• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

Mobile Hydraulic Tips

Mobile Hydraulic Tips focuses on pumps, fittings, valves, manifolds and other products and news in the Mobile Hydraulics industry.

  • Hydraulics Blog
  • Industry News
  • Engineering Basics
  • Components
    • Cylinders
    • Fittings / Couplings
    • Pumps / Motors
    • Sensors / Gauges
    • Valves / Manifolds
    • Related components
  • Design Guide Library
  • Advertise
  • Subscribe

Parker BLA Boost Unit Simplifies Building of Hydrostatic Transmissions

November 22, 2010 By admin

Share

MARYSVILLE, OH –  The BLA Boost Unit from Parker Hannifin Corporation simplifies the building of closed or semi-closed hydrostatic transmissions by replacing the conventional charge pump and corresponding valves in many applications including fan (Figure 1), propeller, generator and pump drives. This can simplify the design and reduce the total cost of a hydrostatic transmission.

BLA-Boost-Unit-Parker-Hannifin-figure-1
FIGURE 1

In a closed circuit hydrostatic transmission, a charge pump is typically included with the main pump to provide make-up fluid to replace pump and motor volumetric losses. The charge pump also maintains pump inlet pressure to avoid cavitation.

Parker’s BLA Boost Unit replaces the charge pump in many applications where the following conditions are met:

* The maximum-to-minimum pump flow ratio does not exceed 2:1
* System pressure changes gradually (no frequent or pronounced pressure peaks)
* The line length between the pump and BLA Boost Unit is relatively short

When fluid flows from the motor outlet through the BLA Boost Unit to the pump inlet (Figure 2), the increased fluid velocity between the boost unit nozzle and injector creates a low-pressure zone, causing additional fluid to be drawn from the tank into the main circuit. Also, because pressure increases after the injector, the pump can be operated at speeds higher than the self-priming speed. Thus, “boost pressure” increases with flow.

BLA-Boost-Unit-Parker-Hannifin-figure-2
FIGURE 2

An additional bleed-off nozzle, meanwhile, diverts approximately 10% of the main flow through a cartridge filter before being directed to the tank.

BLA-Boost-Unit-Parker-Hannifin

Parker offers two BLA Boost Unit models: the BLA 4 is available in four sizes with a maximum recommended flow of 10, 16, 26 and 42 gal/min while the BLA 6 is available in 66, 92 and 105 gal/min sizes. Both are constructed without moving/wearing parts and can be installed either directly to the oil reservoir or connected separately with piping or hoses (in both instances, to function properly, the boost unit must be installed well below the lowest oil level in the reservoir).

Hydraulic Pump Division of Parker Hannifin
www.phpump.com

::Design World::

Filed Under: Pumps / Motors Tagged With: hydrostatic transmission, Parker Hannifin

Primary Sidebar

Fluid Power Design Guides

fluid
“mht
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, tools and strategies for Fluid Power Professionals.

Fluid Power World Digital Editions

Fluid Power World is written by engineers for engineers engaged in designing machines and or equipment in Off-Highway, Oil & Gas, Mining, Packaging, Industrial Applications, Agriculture, Construction, Forestry, Medical and Material Handling. Fluid Power World covers pneumatics, mobile hydraulics and industrial hydraulics.

Footer

Mobile Hydraulic Tips

FLUID POWER WORLD NETWORK

  • Fluid Power World
  • Hose Assembly Tips
  • Pneumatic Tips
  • Sealing and Contamination Tips
  • Fluid Power Distributor Lookup

MOBILE HYDRAULIC TIPS

  • Subscribe to our newsletter
  • Advertise with us
  • Contact us
  • About us

Copyright © 2025 · WTWH Media LLC and its licensors. All rights reserved.
The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media.

Privacy Policy