Page 136 - Gear Technology Solutions

Also, the NVH (Noise-Vibration-Harshness) properties confirm the FFT results in
®
Figure 16; Coniflex Pro differentials roll significantly quieter than forged
®
differentials or differentials cut with the older Revacycle method. In order to
®
achieve the highest possible power density, all Coniflex Pro differential gears use
the duplex taper which was developed in the 1930’s for the Revacycle process.
This blank geometry applies an especially high addendum and dedendum angle
(10° and more) which results in very strong teeth with the highest strength at the
heel where the contact under high load concentrates.

9.10 Summary

®
Coniflex Pro differential gearsets can be designed and optimized in the new
®
®
Gleason GEMS software system. The tools used are Coniflex Plus cutter heads.
Digital flank form information including correction matrixes can be transferred via
network to coordinate measuring machines and a closed correction loop between
measurement and manufacturing machine can be established. Also, the machine
summaries for blade grinding, cutting, and grinding are generated in GEMS and
®
can be transferred to the manufacturing machines. All Coniflex Pro differential
gears can also be ground. Standard differentials might, in extreme cases, see a
maximum of 400RPM relative speed between side gear and planet. For some
eDrive designs, the maximal relative differential speed is six-times higher which
®
calls for a hard finishing operation after the heat treatment. GEMS also generates
grinding summaries and grinding wheel geometry and design data. The grinding
wheels are permanently coated with CBN and can be recoated 6 times which
results in low grinding wheel cost per ground part. Cutter head and grinding wheel
consolidation between different gear designs are easily possible because the
profiles of blades and grinding wheels are simply straight.

®
The cutting tools used for Coniflex Pro are peripheral cutters with diameters of 9”
®
for cars and 15” for heavy trucks. The cutters use Pentac stick blades which can
be two-face or three-face ground. Recommended is the three-face grinding with a
following all around coating which compared to a two-face grinding, delivers twice
®
the tool life and improved surface finish. A 9” Coniflex Plus peripheral cutter head
is shown in Figure 22. The blades are three-face ground and all around coated
®
Pentac stick blades.

121