Back at the end of 2025, the Jufeng team finalized the plan to independently design a front-to-back series-connected two-stage air end and build its dedicated production line. Now that the year 2026 is halfway through, we have achieved major phased results. The first batch of new air end prototypes has been successfully produced and passed all commissioning tests.
The new air end outperforms the traditional model significantly in four key aspects: manufacturing cost, operational stability, energy efficiency and service life. To understand the performance gap, we will first elaborate on their core differences.
Five Core Advantages of Series-Connected Two-Stage Air End vs. Traditional Horizontal Side-by-Side Type
- Higher Transmission Efficiency & Lower Energy Consumption
The intermediate transmission gears are eliminated, removing 3%~5% power loss caused by gear meshing friction. The motor is directly coupled to the main shaft, achieving a transmission efficiency close to 100%. With a properly designed stage pressure ratio (single-stage pressure ratio ≤ 3), internal air leakage is greatly reduced.
This new design cuts power consumption by 8%~15% compared with conventional horizontal two-stage compressors, making it easier to meet or exceed the Class 1 Energy Efficiency Standard (GB19153) of China.
- Longer Service Life & Lower Failure Rate
The back-to-back coaxial structure offsets over 70% of axial force, which greatly reduces load on bearings. The service life of bearings and rotors is extended by 20%~30%, and the risk of bearing seizure due to overheating is minimized.
Without transmission gears, common faults such as gear wear, pitting, tooth breakage and gearbox oil leakage are completely eliminated. The frequency of major overhauls and spare parts costs are largely reduced. (Gears on traditional units require inspection and replacement every 30,000 to 50,000 operating hours).
- Reduced Air Path Loss & Higher Discharge Efficiency
The straight-through axial air flow features no redundant bends. Air flows linearly from the first stage to the second stage, cutting pipeline pressure loss by more than 40%.
Under the same motor power, the actual air displacement of the series-connected model is 5%~10% higher than that of equivalent horizontal units. Users can select lower-power compressors to meet the same air demand and save costs.
- Compact Structure & Easy Installation & Maintenance
The vertically elongated layout of the series-connected air end reduces the overall unit width. The floor area of the compressor cabinet is decreased by 10%~15%, making it suitable for workshops with limited installation space.
Adopting a modular cavity design, the first and second stage cavities can be disassembled separately for inspection and maintenance, without removing the entire air end. Maintenance working hours are reduced by 30%. Meanwhile, its manufacturing cost is about 10% lower than traditional gear-driven horizontal two-stage compressors, delivering a more competitive purchase price.
- Lower Noise & Vibration, Superior Operating Stability
Free from gear meshing impact noise, the mechanical noise of the main unit is 3~6 dB(A) lower than traditional gear-driven models.
The self-balancing axial force of rotors lowers overall vibration amplitude. The unit runs stably under full load, and is ideal for 24-hour non-stop industrial production, such as chemical, auto parts and textile industries.
Follow-up Plan of Jufeng Team
Both theoretical design data and prototype test reports prove that the front-to-back series-connected two-stage air end is superior to the traditional horizontal type in stability, durability, energy efficiency and cost.
The Jufeng team has decided to gradually update the structural design of all two-stage compressors and adopt the new air end throughout this year. Customers can now place orders for the new model compressors.
It should be noted that the traditional horizontal side-by-side design still has its merits. With a lower center of gravity, it is still applied for a small number of customized units working under ultra-high pressure (16 bar and above) and large-displacement models over 300kW.
Feel free to contact the Jufeng team for any inquiries or equipment requirements!