Borelli Support for Group 3 Pumps – 25404-6/25604-6 Series
The Borelli Support for Group 3 Pumps – 25404-6/25604-6 Series isolates Group 3 hydraulic pumps from radial and axial mechanical loads generated by auxiliary transmission components. Equipped with a 3208A bearing and a 35x45x7 shaft seal, it ensures rigid and reliable coupling. The series is available in the 25404-6 version with a 1:8 tapered shaft and the 25604-6 version with a 24 f6 cylindrical shaft.
The available product codes are: 25404-6, 25604-6.
The Borelli intermediate support for Group 3 hydraulic pumps acts as a structural barrier between the drive or auxiliary transmission component and the flanged hydraulic pump. Its primary function is to absorb external stresses, both radial and axial, typically generated by pulleys, belts, chains or gears. By preventing these forces from being transmitted directly to the hydraulic pump shaft and its internal bearings, the support preserves mechanical integrity, prevents abnormal bushing wear and reduces the risk of fluid leakage through the primary seals.
The support structure consists of a housing (code 25004/6.1) designed to ensure dimensional precision and high alignment rigidity. Dynamic and static loads are absorbed by a 3208A bearing (code 503208), positioned and axially secured by UNI 7435-40 Seeger retaining rings (code 904000) and a ring with a diameter of 80 mm (code 25003/C1).
Protection against external contamination and leakage is provided by:
The retaining hardware and coupling components include a UNI 28675 M14x1.5 nut (code 601415), a 14 mm diameter Grower spring lock washer (code 801400) and a standardized 4×7.5 UNI 6606 Woodruff key (code 700475).
The Borelli Group 3 range includes two distinct configurations based on the input drive shaft profile:
On the opposite side, the pump connection features an A35x31 DIN 5482 spline profile, ensuring engagement compliant with standardized Group 3 pump specifications.
The two configurations have different load limits depending on shaft geometry:
The mounting interface features a flange with a 50.75 mm female centering diameter (H7 tolerance) and a 50.75 mm male centering diameter (f8 tolerance). The housing mounting pattern includes 11 mm diameter through-holes arranged on a 106 x 98 mm pattern (121 mm vertical center-to-center spacing, overall housing width of 126 mm and height of 154 mm). The flanged housing has an overall thickness of 52 mm, with an axial dimension of up to 99 mm at the shaft shoulder.
| Specification | Value |
|---|---|
| Compatible Pump Group | Group 3 (Gr. 3) |
| 25404-6 Series Shaft Type | Tapered (1:8 taper ratio, M14x1.5 thread) |
| 25604-6 Series Shaft Type | Cylindrical, 24 f6 diameter (40 mm length, M8x1.25 thread) |
| Pump-Side Spline Profile | A35x31 DIN 5482 |
| Integrated Bearing | 3208A bearing |
| Radial Shaft Oil Seal | 35x45x7 |
| O-Ring Seals | O-ring 3200 and O-ring 174 |
| Axial Retaining Rings | UNI 7435-40 Seeger retaining ring and dia. 80 mm ring |
| Drive Keys | 4×7.5 UNI 6606 Woodruff key (25404-6) / 8x7x40 UNI 6604 parallel key (25604-6) |
| 25404-6 Series Radial Load | 318 daN (at 11.2 mm) |
| 25404-6 Series Axial Load | 245 daN |
| 25604-6 Series Radial Load | 140 daN |
| Mounting Centering Diameter | 50.75 H7 (female) / 50.75 f8 (male) |
| Housing Mounting Holes | 4 through-holes, 11 mm diameter (106×98 mm / 121 mm center-to-center spacing) |
| Housing Dimensions | 126 x 154 x 52 mm |
| Support Model / Code | Shaft Type | Transmission and Shaft End Details | Pump-Side Profile |
|---|---|---|---|
| 25404-6 | Tapered shaft (1:8 taper ratio) | M14x1.5 thread, 4×7.5 UNI 6606 Woodruff key (code AC03/6F) | A35x31 DIN 5482 |
| 25604-6 | Cylindrical shaft, dia. 24 mm | 24 f6 diameter, M8x1.25 thread, 8x7x40 UNI 6604 parallel key (code AC24) | A35x31 DIN 5482 |