KPX Battery-Powered Trackless Flat Car for Heavy Loads

• Unlimited Travel Distance: No conductor rail or cable reel required; battery power allows operation on tracks of any length. Ideal for long-distance material transport across workshops or zones within a plant.
• S-Shaped / Curved Track Capability: Unlike KPC/KPT/KPJ systems that require straight tracks, the KPX can navigate S-shaped and curved rails, offering flexible track layouts that adapt to complex factory floor plans.
• Superior DC Motor Performance: Smooth starting, high starting torque (approximately 2 to 2.5 times the rated torque), reduced impact on the gearbox, and low voltage (24 to 72V) for enhanced safety. Stepless speed control ranges from 0 to 25 m/min, enabling precise positioning at any point.
• No Special Track Requirements: Unlike KPD low-voltage rail cars (which require insulated, sectioned power supply), the KPX operates on standard P-type rails, allowing rapid deployment in both new and existing workshops.
• Optional Explosion-Proof Design: Battery power means no exposed live parts, making it suitable for flammable or explosive atmospheres. An explosion-proof electrical control system and battery box are available, achieving Ex db eb IIB T4 Gb rating.
• Extensive Optional Features: Optional hydraulic lifting platform, tipping device, V-type support, rotating table, remote control system, and explosion-proof electrical controls.

The working principle of the KPX battery-powered electric flat car is based on battery energy storage and DC motor drive:

The battery pack (lead-acid or lithium) is installed in the battery compartment inside the car. A battery management system (BMS) monitors battery voltage, current, and temperature. The battery supplies DC power (24 to 72V depending on the model) to the motor controller.

The motor controller receives operating commands (from the wired pendant or wireless remote control) and uses PWM (pulse width modulation) to achieve stepless speed control and forward/reverse operation of the DC motor. The controller also provides overcurrent protection, undervoltage protection, and over-temperature protection, automatically cutting off output when the battery level drops below a set threshold.

The DC traction motor (1 to 15kW) generates torque under the controller's drive. This torque is reduced by the gearbox and transmitted through an open gear drive to the wheels, propelling the car along the track. The DC motor delivers high starting torque (up to 2 times the rated torque) with smooth inrush current, causing far less impact on the gearbox and gears than direct-on-line starting of AC asynchronous motors.

When the battery is depleted, it is recharged using an external smart charger. Charging time for lead-acid batteries is approximately 6 to 8 hours, while lithium batteries can be fast-charged in about 2 to 3 hours. An optional battery management system (BMS) extends battery life and provides real-time health monitoring.

The KPX battery-powered rail flat car consists of the following main structural components:

• Frame (Load Platform): Welded box-section structure in Q235B steel plate, reinforced with I-beam or H-beam main girders, with graded designs from 2t to 150t. The 150t model uses Q345B low-alloy high-strength steel. The battery compartment is located inside the frame and features ventilation openings and drain holes.
• Battery Pack: Lead-acid battery (standard) or lithium iron phosphate battery (lightweight option). Capacity ranges from 160 to 600Ah, with voltages from 24 to 72V. The battery pack is mounted on a pull-out tray for easy maintenance and replacement. The lithium version is approximately 60% lighter than lead-acid.
• DC Traction Motor: Separately excited / series-wound DC motor, 1 to 15kW. Delivers high torque at low speeds, with maximum torque available from standstill. Motor protection rating is IP44, with Insulation Class F.
• Motor ControllerController: MOSFET/IGBT PWM speed control controller with stepless control (0–25 m/min), forward/reverse control, braking energy recovery (optional), overcurrent/undervoltage/overtemperature protection. Control signals are low-voltage DC (12V/24V).
• Charging Device: Smart charger (optional) that automatically identifies battery type and charging status, with constant-current/constant-voltage intelligent charging and auto shut-off when fully charged. Charging input: AC 220V/380V optional.
• Gearbox & Wheel Block: The gearbox is directly coupled to the DC motor for high transmission efficiency. Cast steel wheels ZG310-570, diameter Φ270–Φ650, with 4 or 8 wheels (150t). Bearings are double-row spherical roller bearings.

• Long-Distance Cross-Workshop Transport: In one heavy industry facility, the distance from the Cutting Workshop to the Painting Workshop is approximately 300m, with two 90° Curved Rail sections in between. A KPX-25t battery-powered flat car handles one-way transport, with travel distance unrestricted by battery capacity, moving steel plates 60 trips per day.
• S-Shaped Curved Rail Production Line: An automotive parts plant with an S-shaped production layout uses a KPX-10t flat car to move workpieces between stations along Curved Rail. Compared to the previous manual forklift approach, transfer efficiency increased by 50% and labor was reduced by 2 workers per shift.
• Flammable and Explosive Environments: A chemical plant's paint shop is classified as an Explosion-proof zone. They selected a KPX-16t Explosion-proof battery flat car (Ex db eb IIB T4 Gb), featuring a nitrogen-blanketed sealed battery compartment and an Explosion-proof DC motor, ensuring spark-free safe operation.
• Transfer Car / Turntable Integration: Between two parallel Crane Rail lines, a transfer turntable connects the tracks. The KPX-40t flat car's onboard battery eliminates the need for track-side power supply, so power remains uninterrupted during turntable Rotation, ensuring efficient transfer.
• Outdoor Yard Transport: A steel warehouse yard has simple track laid out, and a KPX-50t flat car shuttles H-Beam steel between the yard and Warehouse over a distance of about 150m. Equipped with an outdoor Rain Cover control box and weather-resistant battery, it runs 8–10 trips per charge.

• Load Capacity: Select based on the maximum single-trip load weight, with a 20%–30% safety margin.
• Travel Distance: KPX series is not limited by distance, but battery endurance must be considered. For one-way trips ≤100m and ≤10 round trips per shift, standard lead-acid batteries suffice; for long distances or high-frequency use, lithium batteries with fast charging are recommended.
• Track Type: For S-curve or Curved Rail applications, the Wheel Flange must be double-flanged. Minimum curve radius is ≥2m for light loads and ≥3m for heavy loads.
• Environmental Conditions: Explosion-proof environments require customized Explosion-proof electrical controls and battery compartments; outdoor use calls for a Rain Cover and battery insulation; high-temperature environments (>50°C) require High Temperature Resistant batteries.
• Battery Type: Lead-acid batteries are cost-effective (about 1/3 the price of lithium), require regular maintenance including electrolyte topping-up, and last about 2.5 years. Lithium batteries are 60% lighter, maintenance-free, last about 5 years, and charge in 2–3 hours.
• Feature Expansion: Optional add-ons include hydraulic lifting (150–300mm), Stepless control, Wireless remote control, PLC automation, and BMS battery management.

• Pre-Sales Consultation: Free technical solutions, model selection recommendations, and layout drawings.
• Order Processing: Foundation condition drawings provided within 3 days after contract signing; full-machine test run and acceptance before shipment.
• Installation & Commissioning: On-site technical guidance for installation and commissioning available (additional cost applies).
• Training Support: 1–2 days of operator training covering operating procedures, routine inspections, and common fault troubleshooting.
• After-Sales Service: 1-year warranty on the complete machine (wear parts excluded); on-site response within 48 hours domestically.
• Spare Parts Supply: Long-term supply of batteries, chargers, motor controllers, carbon brushes, wheel blocks, and other components.

Q: How long can a KPX battery-powered flat car run on a full charge?

A: Continuous running time at full load is approximately 2.9–5.4 hours (depending on load capacity and battery capacity), with a travel range of about 3.2–8.1 km. Light-load or intermittent operation (start-stop cycles) can extend this by 1.5–2 times. Refer to the "Continuous Running Time at Full Load" and "Travel Range" rows in the Technical Specifications for details.

Q: What's the difference between the KPX and the KPC/KPT/KPJ models?

A: The KPX is powered by onboard batteries, giving it unlimited travel distance, the ability to navigate S-curves and curved tracks, and no special requirements for the rail. However, it requires recharging (6–8 hours for lead-acid, 2–3 hours for lithium), and the battery life is about 2.5 years. The KPC/KPT/KPJ models are powered via cable or conductor rail, allowing 24/7 continuous operation, but travel distance is limited by cable or rail length.

Q: How do I choose between lead-acid and lithium batteries?

A: Lead-acid batteries are more cost-effective (about 1/3 the cost of lithium), making them suitable for budget-conscious applications with moderate usage frequency and available charging/maintenance facilities. Lithium batteries are lighter (approximately 60% weight reduction), maintenance-free, fast-charging (2–3 hours), and have a longer lifespan (about 5 years), making them ideal for lightweight design requirements, high-frequency use, or applications with limited charging time.

Q: Can the KPX flat car be used in explosion-proof areas?

A: Yes. The KPX battery-powered flat car can be equipped with explosion-proof electrical controls (Ex db eb IIB T4 Gb), explosion-proof DC motors, and an explosion-proof battery compartment (with nitrogen purge protection). Battery power inherently has no exposed live parts, making it safer than conductor rail or cable power supply. Please specify the required Explosion Protection Class when selecting your model.

Q: Can the KPX flat car be automated?

A: Yes. The KPX can be equipped with a PLC (Siemens S7-200 SMART), positioning sensors (magnetic strip, laser, or encoder), and integrated with a central dispatching system for automatic travel and loading/unloading alignment. Battery power is well-suited for automated applications (no cable drag interference, simple wiring). We have delivered automated battery-powered flat car solutions to numerous customers, achieving Positioning Accuracy of up to ±10 mm.

Q: What national standards does the KPX battery-powered flat car comply with?

A: The design and manufacturing of the KPX series strictly comply with the JB/T 6127-2010 "Electric Flat Car" industry standard. The battery system meets GB/T 18332.1 "Lead-Acid Batteries" and GB 40165 "Lithium Battery Safety" requirements, and the electrical system complies with GB 5226.1-2019 "Electrical Safety of Machinery." Each machine undergoes a three-stage acceptance process before shipment: full-load test run, Dynamic Load Test, and Static Load Test.