Shijiazhuang Laiye Import& Export Trading Co., Ltd. is one of the leading manufacturers and suppliers of cbnl-e3/e3 hydraulic tandem gear pump in China, also supports customized service. If you're going to wholesale high quality cbnl-e3/e3 hydraulic tandem gear pump made in China, welcome to get pricelist from our factory.
Products Description
Why Choose Tandem Pump?
When you look at a compact machine like a forklift, you'll notice it needs two separate hydraulic systems to operate: one for lifting the heavy mast, and another for steering the wheels. Fitting two independent pumps on a single engine is physically inefficient and takes up too much space. The CBNL-E3/E3 hydraulic tandem gear pump solves this by combining two complete pumping units into one aluminum body. It allows you to power two independent circuits with a single drive shaft, drastically reducing the mounting complexity on the engine.
How it works internally
This isn't just two pumps bolted together. Inside the single housing, we stack two complete gear sets sequentially along one central shaft. When the engine turns the shaft, both the front and rear gear sets rotate at the same time. Each set has its own dedicated suction cavity and pressure outlet. The fluid passes through both stages without mixing. From a hydraulic standpoint, you get two independent power sources from one mechanical input.
The key internal design points
To keep this dual-stage structure running reliably over the long term, three engineering details are built into the body: first, axial clearance floating offset actively compensates for wear inside both stages; second, radial balancing minimizes the side-load stress on the shaft bearings; third, DU self-lubricating bearings protect the high-load areas, especially during slow-speed startup or if oil viscosity is temporarily high due to cold weather.
Features & Advantages
Solving the "Flow Starvation" issue in dual circuits
A frequent challenge we see in the field with tandem pumps is that when one circuit (such as lifting) demands full flow, it can starve the other circuit (such as steering) of pressure. The CBNL-E3/E3 is designed with independent inlet and outlet channels for both stages. This physical separation means that even when your mast is lifting a max-load pallet, the steering stage continues to produce its full rated pressure and flow. The operator won't experience steering lag during critical maneuvering.
Compact packaging for space-limited machinery
Because we build two pumping chambers into one cast housing, you do not need to install a splitter gearbox or deal with two bulky individual pump flanges. This reduces the total footprint on the engine and simplifies the routing of suction and return pipes. For machinery designers, this single-piece approach often means fewer brackets, less welding, and a cleaner final assembly.
Efficiency is split by workload
Instead of one blanket efficiency number, we have tuned the manufacturing tolerances to match the actual displacement. For pumps running smaller stages (10 to 12.5 ml/r), we hold them to 91% volumetric efficiency. For larger stages (14 to 20 ml/r) where the internal flow is higher, we tighten the clearances to achieve 92%. While 1% might seem small on paper, in continuous daily operation it translates to lower fluid heating and reduced energy consumption.
Handling the longer shaft load
A tandem pump has a longer drive shaft than a single pump. This puts extra bending stress on the bearings if the internal components aren't properly supported. The CBNL-E3/E3 hydraulic tandem gear pump uses a thick aluminum body paired with precision radial balance channels. These channels divert side-load forces away from the shaft centerline, helping to maintain shaft alignment when both stages are running simultaneously at max peak pressure.
Technical Specifications
Performance & Dimensional Parameters Table
| Model Combination (Fore/Rear) | Displacement (mL/r) | Rated Pressure (MPa) | Max Pressure (MPa) | Rated Speed (r/min) | Max Speed (r/min) | Vol. Efficiency (Fore/Rear) | L1 (mm) | L2 (mm) | L3 (mm) | L4 (mm) | L5 (mm) | L6 (mm) | Port Thread (In/Out) | Weight (Kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CBNL-E310/E306 | 10 / 6 | 16 | 20 | 2500 | 3000 | 91% / 90% | 50 | 99 | 202 | 48 | 147 | 200 | M20X1.5 | 4.4 |
| CBNL-E310/E308 | 10 / 8 | 16 | 20 | 2500 | 3000 | 91% / 90% | 50 | 100.8 | 205.5 | 48 | 148.8 | 203.5 | M20X1.5 | 4.5 |
| CBNL-E310/E310 | 10 / 10 | 16 | 20 | 2500 | 3000 | 91% / 91% | 50 | 102 | 208 | 48 | 150 | 206 | M20X1.5 | 4.6 |
| CBNL-E316/E306 | 16 / 6 | 16 | 20 | 2500 | 3000 | 92% / 90% | 55 | 104 | 212 | 53 | 157 | 209 | M20X1.5 | 4.7 |
| CBNL-E316/E308 | 16 / 8 | 16 | 20 | 2500 | 3000 | 92% / 90% | 55 | 105.8 | 215.5 | 53 | 158.8 | 212.5 | M20X1.5 | 4.8 |
| CBNL-E316/E310 | 16 / 10 | 16 | 20 | 2500 | 3000 | 92% / 91% | 55 | 107 | 218 | 53 | 160 | 215 | M20X1.5 | 4.9 |
| CBNL-E316/E306 | 16 / 16 | 16 | 20 | 2500 | 3000 | 92% / 92% | 55 | 112 | 228 | 53 | 165 | 225 | M20X1.5 | 5.2 |
| CBNL-E320/E308 | 20 / 8 | 16 | 20 | 2500 | 3000 | 92% / 91% | 56.5 | 109.3 | 222.5 | 56.5 | 165.8 | 220.5 | M20X1.5 | 5.0 |
| CBNL-E320/E310 | 20 / 10 | 16 | 20 | 2500 | 3000 | 92% / 91% | 56.5 | 110.5 | 225 | 56.5 | 167 | 223 | M20X1.5 | 5.1 |
| CBNL-E320/E316 | 20 / 16 | 16 | 20 | 2500 | 3000 | 92% / 92% | 56.5 | 115.5 | 235 | 56.5 | 172 | 233 | M20X1.5 | 5.4 |
| CBNL-E320/E320 | 20 / 20 | 16 | 20 | 2500 | 3000 | 92% / 92% | 56.5 | 119 | 242 | 56.5 | 175.5 | 240 | M20X1.5 | 5.6 |
Operating Environment:
Hydraulic Oil: 20 - 43 cSt (Mineral hydraulic oil, ISO VG 32/46).
Working Temp.: -20°C to 80°C.
Filtration Accuracy: ≤ 25 μm.
Volumetric Efficiency: ≥ 90%.
Dimensional & Interface Options:
Port Configuration: All models utilize uniform M20X1.5 threaded ports for both the Inlet and Outlet. Flange connection options are also available based on the dimensional drawing (D1-D4 values).
Shaft Types: Plain Key, Rectangular Spline.
Mounting: Standard elliptical 4-bolt flange.
Installation Dimensions (L1 to L6): As shown in the table above, the CBNL-E3/E3 series has six modular dimensional lengths. Note that the specific spacing values (L1 through L6) are determined by the combination of the front pump, middle block, and rear pump. Please cross-reference these values with your physical assembly space requirements before finalizing your mounting bracket design.
Application
The CBNL-E3/E3 is built primarily for material handling and compact earthmoving equipment. In the forklift industry, this is a standard choice for 2 to 3-ton capacity trucks. One stage runs the lift and tilt cylinders, while the other stage supplies the power steering unit. Separating these two circuits is important because it prevents the steering from becoming heavy when the operator is lifting a full load.
In the agricultural sector, we often supply this tandem pump to mid-size tractors. The primary stage powers the front loader attachment. The secondary stage is usually dedicated to the rear remote valves that run things like log splitters or hay balers.
For construction equipment, such as compact wheel loaders or backhoes, the dual-output design allows one pump to handle the front bucket hydraulics, while the other stage focuses on the steering system. This layout reduces the number of hydraulic hoses and simplifies the overall system layout on the machine.
Model Selection Guide
Identical Displacement Matches (e.g., CBNL-E310/310, 320/320): Ideal for machines requiring two identical independent circuits. For example, a loader might use both 16 ml/r stages: one for steering, one for the lift arm.
Mixed Displacement Matches (e.g., CBNL-E310/316): Ideal for primary and secondary circuits. In a large tractor, the larger 16 ml/r stage can power the heavy front loader, while the smaller 10 ml/r stage provides precise, low-flow flow for the rear hydraulic remotes.
Port Size Correlations: Unlike some tandem series, all models in the CBNL-E3/E3 family share the same M20X1.5 threaded port sizes. This means you do not need to worry about different fittings when switching between mixed displacement models.
Production and Quality
Decades of Hydraulic Specialization
Since 1988, our engineering team has dedicated over 35 years solely to the hydraulic pump and valve sector. Our production processes and quality control criteria are specifically tailored to meet the rigorous demands of fluid power systems.
Integrated Production Capabilities
We operate a vertically integrated facility with over 200 technicians, encompassing CNC machining, gear hobbing, automated assembly, and a dedicated hydraulic testing lab. This integration allows us to control the quality of every aluminum casting and precision-cut gear tooth.
Industry-Standard Quality Control
To ensure our tandem pumps withstand 20 MPa pressure, we enforce a three-tier pre-shipment Quality Control protocol:
Metallurgical Check: Incoming aluminum and steel batches are tested for hardness and composition.
Dimensional Verification: Critical dimensions for both the front and rear pump stages are verified to maintain correct alignment.
Dynamic Performance Test: Every CBNL-E3/E3 hydraulic tandem gear pump is run on a hydraulic test bench to validate the volumetric efficiency of both independent pump stages and ensure zero external leaks.
Global OEM Support & Service
We offer OEM customization, including specific displacement combinations and shaft lengths. Our packaging complies with ISPM 15 standards (export-grade plywood) to ensure safe overseas transit, backed by a 12-month warranty against manufacturing defects.
FAQ
Q: I see "10/6" and "16/10" in the model name. What does the slash represent?
A: The numbers before and after the slash refer to the displacement of the front and rear pump stages. 10/6 means the front stage has a 10 ml/r displacement and the rear stage has a 6 ml/r displacement. You can choose identical or mixed combinations depending on the flow requirements of your two hydraulic circuits.
Q: Will the front and rear pump stages perform differently in cold weather?
A: Both stages are physically identical in terms of internal material composition and bearing design. However, because oil viscosity is higher at low temperatures, the rotation resistance increases. We recommend letting the system warm up by idling the engine for a few minutes when temperatures are near -20°C. This allows the oil to flow more freely into both suction cavities before engaging heavy lifting.
Q: What is the maximum allowable back pressure on the return side?
A: We recommend keeping the return line back pressure below 0.5 MPa. In a tandem pump, excessive back pressure can push against the shaft seals and cause minor leakage at the drive shaft. If you are using a return manifold, ensure the line diameter is sufficient to keep flow velocity low.
Q: Does this pump require a specific type of hydraulic oil?
A: Standard mineral hydraulic oil with a viscosity of 20 to 43 is acceptable. Avoid using oils with extreme pressure (EP) additives unless they are specifically approved for aluminum component compatibility. The DU bushings are designed to handle standard hydraulic fluids without added friction modifiers.
Q: How do I confirm the overall length fits my mounting space?
A: The length varies depending on the displacement combination. CBNL-E310/E306 is 99 mm long, while the larger CBNL-E320/E320 measures 119 mm. We strongly suggest you check the L1 to L6 dimensional values on our technical drawing before building your mounting bracket. If your space is tight, we can advise if a mixed combination will fit within your existing envelope.
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