centrifugal force (and compression spring) in bendix gear returns idler gear 2 back and it disengages from flywheel gear.
 |
| Bendix - a special mechanism with helical threads - on diagram this is the last bendix generation 3LP-W1551-00-00 without the compression spring |
 |
| Bendix (idler gear) with worn out teeth |
In 1996. the compression spring (#9) was abandoned as redundant because
bendix gear returns back on its own (by centrifugal force), on the other
hand this compression spring was the cause of problems with starter
clutch operation because, even when fully squeezed, this spring
does not allow idler gear 2 (#7) to fully engage in motion transfer and this
causes its quicker wear.
Starter clutch versions
On bigger Virago models there are few generations of starter clutch with some changes. The first generation from 1981. (when first Virago xv750 was launched) until 1985. had compression spring and clips for fixing gears, second generation from 1986. until 1995. does not have clips any more, and third generation from 1996. until 1999. (when the last Virago of these models was produced) the compression spring was abandoned as well.
 |
| First generation of starter clutch - 1981-1985 (#7) idler gear = 4X7-15517-00-00 (#5) starter wheel = 4X7-15524-00-00 (#10) compression spring = 90561-15636-00 |
 |
| Second generation of starter clutch - 1986-1995 (#7) idler gear = 5A8-15517-00-00 (#5) starter wheel = 5A8-15524-00-00 (#10) compression spring = 90561-15636-00 (no more clips) |
 |
| Third generation of starter clutch - 1996-1999 (#4) bendix set = 3LP-W1551-00-00 (no more compression spring) |
Nema komentara:
Objavi komentar