Smooth and Powerful DriveZF Couplings / Clutches for Marine Applications
Highly Elastic Couplings
Experience from more than 20,000 drive installations has led to the high torsional elasticity and excellent dampening capability of the SPIROFLEX shaft coupling that renders this marine coupling indispensable for propulsion systems prone to torsional vibration. The most significant feature of the coupling is its rubber elements’ high torsional flexibility. Various rubber hardness grades effectively influence the natural frequencies arising in the respective drive system. As a result of major development efforts considerable improvements were attained in the area of attaching rubber material to steel parts. The shaping of the vulcanization surfaces of ring elements and segments as well as the shaping of the rubber contours, which has been proven by comprehensive testing and documentation, led to an uniform, low stress/strain distribution over cross sectional area as well as to a low deformation energy density at the segmental faces. The extreme reductions of stresses in the marginal zone of rubber-to-metal bonding interfaces and a high dynamic safety are further advantages.
MAIN ADVANTAGES OF SPIROFLEX COUPLINGS
∙ High torsional flexibility ∙ Different rubber hardness grades available ∙ Especially torsionally soft couplings can be built by arranging rubber elements in series ∙ Elements can be removed radially ∙ Exclusively features frictionally locked connections ∙ Backlash-free torque transmission ∙ Flywheel connecting dimensions acc. to DIN 6288 ∙ Up to four parallel arranged segment rings
The special qualities of a highly torsionally elastic and vibration dampening coupling and those of a pneumatically operated double cone friction clutch are purposefully combined in our PNEUMAFLEX clutch. It reliably interrupts or establishes the flow of power between the diesel engine and the other driving components.
Experience from some 5,000 installations that have been operating the PNEUMAFLEX marine clutch since 1964 has led to the development of the technologically advanced highly elastic clutch as it is offered today. The clutching components comprise two inner friction cones which are pressed against two outer friction conical faces via the pneumatically actuated clutch cylinder. The elastic part comprises rubber elements arranged in parallel which were completely optimized enhancing the coupling’s reliability and performance significantly.
MAIN ADVANTAGES OF PNEUMAFLEX CLUTCHES
∙ Combination of a dry friction clutch and highly elastic coupling without short-lived idle bearing system ∙ Complete separation of primary and secondary sides ∙ Backlash-free, no wear of components subject to backlash ∙ Smooth and easily controllable engaging operation ∙ Protects the propulsion system against overloads if a slip monitoring unit is used ∙ Clutches of type KAP can be vertically removed
The PNEUMASTAR clutch is a torsionally stiff double-cone friction clutch. The clutching components consist of two inner and two outer friction cones of which the inner ones are pneumatically pressed against the outer tapered friction faces via a clutching cylinder. Rubber sleeve springs form the torsionally stiff portion of the clutch. As the clutching components are moved over the rubber sleeve springs during the actuation of the clutch, a wear-causing axial sliding movement between the various contacting parts is avoided. Pneumatic operation of the clutch enables speedy and precise manoeuvring, which is a prerequisite to qualify the clutch for use in the marine application. For example, a twin-engine installation can be manoeuvred with a counter-rotating propeller, without the need to reverse the engines continually. This is achieved by having engines running in opposite rotation to each other and connected via the manoeuvring clutch onto a twin-input/single-output reduction gearbox. Selective engagement/disengagement of the clutches will provide the manoeuvring facility.
MAIN ADVANTAGES OF PNEUMASTAR CLUTCHES
∙ Combination of a dry friction clutch and torsionally stiff coupling without short-lived idle bearing system ∙ Complete separation of primary and secondary sides ∙ Backlash-free, no wear of components subject to backlash ∙ Smooth and easily controllable engaging operation ∙ Protects the propulsion system against overloads if a slip monitoring unit is used ∙ Pneumatically switchable
For PNEUMAFLEX and PNEUMASTAR clutches, the Electro Pneumatic Remote Control Device PFA 8600 serves to adjust the engaging time and trigger alarm in the event of compressed air failure. If the standard solenoid valves have been actuated by external interlocking devices, the remote control device automatically disengages the clutch or blocks its engagement. Furthermore, the device serves to control the automatic changeover from engaging air pressure to operating air pressure as well as the automatic disengagement of the clutch if the clutching air pressure falls below the level required for slip-free torque transmission.
Electronic Alternating Angle Measuring Device FA
The Electronic Alternating Angle Measuring Device FA serves to monitor excessive torques resulting from torsional vibrations. The device measures and monitors alternating angles superimposed on the nominal angle of twist in highly torsionally elastic SPIROFLEX and PNEUMAFLEX couplings respectively clutches. Measurement parameter is the changing angle of twist between the primary and secondary part of highly elastic rubber elements of the coupling. The measuring device is maintenance-free, operates contact-free and does not suffer mechanical wear. To ensure a high degree of functional reliability this monitoring system is equipped with integrated circuits.
Electronic Slippage Monitoring Device CA
The Electronic Slippage Monitoring Device CA indicates on PNEUMAFLEX and PNEUMASTAR clutches inadmissible clutch slippage. The monitoring function of the unit is based on measuring the speed difference arising between the primary and secondary part of the clutch. Thus the maintenance-free and contact-free monitoring unit offers additional safety to prevent damage due to overloading.
Electronic Engaging Blockade Device EEB
The Electronic Engaging Blockade Device EEB is an independent monitoring unit for clutches. It prevents PNEUMAFLEX and PNEUMASTAR clutches from being destroyed in the event the secondary side of a propulsion system is blocked by external influence. During engagement the primary and secondary speed rates are compared within a selectable time span. Measurement is taken in a contactless manner via pulse encoder. Initiating the engagement of the clutch is governed by monitoring the secondary side speed rate. The electronic components are maintenance-free and do not suffer mechanical wear.