Every gearset designed and manufactured by PAR include many innovations and features from the experience gained from working with many race teams and customer around the world over the last 17 years. From items like the Subaru 5MT interlock assembly in 2002 for dog engagement gearsets which came about from rally racing experience of our customers to un-noticed features such as shift stops and needle roller bearings integrated into every design where possible, you are assured the finest quality product with the strength and reliability demanded by the most fastidious customers around the world. Every PAR gearset undergoes a multitude of manufacturing steps and stages including advanced cryogenics, heat treatment and shot peening before undergoing a barrage of Quality Control checks and assurance before being signed off for packaging and delivery.
Material – EN36CThe design and production team’s constant pursuit for perfection has resulted in the use of custom made EN36C steel. This is a major step up from the off the shelf EN36A steel being used for the majority of aftermarket gear trains.
The higher chromium content of EN36C allows a much higher core strength of approximately 37~39HRC compared to a maximum of 33~35HRC for EN36A after tempering. An example of this much increased core strength is the inability to bend a 400mm long, 60mm diameter shaft with a 20 tonne load.
This provides us with the perfect foundation with which to create some of the strongest and durable gears and shafts in the market place.
Gear Teeth ProfilesUsing the very latest CAD/CAM packages and gear design technology, PAR is able to quickly and accurately create optimised tooth profiles for every gear designed. Rather than a single tooth profile across a whole gearset which is not optimal, every gear designed is optimised to provide the very best in strength, durability, minimal lash and noise. Equally important as the strength of the gear tooth is the contact ratio which governs the amount of shear load placed on the gear lubricant. A good example of this is the number of customers commenting that many of our straight cut gearsets are much quieter than expected. A loud, noisy gearset is generating unwanted noise, friction and heat.
In addition to our straight cut gears, all helical gears are cut with a reduced helix angle in order to provide the benefits of minimal thrust loads, heat and noise generation. This provides customers with a fantastic balance of quiet operation along with minimal thrust loads to protect vital bearings and tranmission housing.
Gear turning and CuttingGearset turning and cutting is performed on the latest state of the art CNC machinery and equipment, ensuring the highest repeatability and accuracy with some machines accurate to a level of 1 micron. In house equipment from brands such as Mori Seiki and Okuma from Japan, Liebherr from Germany and Sunnen from the USA are all the very best in their segments with the power and capacity to do the work required effortlessly.
Electron Beam WeldingIncluded in the commissioning of PAR’s new production plant was the purchase of a new Electron Beam Welder. Used to accurately weld dog rings and plates onto gears and shift rods, this is the only method available to weld to the depths required without creating excess heat and material distortion. Working by firing a stream of electrons at the objects being welded, the heat generated melts the material causing the complete fusion behind the electrons.
In actual fact, our engineers pioneered the art of this technique for gear welding with the University of South Australia back in 1998 as one of the first applications of this type in Australia.
Cryogenics and Heat TreatmentWorking closely with one of the best Japanese heat treatment companies in the automotive field and utilising the very latest computer controlled heat treatment and cryogenics technology, PAR has succeeded in achieving the optimal balance of core strength and case hardness for all gearset products.
The use of advanced cryogenics where the products are brought down to deep sub-zero temperatures brings about a change in the material’s microstructure which converts any of the softer retained austenite in the steel into much harder martensite provides a product that is many times stronger in strength and durability. This is a treatment which is impossible to duplicate with the same results without intimate knowledge of material grades and destructive testing after the products have left the factory.
Advanced heat treatment raises the core strength of the steel and provides an extremely hard case (surface layer) which resists wear on all tooth and contact surfaces.
Shot PeeningShot peening is one of the final material processes in which steel balls (shot) is fired at an extremely high speed into the steel products to create a compressive residual stress layer. This layer is extremely resistant to cracks forming and can greatly increase the fatigue life of components treated. This is one of the reasons why shot peening is very popular in the production of aerospace components.
All of PAR’s gearset and drivetrain products are shot peened if possible to maximise both lifespan and durability.
HoningFinal finishing of the internal bores for all gears is performed on the Sunnen ML-5000 CNC honing machine with special diamond coated honing mandrels to cut through the hardened, heat treated gear material. Honing is much preferred to grinding or turning of the internal bore of gears. The final finish is much more accurate boasting a perfectly concentric bore with fewer burrs in the bore and keyways with bore and pitch circle diameter of the gear teeth being concentric to each other and any discrepancies from heat treatment distortion removed. This allows the production of gearsets with minimal run out resulting in much quieter, efficient operation. The crosshatch finish is similar to the cylinder bore of an engine, permitting the retention of oil in rotating gears, even under the heaviest of loads.
GrindingThe final production step is grinding of shafts and gears. Using state of the art Studer CNC grinders, all bearing journals, both internal and outer diameters and synchromesh cone faces are ground to specifications with astounding precision and repeatability.
Quality ControlWith the commissioning of the new manufacturing facility, a dedicated Quality Control department was created in order to provide the highest quality possible with every facit and dimension of each part checked and measured to ensure all specifications and design parameters are adhered to. By using a separate accountable group, the quality and consistency of all parts is guaranteed.