4 Main configuration
This project is composed of two sets of 6-axle self-propelled module transporter including 2 sets Power Pack Unit (PPU), 2 sets of 6-axle module unit without power. And there is another set of PPU for spare. The general arrangement is shown in figure 1.
2 Running conditions
Ambient temperature: -25℃~55℃.
Relative humidity: ≦92%,
Wind scale: ≦6
Ground condition: Bituminous pavement or concrete road (rolling drag as per 0.018-0.020) or pressed earth road (rolling drag as per 0.025-0.035)
3 Technical parameter
The configuration of 6-axle self-propelled module transporter is shown in drawing 1, 1 set of PPU + 1 set of 6-axle module unit.
3.1 The general technical parameters of 6-axle module unit
Axle---------------------------------------------------------------6
Length of platform(mm)--------------------------------9000
Width of platform(mm)----------------------------------3000
Height of platform(mm)----------------------------------980~1650
Max. total mass(kg)---------------------------------------- 204,000
Curb weight(kg)-------------------------------------------------24,000
Rated loading weight(kg)--------------------------------180,000
Load per axle(kg)-------------------------------------------34,000
Load per suspension(kg)--------------------------------17,000
Number of drive axle------------------------------------------2
Qty. of drive suspension--------------------------------------4
Speed(unload Km/h)--------------------------------------8
Speed(full load Km/h)-------------------------------------3
Gradient ability(%)-----------------------------------------9
Hydraulic compensation(mm)-------------------------670
Wheel angle(°)----------------------------------------------±110
Tractive force(kN)-----------------------------------------360
Braking force(kN)------------------------------------------348
Wheelbase(mm)-------------------------------------------1500
Wheel track(mm)------------------------------------------1800
Turning radius(mm)--------------------------------------4847
Qty. of tyre------------------------------------------------------48
Tyre specification---------------------------------------------215/75 R17.5
Electric system(V)-------------------------------------------28
Remote controller--------------------------------------------Radio
Suspension type----------------------------------------------Hydraulic 3 or 4 points supporting
Steering type---------------------------------------------------Electrical control hydraulic combined multi-steering
Frame type------------------------------------------------------Box-shaped structure
Braking system------------------------------------------------Dual-tube diaphragm spring braking system
membrane /spring brake
3.2 Parameters of PPU
L(mm)×W(mm)×H(mm)----------------------2750×2980×850
Lifting angle(°)------------------------------------------6
Dead load(kg)------------------------------------------5000
Manufacturer of engine----------------------------------CUMMINS
Engine type-------------------------------------------------ISDe 180 30
Engine power--------------------------------------------- (kW/ rpm) 132/ 2500
Emission standard---------------------------------------GB/III
Fuel tank volume(l)----------------------------------280
Hydraulic oil volume(l)------------------------------600
Max. operating pressure of driving system(bar)------420
Max. operating pressure of steering system(bar)-----350
4 Main configuration
4.1 PPU
PPU is composed of engine, transfer case, filter, heat radiator, inter-cooler, oil cooler, variable pump, fuel tank, hydraulic oil tank, battery, etc. Steering and elevating electrical control hydraulic valves are also arranged in PPU.
4.2 Frame
Frame is the mainly part of loading part and designed as per the most dangerous loading condition with safety coefficient 1.3. The main bearing parts (such as beam and flat plate) adapt box-shaped beam structure and welded by high quality plate (HG785), yield strength: 685MPa. A detachable cover plate is installed on the surface of transporter.
4.3 Hydraulic system
Hydraulic system is composed of driving, steering, suspension system. Oil pump variable adapts hydraulic variable technique which can prove driving speed effectively. Constant-voltage control is used in steering oil pump. Under high pressure, there is lower displacement with high response characteristic. With independence hydraulic radiator system, radiator system oil pump is installed on engine to make sure the reliability of radiating when there is no displacement to improve oil pump life.
4.4 Hydraulic suspension
Suspension system is hydraulic suspension to keep the loading platform horizontal when driving on convex-concave pavement. Supporting system adapts hydraulic suspension system which can form 4 points (see drawing 2) or 3 points(seen drawing3) supporting.
Axles and frames are connected through suspension and the height can be adjusted. Hydraulic suspension is consists of suspension, swinging arm, suspension cylinder, gyrating device, etc, which is installed on frame crossbeam. Wheel axle is arranged on the top of swinging arm. Suspensions and wheel axles will elevate and swing to make sure all the wheel axles are loaded balanced.
Altitude transducers are arranged on the four corners of the vehicle for each transporter. Elect-proportional multi-valve is standard configuration for PPU which can realize the synchronism elevating of one transporter or more of them.
4.5 Electrical multi-steering system
This system is consists of steering oil pump, multi-valve, steering motor, wormwheel and worm-steering system, angle transducer, controller, etc. (see drawing 4)
4.6 Steering structure
One angle transducer is equipped for each suspension. When slide operating handle, remote controller sends a steering signal and controllers work out each suspension’s theory angle according to the set steering mode. Then controller work out the valve opening through comparing the angle transducer feedback signal and the theory value. At last, hydraulic motor drives suspension to steer to the right position.
There are seven steering modes: crab driving, normal driving, front-axle steering, rear-axle steering, oblique driving, 90°driving, circle driving at one point. And other driving modes can be set according to customer’s requirement. Steering modes of tandem are the same. (see drawing 5 and 6). If steering deviation is over 8°, steering system will be locked and transporter can move anymore or there is a alarm single.
g. Circle driving at one point
4.7 Video of the SPMT steering
Each modular has its own control system, which can achieve its functions such as self-steering synchronization. Through the CAN bus information, the modules can also achieve the coordinate synchronization. During communication, one modular is defined as master unit, the other modules receive the order such as steering, driving, and braking from the master unit.
4.14 Painting
After shot-cleaning, the surface of the steel structure reaches SA2.5 grade. The thickness of the application and paint film must be up to the national standard (more than 150μm). The well-known brand paint is used in painting. Most of the top-coat is R03. All of the small accessories adopt galvanization.