Manufacturing Process

Machining: The gear casings are made of close-grained Cast Iron. The casings received as raw material undergo accurate machining on our lathe and UMA make West German horizontal boring Machine. Horizontal Boring Machine is equipped with an Accurite make Visual Read Out System which hel ps in maintaining center distance accuracy upto 5 microns.

Testing: Pressure testing under normal water pressure is conducted on the assembled castings for porosity check. Test certificates are obtained from our suppliers.

Machining of gears

Blank Turning : All gear blanks, including worm shafts, are manufactured out of 16MnCr5 round bars or forging. The output worm wheels are manufactured out of centrifugally cast Phosphor Bronze alloy rings mounted on Cast Iron Hubs. The output shaft and input pinion shaft are turned out of EN8 T toughened round bars. Each bar and forging is tested for chemical composition, to confirm elements and proportions of 16MnCr5. These tests are conducted at Metallurgical Services laboratories in Mumbai. The round bars or forging undergo precise turning on our lathe. Precise machining of external and internal key way is conducted either on slotting machine or our boring machine using a self-centering vice.

Hobbing

Gears are bobbed using Hobb Cutters Class'C'as per DIN class Six tolerances. The worm shafts are manufactured on thread milling machine.

Case Carburising & Hardening

Gears are case hardened using Fluid Therm Fluidized Bed Furnace. This furnace can perform carburising, carbonitriding, neutral hardening, tempering, normalizing annealing, and stress relieving. During Carburising case depth can be controlled. Our gears are case carburised for a case depth of 0.8mm-1.0mm. Temperature uniformity +/- 30 Degree Centigrade. is controlled using thermocouples. Case depth is checked using a spy piece which is included with the charge in the furnace. Component hardness is checked using a rockwell hardness tester. Gear hardness is maintained as follows:
Driving gears HRC - 58 to 62
Driven Gears HRC - 54 to 58.

Profile Grinding of Gears (when required by customer) The lead, profile and runout of preground and case hardened gears, is inspected on Lead Profile Tester OSAKA - Japan make, and Gear Pitch Tester ZEISS make. The gears are then profile ground on a MAGG (SWISS) or WMW - NILES (German) gear profile grinders. The lead and profile tests are repeated on Lead Profile Tester. Center Distances are verified using matching gears on a Gear Roll Tester - CARL ZEISS make.

The gear motor is mounted on a test bench. At no load conditions, the desired noise levels, backlash, and current drawing at the incoming voltage is measured. Output speed is also compared as per ratio desired by customer. The gear motor is tested in an oil bath. Temperature rise measurements are taken after two hours of testing in both the directions. Adequate care is taken to prevent oil leakage. The entire gear box/motor assembly is tested to ensure that no unusual vibrations are observed. Test Certificates are issued with each gearbox.

As duty cycle of gearbox differs from equipment to equipment, it is imperative for the user to calculate the horsepower, output RPM and relevant Service factor of 1.4 and 2.0 respectively. For light duty the user may, in some cases, obtain gearbox of one smaller size than specified against service factor 1.4, but advisable to consult us, with detail specifications. The customer is required to top the gearbox with oil initially and periodically for proper maintainability and extended life cycle. It is also important that the customer inforin us in case of upward and downward output shaft mounting positions so that we can provide appropriate lubrication nozzle and grease plugs for oil/grease to reach bearings which might not be assisted by splash lubrication.