TABLE OF CONTENTS MAV locking devices.... Pg. 2 Traditional shaft hub connections...pg. 3 Advantages of MAV locking devices...pg. 4 The wedge principle..... Pg. 5 Installation removal...pg. 6 Characteristics.... Pg. 7 MAV series... Pg. 11 Main application fields for MAV locking devices. Pg. 14 Application examples for MAV locking devices... Pg. 15 1
MAV LOCKING DEVICES provide safe, reliable and backlash-free keyless frictional shaft-hub connection and are well suited to transmit TORQUE, BENDING, THRUST and RADIAL LOADS replace keyed, splined, interference fits rely on the wedge principle to create a mechanical fit by converting locking screw preload into radial contact pressures on shaft and hub 2
TRADITIONAL SHAFT HUB CONNECTIONS KEYED CONNECTION keyway notch weakens shaft & hub (fatigue failure) wear of key & keway does not permit a backlash-free connection shaft is oversized to compensate the keyway SPLINED CONNECTION spline notch weakens shaft & hub (fatigue failure) high manufacturing cost INTERFERENCE FITS close manufacturing tolerances must be maintained removal is very difficult 3
ADVANTAGES OF MAV LOCKING DEVICES In the relaxed position, MAV locking devices provide a generous clearance for easy installation and removal. MAV locking devices generate very high contact pressures, thereby allowing high torque and bending capacities. Backlash-free keyless fits allow longer lifetime of the connection, fretting corrosion is eliminated and fatigue failures are extremely reduced. MAV locking devices allow high geometrical precision of the connection. MAV locking devices allow smaller shaft sizes than keyed connections and reduce the shaft and hub processing time (no need of keyway machining), thereby reducing weight and cost. MAV locking devices can be used directly on existing keyed shafts. The wide range of MAV series allows the use for any kind of standard and customized application. 4
THE WEDGE PRINCIPLE During tightening, the screw preload Fv (which depends on tightening torque) is converted into the radial force Nr. This conversion is obtained by means of the tapered surface of the locking rings (wedge principle). The radial force Nr generates the friction force Fattr, which also depends on the friction coefficient between the contact surfaces. The friction force permits the transmission of applied loads (torque, axial force, bending moment, radial force). 5
INSTALLATION - REMOVAL INSTALLATION Loosen all screws by a few turns to facilitate mounting and insert the locking device (fig.1). Tighten all screws in several passes by means of a torque wrench, until specified tightening torque is reached (fig.2). REMOVAL Loosen all locking screws and tighten some of them into the push-off threads, until the locking rings are disengaged and the unit can be removed (fig.3). Self-releasing devices will disengage just by loosening of locking screws. fig.1 fig.2 fig.3 6
CHARACTERISTICS INTERNAL DEVICES: LOCKING ASSEMBLIES Locking assemblies are mounted between shaft and hub. EXTERNAL DEVICES: SHRINK DISCS & RIGID SHAFT COUPLINGS Shrink discs are used to connect an hollow shaft to a shaft. The shrink disc is mounted on the outer diameter of hollow shaft. Rigid shaft couplings are used to connect two shafts, even of different sizes. 7
CHARACTERISTICS SELF-CENTERING The locking device will automatically center hub & shaft. Axial and radial runout of the connection are 0.02-0.05mm. This feature is typical of long and shallow taper design. Not self-centering devices need a centering face in the hub. self-centering not self-centering SELF-LOCKING The pressure generated by tightening self-locking devices is maitained even in case of loosening of the screws, thereby allowing the transmission of applied loads even in this condition. In addition, self-locking feature avoid dynamic stress of the screws in case of cyclic loading (ex. rotational bending moment). This feature is typical of shallow taper design. Removal is obtained by means of integrated push-off threads. 8
MATERIALS CHARACTERISTICS MAV locking devices are made of carbon or alloy steel, depending on the stress they must withstand. MAV locking devices can be made of stainless steel or protected with surface treatments as nickel plating, zinc plating, phosphate coating. TEMPERATURE MAV locking devices can be used between 20 C and 150 C and are not affected by temperature changes as long as they apply equally to shaft and hub. LUBRICATION MAV internal devices (locking assemblies) are supplied lightly coated with ordinary machine oil. MAV external devices (shrink discs & shaft rigid couplings) are supplied with grease applied to the tapers and to the locking screw threads and head contact areas. SHAFT & HUB SIZING MAV locking devices generate high contact pressures exerted on both the shaft and hub. The connected components must withstand these pressures without yielding, so that proper material and size must be selected. 9
CHARACTERISTICS INSTALLATION OF MAV LOCKING ASSEMBLIES ON KEYED SHAFT The locking assembly can be installed directly on the keyed shaft. If the keyed shaft is damaged, few millimeters can be machined and an adapter sleeve must be used to fit the locking assembly. 10
MAV SERIES: : LOCKING ASSEMBLIES MAV series torque capacity bending capacity hub contact pressure self-centering self-locking fixed axial hub position during tightening MAV1061 medium medium medium yes yes yes MAV1062 medium medium medium yes yes no MAV2005 medium low high no no yes MAV3003 low - low no no no MAV4061 high high medium yes yes no MAV1008 high high medium yes yes no MAV5061 medium medium low yes yes yes MAV6901 medium medium medium yes yes no MAV6902 medium medium low yes yes yes MAV6002 high high medium yes yes yes MAV6903 medium medium low yes yes yes The series described above are the main series. Full range of MAV locking assemblies include approximately 30 series. In addition, MAV can offer any kind of customized execution. Please contact us with your inquiries. 11
MAV SERIES: : SHRINK DISCS MAV series torque capacity bending capacity MAV2008 medium medium MAV2108 low medium MAV2208 high medium also available in SPLIT and HALF HC & HT designs MAV3008 MAV3009 medium low MAV3108 low low MAV3208 MAV3209 high low In addition to the series described above, MAV can offer any kind of customized execution. Please contact us with your inquiries. 12
MAV SERIES: : RIGID SHAFT COUPLINGS MAV series torque capacity bending capacity MAV1004 low - MAV1204 medium medium MAV FC2008 medium medium MAV SC2008 medium medium MAV SC2208 high medium In addition to the series described above, MAV can offer any kind of customized execution. Please contact us with your inquiries. 13
MAV MAIN APPLICATION FIELDS FOR MAV LOCKING DEVICES Bending machines Bottling and filling machineries Bucket wheel excavators Cable and wire machines Calenders Ceramic processing and production machineries Chemical, cosmetic, pharmaceutical industry Colouring systems Conveyors Crushers Dry cleaning machineries Dryers Food processing plants Gearboxes, speed-reducers, gear motors Indexing tables Iron and steel industry Labelling machineries Lifting plants and cranes Machine tools Materials handling machines Mining trucks and plants Mixers (clay, liquid, sand, food industry) Packaging machineries Pallet handling systems Paper processing plants Plate processing machineries Presses (mechanical, plastic industry) Printing machineries Pumps Rolling mill plants Rubber processing and vulcanization plants Screw-type automatic injection moulding machine Shearing machines Ship propellers Snow tools and machineries Textile plants Windmill power generators Wood processing machineries 14
MAV APPLICATION EXAMPLES FOR MAV LOCKING DEVICES PELTON HYDRAULIC TURBINE connected with series MAV4061 CONVEYOR PULLEY connected with series MAV4061 MILL PULLEY connected with series MAV2005 PLANER FEEDER ROLL connected with series MAV1061 15
MAV APPLICATION EXAMPLES FOR MAV LOCKING DEVICES DEBARKER connected with series MAV4061 SPROCKETS connected with series MAV2005 CONVEYOR PULLEY connected with series MAV2005 LEVER ARMS connected with series MAV4061 & MAV1061 16
MAV APPLICATION EXAMPLES FOR MAV LOCKING DEVICES ACTUATOR connected with series MAV2005 SPROCKET connected with series MAV2005 REVOLVING TABLE connected with series MAV2005 FLYWHEEL connected with series MAV2005 17
MAV APPLICATION EXAMPLES FOR MAV LOCKING DEVICES DRIVE SHAFT DRIVEN SHAFT of PLANER FEEDER connected with series MAV2008 DRIVE SHAFT DRIVEN SHAFT of VENEER PANEL UNSTACKER connected with series MAV2008 HOLLOW SHAFT GEARBOX connection with series MAV2008 HUB connection of FLEXIBLE COUPLING with series MAV2008 18
MAV APPLICATION EXAMPLES FOR MAV LOCKING DEVICES GEARBOX of WINDMILL POWER GENERATOR connected with series MAV3008 HOLLOW SHAFT GEARBOX connection with series MAV2008 CLUTCH SHAFT connected with series MAV2008 19
MAV APPLICATION EXAMPLES FOR MAV LOCKING DEVICES Components of MAV FC2008 DRIVE SHAFT - DRIVEN SHAFT connection of CONVEYOR for MINING INDUSTRY with series MAV FC2008 Series MAV1204 with STEPPED BORE to accomodate DIFFERENT SHAFT DIAMETERS Sleeve coupling series MAV SC2008 (standard duty) & MAV SC2208 (heavy duty) Series MAV1204 with ADAPTER SLEEVE to accomodate DIFFERENT SHAFT DIAMETERS 20
MAV APPLICATION EXAMPLES FOR MAV LOCKING DEVICES SPECIAL INTERNAL SHRINK DISC for STUB SHAFT connection of LOW SPEED GRINDER SPECIAL SHRINK DISC SPLIT execution - for WORM GEAR connection SPROCKET connected with series MAV3023 Connection of FLEXIBLE COUPLING S HUB with series MAV7107 special 21
MAV APPLICATION EXAMPLES FOR MAV LOCKING DEVICES SPROCKET connection with special FLANGE and SHRINK DISC series MAV2108 PINION GEAR connection with SPECIAL THRUST RING FAN HUB connected with series MAV5061 PULLEY connected with series MAV6903. The locking device applies thrust, thereby holding the bearing in place BRAKE DISC connected with special CONE INTEGRATED FLANGE 22