ebm-papst

About: ebm-papst is a company organization based out in Mulfingen, Germany. It is known for research contribution in the topics: Rotor (electric) & Stator. The organization has 572 authors who have published 736 publications receiving 3763 citations.

Fan assembly and its fabrication method

Abstract: The fan(10) comprises a housing(30) enclosing an impeller(18) which conveys air from the suction side to a pressure side. A supporting frame(34) surrounds and holds the fan arrangement(40). A membrane(32) made of an elastic material forms a flexible connection between (30) and (34). The fan(10) comprises a housing(30) enclosing an impeller(18) which conveys air from the suction side to a pressure side. A supporting frame(34) surrounds and holds the fan arrangement(40). A membrane(32) made of an elastic material forms a flexible connection between the housing and the supporting frame. Openings(33) in the membrane permit air from the impeller to flow back from the pressure side to the suction side when the pressure side is closed off. The membrane(32) is connected around the whole outer circumference of the housing(30) and over the entire inner circumference of the supporting frame(34). Connection between the membrane, housing and/or supporting frame. Membrane cross-section in the radial plane can be a U-shape or a wave form. Thickness of the membrane at the connection points to the housing and supporting frame is greater than at points between the two points. The U-shaped membrane has a bulge(32''') and openings(33) are located in this region. Openings may be round, rectangular or square or may be elongated holes with rounded or sharp cornered ends. An independent claim is included for a process for manufacturing the fan arrangement(40) in which first and second moving tool parts of an injection molding tool are moved into position between the fan housing and the supporting frame and a membrane is injection molded in a plastic between the two tool parts to join the housing and frame together.

Excess air coefficient adjusting process for firing apparatus involves determining maximum temperature, adjusting setpoint value and measuring setpoint temperature

Abstract: The adjusting process involves determining the maximum temperature generated by the firing apparatus, and adjust in the desired setpoint value of the excess air coefficient. The associated setpoint temperature is measured. From these data, a characteristic curve for the correlation between the respective air mass flow rates and setpoint temperature is at the desired setpoint value can be determined.

Fan with laminar flow element in front of the suction hole

Abstract: A radial fan (1) with a housing (2) and a fan impeller (3) disposed therein, an air inlet (4) and an air outlet (5) is provided, a pressure space (6) being formed between the latter, and in front of the air inlet (4) a laminar element (7) being disposed which, in a bypass (8) formed therein, has a sensor (9) for recording at least one parameter of the medium flowing through the air inlet (4).

Inverse Aeroacoustic Design of Axial Fans Using Genetic Optimization and the Lattice-Boltzmann Method

Abstract: The noise emitted by axial fans plays an integral role in product design. When conventional design procedures are applied, aeroacoustic properties are controlled via an extensive trial-and-error process. This involves building physical prototypes and performing acoustic measurements. In general, this procedure makes it difficult for a designer to gain an understanding of the functional relationship between noise and geometrical parameters of the fan. Hence, it is difficult for a human designer to control the aeroacoustic properties of the fan. To reduce the complexity of this process, we propose an inverse design methodology driven by a genetic algorithm. It aims to find the fan geometry for a set of given objectives. These include, most notably, the sound pressure frequency spectrum, aerodynamic efficiency, pressure head and flow rate. Individual bands of the sound pressure frequency spectrum may be controlled implicitly as a function of certain geometric parameters of the fan. In keeping with inverse design theory, we represent the design of axial fans as a multi-objective, multi-parameter optimization problem. The individual geometric components of the fan (e.g., rotor blades, winglets, guide vanes, shroud and diffusor) are represented by free-form surfaces. In particular, each blade of the fan is parameterized individually. Hence, the resulting fan is composed of geometrically different blades. This approach is useful when studying noise reduction. For the analysis of the flow field and associated objectives, we utilize a standard RANS solver. However, for the evaluation of the generated noise, a meshless Lattice-Boltzmann solver is employed. The method is demonstrated for a small axial fan, for which tonal noise is reduced. NOMENCLATURE N … number of blades [1]

Method and control system for driving a brushless electric motor

Abstract: In a method and control system for controlling a brushless, electronically commutated electric motor (M), a three-phase source AC voltage (U N ) is rectified and fed to a DC link voltage (U ZK ), which is supplied to an inverter ( 2 ) via a slim DC link circuit ( 6 ). A motor control unit ( 10 ) for PWM pulsing controls the inverter for commutating the electric motor (M) and adjusting the motor speed with a variable duty cycle (A). The duty cycle (A) is influenced by a compensating factor (k) such that the product of the DC link voltage (U ZK ) and a resulting DC link current (I ZK ) is kept constant in the link circuit ( 6 ). The DC link voltage (U ZK ) is monitored. When a first threshold value (U ZKac.max1 ) of an AC component (U ZKac ) is exceeded, the compensating factor (k) is modified to lower the current AC component (U ZKac ) below the threshold value (U ZKac.max1 ).