Add: No. 1201, E-commerce Building, Qingzhou City,
Shandong
Province,
China,
262500
Tel/Fax:
+86-536-3027478
山东省青州市开发区电商大厦
1201
号
Email:
Http://
www.sdbeyondpetro.com
shifting cylinder (use wire rope or cable attached to the derrick leg), to make the
tongs head align the mouse hole, then throw-off the single.
2.5 To keep rotation of drill string (bottom hole assembly) when rig is in trouble.
If transmission system of drilling rig is out of order. Draw works and rotary table will
not go on working, and drill string from sticking, removing the jaws from the low
tongs onto well head, an attached cable to both sides of the tongs end to prevent
the tongs from rotating. Then install the corresponding jaws into the upper tongs
according to the size of drill stem, let the laws engage with Kelly joint or drill pipe
joint, disengage the pin and clutch of rotary table and then operate the upper tongs
to drive drill stem of drill string rotating. The time to rotate drill string is well bore at
low speed (2. 7 rpm) should not be too long (usually less than half hour) .
3. Structure of Main Parts
3.1 Two-speed planet gear box
In order to achieve low torque spinning at high speed and high torque make up
or break out at low speed, the tongs is provided with a two- speed planet shift gear
and unique breaking mechanism for shifting the gear without stopping the tongs.
The efficiency of the tongs is therefore raised (Fig. 1 -3). See Fig. 3, high speed is
obtained as hydraulic motor drives planet gear(Z2) on the frame to rotate, power
comes from the sum gear (Z1) when the internal gear (Z3) is braked. For low speed,
the sequence is reversal, hydraulic motor drives the sun gear (Z6) to rotate, power
comes from the frame fitted with the planet gear (Z4) when the internal gear (Z5) is
braked.
3.2 Reducer Assembly Refer to Fig. 3, the output shaft of the two-speed planet
gear box is the input shaft of the two-speed gear reducer assembly, the notched
gear (Z11) is driven to rotate through the first step deceleration (ZI -Z8) and the
second step deceleration (Z9- Z10- Z11 ) . The function of two- idle gear (Z10) is to
keep the notched gear (Z11) rotating continuously by (Z9). This is necessary for
passing the notch.
3.3 The Tongs Head (See Fig. 1 )
3.3.1 Gripping mechanism: The notched gear(7) of transmission drives the
floating body (1) to rotate through three pins (5) . If brake band (32) continuously
prevents the brake disc from rotating with about 1 kN. m torque and the law rack
(29) with laws (31 ) is connected with the brake disc by screws , when the floating
body begins to rotate, both brake disc and the jaw rack is braked to stop because
