Generic Marley Replacement Gear

“A” Series Cooling Tower Fan Drives

The “A” Series right angle gear drives for cooling towers from AMARILLO GEAR are designed as direct replacements for the Marley® Cooling Tower line of right angle drives.

New Product

Operation & Maintenance Manuals

*The input shaft diameters and keyways are the same, so existing couplings and drive shafts do not have to be replaced. All service ports are also easily accessible. Reduction ratios are within +/-2% of the Marley® reduction ratios, eliminating the need to make costly fan pitch adjustments.

Marley® Model Amaeillo Model Horsepower Rating
Series 20
A20
20
25
30
35
Series 22
A22
47
53
60
70
Series 27
A27
40
60
75
80
Series 32
A32
160
Series 34
A34
180
Series 36
A36
200
220
230
250
Series 38
A38
250

All ratios are reducing and defined as the ratio of input speed to output speed. Single and double reduction ratios shown are exact within +/- 2%. Ratios shown in blue in each table are normally stocked and drives ordered with these ratios can be shipped within our normal lead time. Check with the factory for availability of all model ratios not shaded.

AGMA and CTI recommend a minimum service factor of 2.0 for gear drives in cooling tower fan service when driven by electric motors or steam turbines. All ratings are service ratings and include a 2.0 service factor unless otherwise noted. Ratings are listed for 60 cycle electric motor speeds. Ratings for speeds less than 1750 rpm are proportional to the rating at 1750 rpm. Contact the factory for recommendations when the driver speed exceeds 1800 rpm.

The Amarillo Right Angle Gear Drive is guaranteed against defects in workmanship and material for a period of one year after installation when operated under normal service at rated capacity. Within the above stated period, the manufacturer will replace the defective parts returned transportation prepaid. The buyer shall not be entitled to incidental or consequential damages, losses or expenses. The guarantee will not apply to repairs made outside the factory without the consent of the manufacturer or to drives that have been subject to abuse, accident, neglect or improper installation. No warranty is made in regard to bearings, trade accessories, machinery, or other articles or merchandise not manufactured by us. This warranty is expressly made in lieu of any warranties otherwise expressed or implied by law.

Normal rotation is both shafts clockwise as shown in the illustrations. Occasional use with both shafts rotating counterclockwise is permissible. Special bearing arrangements are used when the primary direction of rotation is counterclockwise and the gear drives should be ordered accordingly.

Rotational schemes with the shafts rotating in opposite directions are available on special order.

All AMARILLO “A” series right angle cooling tower drives may be furnished, upon request, with a cylindrical output shaft. The most common cylindrical shaft diameter is shown in the following table, however, other shaft diameters can be supplied within engineering limits. When requesting a cylindrical shaft the following information must be provided before an order can be accepted.

Model Diameter
A20
2 in.
A22
2 ⅝ in.
A27
3 in.
A32
4 ½ in.
A34
5 in.
A36
5 in.
A38
5 in.
  • C – Overall Height: _________
  • D – Length of Shaft: _________
  • E – Shaft Diameter: _________
  • F – Keyway Size: _________

All AMARILLO “A” Series right angle cooling tower drives may be furnished, as standard, with the tapered output shaft shown in the drawing. On rare occasions, the gear drive being replaced may have a different output shaft taper. Amarillo Gear Company will provide a matching shaft when the following information (or shaft drawing) is provided. This information is required before an order can be accepted.

  • C – Overall Height: _________
  • D – Length of Taper: _________
  • E1 – Small End Diameter: _________
  • E2 – Large End Diameter: _________
  • F – Keyway Size: _________
  • Keyway Parallel to Centerline or Taper: _________
Model Net Weight (lbs) Weight With Export Boxing (lbs) Export Box Dimensions (LxWxH) (in.)
A20
200
240
29 x 19 x 27
A22
440
500
36 x 23 x 34
A27
840
940
36 x 40 x 30
A32
1575
1720
55 x 36 x 40
A34
2225
2405
58 x 46 x 40
A36
2245
2425
58 x 46 x 40
A38
2300
2480
58 x 46 x 40

Parts Support Center

Give us a call, shoot a quick email, or submit your questions or parts requirements using our form and a STAR representative will respond promptly via email with prices, availability and product information.

More than 60 years of experience in securing the best prices on parts.

Get personalized help from a STAR Parts Specialist