GENERAL TECHNICAL INFORMATION BUFFERS
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RÖMER Fördertechnik GmbH Specialists in brake and drive technology Allg. technis che I nfor matio n en - H ydraulik puffer s ys teme Ge n e ra l te c h n ica l in fo rm at ion - H yd ra u lic B u f f e r Sy stem s - Technische Daten / Zeichnung technical data / drawing 140314 Quality. Safety. Efficiency www.rft-germany.com

Technical Information Hydraulic Buffers Fördertechnik GmbH Page 1 of 1 Nielandstrasse 53 · 58300 Wetter / Ruhr Contents: - performance characteristics of different buffer systems - force/stroke characteristics of a hydraulic buffer - general operating principle of hydraulic buffers - operating principle of hydraulic buffer series Herkules ll and PUDZ ll - operating conditions and design features - accessories and special designs - selection of buffer stroke - selection of buffer size - list of symbols and units of measure used in the formulas - basic calculations with formulas eMail:...

Performance Characteristics of different Buffer Systems RÖMER Fördertechnik GmbH Page 1 of 2 Operational speed of modern transport systems is continually increasing in order to increase capacity. The increase of operational speed gives rise to increased loads on vehicle structures and upon associated supporting structures, especially in an emergency situation such as an emergency stop or buffer impact. This imposes increased performance requirements on the buffer system which cannot be met by some conventional systems. The most common buffer systems are: rubber - buffers cellular - buffers...

Performance Characteristics of different Buffer Systems RÖMER Fördertechnik GmbH Page 2 of 2 The shape of the force/stroke diagram for a buffer is a function of the buffer system. Referring to Fig. 1, the area below curve 1 in each case is the total energy absorbed by the buffer during the buffer stroke. During the buffer stroke, part of the energy absorbed by the buffer is dissipated to the environment as heat energy, the actual amount of energy dissipated is a function of the buffer system. The rest of the energy absorbed (the area below curve 2 in Fig. 1) is stored within the buffer as...

General Operating Principle of Hydraulic Buffers Herkules II and PUDZ II Page 1 of 2 RÖMER Fördertechnik GmbH Nielandstrasse 53 · 58300 Wetter / Ruhr General Operating Principle of Hydraulic Buffers Referring to Fig. 3, under the influence of an external force the piston rod (or plunger) (1) is pushed into the cylinder (2) filled with a Newtonian, incompressible fluid (3), for example hydraulic oil. During movement of the piston into the cylinder the fluid is forced through precisely calibrated orifices which can be either annular orifices, slots or a series of small holes. The orifices act...

General Operating Principle of Hydraulic Buffers Herkules II and PUDZ II Page 2 of 2 The pressure of the compressed gas in the reservoir (4) forces the oil back into the cylinder tube (2), which in turn forces the piston (1) back out to its fully extended position. This process is repeated after each buffer stroke, irrespective of the orientation of the buffer (closed system). In the Herkules II series of buffers the oil seals (7) operate on the piston rods which are hard chrome plated. In the PUDZ II series of buffers the oil seals (7) operate internally on the bore of the cylinder tubes...

Fundamental - Dimensioning Fördertechnik GmbH Page 1 of 3 Nielandstrasse 53 · 58300 Wetter / Ruhr Operating Conditions and Design Features For standard models the impact speed should be within the range 0,5 m/s to 4 m/s. Higher impact speeds are possible with reduced energy absorption. The range of operating temperatures is normally within -30 °C to +100 °C. Special seals and oils are available for higher temperatures. Special measures need to be taken at extremely low temperatures. For standard types a high-grade hydraulic oil HLP is used as the working medium. The hydraulic buffers are...

Fundamental - Dimensioning Fördertechnik GmbH Page 2 of 3 When a buffer is subjected to a high frequency of compression z the energy absorption per hour Wh must be calculated: Nielandstrasse 53 · 58300 Wetter / Ruhr There is often angular misalignment in rotating or free falling loads or very flexible structures and this must be checked against the permitted angular misalignment γ for the selected buffer. If necessary a larger buffer must be selected. The deceleration time t (the duration of the buffer stroke) and the deceleration a during the buffer stroke can be calculated for all...

Fundamental - Dimensioning RÖMER Fördertechnik GmbH Nielandstrasse 53 · 58300 Wetter / Ruhr List of symbols and units of measure Ekin Epot Erot Eges FD FP FV J P T W Wh a fKM g kinetic energy potential energy kinetic energy of rotating driving parts total energy of the system pressure force of the cylinder, propelling force buffer force propelling force inertia moment nominal capacity of the driving motor propelling torque buffer work energy consumption per hour deceleration pull-out torque factor acceleration due to gravity height of fall (decline of gravity centre) buffer characteristic...

Impact Cases with Formula Fördertechnik GmbH Page 1 of 3 Nielandstrasse 53 · 58300 Wetter / Ruhr The following examples are given for the determination of kinetic and potential energy and design data for selection of the appropriate buffer for an application: - mass to be braked per buffer - impact speed per buffer - propelling force per buffer Conversion Formula Horizontally Moving Mass a) mass without propelling force b) mass with propelling force V c) mass on driven rolls d) mass with motor drive Observe limit of adhesion of the driving wheels ! e) mass with motor drive and rotating...

Impact Cases with Formula Fördertechnik GmbH Page 2 of 3 Application Case B: Vertically Moving Mass Nielandstrasse 53 · 58300 Wetter / Ruhr Conversion Formula b) lowered mass, constant speed Application Case C: Mass on an Inclined Plane a) free rolling, without propelling or braking force Conversion Formula α b) with propelling or braking force s Force Direction: + : propelling force F D acting in direction of motion - : propelling force F D acting opposite to direction of motion eMail: info@roemer-foerdertechnik.de Internet: www.roemer-foerdertechnik.de Data subject to change without...