Borelli Group 4 Pump Speed Increaser – 91000 Series
The Borelli Group 4 Pump Speed Increaser – 91000 Series is designed to connect gear pumps to the power take-offs of agricultural tractors (540 rpm). Manufactured with cast aluminium and high-strength cast iron housings, it ensures reliable continuous operation at temperatures of up to 120°C. The gears, manufactured from UNI 18NiCrMo5 steel in accordance with ISO/DIN 3990-80 standards, ensure quiet operation and high mechanical strength.
The available product codes (models and flange configurations) are: 91001, 91002, 91003 and flange series 80104/4, 80103/4, 80102/4, 80108/4, 80105/4, 90201/4, 90202/4, 90203/4, 90205/4, 90207/4, 90209/4, 90208/4.
The Borelli Group 4 Pump Speed Increaser – 91000 Series is a speed-increasing gearbox specifically engineered to connect gear pumps to the power take-offs of agricultural tractors. The standard PTO output speed is 540 rpm; this device increases that speed to match the optimal operating speeds required by hydraulic pumps. The unit is also designed to accommodate different input speeds, provided that the output speed of the speed increaser never exceeds the maximum limit of 3000 rpm. This flexibility makes it an essential component for smooth and efficient power transmission in mobile and stationary agricultural applications.
The structural strength of the unit is ensured by the use of high-quality materials. The housings are manufactured from cast aluminium and high-strength cast iron, protecting the internal transmission mechanisms even under demanding environmental conditions. The internal gears are carefully designed in compliance with international ISO/DIN 3990-80 standards and manufactured from UNI 18NiCrMo5 alloy steel. The gear teeth feature a corrected, low-profile design: this specific geometry provides significantly greater mechanical strength and ensures quiet operation during torque transmission.
Power transmission is handled by shafts manufactured from UNI 16CrNi4 steel. The shafts and gears are connected through splined couplings, a technical solution that enables the assembly to withstand high torsional stresses and safely handle the torque ratings specified in the catalogue.
The speed increaser is optimized for continuous-duty operation. The torque values specified range from a maximum of 177 daNm (M1) to a minimum of 20 daNm (M2), depending on the selected transmission ratio (from 1 to 3.8). Under intermittent-duty conditions, the nominal torque ratings may be exceeded by up to 20%. During continuous operation, the operating temperature must not exceed 120°C.
To preserve component integrity and ensure a long service life, SAE 90 lubricating oil must be used, with a maximum oil capacity of 1.80 litres. Maintenance procedures require visual inspection of the lubricant level through the dedicated sight glass every 1500 operating hours. The first oil change is mandatory after the initial 60-80 hours of operation.
Installing hydraulic pumps onto the speed increaser always requires a coupling half and a specific adapter flange suitable for the relevant pump group. The 91000 Series offers extensive compatibility with various flange configurations (e.g. Group 2, Group 3, Group 4, SAE A, B and C standards, and LG variants). During configuration, it is essential to specify the flange type and the pump shaft used to ensure correct alignment and efficient power transmission without losses.
| Specification | Value / Specification |
|---|---|
| Power Take-Off Output Speed (Standard Input) | 540 rpm |
| Maximum Speed Increaser Output Speed | 3000 rpm |
| Housing Material | Cast aluminium and high-strength cast iron |
| Gear Material and Standards | UNI 18NiCrMo5 steel, designed according to ISO/DIN 3990-80 |
| Shaft Material and Coupling | UNI 16CrNi4 steel, splined coupling |
| Torque Overload Allowance (Intermittent Duty) | +20% compared to continuous duty |
| Lubricating Oil Type | SAE 90 Type |
| Maintenance (Inspection / First Oil Change) | Visual inspection every 1500 hours / First oil change after 60-80 hours |
| Maximum Oil Capacity | 1.80 litres |
| Maximum Operating Temperature | 120°C (continuous duty) |
| Transmissible Power (for ratios from 1 to 3.8) | 74 kW |
| Approximate Weight (G) | 20 kg |
| Model / Flange | Product Code | Details / Dimensions (G x H) |
|---|---|---|
| Standard Speed Increaser Housing | 91001 | Male Shaft 1″3/8 Z6 DIN 9611 |
| Standard Speed Increaser Housing | 91002 | Female Shaft 1″3/8 DIN 9611 |
| Standard Speed Increaser Housing | 91003 | Dual Shaft, DIN 5482 |
| Group 2 Flange | 80104/4 | 21 x 21 mm |
| Group 3 Flange | 80103/4 | 22 x 22 mm |
| Group 3.5 Flange | 80102/4 | 24.5 x 24.5 mm |
| Group 4 Flange | 80108/4 | 36 x 36 mm |
| Group 3 Bosch Flange | 80105/4 | 12 x 24 mm |
| SAE A Flange | 90201/4 | 25 x 25 mm |
| SAE B Flange | 90202/4 | 12 x 25 mm |
| SAE C Flange | 90203/4 | 15 x 28 mm |
| LG 20-35 Flange | 90205/4 | 20.5 x 26.5 mm |
| L.G. 50 Flange | 90207/4 | 33 x 43 mm |
| L.G. 75 Flange | 90209/4 | 57 x 72 mm |
| ULTRA 3PL DOWTY Flange | 90208/4 | 10 x 24 mm |