Balance Crane Series: PDJ, PJ, PAJ, PJZ & PAY Models Compared
Key Point The balancer (also known as a balance crane or jib balancer) uses a parallelogram linkage mechanism with counterweight balancing to allow effortless load movement in both horizontal and vertical directions. ①Five structural types: PDJ high-profile, PDJA low-profile, PJ standard, PJSZ two-speed, PAJ low-profile (lathe-specific), PJZ heavy-duty, and PAY hydraulic; ②Lifting capacity from 50 to 1,000 kg, lifting height from 1.2 to 4 m, working radius from 1 to 3.5 m; ③Two-speed models offer fast/slow switching, while heavy-duty units handle large workpiece assembly; ④Balancers deliver smooth operation and precise positioning, making them ideal for machine tool loading/unloading and assembly line workstations. Kelude Heavy Industry offers a full range of 12 balancer models covering lifting capacities from 50 to 1,000 kg.
Balancer Types and Configurations
A balancer is a lightweight lifting device that leverages the lever-balance principle to move loads effortlessly in both vertical and horizontal directions, offering flexible operation and precise positioning. Compared to electric hoists, balancers are better suited for frequent, short-distance workpiece handling—operators can guide the load with one hand while maneuvering the crane lighter with the other, as naturally as moving their own arm. Kelude Heavy Industry's balancer lineup spans five series—PDJ, PJ, PAJ, PJZ, and PAY—widely used in machine tool loading/unloading, assembly line workstations, and component handling applications.
| Series | Model | Lifting Capacity(kg) | Lifting Height(m) | Working Radius(m) | column height(m) | Reference Price(CNY) |
|---|---|---|---|---|---|---|
| PDJHigh-Profile | PDJ-50~300 | 50~300 | 1.2~3.0 | 1.0~2.5 | 2.4~4.0 | 2800~7000 |
| PDJALow-Profile | PDJA-50~200 | 50~200 | 0.5~1.5 | 0.8~1.5 | 1.2~1.8 | 2000~4000 |
| PJ-100~600 | 100~600 | 1.5~3.5 | 1.3~3.0 | 3.0~4.5 | 3500~8000 | |
| PJSZ-100~500 | 100~500 | 1.8~3.5 | 1.8~3.0 | 3.2~4.5 | 6000~10000 | |
| PJZHeavy-Duty | PJZ-600~1000 | 600~1000 | 2.0~4.0 | 2.0~3.5 | 3.5~5.0 | 10000~18000 | PAY-100~500 | 100~500 | 1.5~3.0 | 1.3~2.5 | 2.8~4.0 | 5000~12000 |
Note: The above is the reference price for Kelude Heavy Industry balancers, including the column and crane lighter assembly, excluding foundation work and installation fees. Non-standard sizes can be customized for all series upon request.
Balancer Selection: Key Considerations
How a Balancer Works: Operating Principle & Core Components
A balancer uses a parallel-linkage mechanism combined with a pneumatic or spring balancing system to keep the load in a state of gravitational equilibrium within the vertical plane. The operator only needs to apply minimal force to move the load up, down, left, or right. The core structure consists of: ① a balance arm (parallel linkage that maintains the load height constant as the hook moves horizontally); ② a balancing system (spring cylinder or pneumatic cylinder that generates a force equal to the load weight); ③ a slewing column (fixed or mobile base with a rotation angle of 270–360°); and ④ a lifting spreader (hook, fixture, lifting magnet, etc.).
The fundamental difference between a balancer and an electric hoist: an electric hoist uses an electric motor to lift the load (inching control), while a balancer uses a spring or pneumatic balancing mechanism to make the load "float" (zero-gravity operation). The operating force of a balancer is ≤30N (approx. 3kgf), making it over 80% more effortless than manual operation of an electric hoist.
Balancer Sizing: Pneumatic vs. Spring Balancing
Spring-balanced: The spring preload is adjusted to match the load weight. Simple construction, no air supply required. Suitable for loads from 0.5 to 100kg, with an adjustment accuracy of ±1kg. Spring fatigue life is ≥500,000 cycles. Kelude Heavy Industry PDJ series spring balancers come standard with an adjustable spring seat offering a ±20% adjustment range.
Pneumatic-balanced: Compressed air drives a pneumatic cylinder to generate the balancing force, with stepless adjustment via a pressure reducing valve. Suitable for loads from 10 to 500kg (depending on cylinder bore), with higher adjustment accuracy (±0.5kg). Requires an air supply pressure of 0.4–0.6MPa and consumes approximately 0.1–0.5m³/h. PJ series pneumatic balancers are equipped with a filter-regulator-lubricator and oil mist separator.
Sizing formula: Required balancing force Fbal = m×g + Fspreader (including fixture dead weight). For spring types, select the spring specification based on Fbal; for pneumatic types, select the cylinder bore based on Fbal ÷ air supply pressure. A safety factor of 1.2 is applied. Kelude Heavy Industry offers free sizing calculations.
Installation Requirements & Safe Operating Practices
Installation: The balancer base must be anchored to a concrete floor of at least C25 grade (mobile units come with swivel casters and braking wheels). Column perpendicularity must be within 1/1000. For pneumatic models, ensure a stable air supply pressure and fit the inlet with a filter-regulator-lubricator (FRL) unit.
Safe operation: ① Verify the balance setting matches the load weight before use; ② never overload — overloading breaks the balance and causes the load to drop suddenly; ③ keep the operating area clear of obstructions; ④ after use, lower the load to the ground and release the stress on the balancing system. Kelude Heavy Industry balancers come standard with overload protection valves (pneumatic models) and explosion-proof spring breakage protection (spring models), with a safety factor of ≥4.
Five Balancer Series: Full Parameter Comparison
| Series | Balancing Method | Load Capacity Range(kg) | Working Radius(m) | Lifting Height(m) | Air Supply Requirement | Typical Application | Reference Price(CNY) |
|---|---|---|---|---|---|---|---|
| PDJ | Spring Balanced | 5~100 | 1.5~3.0 | 1.5~3.0 | Not Required | Assembly Line, Light Load Handling | 3,000~8,000 |
| PJ | Pneumatic Balanced | 10~500 | 2.0~4.0 | 2.0~4.0 | 0.4~0.6MPa | Machining Top Cutting, Die Changing | 6,000~20,000 |
| PAJ | Pneumatic+Assist Arm | 50~300 | 2.5~4.5 | 2.0~3.5 | 0.4~0.6MPa | Fixture Light Load Handling, Precision Assembly | 12,000~30,000 |
| PJZ | Pneumatic+Column Slewing | 20~200 | 2.0~4.0 | 2.0~3.0 | 0.4~0.6MPa | Multi-Station, Cross-Station Transfer | 15,000~35,000 |
| PAY | Rigid Arm Pneumatic Balanced | 20~300 | 2.0~4.0 | 1.5~3.0 | 0.4~0.6MPa | High Accuracy Assembly, Overhead Conveying | 20,000~50,000 |
Balancer Safety Devices and Operating Guidelines
Safety Devices: Kelude Heavy Industry balancers come standard with four key safety protections: ① Overload protection valve (pneumatic models) — automatically cuts off the air supply when the load exceeds 120% of the set value, allowing the load to lower slowly; ② Explosion-proof spring fracture device (spring models) — if the spring breaks, a mechanical locking mechanism immediately secures the cantilever to prevent the load from falling; ③ Limit protection — travel switches are installed at the upper and lower travel limits to cut off the balance circuit when exceeded; ④ Emergency release valve — in the event of power or air supply failure, the load can be lowered manually via the release valve. All safety devices are individually tested before leaving the factory, and test reports are provided.
Selection Guide: For light-load precision assembly, choose the PDJ spring-type balancer (no air supply required, low cost). For medium-load repetitive handling, the PJ pneumatic model offers infinitely variable adjustment with minimal operating effort. For applications requiring wide-range movement across workstations, the PJZ column-type balancer provides slewing up to 270°. For high-precision positioning, the PAY rigid-arm balancer delivers horizontal positioning accuracy of ±1 mm. Kelude Heavy Industry offers a 7-day on-site trial of demo units for evaluation.
Related Standards
• ASME B30.28 — Safety Standard for Balancers
• ISO 4301 — Crane Design Standard: Key Provisions on Loads, Structures, Mechanisms, Electrical Systems, and Safety
Frequently Asked Questions
Q: What is the difference between a balancer and an electric hoist?
A: A balancer uses a parallelogram linkage with counterweight balancing, allowing the load to move freely in both vertical and horizontal directions. The operator can guide the load with one hand while controlling the crane lighter with the other — much like extending their own arm. An electric hoist, by contrast, provides vertical lifting plus horizontal movement (requiring manual pushing or a trolley), offering less maneuverability. Balancers are better suited for machine tool loading/unloading and assembly stations.
Q: Does a balancer require mandatory inspection?
A: Balancers are not classified as special equipment (lifting capacity ≤ 1000 kg), so no manufacturing license or periodic inspection is required. However, all Kelude products are designed and manufactured in accordance with ISO 4301 crane design standards, ensuring safety and reliability.
Q: What is the purpose of a two-speed balancer?
A: The PJSZ two-speed balancer allows switching between fast and slow speeds. Fast speed is used for rapid positioning across a wide area (improving efficiency), while slow speed enables precise load alignment (positioning accuracy up to ±2 mm). It is particularly suited for mold installation, precision assembly, and other tasks requiring fine adjustment.
Q: What is the warranty period for a balancer?
A: Kelude balancers come with an 18-month warranty from the date of shipment, covering the column, crane lighter, counterweight, and hook. Non-accidental damage during the warranty period is repaired or replaced free of charge. With their simple, durable construction, balancers typically have a service life of 10 years or more.
This completes the full guide to the PDJ/PJ/PAJ/PJZ/PAY balancer series, covering parameters, pricing, and selection. Kelude Heavy Industry offers 12 balancer models with lifting capacities from 50 to 1000 kg, plus custom non-standard options. Contact the Kelude technical team for a tailored selection proposal.
