Page 68 - Vetus

FLEXIBLE COUPLINGS

Type Bullflex
Ensuring optimum damping of vibrations
The Bullflex is the answer to the increasing demand of greater boating comfort. It is especially designed to ensure optimum
damping of vibrations. Torsional vibrations are smoothed out extremely efficiently by its very flexible rubber element, ensuring
low-noise and vibration-free transmission without backlash between the engine and propeller shaft. Another strong characteristic
is the excellent alignment of the propeller shaft. For the most popular Volvo, Yanmar and Kanzaki gearboxes special (also custom
made) adapter flanges are available (see page 71 ).
Features
• Very high flexibility
• Secured against shearing off (axially and radially) ensuring safe transmission under all circumstances
• Misalignment of up to 2º permissible
• Excellent centring of the shaft, allowing high shaft revolutions
• Shaft remains centred even in reverse gear
• Possibility to remove the centring ring, in case two or more bearings are applied
• Built-in thrust damper reducing axial vibrations
• Non-tapered clamping hub for perfect centring and easy dismantling of the shaft assembly

Specifications
• Models 1, 2 and 4 have a 4” gearbox connection
• Models 8, 12 and 16 feature a 4 and 5” gearbox connection
• Model 32 is provided with 6 threaded M16 holes on a pitch circle diameter of Ø 4,75” (120,65 mm)
enabling mounting of the couplings to most models of gearboxes (Hurth, Velvet, TD, ZF and P.R.M.)
• VETUS can also supply the required fastenings for installation of the Bullflex onto the gearbox.
This coupling is not suitable for V-Drives

For specifications, please see table on the next page.

BULFL

Centring the Bullflex
An engine on flexible mountings will by definition, always move. When
the propeller shaft is installed rigidly - which means to say: supported
by two or more non-flexible bearings - the propeller shaft should not be
affected by engine movements.
If this should happen, damage of engine mounting, coupling and sealing
of the shaft may result. Where a rigid shaft assembly is installed, the
centring ring can be removed from the Bullflex coupling. This must be
done if the distance between the output flange of the gearbox and the
first shaft bearing is less than 20 times the shaft diameter. Pendulum
movements of the flexibly mounted engine will then not be transmitted
onto the propeller shaft, but will be effortlessly absorbed by the Bullflex
coupling. Naturally, removal of the centring ring has no adverse effects on
the vibration damping properties. Where the propeller shaft is supported
by one rigid bearing only, the Bullflex coupling - with its centring ring
installed - will function as a flexible ball joint. The propeller shaft will thus
be supported and centered inside the Bullflex coupling, regardless of any
engine movements.

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