The transformation of the TH286 fully hydraulic rock drilling jumper

1. Reasons for renovation

The Atlas TH286 fully hydraulic rock drilling rig introduced by our unit in 1984 was an advanced device at that time. It features a high degree of automation, a large number of arms (4), and a fast tunneling speed. However, there is also the drawback of overly large external dimensions. During transportation, it must be disassembled into three parts. Even so, some of them are still considered oversized goods during railway transportation. Compared with the rock drilling jumbos produced in recent years, it has become outdated in some aspects. Besides, this machine has reached a period when it is prone to frequent malfunctions. It would be uneconomical to continue using it. For the reasons mentioned above, we have decided to carry out technological transformation on this vehicle during its major overhaul.

2 The part to be modified and its effect

(1) The boom structure was changed. Three arms of the B353E rock drilling trolley were used to replace four arms on the TH286 trolley, reducing the width of the trolley from the original 3.5m to 2.5m, the height from 4.3m to 3.4m, and the weight from 45.4t to 36.8t. In this way, the trolley can be transported as a full truckload in both railway and road transportation. The change in the boom type has transformed the excavation section from the original 45-156 square meters to 25-168 square meters, enhancing the applicability of the trolley.

(2) The original BHV38 hydraulic system was replaced by the advanced DCS12 hydraulic system, and the A8V58 double axial piston pump on it was also replaced by the A10V71 axial piston pump. This enhanced the reliability of the hydraulic system, improved its efficiency, and made it cheaper.

(3) The advanced BMH6318 type propulsion device has replaced the BMH618 type device, making the rock drill run more smoothly, the connection of accessories easier, and the adjustment of hoses, steel wires and wear clearances more convenient.

(4) The type of collector ring in the cable reel has been improved. The flat ordinary carbon brush ring has been replaced by a concave multi-slot claw type metal brush ring. After the improvement, the dust-proof performance has been enhanced and the service life has been prolonged.

(5) The starting method of the main hydraulic pump motor in Taiwan has been changed from direct starting to Y-△ type, making the starting process easier.

(6) The connection method between the air compressor and the motor was changed from belt connection to direct connection, which solved the problem of the belt being prone to slipping.

(7) The installation position of the hydraulic oil filter has been changed from being scattered externally to being centralized inside the oil tank, making it easier to disassemble and assemble and reducing pollution.

(8) The chassis and engine were modified. The original single-axle drive and air brake were replaced with dual-axle drive and oil braking, which improved the off-road performance and driving safety of the trolley and reduced the pollution emissions from the engine.

After the transformation, the tunneling speed of the trolley has increased and the tunneling cost has decreased. By the end of 1998, each arm had been in impact operation for 2,600 hours. Although the trolley underwent another major overhaul, the technical performance parameters of the entire vehicle remained largely unchanged and it is still in use.