MECHANICAL SPECIFICATIONS FOR HGD SERIES TOP ENTRY MIXERS
The mixer assembly shall consist of a vertical NEMA C-face motor, a parallel shaft double reduction speed reducer, mounting base, impeller shaft and impeller(s).
1.0 - Agitator Drive Design The reducer shall be a vertical parallel shaft design with cast iron housing, designed specifically for mixer service. Double reduction helical gearing shall be high-hardness surfacefinished with 25 degree pressure angle and universal full-depth tooth form. All pinions shall be solid- onshaft and all gearing straddle mounted on large diameter shafts to minimize deflection. Reducer efficiency shall be 95-97%.
2.0 - Reducer Rating Reducer shall be rated in excess of AGMA 6010. Thermal ratings shall exceed mechanical ratings and shall be calculated for continuous operation per AGMA standards based on a maximum sump temperature of 200 degrees F and an ambient temperature of 100 degrees F.
Bearing ratings shall be based on a minimum L10 life of 30,000 hours at a service factor of 1.25, 60,000 hours at a service factor of 1.50, and 140,000 hours at a service factor of 2.00, under worst conditions of loading. Service factors shall be based on motor nameplate horsepower.
3.0 - Bearings High speed and intermediate bearings shall be ball bearings. The low speed shaft shall employ a three bearing support system, two tapered roller bearings and an external self-aligning doublerow spherical roller bearing to provide a wide span for mixer shaft support.
4.0 - Lubrication All gearing shall be lubricated by splash, dipping in oil, or a combination of the two. A drywell around the output shaft shall prevent oil leakage. The housing shall include a fill hole with vented breather plug and two drain holes, the lower with a magnetic drain plug. Oil level shall be checked with a dipstick. The upper high speed and intermediate bearings shall be sealed for life. The upper low speed bearing and the external low speed bearing are grease lubricated. The lower internal bearings are immersed in oil.
5.0 - Shaft Design Agitator shaft stresses, considering combined torsional and bending loads, shall not exceed 6,000 psi. Non-stabilized shafts shall operate at less than 60% of first critical speed. Stabilized shafts shall operate at less than 80% of first critical speed. The shaft shall be of the specified grade of carbon or stainless steel. All points of support and impeller connection areas shall be concentric to within 0.010" tin
7.0 - Motors Electric motors shall be constant speed, 1800 or 1200 rpm, and suitable for operation on 230/460 volt, 3 phase, 60 Hertz alternating current, or as specified. The motor shall be TEFC squirrel cage induction type built in accordance with current NEMA design B standards with Class B or F insulation, and C-face mounting.
8.0 - Manufacturer Mixer shall be Series HOD as manufactured by EMI / Cleveland Mixers, Clinton, CT.