In order to meet the individual requirements of our customers and innovatively solve problems, we are dedicated to the continued improvement of the quality of our products, processes and services. That is why the results we deliver – backed by an experienced project management – are always tailor-made solutions. These are applied in a wide range of industries.
AdBlue is an aqueous urea solution that helps to drastically reduce the emission of nitrogen oxides of diesel engines. Precisely dosed, a pump injects the solution into the exhaust flow.
For the drive of the pump, MS-Schramberg developed a six-pole neodymium iron boron ring magnet for the rotor. The element neodymium is one of the rare earth metals, which are very susceptible to corrosion. Since the pump is exposed to an aggressive urea solution, the corrosion resistance was increased by integrating the magnetic particles into a thermoplastic plastic compound. In addition, the ring magnet of the rotor was tightly overmoulded with plastic. A special challenge consisted of ensuring that the overmould had a very thin wall in order not to negatively impact the performance of the pump.
For the angular position detection of a throttle, a magnetic system was developed that is exposed to temperatures of up to 160° Celsius in the engine compartment. The critical ambient conditions require a detailed functional design for the entire magnetic and sensor system. Using finite element method (FEM) simulations, the magnetic properties of the entire unit were designed and ensured for the tolerance chains of high temperatures and service life.
In order to facilitate the installation for the customer, we designed a complete coupling system that is also well-suited as an interface for additional vehicle models. Thanks to a Moldflow simulation, a tailor-made solution was developed in spite of the limited room available.
This gear with integrated magnet serves as a throttle actuator in the engine compartment, where it is exposed to temperatures of up to 160° Celsius. In order to ensure the magnetic ageing and dimensional stability of the gear in these operating conditions, highly temperature-resistant plastics are used, which are produced via a 2-component injection moulding process. Thanks to the suitable magnet design, a linear sensor signal is generated via the angle.
Generally, gears with integrated magnets not only reduce production costs but also the tolerance chain, which is a particular challenge due to the combination of mechanics and electronics and their reference plains.
In order to get clear indicators for the position of a gear lever or the position of the gear, we have developed a magnet component with a total of 4 tracks and multiple poles each. It allows the detection of many switching positions on a very small space.
Corresponding to the enormous requirements due to the high temperature, contact with transmission oils and the need for a long service life, the decision was made to use an injected hard ferrite magnet that is produced in a 2-component injection moulding process. This creates a positive-locking connection between magnet and carrier. The magnet is then aligned in a preferred direction in a fully automated process and then magnetised on the surface in a precise position. Thanks to the high degree of automation, top efficiency and quality standards can be implemented.
This magnet component is used in transmissions as a so-called "parking disk". It is exposed to great temperature swings from -40° to 180° Celsius and therefore to extreme stresses.
The component is magnetised in multiple tracks in order to ensure a precise position detection. The magnet consists of a plastic-bonded neodymium iron boron compound on a polyphenylene sulphide (PPS) basis and it is injected directly into the steel part. As a means of corrosion protection, the steel then receives an organic coating.
In order to be able to produce particularly efficiently, the plant is fully automated and also monitors all quality requirements of the magnetisation inline. This ensures that only perfect parts reach the packing station.
The ambient conditions with up to 180° Celsius at 3,500 rpm in transmission oil pose a particular challenge for this magnet assembly that measures speed in automatic transmissions.
The magnet solution we developed to overcome this challenge consists of a 72-pole injected hard ferrite magnet, which is magnetised in the injection mould and then magnetically tested in the same system.
The hard ferrite magnet is then glued into an aluminium ring in a fully automated process. State-of-the-art technologies, such as plasma treatment and laser technology are used during the pretreatment phase.
Another particular challenge is the selection of a suitable adhesive. To overcome it, we work closely with the adhesive manufacturers. In this case, we used a single-component adhesive that reliably meets the extreme requirements.
In spite of the high demands on the component, we have had no complaints for many years and are therefore meeting our high quality standard.
Using glueing technology, a plastic-bonded, pressed neodymium iron boron ring magnet is installed in the pan of an external rotor motor.
The motor serves as the drive for a membrane pump for exhaust gas treatment via urea injection.
The particular challenge for this magnet solution is the relatively thin wall thickness combined with the required magnet height and very narrow tolerances.
In the case of this rotor assembly with return flow ring and glued neodymium iron boron rectangular magnets, which serves as an external rotor motor for bike and wheelchair drives, the need for robustness is particularly great. The stresses from shocks and vibrations that are generated when riding a bike or driving a wheelchair are enormous. In addition, neither humidity nor the adhesion must damage the magnet. In order to be able to use the rotor at the required temperatures, the magnets were coated correspondingly and a suitable adhesive system was selected.
Challenges for this application are the exact positioning of the magnets once they have been magnetised, checking the magnetic flow in the overall system and ensuring the bonding strength at the operating temperature.
The magnet assembly consists of a plastic-bonded, pressed neodymium iron boron magnet that is coated with parylene. In agricultural or construction machinery, it is used as a rocker switch that controls hydraulic units.
The magnet is glued onto a carrier. The diametrical magnetisation occurs afterwards. In order to ensure the permanent adhesion of the different composite materials, special adhesives and processes are required.
In addition, a spring is installed that returns the switch to its zero position after it was manually actuated. Hall sensors that are placed in the rocker switch measure the flux density in a defined air gap and control the proportional valve. An example for this application is when, corresponding to the signal, a hydraulic cylinder lifts the excavator shovel of an excavator.
The challenge for this magnet assembly is the very precise magnetisation with regard to the zero crossing.
Together, the two magnet assemblies form the radial coupling of a dialysis machine. The internal part of the coupling is connected to the pump that extracts the dialysate by cleaning the blood via the capillary filters. Since this part comes into contact with the dialysate, the magnet is overmoulded with medical plastic and it meets the strict medical technology quality requirements. Carbon bushings, which are also injected in a positive locking manner, serve as bearings. The external part of the coupling is connected to the drive motor. Both parts are strictly separated from each other. This allows power to be transferred contact-free and wear-free from the motor to the pump without contaminating the dialysate. The magnets that are being used consist of a plastic-bonded hard ferrite material and have received an 8-pole magnetisation at the inner and/or the outer diameter.
This magnet is used as a counting system of an asynchronous motor in order to detect the position of shutters or awnings. An anisotropic, plastic-bonded hard ferrite magnet is used for this purpose. Its perimeter receives a 10-pole magnetisation. The magnetisation takes place right in the tool. For this purpose, our experienced mould making department developed a tool with 8 cavities. This allows for the efficient production of large quantities and a high degree of automation for maximum efficiency. For example, the magnets are automatically packaged in tubes at the end of the production process.
In this magnet application, a motor with magnetic bearings with a total of 4 magnetic systems is being used. The rotors are accelerated greatly and run with a speed of up to 200,000 rpm. Since the rotors cannot be balanced, the required balance quality can only feature a very narrow tolerance range following the installation of the individual parts.
The four bearing magnets made from sintered neodymium iron boron are all precisely ground and axially magnetised. The magnetic requirements allow nearly no deviation with regard to angle and flux density.
Since gluing the magnetic rings would lead to an imbalance that is too great, we developed an assembly process that does not require adhesives. The brittle magnetic rings are provided with a CFK "bandage" that protects them from bursting. The bearing covers are equipped with a coil system that controls the bearing.
In order to meet the high quality requirements for the bearing magnets, the production processes had to be very well coordinated. Prior to the final assembly within the production facility, important magnet parameters are checked completely.
The magnetic spring serves as a reversal aid for the rotary oscillation drive (angle of ±37°) of a yarn rewinding machine. The magnetic spring consists of a bearing shield that is installed with the motor and a magnetic holder that is installed on the shaft. The neodymium iron boron magnets with high coercivity are glued into aluminium parts that are provided. As opposed to a mechanic spring, this solution, which is implemented via a "magnetic coupling", is totally wear-free.
The housing and counter of a water meter usually consist of separated chambers. They are connected contact free via a magnetic coupling. For this magnet application, we have developed sintered hard ferrite magnets with 4-pole magnetisation on the front surface. As a magnet pair, they create the coupling effect.
In order to facilitate the assembly for our customers, the magnet is then overmoulded with a thin-walled technical plastic. Naturally, the selected plastics and magnetic materials are approved for drinking water.
The plastic-bonded neodymium iron boron ring magnet is injected onto a rotor body and its perimeter then receives a 6-pole magnetisation. The rotor spins at approx. 3,000 rpm at a maximum temperature of 100° Celsius.
The rotor is clamped onto one side of the shaft via a screw. In order to ensure that it does not have to be balanced, the base unit is already equipped with a balance compensation device.
Since the base unit has a large diameter (31 mm), the challenge is to ensure the connection of the magnetic material on the base unit without the formation of cracks. In order to do so, the optimal process parameters were determined via statistic designs of experiments (DOE). The results of distortion and stress analyses as well as filling studies guarantee the best possible tool design. Optimised magnetic compounds we produce in-house guarantee top quality.
This magnet solution features a hard ferrite compound that is injected directly onto a motor shaft in a pole-oriented manner using injection moulding. A knurl on the shaft serves as a form fit. The armature is installed in a drive via the bearings and directly drives, for example, a fan in a refrigerator. Our magnet solutions meet top standards with regard to running smoothly and avoiding imbalances and noise.