Core technology comparison: efficiency, cost and environmental protection
1. Electric drive: a new force in the energy revolution
Advantages:
(1) High efficiency and energy saving:
The energy conversion efficiency of the motor can reach more than 90%, while the efficiency of the hydraulic system is usually only 60%-70% due to losses such as friction and leakage of hydraulic oil.
(2) Clean and zero emission:
No exhaust pollution, noise as low as 70 decibels (hydraulic presses are usually more than 85 decibels), suitable for urban construction.
(3) Simple maintenance:
The motor structure is simple, no hydraulic oil replacement, filter element maintenance, etc. are required, and maintenance costs are reduced by 30%-50%.
Disadvantages:
(1) Endurance and charging limitations:
The endurance of electric excavators is usually 3-8 hours, which depends on charging facilities. For example, the Caterpillar 320EV electric excavator takes eight hours to charge and is only suitable for short-cycle operations.
(2) Poor low temperature performance:
The capacity of lithium batteries decays significantly below -20℃, and the hydraulic system is more stable at extreme temperatures.
2. Hydraulic drive:
Advantages:
(1) High power density:
Hydraulic systems can provide hundreds of tons of thrust
(2) Precision control:
Hydraulic valves have a fast response speed and are suitable for scenes that require micron-level precision, such as injection molding machines.
(3) Strong environmental adaptability:
Hydraulic oil is resistant to extreme temperatures (-40°C to 150°C)
Disadvantages:
(1) Energy consumption and pollution:
Hydraulic oil has a high risk of leakage. Although biodegradable hydraulic oil reduces pollution, its cost is 20%-30% higher than traditional hydraulic oil.
(2) Complex maintenance:
Hydraulic systems require regular replacement of hydraulic oil and seals, and the annual maintenance cost is 15%-20% higher than electric ones.
Scenario-based selection: Typical cases of excavators and injection molding machines
1. Excavator: Electrification is accelerating its penetration, and hydraulics are still the main force
(1) Electric excavator:
Applicable scenarios: urban infrastructure, port short-haul, tunnel construction.
Cost advantage: The life cycle cost of electric excavators is 20%-30% lower than that of hydraulic machines, but the initial procurement cost is 30%-50% higher.
(2) Hydraulic excavator:
Applicable scenarios: mining, heavy-duty excavation.
Technological innovation: Hybrid technology (combined with oil-electric drive, saving 60% energy in plateau operations.
2. Injection molding machine: the “precision war” between electric and hydraulic
(1) Electric injection molding machine:
Advantages:
Energy consumption is reduced by 50%-70%, and the repeat positioning accuracy reaches 0.02mm, which is suitable for high-precision production of electronic components, medical equipment, etc.
Limitations:
It is difficult to meet the needs of large molds.
(2) Hydraulic injection molding machine:
Advantages:
It is suitable for large products such as car bumpers and home appliance shells.
Environmental improvement:
The use of biodegradable hydraulic oil reduces leakage pollution by 80%.
The relationship between electric and hydraulic drive is complementary and coexists. In the future, hybrid technology will become the mainstream, and policy promotion and cost reduction will accelerate the electrification process. Enterprises need to make comprehensive decisions based on the operating environment, budget cycle and environmental protection requirements to find the optimal solution between efficiency, cost and sustainability.
