Technical and construction features
- basic sized with torque capacity up to 42.000 Nm and 17 tons rope pull.
- gear units with rotating housing to be inserted into winch drum.
- broad range of reduction rations.
- heavy loading capacity, drum is directly supported by the gear unit with an external bearing installed at the opposite side.
- hydraulically released failsafe parking or emergency brake, multidisc type, spring operated.
- brake capacity exceeds 150% of motor torque.
- free wheel available on request allows to lift the load with brake locked. The brake is then released for lowering the load.
- accomodations for various makes of hydraulic motors.
The gearboxes and cranes of the 800 series are built in 4 sizes for rope traction up to 14.000 daN.
These units are designed to be integrated inside the crane drum. They have a planetary gearbox type with 2 or 3 reduction stages and have a built in parking brake.
The outer housing is rotating and is flanged directly to the drum, while the fixed side is flanged to the frame. Besides the drive transmission the gearboxes have the load-bearing function of one drum side while on the opposite one a simple support with a bearing is assembled. The planetary gearboxes are similar to other series of Trasmital reducers, they have finished shaved gears that are cemented and hardened. All toothings are corrected to obtain a high resistance at the tooth's foot and limited smears.
The inner toothing crowns, on the contrary, are made of corrected and hardened steel; the brake, which in integrated in the input side of the gearbox, is of the multiple disks type and is negative and in oil-bath, while the release is hydraulic.
The breaking torque of the brake is designed to have an average drum braking torque from 1,6 to 1,8 with respect to the rated torque. All groups are equipped with input freewheels in their standard version so that they allow a rotation which is related to the rope winding direction with closed brake. With such device, all upshifting cargo manoeuvres are accomplished with extremely precise stop and go, even though the command is given by low starting torque hydraulic motors, such as gearmotors or blade motors. The opening of the brake is therefore active only during the unwinding of the rope.
The braking gearbox groups can be considered self standing units indipendent from the rest of the crane, the gearbox The gearbox groups with brakes are independent units from the rest of the crane, the gearbox lubrication is with splash gear oil, while the brake is lubricated separately with hydraulic oil.
All groups are appropriate to be controlled by any high speed hydraulic motor: with gears, with blades or with axial pistons.
The gearbox group may be supplied with a drum and relevant bearing on the opposite side, so that it can be assembled directly on the crane arm or any other device made by the customer. It can be supplied also complete with frame.
Drum and frame are made of welded steel sheet in a particularly compact and rugged version.