Crane Control Equipments makes Electro Hydraulic Thruster that is a sturdy Electro –Hydraulic device for exerting a smooth controlled upward Thrust on any device with rated capacity from the beginning to the end of the full rated stroke. We are well reckoned as the most preeminent Hydraulic Thruster Manufacturer based in India.
Our Crane Electro-Hydraulic Thruster is provided with Clevis-Lug mounting, allowing them to be mounted up to ten degrees either way from the vertical.
All the Rubber surfaces are immersed in Oil, there by requiring very less maintenance.
One outstanding feature of Crane Control Equipments make Thrustor is that any Mechanical Overloading cannot cause Overloading of the Electric Motor.
If the Load is greater than what the Thrustor can lift, the Piston will remain at the bottom of the Cylinder and the impeller will rotate harmlessly in Oil.
In the absence of Load the Piston stops at the end of the stroke and the Impeller rotates in the Oil as mentioned above.
Basically Crane Control Equipments make Electro Hydraulic Thrustor comprises of a Centrifugal Pump Impeller spinning in Oil there by developing a pressure head. Since there is no outlet, delivery port as in case of a Pump, the pressure developed is impressed on the Piston which is directly coupled to the Load to be lifted. Thus a part of the pressure head is expanded in forming a kinetic head required to lift the Load.
At the end of the Lift, either partial or full i e., when the Thrustor stalls, it is the full pressure head which is available. Thus the maximum thrust in the stalled position is always higher than the rated thrust.
The Centrifugal Pump Impeller is driven by an Electric Motor the capacity of which depends upon the capacity of the Thrustor .For example in case of a 18 kg Thrustor the Motor is of 0.1 HP and in case of 34 kg it is 0.17 HP.
The major components of the Crane Control Equipments make Electro Hydraulic Thrustor are, a Cast Iron cylinder filled with Transformer Oil, with a Aluminum Piston moving freely in it and a Drive Shaft down the center, through the Piston , to the cylinder.
The Impeller draws Oil from above the Piston forcing the Oil beneath the Piston to give it an upward movement in the cylinder with pressure. The pressure is maintained whether the Piston is in motion or has come to a halt at the end of the intermediate position of the upward stroke.
During transportation the Oil is drained out from the Thrustor hence at the time of commissioning the system required quantity of Oil needs to be filled up in the Thrustor. It is advisable to use only fresh Grade transformer Oil.
The quantity of Transformer Oil required to be filled up in the Thrustor depends upon the capacity of the Thrustor. Recommended grade of Transformer Oil is BS 148 or equivalent.
|Capacity of Thrustor||Quantity of Oil|
|18 Kg||1.85 Ltrs.|
|34 Kg||2.50 Ltrs.|
|46 Kg||2.50 Ltrs.|
|68 Kg||4.25 Ltrs.|
|114 Kg||4.25 Ltrs.|
|When the Thrustor Motor is de-energised, the Electro Hydraulic Thrustor drops from the lifted position, assisted by the dead weight or spring force provided for this purpose. The Thrustor Motors are totally enclosed type and Stators are wound with class ‘B’ insulation. These are designed for satisfactory operation at rated voltage of 415 Volts, 3 Phase, 50 Hz. The allowable Voltage fluctuation is +- 5 %. The power supply is given through Terminal Box fitted to the Thrustor which has provision for ¾ “Conduit entry. The maximum cross section of Cable that can be accommodated is 2.5mm2. The supply leads must be of flexible type so as to allow free movement to the Thrustor when operating. INSTALLATION PROCEDURE OF THRUSTER Mount the Thruster vertically and connect it by Pin joints to its load so that the side pressure which may cause jamming is avoided. The Thruster when in operation should have complete freedom to pivot slightly. The Thrusters are supplied with out Oil.Wipe away any dirt accumulated around the Oil Plug in the Tank cover. Remove the Oil Plug and fill up Transformer Oil slowly as per the quantities mentioned above. Replace the Oil Plug and operate the Thruster several times. You will observe that the Thruster will operate in a jerky and irregular manner due to fall in the Oil level. This is due to the Air trapped in the Cylinder. Remove the Oil Plug and top up the Oil level. Repeat this procedure till the Thruster comes in smooth operation. A 3 Core supply cable is to be terminated on the Three Terminals inside the Terminal box. The Thruster Motor Windings are STAR connected with Internal Star point. Any phase sequence is permitted for connection as the Thruster is designed for bi-directional working. PROCEDURE FOR MAINTENANCE OF THRUSTER The Transformer Oil requires changing every one year. How ever it is advisable to check the Oil level periodically as the level does come down due to evaporation. At the time of replacing the Transformer Oil do not dismantle the Thruster as a Drain Plug is provided at the bottom of the Thruster. Once the correct quantity of Oil is filled up repeat the procedure as mentioned above for smooth operation of the Thruster.|
Mukesh Malkani (Partner)
F-66, Okhla Industrial Area, Phase - I, Delhi, Delhi - 110020, IndiaView Mobile No.