PMB - Präzisionsmaschinenbau Bobertag GmbH
Contract Balancing and Balancing Service - Some selected examples to illustrate the wide spectrum of our know-how
The application possibilities of balancing technology and the improvements achieved with it are always inspiring even for us as specialists. For contract balancing in particular we very early receive the newest developments of our customers and their future products of tomorrow. We are not allowed to present all of this here, but we would like to show you an excerpt of our activities.
From microturbines, compressor wheels, spindles and rotors to large gears, we have balanced almost everything with precision. We balance up to the range of 0.001 gmm residual unbalance or better and for speeds of 800.000 RPM or faster.
... usually consist of the cast turbine wheel and a welded shaft. For the high operating speed up to more than 300,000 rpm a particularly good balancing is important to ensure the function and to achieve low operating noise. The most favourable way of balancing, also because the rotor is usually no longer accessible to the trunk group in later operational balancing: balancing as a separate part to impressively low residual imbalances. Whether on our bearing blocks or directly in the PMB air bearing. More about this topic..
... whether milled or cast, whether for the turbocharger or hydrogen compressor: to ensure the later balancing of the hull assembly during operational balancing, it is highly recommended to balance the compressor wheel very well already as an individual part. After all, it will later rotate up to over 300,000 rpm. The best way to balance compressor wheels is to balance them on our PMB air bearing mandrels, so that mechanical tension influences do not occur. The short-term design and manufacture of these air bearing mandrels is a speciality of PMB, so that PMB contract balancing quickly achieves outstanding balancing qualities. More about this topic..
... for machine tools (turning/grinding/milling spindles) are precisely mounted. Their running smoothness due to the state of balance is decisive for the performance, service life and accuracy/surface quality of a machine tool. It is better to balance a spindle better than to manufacture a spindle more precisely - the manufacturing tolerances are already at the limit. For balancing, the motor spindles' own drive is usually used over the full speed range. Balancing as a complete spindle also directly compensates for mounting influences on the unbalance. We are proud that Fischer precision spindles, for example, are balanced with our systems. More about this topic..
... are used as energy storages, e.g. for the compensation of rotational vibrations and load changes. Higher speeds increase efficiency, but require good balancing. The aim of balancing: To extend the service life and increase quality through smooth running.
TURBOCHARGER CORE ASSEMBLIES
... turbine rotors in the bearing housing with mounted compressor wheel are the core of every turbocharger. Balancing of core assemblies is usually performed at high speed over almost the full operating speed range. Even with perfectly balanced individual parts, assembly into a core assembly results in unbalance - usually on the side of the assembled compressor wheel. PMB's contract balancing department has experience with all types of turbochargers and ensures the acoustic quality and function of the turbo from prototype to series by balancing to low residual unbalance.
ASSEMBLIES WITH OWN DRIVE
… are e.g. motor spindles, electric motors and pumps. Balancing as an assembly with its own drive compensate influences on the unbalance of the assembly, too. This is where the perfect vibration quality of the assemblies is most efficiently achieved.
DENTAL TURBINES / MEDICAL TECHN.
... are used at the dentist and drive the drill with compressed air. Dental turbines reach operating speeds of up to 500,000 rpm and have to be particularly well balanced to reduce noise and ensure a long service life. Dental turbines balanced with PMB machines were in comparative tests 50% quieter than comparable turbines that were not balanced with our technology! For high-precision and gentle mass removal, we use lasers as removal tools. More about this topic..
Whether as a spindle shaft, gear shaft, drive shaft or shaft of a transport roller: Good balancing of this individual part lays the foundation for smooth running. Our test benches and the PMB contract balancing department achieve exceptional balancing qualities for these standard components. The variety of shaft designs is high - please contact us for the exact shaft you need, we will be happy to advise you. More about this topic..
ELECTRIC ROTOR / Anchor
… are the rotating parts of the electric engine. Ideally, the mounted electric motor should be balanced - as this is usually not possible, the rotor is balanced before mounting into the housing. The aim of balancing: To reduce the vibrations generated. Increasing the service life of bearings and connected components. More about this topic..
Highspeed electric rotors
... depending on the application in electric turbochargers, compressors, hydrogen pumps or even modern vacuum cleaners, some of them rotate at over 100,000 rpm and must therefore be particularly well balanced. Read more about this important balancing, which makes the operation of such high-speed rotors. More about this topic..
... are ideally assembled ready to run and balanced with their own drive, so that influences of the assembly are compensated. The aim of balancing is to increase the service life. Reduction of vibrations and noise. Adjustment of quality - a quiet electric motor is always considered to be of higher quality. More about this topic..
FANS / FAN WHEELS
... move air and are particularly efficient at high speeds. Since air as a sound carrier and transmits vibrations, fans are particularly well balanced - or uncomfortably loud. More about this topic..
PUMPS / IMPELLERS
... transfer their vibrations to the pumped medium and run more efficiently with increasing speed. Reliable high-quality balancing enables speed increases with low noise emission. PMB has experience with a wide variety of impellers from many fields of application. Please contact us for the best solution for your application, we will be pleased to advise you.
HSK TOOL HOLDERS
... connect the tools in machines to the spindle. In order to maintain good spindle balancing, this tool clamping system must also be very well balanced. The aim of balancing: To extend the service life of the tool and motor spindle. Improved surface quality and dimensional accuracy of the machined workpieces.