MODEL XQ140/20 HYDRAULIC POWER TONG OPERATION MANUAL
YANCHENG TEDA DRILLING & PRODUCTION EQUIPMENT CO.,LTD
3.2 Tong Head Assembly
(Fig.3-2, Fig.3-3, Fig.3-4)
Fig 3-2 Main View of Tong Head Assembly
1. upper roller support frame
；
2. centralizing roller
；
3. jaw plate frame
；
4. braking plate
；
5.tong head cover
；
6. upper centralizing roller assembly(2)
；
7. reversing shaft
；
8.connection
plate
；
9.shaft cover
；
10.bake band
；
11.stop ring
；
12. hexagon socket head cap screw
；
13.open
gear cover
；
14.open cover
；
15.lowerroller support plate
；
16. centralizing roller shaft
；
17.
centralizing roller
；
3.2.1 Clamping Mechanism
(Fig.3-2, Fig.3-3)
The clamping mechanism adopts inner curved bilateral clamping mechanism. It
consists of ramp plate, roller, roller axle, jaw plate, die seats, tong dies and jaw plate
frame assembly. The jaw plate frame assembly is fixed in the inner side of the open
gear. The spline on the board matches the spline on the connection plate of braking
mechanism. When the transmission system starts to drive the open gear to turn, the
jaw plate frame assembly doesn
’
t turn first at all under the braking force from the
braking mechanism, the curved ramp plate turns together with the open gear, the
roller on the jaw plate climbs along the curved surface of the ramp, moving jaw plate
assembly towards the center, thus the preliminary clamping is achieved.
As the torque increases and exceeds the braking moment, the open gear drives
the spline connection plate, braking disc, jaw plate frame assembly and the jaw plate
in the braking mechanism to turn together with the pipe string. The backup tong
clamping mechanism is the same as that of the master tong. The hydraulic oil drives
rack plunger to make reciprocating movement and also drives the duplex gear and the
jaw plate frame to turn inside the main body of the backup tong, which drives the
roller to climb, finally clips or loses the pipe string.
3.2.2 Braking Mechanism
(Fig.3-2)
Jaw plate frame assembly must be braked to drive roller and ramp to move in
opposite directions (i.e. climbing and resetting). The braking mechanism consists of
braking plate, braking steel disc, spline connection board, upper and lower friction
disc, adjusting screw, spring and lock nut. It can change braking moment by adjusting
the compress force from the spring.
