Chengdu COBRA Trading Co., Ltd.
Add.: No. 323, Shi Ji Avenue, Economic Development Zone, Chongzhou, Chengdu City, Sichuan Province
The water-cooled eddy current brake is widely applied as the auxiliary brake for the draw-works of drilling rig all over the world. This electromagnetic brake delivers abrasion-free effect, stable performance and large torque. The variable speed control enables the drilling tool to act at any speed during the entire drilling process. Besides, the outstanding reliability offers longer service life and easier maintenance.
At present, the air-cooled design generates so much heat during application that it brings negative impact to the brake torque and exciting coil, especially in the Chinese desert areas and Middle East where the highest temperature reaches 50℃to 60℃. Therefore, the air-cooled design isn’t quite applicable to these high temperature regions.
However, the current water-cooled eddy current brake normally has poor cooling system and layout, which easily creates huge temperature difference between the environment and the brake itself. As a result, condensed water is conducted inside the seal cover of magnet exciting coil. This may lower the insulativity, shorten the service life of the brake and increase the safety risks.
With the commitment to solve these problems, we launch the oil-immersed water-cooled eddy current brake. This new product combines water with oil which prevents the condensation. With the aid of forced cooling function, it can constantly be in working state under the rated voltage.
As a result, this new water-cooled eddy current brake can be applied to facilitate the drilling process, and drastically reduces the failure rate and lengthens the service life. In addition, it is also applicable as the auxiliary brake for onshore and offshore drilling rigs with drilling depth of 7000m. Meanwhile, it can either be supplied together with draw-works, or as an independent part for drilling rig accessories.
The electromagnetic eddy current brake consists of main brake, power supply, switch, cable and the support. The shaft of DS brake rotor is supported by the two double-row redial ball bearings, which has much larger loading capacity than the actual need. When the brake is installed on the draw-works and fine adjusted in order that it produces same electromagnetic force in every direction during operation. So the bearings only sustain the dead weight of the shaft and the rotor.
The rotor and the stator are both made up from high-quality magnetic material that has been through heat treatment. The coils are sealed by stainless steel cover and placed in the rotors and stators on both sides. The rotor shaft is connected with the drum shaft by the toothed clutch. Normally, part of the rotor is in the water, and all the rotor can be supplied with sufficient cooling water during running. The cooling water is forced to circulate by the water pump.
On the outside of the water-cooled eddy current brake housing, there are four breathing device that help to drain the condensed water in the stainless steel cover. Also, there are two grease nozzles for bearings.Specification
|Suitable well depth (4/2 drill pipe)||4500-7000m|
|Working principle||Induction eddy current brake|
|No. of coils||4|
|Rated resistance of each coil (at 40℃)||16.5|
|Coil insulation class||H Class|
|Max. excitation current (4 coils in parallel connection)||75A|
|Max. outlet water temperature (inlet water is at 42℃)||72℃|
|Class of weight||12000kg|
|The overall dimension of the 1.25:12 standard tapered brake in 7.5 inch (190.5mm) diameter:|
|Center height 850mm||Width 1004mm||Diameter 1835mm|