Technical Benefits of Press Quenching Gears and Bearings

Superior Distortion Control: Traditional quenching methods often lead to warping and distortions due to non-uniform cooling. With press quenching, the mechanical force applied ensures uniform cooling, significantly reducing distortion risks. This is paramount for precision applications where even minute deviations can be detrimental.

Cost-Efficiency: Reduced distortion means fewer post-heat treatment machining operations are required, leading to cost savings for manufacturers.

Versatility: Press quenching can be applied to numerous gear and bearing configurations including bull gears, ring gears, spur gears, bevel gears, helical gears, inner race bearings, and outer race bearings. Press quenching goes well beyond gears and bearings as well. Almost any type of part that is desired to be kept as round and flat as possible can be press quenched, so long as it fits within the size envelope of the press.

Typical Results: Customers can generally expect the following dimensional results after press quenching:

• Gear tooth taper under .005”
• Flatness under .003”
• Out-of-Round under .005”
• Step alignment within .003” of print callout
• Involute spline taper/roundness under .003”

Interested in Press Quenching Gears or Bearings at ThermTech? Here is What to Expect:

Tooling: Every part that is press quenched requires tooling that is customized to the part in order to ensure that desired dimensions are achieved. There are several possibilities for tooling solutions to be achieved for your part:

• Tooling is already owned by the customer and can be transferred to ThermTech with the parts at time of processing. Most customer owned tooling can be readily adapted to ThermTech’s presses and our expert operators will ensure that it is set up according to our equipment standards to produce the best possible parts.
• Provide ThermTech with a drawing that is representative of the dimensions of the part in the PRE-HEAT TREAT configuration. ThermTech’s press quench experts will then evaluate our industry-leading tooling inventory to see if we currently own tooling that could be adapted to your part without need for new tooling builds. In many cases, ThermTech already owns tooling that will work for a new part, or perhaps just a simple piece of tooling needs to be made for nominal cost.
• ThermTech can custom build tooling sets for any part. ThermTech’s press quench engineering experts will consult with our local tool maker partners to design and build a tooling solution that will set up your part for press quench success.
• It should be noted that ThermTech also boasts a vast library of press quench process data for countless gear and bearing configurations. This means that there is almost no part in existence that we would not have some experience to draw from in order to establish a capable press quenching process, even if your part has never been press quenched in the past.

Dimensional Needs: Before parts are processed, it is important for ThermTech to understand your expectations for final dimensions off of the press. While the dimensions listed above under “typical results” are achievable on most parts of moderate size, some attributes may change based on unique features of your part. Beyond actual distortion expectations, it is also critical for ThermTech to understand the overall sizes (pin diameters, minor diameters, etc) that are desired for your part prior to final grind. This information will allow us to achieve the optimal press setup. This information can be provided via final part print or instructed in an RFQ.

Processing:

• Bearings or similar components that are made from 52100 or similar through-hardening alloys will be directly press quenched
• Carburizing grades such as 8620, 4320, 9310, 3310 will first be carbuzied (link to carburize page) in one of ThermTech’s numerous integral quench carburizing furnaces using a customized fixturing plan and furnace recipe that is tailored to your part and controlled for future use. Upon completion of the carburize cycle, the parts will be transferred to a protective atmosphere cooling box or cooled within the furnace chamber so as to minimize residual stress within the part prior to reheat for press quenching.
• Parts are then transferred to ThermTech’s press quench department for setup. One of our expert press quench technicians will set up a press quench unit with the designated tooling and perform any necessary pre-check measurements on the workpieces that will allow for more precise tooling adjustments.
• After setup completion, parts are loaded into one of ThermTech’s rotary reheat furnaces. In these furnaces, part are heated to approximately 1550°F under controlled atmosphere for a set time. Upon completion of reheat soak, the hot part is transferred to the press quench unit using an overhead hydraulic manipulator system that allows for safe and rapid transfer. The workpiece is set on the press bed and the operator initiates the quench process. The press unit then runs a programmed quench process in which the following variables are programmed and controlled from the custom recipe for your part
  • Oil temperature
  • Oil flow rate
  • Hydraulic pressure on part
  • Pulsing of hydraulic pressure
  • Quench time
• Upon completion of the automated quench cycle, the part is carefully removed, cleaned, and measured according the to dimensional targets established for the part. ThermTech’s expert press quench technicians use real-time process measurements as inputs to make any necessary adjustments to press/tooling parameters in order to maintain part-to-part consistency.