What the BRB Trochoid Pump Does
The BRB trochoid pump is an internal gear oil pump for low-pressure, continuous lubrication circuits on machine tools. Six sizes from 0.8 to 4.2 ml/r run at 300 – 2000 rpm against a rated pressure of 0.4 MPa.
This page covers the supply pump only. Per-point dosing belongs to the metering unit, feed lines to 4 mm nylon pipe, and grease duty to an electric grease pump. For near-dry cutting lubrication, see the MQL trace lubrication cooling system.
Specifications
| Model | Displacement (ml/r) | Speed (rpm) | Inlet port | Shaft key |
|---|---|---|---|---|
| BRB-1 | 0.8 | 300 – 2000 | Rc 1/8 | K1 |
| BRB-2 | 1.35 | 300 – 2000 | Rc 1/8 or Rc 1/4 | K1 |
| BRB-3 | 2.1 | 300 – 2000 / 300 – 1000 | Rc 1/4 | K1 |
| BRB-4 | 3.0 | 300 – 2000 | Rc 3/8 | K1, K2 |
| BRB-5 | 3.5 | 300 – 2000 | Rc 3/8 | K1, K2 |
| BRB-6 | 4.2 | 300 – 2000 / 300 – 1000 | Rc 3/8 | K1, K2 (K3 on BRB-6R) |
Dual speed values mean one part number variant of that model is limited to 300 – 1000 rpm. Oil viscosity range is 20 – 320 cSt. Rated pressure is 0.4 MPa, maximum 0.5 MPa. Every size has an R variant: viewed from the shaft end, standard turns clockwise (CW) and R turns counterclockwise (CCW).
Part numbers: BRB-1: 28023. BRB-2: 30265 / 28031. BRB-3: 25668 / 31853. BRB-4: 30274 / 25831. BRB-5: 30275 / 28032. BRB-6: 30264 / 22340 / 33148. Additional variants: 43874 / 30246-R / 43874-R.
How the Trochoid Principle Works
The inner rotor has one tooth fewer than the outer rotor and meshes eccentrically. Chambers expand on the inlet side to draw oil in and contract on the outlet side to push it out, so delivery is low-pulsation and quiet, with few moving parts.
Sizing a BRB Pump
Required flow equals the dose per point times the number of points, plus a 15 – 20% margin. Displacement equals flow divided by shaft speed. Example: 700 ml/min at 500 rpm gives 700 / 500 = 1.4 ml/r, so BRB-2 at 1.35 ml/r is the match. Or send your flow and speed requirements and we will confirm the size.
Installation Limits to Respect
Rated 0.4 MPa continuous, 0.5 MPa short-term ceiling: fit an outlet relief valve set at 0.5 MPa or lower, and do not use this pump in high-pressure hydraulic circuits.
It moves lubricating oil of 20 – 320 cSt only; grease of any NLGI grade cannot be pumped. Too thin an oil gives a weak film; too thick raises suction resistance and risks cavitation.
Rotation matters: the wrong CW/CCW choice makes the pump draw air and deliver nothing, so confirm drive shaft direction before ordering.
Self-priming is strong, but mounting below tank level for flooded suction is recommended. Keep the suction line short and straight, fill the inlet port with clean oil before the first start, and stay inside the rated speed range, because overspeed causes cavitation and wear.
Typical Applications
Machine tool slideway lubrication, spindle bearing oil circuits, gear and chain lubrication, hydraulic charging circuits, textile machinery, and printing and packaging equipment.
Frequently Asked Questions
Should I choose a BRB trochoid pump or an external gear pump?
For lubrication circuits needing a low-pulsation, steady oil film, choose the trochoid design. For high-pressure hydraulics, neither fits, since this is a 0.4 MPa class pump. Grease duty belongs to a different pump family.
How do I calculate which BRB size I need?
Multiply the dose per point by the number of points, add a 15 – 20% margin, then divide by shaft speed. At 700 ml/min and 500 rpm, 700 / 500 = 1.4 ml/r points to BRB-2 (1.35 ml/r).
What does the R suffix mean, and what happens if I pick the wrong one?
R means reversed rotation: standard runs clockwise from the shaft end, R runs counterclockwise. The wrong rotation draws air and gives no output, so confirm shaft direction first.
How do K1, K2, and K3 shaft keys differ?
K1 fits all sizes. K2 is offered from BRB-4 up, and K3 only on BRB-6R. Match the key to the keyway on your drive shaft.
Why are there two pressure figures, 0.4 MPa and 0.5 MPa?
0.4 MPa is the continuous rating; 0.5 MPa is a short-term ceiling. Set the outlet relief valve at 0.5 MPa or lower.
What oil viscosity can the pump handle?
The range is 20 – 320 cSt. Thinner oil weakens the film; thicker oil raises suction resistance and risks cavitation, especially at low speed or cold start.
Can this pump deliver grease?
No. It is an oil pump and cannot move grease of any NLGI grade; grease points need an electric grease pump.
Which inlet thread does each size use?
BRB-1: Rc 1/8. BRB-2: Rc 1/8 or Rc 1/4. BRB-3: Rc 1/4. BRB-4 to BRB-6: Rc 3/8. Match your suction line fittings.
What should I do before the first start?
Mount below tank level for flooded suction, keep the suction line short and straight, and fill the inlet port with clean oil before starting.
Who supplies the BRB trochoid pump?
IsoHiTech Lubrication Systems was founded in 2023, engineering since 2006, and supplies lubrication pumps, metering units, and pipework. Request a quotation for your pump size or write to inquiry@isohitech.com with your flow, speed, and rotation details.
