Modern construction and cargo transportation cannot be imagined without universal special equipment capable of independently performing loading and unloading operations. Faucet with ball is the popular name for manipulators equipped with an articulated boom that, when folded, forms a characteristic curved shape. This technique is indispensable in confined areas where the use of traditional telescopic boom cranes is physically impossible or economically infeasible.
Unlike classic cranes, here the main emphasis is on maneuverability and the ability to work in cramped conditions. Hydromanipulator installation (KMU) is mounted directly behind the truck cab, which allows the driver to independently carry out lifting operations. This significantly reduces equipment downtime and eliminates the need to rent a separate crane for each delivery point.
The operating principle is based on a hydraulic drive, which ensures smooth movements and high accuracy of load positioning. A key feature of articulated booms is the ability to navigate around obstacles such as fences, building roofs or power lines, delivering the load precisely to a predetermined point. Understanding the technical nuances of this machine is critical to safe and efficient operation in all climates.
Design features of articulated booms
The basis of any manipulator is the boom, which in this case consists of several sections connected by hinges. Each section is driven by a separate hydraulic cylinder, which creates a complex kinematic chain. This design allows the boom to be folded into a compact “envelope”, taking up minimal space on the vehicle frame in the transport position.
The most important element of the system is rotary column, on which the boom itself is installed. It is this unit that ensures the rotation of the entire mechanism around its axis, usually 360 degrees, although there are models with a limited rotation sector. The structure must withstand colossal dynamic loads that occur when the load is lifted off the ground or during sudden braking of rotation.
- 🏗️ Sectional architecture: the number of sections varies from 4 to 8, which directly affects the boom reach and lifting height.
- ⚙️ Hydraulic system: uses axial piston pumps to create operating pressures up to 350 bar.
- 🔒 Security system: load limiters (LOL) prevent the machine from tipping over when the permissible moment is exceeded.
It is worth noting that modern models are often equipped with an additional elbow (“jib”) at the end of the main boom. This allows you to increase the working radius without significantly increasing the weight of the structure itself. Hydraulic drive All joints ensure independence of movement, allowing the operator to perform complex combined operations with one joystick hand.
⚠️ Attention: Operating a crane with a faulty load limiter is strictly prohibited, as this is a direct path to vehicle overturning and injury.
When working on soft ground, always use special pads under the outriggers (supports), even if the surface seems hard. This will prevent subsidence of the supports and loss of stability of the crane.
Classification of loader cranes by lifting capacity
The choice of equipment begins with determining the required tonnage. The market offers a wide range of solutions: from light manipulators for transporting building materials to heavy machines for installing concrete structures. Load capacity is indicated in two parameters: maximum load weight and lifting capacity at maximum boom reach.
The light class, as a rule, includes machines with a torque of up to 10 t·m. They are often installed on the chassis of Gazelle or Valdai type cars. The middle class covers the range from 10 to 25 t m and is based on two- or three-axle trucks. Heavy manipulators, whose torque exceeds 30 t m, require a powerful chassis with three or more axles, often with an 8x4 wheel arrangement.
It is important to distinguish between static and dynamic load capacities. The equipment passport always indicates the static weight, but when lifting a load from the ground or in motion, dynamic coefficients arise that reduce the real capabilities of the machine. Dependence of boom radius on weight is nonlinear: as the operating radius increases, the load capacity decreases exponentially.
To accurately select equipment, it is necessary to take into account not only the weight of the load, but also the type of grip. If a grab or auger is used, its dead weight is deducted from the payload capacity. You should also pay attention to the lifting height, which is often a limiting factor during installation work at height.
Chassis requirements and installation installation
Installation of a crane installation is a complex engineering process that requires precise calculations. The vehicle chassis must have sufficient frame load-bearing capacity. Installing a heavy manipulator on a weak chassis will lead to deformation of the side members and loss of vehicle controllability. Axial load distribution must strictly comply with the requirements of the chassis and CMU manufacturer.
The installation process begins with dismantling the standard body or platform. Then the rotary support device is installed. A critical step is tapping into the vehicle's hydraulic system. The crane hydraulic pump is usually driven from the power take-off (PTO) or directly from the engine via the driveshaft.
| Chassis type | Loading capacity of CMU (t) | Max. moment (t m) | Required engine power (hp) |
|---|---|---|---|
| Light (3-5 t) | 3 - 7 | up to 10 | from 120 |
| Medium (10-15 t) | 10 - 15 | 10 - 25 | from 240 |
| Heavy (20-30 t) | 20 - 30+ | 30 - 80+ | from 300 |
| Off-road | 10 - 20 | 15 - 30 | from 280 |
After mechanical installation, the hydraulic system is run-in and safety valves are adjusted. Electrical diagram is also being modified to connect the control panel and security system. Errors at this stage can lead to hydraulic failure at the most inopportune moment.
☑️ Check after installation of the CMU
Equipment and additional attachments
The versatility of a ball crane is largely determined by the type of attachment used. The basic element is hook suspension, but for specific tasks it is often replaced or supplemented by other devices. The correct choice of equipment increases labor productivity significantly.
One of the most popular additions is the hydraulic drill. It allows you to carry out excavation work to install pillars, piles or foundations. The drill can be installed either at the end of the boom or between sections. The second most popular option is rotator - a device that allows you to rotate a load around its axis, which is indispensable when working with long loads or in narrow trenches.
- 🪝 Grabs: designed for bulk cargo (crushed stone, sand) or scrap, they work on the principle of gripping with “paws”.
- 🪵 Forest grips: special pliers for working with logs, often used in logging.
- 🧱 Forks: analogue of a forklift for working with pallets and Eurocubes.
When using additional equipment, it is necessary to readjust the load limiter. The weight of the hitch must be entered into the controller’s memory, otherwise the system will incorrectly calculate the permissible weight of the load. Ignoring this rule may result in the arrow being overloaded and destroyed.
⚠️ Attention: The use of homemade traverses or extended hooks without recalculating the load characteristics is prohibited, as this changes the center of gravity and the actual reach of the boom.
Safety rules and common operator mistakes
Safety when working with a manipulator is priority number one. Statistics show that most accidents occur not due to equipment failure, but due to the human factor. Rollover - the most common and dangerous accident that occurs when working without fully extended outriggers or on an inclined platform.
The operator is required to carry out a visual inspection of cables, hooks and hydraulic hoses before starting work. The presence of abrasions on the cable or drops of oil under the hose connection is a signal to immediately stop work. Crane operating area must be fenced, the presence of people within the range of the arrow is strictly prohibited.
A typical mistake is an attempt to move the load using the lateral force of the boom (“to stall”). This places a huge lateral load on the sections that they were not designed to support. Loads can only be lifted vertically. It is also dangerous to sharply decelerate the rotation of a platform with a load at maximum reach - inertia can overturn the machine even with the supports in place.
What to do if the cable breaks?
If the cable breaks, you must immediately stop the engine, evacuate people from the danger area and call a repair team. Trying to secure the broken end under load on your own is deadly.
Maintenance and troubleshooting
Regular maintenance is the key to a long life of the manipulator. The main attention should be paid to the condition hydraulic oil. It works under conditions of high pressure and temperatures, so over time it loses its properties and becomes saturated with water. Oil and filter changes must be carried out strictly according to engine hour regulations.
The hinge joints require constant lubrication. Lack of lubrication in the pins and bushings leads to rapid wear of the rubbing pairs and the appearance of backlashes, which negatively affect positioning accuracy. Visual control welds of the boom and rotary column should be carried out every shift to check for the appearance of cracks.
Common malfunctions include:
- 📉 Pressure drop: often caused by pump wear or oil overflowing the relief valve.
- 💧 Leaking hydraulic cylinders: requires replacement of lip seals; failure to comply will lead to contamination of the hydraulic system.
- ⚡ Electronics failure: problems with OGP sensors or joysticks, often associated with oxidation of contacts.
Diagnostics should begin with measuring the pressure in the system. If the pressure does not reach the nominal value, check the safety valve adjusting screw. However, it is strictly forbidden to turn it without a pressure gauge - this can lead to rupture of the hoses or destruction of the hydraulic cylinders.
Preventative replacement of hydraulic oil and filters is 10 times cheaper than repairing a pump group or replacing hydraulic cylinders after a hydraulic shock.
How often should the manipulator joints be lubricated?
Lubrication of articulated joints must be carried out every 8-10 operating hours or daily if the equipment operates intensively. In winter or when working in dusty conditions, the interval should be shortened. Use only lubricants recommended by the manufacturer that are resistant to water washout.
Is it possible to operate the manipulator in strong winds?
Work in wind speeds exceeding 10 m/s (6 points on the Beaufort scale) is prohibited. The wind creates windage of the load and the boom itself, which significantly increases the overturning moment. Even with the legs fully extended, a gust of wind can be fatal to the stability of the machine.
Why does the boom shake when lifting a load?
Shaking (jerking) of the boom most often indicates air entering the hydraulic system or low oil level in the tank. The cause may also be wear on the pump group or clogged bypass valves. It is necessary to bleed the system and check the level of the working fluid.
What protection class should the control panel have?
The control panel must have a protection class of at least IP65, which means complete protection from dust and jets of water. Considering the operating conditions on construction sites and open areas, the tightness of the housing and buttons is a critical reliability parameter.
Is it necessary to register the manipulator with Gostekhnadzor?
Yes, if the handling unit is removable equipment, it must be registered, and changes must be made to the vehicle title. If the CMU is installed permanently (welded or bolted as a single unit), then the entire vehicle is registered as special equipment, indicating the total weight and characteristics of the CMU.