Speciality Lubricant for Electric Vehicles

With electric and hybrid vehicles becoming more widespread, and autonomous vehicles awaiting a grand roll-out, the automotive industry is witnessing hitherto unknown technological transformations.

Lubricants were optimised for vehicles with internal combustion engines over decades of joint development efforts, and now they have to master the new challenges of electric mobility. The development of corresponding new lubrication solutions is in full swing. These efforts have brought about first results that design engineers can work with.

Small engine size, big lubrication challenge

Due to smaller and simpler gearboxes, more compact powertrain designs will be feasible. This downsizing, however, will bring about new challenges, for example, more heat being generated,
and higher RPM. For design engineers, this entails the need for efficient, simple solutions, for example in the form of a lubricant that is better at providing the required cooling effect.

Besides, there are electrical drive trains where the electrical motor is not lubricated by the transmission fluid. The electrical motor bearings need grease for a lifetime performance. This is a challenging application because the requirements for electrical motors, the drive trains have just started to develop and we are witnessing an upward trend towards higher speeds.

Sustainable solution from Klüber Lubrication

Globally, Klüber Lubrication has been making waves with its innovative and groundbreaking technological solutions. The core strength of Klüber Lubrication lies in its innovation and adaptive technology. Klüber in India is working on evolving hydro lubricants technology, its aftermarket business, associating closely with OEMs and catering to their needs for specialty lubricants besides positioning themselves as preferred partners.

Water – quenching a different thirst
Water’s ubiquitous nature has now caught the attention of automotive lubricant makers all over the world. Water is now being utilized as a replacement for base oils in lubricants used in new mobility options. This pioneering technology is now gaining ground as Klüber continues to work on the evolution of the process.

Hydro Lubricants containing water as a base oil show extraordinarily low friction and an improved cooling effect. The lubricant can help to extend the travel range of electric vehicles and reduce gearbox temperature by up to 17 °C compared with conventional lubricants. With the lower temperature, engineers have more options for their vehicle design.

Klüber is developing more on the technical development of electric drive trains for multiple benefits like higher load capacities without losing the efficiency of the transmission, and better heat management in the drive train including the transmission. Water has a high heat dissipation capacity compared to synthetic or mineral oils, is easily available, non-toxic, non-flammable and is sustainable.

Work in progress
As of now, hydro lubricants are in the early evolving stage, advantages and pain points are identified by using this technology on vehicles and test rigs to solve the challenges so that it can be implemented in a series of applications. Electric vehicles are being built to be cost-effective, and offer efficiency, range, and sustainability, and in that context, hydro lubricants have the potential to deliver.

Klüber Lubrication launched its first hydro lubricant in 2018 for industrial gearbox application for which it was conferred with the German Innovation Award. Hydro lubricants are under test conditions in India as is the case across the world, by various EV manufacturers and design companies. Besides offering numerous greasing solutions, Klüber is supplying transmission oil to one of the biggest EV manufacturers in India and helping others to develop their models.

Preferred Partners

Klüber Lubrication is a world market leader in specialty lubricants and has been successful in solving demanding conditions for lubrication. It has documented successful associations with Indian, European, Japanese and Korean besides popular US-based EV makers.

Klüber expects every function in the autonomous vehicle to be actuated electromechanically by e-motors and gear units in the future. And these gear units need specialty lubricants for them to work a lifetime under harsh conditions. The lubricants, hence, will need to be compatible and able to work efficiently with newer materials that are going to be in use.

With the evolution of the electric cars, the battery unit in these cars needs to be maintained at optimal temperatures at all times, to ensure longer battery life, efficient charging and longer operating miles. Most of the e- vehicle manufacturers are looking at cooling liquids as the viable solution to operate battery packs at optimal temperatures.

For the efficient cooling of the battery packs most of the designs incorporate actuators, which control the flow of the cooling liquids around the battery. These actuators need to have high reliability to ensure that the cooling liquid operate as per the designed flow algorithm.

Some of the advanced designs even incorporate more than 5 actuators in a single cooling system control. Lubricants play a pivotal role in the reliable operation of these actuators. The gears and other critical components inside these actuators need to be lubricated well, even when exposed to varying temperatures.

These actuators need to operate at -40 deg C during peak winters and also operate at temperatures close to 150 deg C, as the battery packs can reach very high temperatures during operation. The lubricant used for these actuators also need to work under these extreme temperatures and provide excellent lubrication properties.

Another major challenge for the lubrication of the actuators are the compatibility with the different plastic and non ferrous materials being used in the actuators. Generally available lubricants either swell or shrink these plastic and non ferrous components, creating structural damage to actuators over a period of time.

Klüber Lubrication a world market leader in speciality lubricants has been successful in solving these demanding conditions for the lubrication of these actuators. They provided a specially engineered PFPE/PTFE-grease as the lubrication solution. This grease can operate at -65 deg C to 200 Deg C and at the same time provide excellent material compatibility. On extensive testing of this solution from Klüber Lubrication, the OEM's not only found the right lubricant solution but also realized higher service life for their actuators.

The brake booster is one of the most important systems in a vehicle, which ensures effortless application of brakes in a vehicle. Until recently, majority of brake boosters used the vacuum generated by the internal combustion engine’s intake section to operate. With new engine technologies (e.g. electric vehicles or fuel cell technology ) there is no engine and hence the vacuum produced by the engine is no longer available. This has led to the development of the electric brake booster. For the effective and efficient operation of electric brake booster, lubricants are an integral part of the design.

Klüber Lubrication has been an innovation partner in the development of the optimal lubricant for the electric brake booster.

Klübersynth RG 86-121 provides excellent wear protection on mostly polyamide and glass fiber mating components. The lubrication of these mating surfaces has been a big challenge for many years, due to the high wear properties of these surfaces and component compatibility issues with most commonly available lubricants. 

This polyglycol oil and PTFE based grease also provides extended lifetime lubrication on the brake boosters.

"Solving the lubrication requirements of an electric brake booster was an uphill task, the OEM's were testing new material compositions and the initial lubrication concepts were failing. The concept of Klübersynth RG 86-121 evolved from extensive research and testing. We are happy that we now have a foolproof lubricant solution for the electric brake boosters and braking remains an effortless and safer process even on electric vehicles" says  Hitendra Bhargava, CEO Klüber Lubrication India Pvt Ltd.

The lubrication requirements of Constant Velocity ( CV) joints in an electric vehicle is quite different to that of the CV joint in an internal combustion engine. The CV joints in an electric vehicle have to operate with higher initial torque being provided by the electric motor. This leads the CV joint to be subjected to higher wear during the starting phase itself, as lubricant may not be available at the mating surfaces during the start of the vehicle.

This has been a challenge for the grease in CV joints due to the higher load and herewith the potential higher operating temperature. Those new requirements are asking for greases with better load capacity and lowest friction as possible.

The earlier generation lubricants used for the design of the CV joint are not able to meet the higher torque operating conditions. This has led to higher temperatures, oil leakage from the grease and higher evaporation of the grease in the CV joint. These adverse operating conditions have even led to the CV joint boot to blow up during operation.

Klüber Lubrication, a world market leader in speciality lubricants, has developed and successfully implemented the Klübersynth HE 74-81 as the right solution for CV joints even for the electric vehicles. This specially engineered fully synthetic grease comes with a special polyurea thickener which ensures that the lubricant provides excellent lubrication property. This grease also provides excellent false brinelling property which also ensures that the CV joint do not undergo wear during vehicle on vehicle transport or during drives on straight roads.

"We are happy to be chosen as the innovation partner by multiple CV joint manufacturers around the world, for developing the right lubricant for the new CV joints to be used in the electric cars. With our extensive knowledge in dealing with applications where higher torques are available right at the start, we were able to quickly come up with the solution in the form of Klübersynth HE 74-81. We feel projects like these are a step in the direction of partnering with many more designers, to develop the vehicles for the future together" says Hitendra Bhargava , CEO Klüber Lubrication India Pvt Ltd.

With comfort and efficiency being a key focus in the auto industry the brake by cable parking brakes are slowly giving way to electric parking brakes.

With this shift in the parking brake system, there is more space in the cabin to accommodate more feature and the effort of parking has also reduced drastically. This change in technology also puts in new requirements on the lubrication of the components in the parking brake system.

The lubricant has to provide excellent wear protection on the gears used in the parking brake system and at the same time also operate at lower and higher operating temperatures. As one of the critical component used in the electric parking brakes is made of EPDM material, the lubricants should have excellent compatibility with EPDM to ensure neither swelling of shrinking of components, which might lead to component failure over a period of time.

Klüber Lubrication, a world market leader in specialty lubricants has been successful at developing and testing the new range of lubricants that meet these stringent requirements. The Klübersynth LRG 86-21 and the Klübersynth LRG 46-21 have been successfully able to deliver optimal lubrication for the electric parking brakes. These greases are developed from a PTFE and polyglycol oil composition, which provide extremely low co-efficient of friction and excellent EPDM compatibility. These greases also meet the stringent -40 Deg C to 120 Deg C temperature requirement making it reliable for use in extreme weather conditions.

Major brake manufacturers around the world have been successful using the products Klübersynth LRG 86-21 and the Klübersynth LRG 46-21 for the manufacturing of the electric parking brakes, making these electric brakes more reliable and long lasting than the past.

"We are very happy to be one the first movers in the industry to have successfully solved the lubrication requirements for electric parking brakes. We have not only met the lubrication requirements but also successfully passed the life time requirement of such a critical component in the car." says Hitendra Bhargava, CEO Klüber Lubrication India Pvt Ltd.