Plastic Injection Molding Gears

Our company with advanced processing equipment,rich manufacturing experience,mature design and experienced manufacturing engineer can produce various JIS3 level precision plastic linear gear, angle gear, worm wheel and worm products, the mold precision can reach 0.003mm. Our common used plastic material is POM\PA\PBT.

• Equipment

The needed equipment for precision gear: wire cut, C-axis EDM, inner and outer grinding, coordinate grinding, roll gear machine, CNC lathe, gear jumped measure apparatus, precision injection molding machine.

• Keystones and Difficulties

1. The gear with accuracy JIS3-5 level requires special processing machinery and equipment. Such as: C-axis EDM, roll gear machine, inner and outer grinding, coordinate grinding, wire cut and so on.

2. The machining precision of precision gear is very high and professional. Otherwise, affecting working stability of the equipment, causing noise, too large vibration and a short lift.

3. Requires specialized testing equipment, such as standard gear, gear jumped measure apparatus, gear joggle measure machine.

4. Mold design is rather special,requires high professional technique.

5. The manufacturing difficulties of high precision gear:1)control joggle precision(plastic contraction causing changes of communal normal,press angle and gear thickness;2)control precision of gear jumpping(concentric degree of gear and shaft).

• Solution: reference to the mold figure of spur gear in the left shows the guarantee of processing precision.

• The accuracy guarantee of printer linear gear:

1. An important condition for ensuring the accuracy of the product is gating with 1 or 3 points to ensure moulding uniform.

2. The purpose of A/B through vavity is machining with coordinate grinding to ensure absolute concentric degree of the cavity.the core need to be done into circular and all need to be machined with inner and outer grinding, the precision is controlled between 0.003-0.005. 

3. The core be machined with wire cut need to be designed into gear shape. Because precision gear is very difficult to success for one time normally,it need to be adjusted gear shape of processing according the result of inspecting samples after T1, control the shape and accuracy of gear thickness through compensation adjustment.

4. The mold core and gear shaft holes must be positioned precisely,the positioning hole is machined through inner and outer grinding to ensure concentric degree. 

5. The hole of PI lock needs to be processed with coordinate mold firstly before processing thread, the purpose is to ensure concentric degree.

6.The core is round core that also need to be designed rationally to facilitate to process with inner and outer grinding to ensure accuracy of 0.003.

7. The core need to be designed even cooling circle, usually, it is alone to ensure uniform cooling.

8. The hole of ejector sleeve also need to be machined with inner and outer grinding to ensure the accuracy of 0.003.

9. Need to test mold by precision injection molding machine, for example Toshiba machine.

10. Detecting accuracy and jumping according samples, modifying gear shape according test report(this is the most critical technology, it need rich experience if compensation)