Process and Operation Routing and Feasibility for Gears
The processes listed below are the specialized AxiGroove-making processes. These processes can be included in turning routings, following a lathe or mill turn process. Each process has a single operation, Setup, associated with the component GCD, and one or two operations associated with the AxiGroove GCD. Following are the AxiGroove operations by process:
• Bevel Gear Cutting Machine
o Spiral BG Face Milling
o Straight BG Face Milling
• Broach
o Internal Gear Broaching
o External AxiGroove Broaching
• Spline Roller
o Spline Rolling
• Hob Machine
o Hobbing
• Shaper
o Shaping
• Shaver
o Shaving
The processes listed below are the AxiGroove-finishing processes. Each process has a single operation, Setup, associated with the component GCD, and a single operation associated with the AxiGroove GCD. Following are the AxiGroove operations by process:
• Threaded Wheel Grinder
o Threaded Wheel Grinding
• Profile Grinder
o Profile Grinding
Routings for the specialized AxiGroove-making processes are determined as follows:
• Spiral bevel gears must be routed to the Bevel Gear Cutting Machine.
• Internal gears and internal splines are routed to the Broach, unless a shoulder interferes with tool access to the AxiGroove, in which case the Shaper process is used.
• External splines use the Spline Roller process, unless one of the following is the case:
o Part is too big
o Material is too hard (see Spline Roller in this section below)
o Pressure angle is too shallow
o Teeth are too big
If one or more of the above holds, the Hob Machine process is used if feasible (otherwise the Shaper process is used).
• External gears (other than bevel gears) and sprockets use the Hob Machine process, unless one or more shoulders come too close the AxiGroove, in which case the Shaper process is used. The Shaver process optionally follows hobbing (see Shaver in this section below).
Flutes and gears of unknown type are routed to milling processes that are not specific to gear making (so specialized gear-making tools and tool paths are not used in this case).
Finishing operations are used when quality requires them.
Heat Treatment is turned on to Carburizing when at least one AxiGroove exists on the part and when carburizing is generally recommended for the material type.
Following are the process and operation feasibility requirements:
• Bevel Gear Cutting Machine: AxiGroove must be a bevel gear.
• Internal Gear Broaching: the AxiGroove must be one of the following:
o Internal spur gear
o Internal helical gear
o Internal spline
There must be no shoulders that obstruct tool access, that is, there must be a clear line of sight through the gear valley and the rest of the part.
• External AxiGroove Broaching: geometry can be generated by extruding the tooth/valley profile in a straight direction (geometric property isStraighExtrude is true).
• Spline roller: AxiGroove must be all of the following:
o External spline
o Not too big—its diameter must not exceed the machine property maxSplineDiameter.
o Tooth size and pressure angle must be in range, as controlled by the cost model variables splineRollingMaxModule and splineRollingPressureAngle.
o Made from material that is rollable (specified by cut code family in the lookup table tblSplineRolling) and not too hard (specified by the cost model variables rollabilityBrinellThreshold, rollabilityRockwellCThreshold, rollabilityTensileStrengthThreshold).
• Hob machine: AxiGroove must be one of the following:
o External spur gear
o External helical gear
o External spline
o Sprocket
There must be no shoulders that obstruct hob approach and overtravel.
• Shaver: AxiGroove must be one of the following:
o External spur gear
o External helical gear
Either the number of hob starts must be greater than one or the AxiGroove must have DIN quality 6 or 7 (or their equivalent), by default. This can be configured as followed:
o VPE administrators can configure the required quality with the Must Shave column of the lookup table tblGearQuality.
o Number of hob starts (parallel helices of hob teeth) ranges between one helix (best quality and slowest cycle time) and three helices (poorest quality and fastest cycle time).
• Shaper: AxiGroove must be one of the following:
o External spur gear
o Internal spur gear
o External helical gear
o Internal helical gear
o Internal spline
o External spline
aPriori assumes that a gutter for chip evacuation is provided for any gears with zero shoulder distance on one side.
• Threaded Wheel Gear Grinder: AxiGroove must be one of the following:
o External spur gear
o External helical gear
o Sprocket
All the following must hold:
o AxiGroove must have DIN quality 2, 3, 4, or 5 (or their equivalent), by default. VPE administrators can configure the required quality with the Must Grind column of the lookup table tblGearQuality.
o The AxiGroove’s Max Diameter must not exceed the value of the cost model variable TWGMaxDiameterThreshold (1200mm by default).
o The production volume must not be less than the value of the cost model variable TWGProductionVolumeThreshold (150 by default).
o There must be no shoulders that obstruct grinding wheel access.
• Profile Gear Grinder: AxiGroove must be one of the following:
o External spur gear
o External helical gear
o Sprocket
Both the following must hold:
o AxiGroove must have DIN quality 2, 3, 4, or 5 (or their equivalent), by default. VPE administrators can configure the required quality with the Must Grind column of the lookup table tblGearQuality.
o There must be no shoulders that obstruct grinding wheel access.