Induction Shrink Fitting Assemblies

Induction Shrink Fitting Assemblies

Objective To use induction to prepare cast iron assemblies for shrink fit assembly
Material Customer supplied cast iron rocker arms of varying sizes
Temperature 450 ºF (232 °C)
Process Time 20 seconds
Frequency 148 kHz
Equipment DW-UHF-5.0 kW, 150-400 kHz solid state induction heating system, equipped with a remote heat station containing one 1.0μF capacitor
An induction heating coil designed and developed specifically for this application.
Process A four-turn helical coil heats the ring at one end of the assembly. The coil is designed to concentrate the field towards the center of the assembly where the thermal mass is greatest.
Across the heated ring, the coil presents a lighter field. After heating, a pin is place within the ring and the assembly is water quenched.
The heat time varies from part to part but is less than 20 seconds.
Results/Benefits Induction heating satisfies the needs of this process for:
• rapid part heating
• flexibility for parts of differing geometries
• individual, series part heating, suitable for automation
• a clean source of heat
• even heat distribution

Induction Shrink Fitting Assemblies

Heating Shrink Fitting Camshaft Gear

Induction Heating Shrink Fitting Camshaft Gear with IGBT Induction Heater

Objective: Heating a camshaft gear with a bore size of 1.630″ to shrink fit over a steel shaft that has a diameter of 1.632″. A temperature of 5000F is required for the gear to expand 0.002″ in order to slip over the shaft. Production is presently done at a rate of 15-20 gears per 24 hour shift by heating the gear
on a hot plate. The hot plate heating cycle lasts for approximately 45 minutes.
The customer would like to explore the options available in terms of heating times and machine size.
Material: Steel Camshaft Gear measuring 7″ in diameter, 1″ thick, with a bore size of 1.630″.
Temperature: 5000F
Application: A unique three (3) turn helical coil along with the various DAWEI solid state induction power supplies were used to achieve the following results:
– 5000F was reached in three (3) minutes while using the DW-HF 5, 5 kW output solid state induction power supply.
– 5000F was reached in five (5), eight (8), and ten (10) minutes using the DW-HF-3, 5 kW output solid state induction power supply.
– Even heating was observed as a result of the unique three (3) turn helical induction coil.
Equipment: DW-HF-35 and DW-HF-55 kW output solid state induction power supplies respectively, including remote heat stations and a unique three turn helical coil made from 3/16″ copper tubing and having a 4.4″ inside diameter.
Frequency: 62 kHz

Shrink Fitting Camshaft Gear

Induction Shrink Fitting For Inserts

Induction Shrink Fitting For Inserts with IGBT Shrink fitting Heater

Objective: To heat an aluminum fuel pump housing measuring 8″ x 4 1/2″ x 3 1/2″ to 3750F, allowing steel parts to be inserted. Presently the housings are heated for over one hour in a convection oven. The areas that are to have steel parts inserted measure 1.5″ and 0.6875″ in diameter. In addition, the insertion process lasts for a little over one minute, so 3750F should be maintained for a
period of time to complete the process.
Material: Aluminum Pump Housing measuring 8″ x 4 1/2″ x 3 1/2″
Steel insertion parts.
Temperature: 3750F
Application: By using the DW-HF- 25, 25 kW output solid state induction power supply the following results were achieved.
– 3750F was reached in one (1) minute to allow for insertion.
– 20 housings were successfully heated using a five (5) turn right angle pancake coil.
Equipment: Ameritherm SP 25, 25 kW output solid state induction power supply including one (1) remote heat station containing four (4) capacitors totalling 1.0 μF, and  a five (5) turn right angle pancake coil made from 3/16″ copper tube.
Frequency: 80 kHz

shrink fitting for inserts

 

Induction Shrink Fitting Steel Tube

Induction Shrink Fitting Steel Tube With IGBT Heating Units

Objective Heating a steel tube to 500-1000°F for a shrink-fitting application. Determine expansion (growth) of ID at varying temperatures.
Material Steel tubes 7” OD x 4.75” ID x 5” heat zone
Type ‘K’ thermocouple to measure temperature
Thermal blanket
Temperature 500, 800, 1000 °F (260, 427, 538° C)
Frequency 66 kHz
Equipment DW-HF-7.5, 7.5 kW, 150-400 kHz induction power supply, equipped with a remote heat station containing two 1.5 μF capacitors (for a total of 0.75 μF)
A multi-turn, special series-parallel induction heating coil designed and developed specifically for this application.
Process Initial tests were completed on a sample without a thermal blanket. A thermocouple is slipped between the copper ring and the steel tube to measure temperature. The part measured
4.940” (at room temperature with an ID gauge.) The part reaches 1000°F (538°C) in about 10 minutes.
The chart below shows the comparison between theoretical and experimental measured results

1

Results/Benefits The part measures 4.975” at 1000°F yielding an expansion of 0.035” (4.975 minus 4.94). At 500 and 800°F the expansion numbers were 4.950 and 4.964 respectively. When using a
thermal blanket the heat time is reduced by about 90 seconds (8.5 minutes as opposed to 10 minutes).

 

Heating shrink tube

 

 

 

 

 

 

induction shrink fitting tube

 

 

 

 

 

 

 

Shrink Fitting Steel Tube

 

 

 

Induction Heating Plastic Catheter Tube

Induction Heating Plastic Catheter Tube With IGBT High Frequency Heating Units

Objective Heat a metal braid in a plastic catheter tube to 250°F (121.1ºC) so that another catheter tube can be bonded to it.
Material 0.05” (1.27mm)diameter catheter tubes, some with a metal braid, ceramic rod
Temperature 250°F(121.1ºC)
Frequency 306kHz
Equipment • DW-UHF-4.5kW induction heating system equipped with a remote workhead with one 1.2 μF capacitor
• An induction heating coil designed and developed specifically for this application.
Process A single turn helical coil is used to heat the metal braid for plastic reflow. To maintain the correct inside diameter of the tubing. A ceramic rod is inserted through the tubing. Heat is applied for 3.5 seconds to reach 250°F (121.1ºC). The metal braid melts the plastic and creates a bond.
Results/Benefits Induction heating provides:
• Controlled rapid application of heat
• Consistent, repeatable results
• Energy efficient

Heating Plastic Catheter Tube

Induction Heating Molding Catheter Tip

Induction Heating Molding Catheter Tip With IGBT High Frequency Heating Units

Objective Heat a water-cooled steel mandrel to 700°F (371ºC) to form a high quality Teflon catheter tip.
Material Teflon catheter tubing, mandrel assembly
Temperature 600-700°F (315-371ºC)
Frequency 376 kHz
Equipment • DW-UHF-6 kW induction heating system, equipped with a remote workhead containing one 0.66μF capacitor.
• An induction heating coil designed and developed specifically for this application.
Process A two turn coil is used to heat the steel mandrel to 660ºF (371ºC) in 2.7 seconds. To form the catheter tip, RF power is applied while the catheter is held over the mandrel. The tubing is then pushed on to the mandrel to form a consistent, even tip.
Results/Benefits Induction heating provides:
• Precise, repeatable application of heat
• Non-contact heating
• Faster cycle times

Heating Molding Catheter Tip

Induction Heating Aluminum Catheter Tipping

Induction Heating Aluminum Catheter Tipping With IGBT Heating Units

Objective: To heat an aluminum catheter tipping die to above 2850F within 2 to 5 seconds for the forming of catheter material. Presently, heating is performed in 15 seconds with older induction equipment. The customer would like to use solid state induction equipment to reduce the heating times and develop a more efficient process.
Material: Aluminum catheter tipping die measuring 3/8″ OD and 2″ long with a nonmagnetic sleeve over the heat zone. The catheter material was described as being similar to polyurethane plastic. Also, a 0.035″ diameter steel wire was inserted into the catheter tube to prevent collapsing.
Temperature: 5000F
Application: The DW-UHF-4.5kW solid state induction power supply was determined to most efficiently produce the following results:
A heating time of 3.3 seconds to reach 5000F and form the catheter was achieved through the use of a two (2) over two (2) turn helical coil.
A quality catheter was formed by pressing 1/2″ of the polyurethane tube into the mold while retaining shape through the use of a 0.035″ wire to prevent collapsing of the tube.
Laboratory results show that a substantial time decrease was accomplished which will allow for a significant increase in production while not sacrificing quality.
Equipment: DW-UHF-4.5kW solid state induction power supply including a remote heat station containing one (1) capacitor totalling 1.2 μF.
Frequency: 287 kHz

Induction Heating Aluminum Catheter Tipping

Induction Soldering Fuse Caps

Induction Soldering Fuse Caps With IGBT Induction Heating Units

Objective Soldering three fuse caps simultaneously to reflow lead free solder and make a joint between the fuse cap and fuse wire guide
Material Plated copper end caps 0.375” (9.5mm) OD x 0.375” (9.5mm) height, ceramic fuse tube 1.5” tall (38.1mm) , lead free solder preforms
Temperature 700 ºF (371 ºC)
Frequency 286 kHz
Equipment • DW-UHF-20 kW induction heating system, equipped with a remote workhead containing two 1.0μF capacitors for a total of 0.5μF
• An induction heating coil designed and developed specifically for this application.
Process A three position two turn helical coil is used to solder three fuse caps simultaneously. The fuse assemblies are placed in the coil and the heat is applied in three cycles at 3.5 seconds per cycle to reflow the solder. On the production line the bottom caps are soldered first. The fuses are filled with sand and without flipping the assembly the top cap is soldered.
Results/Benefits Induction heating provides:
• Consistent, repeatable results
• Precise & accurate heat application
• Hands-free heating that involves no operator skill for manufacturing
• Even distribution of heating

induction soldering coil

 

 

 

 

 

 

Soldering Fuse Caps

Induction Soldering Brass Connector

Induction Soldering Brass Connector In Solar Panel With IGBT Induction Heater

Objective Solder three brass connectors one at a time in a solar panel junction box without affecting the components in the junction box
Material Solar panel junction box, brass connectors, solder wire
Temperature 700 ºF (371 ºC)
Frequency 344 kHz
Equipment • DW-UHF-6 kW induction heating system, equipped with a remote workhead containing one 1.0 μF capacitor.
• An induction heating coil designed and developed specifically for this application.
Process A three turn oval shaped helical coil is used to heat the connectors. A piece of solder wire is placed onto the joint area and each joint is heated separately for 5 seconds to solder the connector. The total process time is 15 seconds for the three joints.
Results/Benefits Induction heating provides:
• Pinpoint accuracy deliver heating only to joint; does not affect surrounding components
• Localized heat produces neat and clean joints
• Produces high quality, repeatable results
• Even distribution of heating

brass connectior

 

 

 

 

 

 

 

rf soldering brass connector

 

 

 

 

 

 

 

induction soldering brass connector

Induction Soldering Steel Cover

Induction Soldering Steel Cover With High Frequency Heating Units

Objective Soldering a nickel plated steel cover onto a nickel plated steel EMI filter housing without damaging the RF circuit
Material 2” x 2” (50.8mm) nickel plated steel cover, 2” x 2” (50.8mm) nickel plated steel box and lead-free solder and flux
Temperature 573 ºF (300 ºC)
Frequency 229 kHz
Equipment • DW-UHF-3 kW induction heating system, equipped with a remote workhead containing two 1.2μF capacitors for a total of 2.4μF
• An induction heating coil designed and developed specifically for this application.
Process A single turn square helical coil is used to solder the cover to the filter box. Solder flux is applied to the filter box and two solder turns (preforms) are placed covering the perimeter of the cover. The assembly is positioned under the coil and power is applied for 7 seconds to solder the seam.
Results/Benefits Induction heating provides:
• Hands-free heating that involves no operator skill for manufacturing
• Repeatable, non-contact clean heating
• Fast precise heating
• Good solder flow without over heating the box and damaging RF circuits.
• Even distribution of heating

induction soldering steel cover

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