Roadheader type: AM 75
The AM 75 roadheader is an advanced high-performance mining machine and a continuation of the popular series of roadheaders used in coal mines in Poland and around the world. These roadheaders are designed for driving headings with a significantly larger cross-section and in more difficult geological conditions than the lighter models from the same series.
The AM 75 has more than double the horsepower of the AM 50, with impressive capabilities for mining harder rock, making it an excellent choice for demanding underground mining applications.
New generation of roadheaders
Over more than a decade, the AM 75 type roadheader has been replaced with the newer MR300 series, which is the most sought-after roadheader in its class. Thanks to extremely high technical functionality and mining efficiency, maximum productivity and profitability are guaranteed. The machine has set international production records in various materials (coal, rock, gypsum, potash and salt), as well as in heading construction. The machine is available in four models with different heights:
- MR320: maximum mining height of 4.54 m.
- MR340: maximum mining height of 4.87 m.
- MR360: maximum cutting height of 5.06 m.
- MR380: maximum cutting height of 6.30 m.
Operational capabilities of the AM 75 roadheader
The AM 75 roadheader stands out from other mining machines due to its impressive mining capabilities. This medium-heavy machine is designed for driving dog headings with a cross-section of 34 m² to 35.4 m², which demonstrates great capabilities.
This is a significant improvement over the AM 50 model, which handles cross-sections of up to about 16-22 m² (depending on the version). The AM 75 performs well in rocks with compressive strengths of up to 100 MPa, which means it to work in heavier rock formations than lighter models, which are typically limited to rocks with a compressive strength around 60-80 MPa.
Application of the AM75 model
The AM 75 roadheader can be used in underground mines – both in non-methane and methane fields. It is designed to operate in workings classified as methane explosion hazard levels “a”, “b”, or “c”, and coal dust explosion hazard classes “A” or “B”.
The practical use of the AM75 roadheader primarily involves the driving of main dog headings in hard coal mines, where larger cross-sections are required and operation in harder rock formations is necessary.
Need help with your AM 75 roadheader?
Minostar offers comprehensive repair and revamping services for AM 75 roadheaders. With many years of experience and a team of qualified specialists, we are able to offer solutions tailored to the individual needs of our customers.
We restore roadheaders to full working order and even boost their original performance with modern technical solutions and high-durability materials. Our comprehensive overhauls and upgrades not only restore the machine to its factory condition, but also significantly increase its efficiency, service life and range of applications.
Technical specifications
The AM 75 roadheader is available in a variety of versions and configurations depending on specific operational needs. The following technical specifications show typical parameters for this model.
| Parameter | Value |
| Total length | approximately 10,320 mm |
| Total height | approximately 2045 mm |
| Width | 2600-2800 mm |
| Total weight | approximately 52 t |
| Unit ground pressure | 0.13 MPa |
| Floor clearance | 240/420 mm |
| Power supply | |
| Supply voltage | 500 V, 660 V or 1000 V (depending on version) |
| Cutter motor power | 200-230 kW |
| Total installed power | approximately 357 kW |
| Cutting parameters | |
| Maximum cutting cross-section from one position | minimum 34 m² |
| Cutting speed | approximately 2.3 m/s |
| Loading table width | 2800 mm |
| Additional table extension | 5220-5620 mm |
| Maximum compressive strength of excavated rock | up to 100 MPa |
| Minimum floor undercut | 200 mm |
High performance in difficult conditionsThe AM 75 roadheader is designed to work in harsh geological conditions, where the compressive strength of rock can reach 100 MPa. Unlike lighter models, which typically work most efficiently in rocks with a strength of up to 60-80 MPa, the AM 75 maintains high efficiency even when mining harder formations. |
Modular designLike other roadheaders from the series, the AM 75 features a modular design that makes transporting individual components much easier in harsh underground conditions. Each component can be transported separately and then assembled at the work site. |
Advanced control and safety systemThe AM 75 roadheader can be equipped with modern control systems, including optional radio control, enhancing operator safety and comfort in difficult and dangerous conditions. |
ExpandabilityThe AM 75 can be adapted to different operating conditions by installing additional equipment. The roadheader can be fitted with a support setting device combined with a set of platforms for roof support installation, or with a drilling and bolting platform. |
- Drilling and bolting units enabling immediate roof bolting after excavation.
- Hydraulic working platform with a support setting mechanism to facilitate roof support installation.
- External (curtain-type) and internal (track spray) water spraying systems for effective dust suppression.
- Drilling and bolting system powered directly from the hydraulic system.
- Automatic central lubrication system ensuring optimal maintenance of moving parts.
- Working platform with a support setting mechanism, improving safety and ergonomics during roof support installation.
- Radio remote control systems enhancing operator safety by allowing the roadheader to be operated from a safe distance.
Our offer
We offer comprehensive repair and revamping services for machinery used in the mining industry, especially for roadheaders. We provide professional servicing, regeneration of components and innovative technical solutions under our special programme. Feel free to check out our offer
Design and main components
The AM 75 roadheader consists of several main components that form a high-performance machine for driving headings.
Cutting head gearbox of the AM 75 roadheader
The cutting head gearbox is the most critical component of the roadheader, responsible for milling the rock face. The AM 75 model features a compact 3-stage bevel-helical/planetary gearbox, flange-mounted directly to a 200–230 kW motor. The motor features a self-supporting water-cooled design. The cutting head consists of two halves mounted on the output shafts of the cutting gearbox via splined connections. The splined connection serves both as a mounting interface and as mechanical protection against overload. The available gear ratios are respectively: XL i = 34.62 , L i = 54.96, M i = 64.57, S i = 73.34, reaching maximum mining speeds of: XL = 2.33, L = 3.02, M = 3.55 , S = 4.03 [m/s].
Swinging mechanism – turret
The turret is screwed to the main frame. The disc bearing ensures very little vibration during operation, even in harsh conditions.
Horizontal rotation is achieved by a rack-and-ring gear mechanism driven by four integrated hydraulic actuators, ensuring a constant rotational speed across the entire range of motion. The range of rotation is about 45° in each direction, right and left. Vertical rotation is achieved by two hydraulic cylinders that are attached to the cutting boom and turret. The vertical rotation range is about 85°.
Excavated material loading and transport system
The loading assembly consists of a loading table (‘loading pan’) that can be hydraulically raised and lowered, two feeder gearboxes, and optionally loading arms or loading stars.
The loading table has a sturdy design with a basic width of 2800 mm. Optional loading table extensions are available for different widths – both fixed extensions and variable extensions operated hydraulically. The basic machine features a variable loading table extension from 4.72 to 5.12 meters in length.
The entire top surface of the loading table, which is in contact with the loaded material, is covered with wear-resistant plates 10 mm thick. The loading table is also used to stabilise the machine during cutting with two hydraulic cylinders.
A chain conveyor is located in the centre of the machine. It transports the material collected in the loading table to the rear end of the machine, using a double chain conveyor system. The chain is a standard continuous mining chain with dimensions of 19 x 64.5 mm. The chain conveyor is driven by loader gears and electric motors.
The surface of the chain conveyor in contact with the material to be transported is protected by 10 mm thick wear-resistant plates. The unloading end of the double chain conveyor is located high enough to allow easy loading.
The maximum capacity of the conveyor is 300 m³/h, allowing for fast loading.
Main frame and stabilising supports in the AM 75
The frame is a one-piece steel structure. It carries over all other assembly groups. Hydraulically-controlled stabilising supports are mounted at the rear and serve as support during drive-up and cutting operations. The stabilisers, which are located on the right and left side of the rear frame, can be raised and lowered using hydraulic cylinders. The stabilisers transfer the weight of the machine to the front to help compensate for cutting forces when cutting the rock face.
Electric system
The flame-proof electrical equipment of the roadheader is designed for operation at 1100 V / 50 Hz. Electrical equipment uses an isolated neutral system. All parts of the electric system which may come into contact with the body are connected with a protective conductor. The motors are monitored for earth fault in the off state. In case of an earth fault the motor cannot be started. The lighting and control system is constantly monitored for earth fault. In case of an earth fault the circuit is switched off. All switching equipment is housed in a flame-proof enclosure, to which the motors, headlights, intrinsically safe control devices and the power supply cable are connected. The electrical system is designed as EExdl explosion proof and is available in versions working with different voltages and according to the required regulations.
Why us?
10 years of experience
Over a decade of activity, we have acquired knowledge and practical skills that allow us to successfully implement even the most complex projects.
An experienced team
Qualified engineers, mechanics and specialists with many years of experience in the mining industry who are constantly improving their competences.
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We offer a wide range of machines, parts and services. We provide support at every stage of the equipment life cycle.
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We deliver our solutions to customers from all corners of the world, gaining valuable experience in many demanding environments.
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