WK900 – Pump Group 2 – Calma-Series (Low Noise)

High-Performance external gear pump in Calma-Series with low pressure pulsation for noise sensitive application
Dual flank engagement (75% reduced pressure pulsation vs. traditional gear pumps)
Compact 3-piece design
Aluminum housing (standard), cast iron (option)
Multiple sections possible (up to 4 sections)
Standard interfaces available
Reinforced front bearings (4-bolt interface) available
Customized options on demand

Displacement : 5,1 – 23,7 cm³/rev (0.311 – 1.446 in³/rev)
Max. rated pressure : 230 bar (3335 PSI)
Speed range : 500 to 4000 RPM

Displacement (in³/rev) / (cm³/rev – for reference)	Rated pressure (PSI)	Maximum speed (RPM)
.311 / (5.1 cm³/rev)	3335	4000
.378 / (6.2 cm³/rev)	3335	4000
.506 / (8.3 cm³/rev)	3335	4000
.690 / (11.3 cm³/rec)	3335	3600
.885 / (14.5 cm³/rev)	3335	3500
1.007 / (16.5 cm³/rev)	3335	3500
1.196 / (19.6 cm³/rev)	3335	3500
1.446 / (23.7 cm³/rev)	3002	3500

Displacement (cm³/rev)	Rated pressure (bar)	Maximum speed (RPM)
5,1	230	4000
6,2	230	4000
8,3	230	4000
11,3	230	3600
14,5	230	3500
16,5	230	3500
19,6	230	3500
23,7	207	3500

Product Features

Low Noise Technology (Calma-Series)

Low Noise Technology – Calma-Series (Dual Flank Engagement)

Concentric has developed the Low Noise Calma-Series for gear pumps, based on the patented Dual Flank Engagement. The Calma-Series provides a reduced pressure pulsation by 75% vs. traditional gear pump designs, resulting in a low noise operation.

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Calma-Series gear pumps are well suited to applications on electrical forklift trucks and other mobile equipments, where low noise and high efficiency are required.

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The Calma-Series is available for Concentric gear pumps Group 1 and 2 and 2.5 (Group 3 on demand).

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Low Speed Technology

Low Speed Technology – L-Design (W900 range)

Concentric has developed the Low Speed Technology (L-Design) for gear pumps which provides an extended speed range, particularly for low speed operation (< 500 rpm) at high pressure, compared to the standard A-Design.

Low Speed (L-Design) gear pumps are well suited to applications on electrical drives (e.g. electrical forklift trucks), when a wide variable speed range under pressure load is required. Also other mobile applications can benefit from the L-Design.

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Multiple Sections

Multiple Sections – Pumps

To meet specific customer needs, Concentric can design multiple section gear pumps, also in combination of different pump groups (e.g. Group 2 + Group 1).

These pumps are ideally suited to supply flow to multiple hydraulic functions from one power source.

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Customer Value:

Compact design

Costs saving compared to separate pumps with associated fittings and hoses.

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Multiple gear pump combinations are available with up to four sections with a wide interface range.
Cast Iron Housing

Cast Iron – W900-Series

Concentric offers cast iron housings for the gear products. Cast iron is adding benefits to the gear unit regarding housing durability, reduced noise radiation and stabilized volumetric efficiency, especially at high operation temperatures (> 80°C).

The cast iron components are Cr6-free surface protected.
Valve Integration

Valve Integration – W-Series and F12-Series

Concentric offers a wide range of integrated valve solutions for gear pumps and motors.

Examples:
Anti-cavitation check valves
(Proportional) pressure relief valves
Valve manifolds for multiple functions

Also speed sensors can be integrated.
Reinforced Front Bearing

Reinforced Front Bearing – W900-Series
Concentric offers reinforced front bearings (with 4-bolt interface) for extended radial and axial drive shaft load capabilities in two versions:

Medium duty version (001M): max. radial load: 1350 N / max. axial load: 1000 N
Heavy duty version (001V): max. radial load: 3600 N / max. axial load: 1300 N

Examples:
Fan drives
Belt drives