The Welding of Differential Gears for e-mobility Applications
Differentials are an important component, which every electric car will need. Automotive manufacturers are ramping up their capability and one important requirement is the mass production of differentials for the burgeoning electric vehicles market. Fiber lasers can help massively by replacing traditional differential manufacturing techniques, which we go on to discuss.
What is an electric differential?
Differentials are used in all cars including electric and internal combustion engine (ICE) models. The differential enables the required torque for each driving wheel, and it is the differential, which allows wheels to operate at different speeds. An electric differential replaces a manual differential used in ICE cars. The differential really comes into play when the vehicle is cornering, as here the inner/outer wheels are rotating at differing speeds (hence the name “differential”). The electric differential ensures that the correct amount of torque is supplied to power each wheel as the corner is navigated and also in all driving of the vehicle.
Traditional differential housing assembly production
Traditionally produced differentials require a classic screw/bolt type connection between a ring gear and a differential housing. The screw/bolt used is sizable as it requires high-strength levels.
Various machining and assembly processes are required to complete the final differential.
Describing the laser welding of differential gears process
The processes where fiber lasers are used include:
- Pre-cleaning – the fiber laser crucially can be used to pre-clean the differential parts of any contaminants (e.g. assembly pastes and oils). These will have arisen from previous production processes and from transport and whilst in storage. These contaminants must be removed prior to welding as if not, the welding will become problematic and can cause cracks and porosity
- Laser beam welding – using standard laser beam welding techniques, the various differential parts are seamlessly welded together. The fiber laser is programmed to exactly weld in the precise places required. The depth and weld shape can be varied as is required.
The welding of differential gears process benefits
Electric vehicle Manufacturers are working with laser manufacturers in the mass production of high-quality lightweight differentials for electric vehicles. The benefits of this process include:
- Error free – the process is completed without any errors, this is critical for the smooth running of the differential. Also, human errors are removed in this process
- Fusing of dissimilar metals – even dissimilar metals can be seamlessly welded during this process
- Laser process integration – other laser processes as required can be integrated within the process, e.g. cleaning of parts prior to welding
- Low heat input – the process is completed with low heat input which ensures there is no damage to surrounding materials
- Non-contact – the process is totally contact-free, the laser welds without contact, this reduces employee injury risk (which is high in welding applications) and contamination
- Precision – the welding precision level is precise, with welding to the exact specification required
- Repeatable – an essential part of the process is that it is repeatable and highly reliable. On a production line, the laser can be kept in position and the next parts can be moved in to repeat the laser operation
Differential end-product benefits
The benefits of this process include:
- Automotive “light weighting” – laser welding is an example of automotive light weighting where traditional processes are replaced with new lightweight processes. The same vehicle functionality is delivered, at a lighter weight vehicle giving the following benefits:
- Increased fuel economy
- Lower parts costs
- A saving in weight of between 0.6kg and 1.2kg per vehicle
- Durability and strength – the durability and strength are improved through a more continuous connection between the various differential parts (when compared to traditional manufacturing techniques)
- Increased power – larger torques can be transmitted, this is because the increased bond between parts drives higher torque transmission from the differential to the wheels
- Fewer materials – screw fasteners, which are required traditionally are eliminated. The same strength can be delivered with new “slimmer” designs, which save vehicle weight
- Noise reduction – the electric differential produced is renowned to operate at a lower level of noise than traditionally produced ICE model differentials
Watch our 1-hour plus video which discusses fiber laser welding processes in detail
SPI Lasers – let us help with differential welding
Laser welding is just one of the applications that an SPI fiber laser can deliver. We embrace the “e-mobility” revolution and welding of differential gears is just one important example. Why not contact SPI Lasers now to discuss the many ways in which our fiber lasers can help to transform your processes? To read further new articles from SPI Lasers, Click here to subscribe to future updates.
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