Borelli Group 2-3 Cast Iron Speed Increaser – 97701 Series
The Borelli Group 2-3 Cast Iron Speed Increaser – 97701 Series provides precise coupling between gear pumps and agricultural tractor power take-offs. Featuring a high-strength housing and UNI 18NiCrMo5 steel gears (ISO/DIN 3990-80), it ensures maximum mechanical efficiency. It supports operating temperatures of up to 120°C and maximum speeds of 3000 rpm, using SAE 90 oil to ensure durability during continuous operation.
The available models in this series (speed multiplication ratio variants) are: Ratio 1:2, Ratio 1:2.5, Ratio 1:3, Ratio 1:3.5, Ratio 1:3.8.
The Borelli Group 2-3 Cast Iron Speed Increaser – 97701 Series is a high-performance technical solution for connecting agricultural tractors to hydraulic systems.
The 97701 Series speed increasers are designed to connect gear pumps directly to the power take-offs of agricultural tractors. The standard PTO output speed is 540 rpm; this component increases that speed to the optimal operating speeds required by hydraulic pumps. Different input speeds may be used, provided that the output speed of the speed increaser never exceeds the maximum limit of 3000 rpm. The rated power capacity is 68 kW for all variants in this series, regardless of the transmission ratio.
The Borelli Group 2-3 Cast Iron Speed Increaser – 97701 Series is designed to withstand demanding industrial and agricultural operating cycles. The housings are manufactured from cast aluminium and cast iron, ensuring exceptional mechanical strength. The transmission assembly incorporates gears designed and dimensioned in strict compliance with ISO/DIN 3990-80 standards. Manufactured from special UNI 18NiCrMo5 steel, these gears feature a corrected, low-profile tooth design that provides superior resistance to mechanical stress and significantly reduces noise during rotation. The shafts, manufactured from UNI 16CrNi4 steel, are connected to the gears through splined profiles, a configuration that enables safe transmission of the nominal torque loads.
To ensure maximum durability and proper operation of the unit, SAE 90 lubricating oil must be used. The maximum oil capacity is 1.50 litres. The lubricant level must be visually inspected through the dedicated sight glass every 1500 operating hours. The first complete oil change is mandatory after the initial 60-80 hours of running-in. Regarding thermal limits, the operating temperature must not exceed 120°C under continuous-duty conditions.
The torque values specified in the technical specifications refer to continuous-duty operating conditions. Under intermittent-duty conditions, torque loads may be increased by up to 20%. Mounting hydraulic pumps requires a coupling half and an adapter flange specifically suited to the application; therefore, it is essential to specify the flange type and pump shaft configuration when requesting the product. The complete assembly weighs 16 kg.
As detailed in the official spare parts diagram for Group 2-3 pumps, the mechanism incorporates highly reliable components. The primary male PTO shaft measures 1 3/8″. The system is protected by oil seals measuring 50x90x10 and 45x72x8, together with high-performance bearings (models 6209 and 6210) that stabilize the crown gear and pinion. The housing assembly is secured using standard fasteners and pump centering rings, ensuring precise alignment of the mechanical system.
| Specification | Value |
|---|---|
| Housing Material | Cast aluminium and cast iron |
| Gear Material | UNI 18NiCrMo5 Steel (ISO/DIN 3990-80 Standards) |
| Shaft Material | UNI 16CrNi4 Steel |
| Rated Power | 68 kW |
| Standard Input Speed (PTO) | 540 rpm |
| Maximum Output Speed | 3000 rpm |
| Maximum Operating Temperature (Continuous Duty) | 120°C |
| Recommended Lubricant Type | SAE 90 Oil |
| Maximum Oil Capacity | 1.50 litres |
| Total Weight | 16 kg |
| Model (Ratio N.1/N.2) | Input Speed (N.1, rpm) | Output Speed (N.2, rpm) | Torque M1 (daNm) | Torque M2 (daNm) |
|---|---|---|---|---|
| Ratio 1:2 | 540 | 1080 | 98 | 49 |
| Ratio 1:2.5 | 540 | 1408 | 112.5 | 45 |
| Ratio 1:3 | 540 | 1620 | 132 | 44 |
| Ratio 1:3.5 | 540 | 1836 | 112.5 | 35 |
| Ratio 1:3.8 | 540 | 2057 | 110.2 | 29 |