How Much Load Can THK HCR25A Carry?
What Is THK HCR25A?
THK HCR25A belongs to the HCR Curved LM Guide Series, designed specifically for applications requiring precise circular or arc motion.
Unlike conventional linear guides, the HCR series allows smooth movement along a curved rail while maintaining the same four-direction load capability found in THK's standard LM Guide technology.
Typical applications include:
- Rotary indexing tables
- Semiconductor equipment
- Packaging machinery
- Automated inspection systems
- Amusement equipment
- Circular transfer systems
THK HCR25A Block Dimensions
According to the HCR series dimensional table, the HCR25A block features:
| Item | Specification |
|---|---|
| Model | HCR25A |
| Height (M) | 36 mm |
| Width (W) | 70 mm |
| Length (L) | 81.6–82.5 mm |
| Mounting Thread | M8 |
| Block Length (L1) | 59.5 mm |
| Grease Nipple | B-M6F |
| H3 | 7 mm |
These dimensions correspond to the HCR25A+60/500R, 750R, and 1000R configurations shown in the technical drawing provided.
HCR25A Load Rating
The most important specifications for engineers are the dynamic and static load ratings.
Basic Load Ratings
| Specification | Value |
|---|---|
| Dynamic Load Rating (C) | 19.9 kN |
| Static Load Rating (C₀) | 34.4 kN |
This means:
Dynamic Load Rating (19.9 kN)
The dynamic load rating represents the constant load under which the guide can theoretically achieve its rated service life.
19.9 kN equals approximately:
- 19,900 N
- 2,029 kgf
- 4,474 lbf
Static Load Rating (34.4 kN)
The static load rating indicates the maximum allowable stationary load before permanent deformation may occur.
34.4 kN equals approximately:
- 34,400 N
- 3,508 kgf
- 7,733 lbf
These values are specified by THK for HCR25A curved guides.
Moment Load Capacity
Besides vertical load, engineers must evaluate moment loads caused by offset mounting or overhanging payloads.
For a single HCR25A block:
| Moment Direction | Capacity |
|---|---|
| MA | 0.307 kN·m |
| MB | 0.307 kN·m |
| MC | 0.344 kN·m |
Using two blocks significantly increases rigidity:
| Moment Direction | Double Blocks |
|---|---|
| MA | 1.71 kN·m |
| MB | 1.71 kN·m |
| MC | 1.71 kN·m |
This is why many rotary automation systems utilize dual-block configurations for higher stability and positioning accuracy.
Rail Radius Options
THK offers three standard radius options for HCR25A:
| Model | Radius (R) |
|---|---|
| HCR25A+60/500R | 500 mm |
| HCR25A+60/750R | 750 mm |
| HCR25A+60/1000R | 1000 mm |
All three versions share the same block size and load ratings but differ in travel path geometry.
Example Load Calculation
Application
Rotary inspection table
Payload:
- Fixture = 25 kg
- Product = 15 kg
- Total = 40 kg
Load force:
Result:
F ≈ 392 N
Compared with the HCR25A dynamic load rating:
- Applied load = 0.392 kN
- Dynamic capacity = 19.9 kN
Safety factor:
≈ 50×
This indicates the guide has more than sufficient load capacity, and the design will usually be limited by moment loading rather than pure vertical load.
Why Engineers Choose HCR25A
Four-Direction Equal Load Design
The HCR series supports:
- Radial loads
- Reverse radial loads
- Lateral loads from both directions
This allows stable operation under complex loading conditions encountered in rotary automation systems.
High Positioning Accuracy
The Gothic-arch raceway design provides:
- High rigidity
- Smooth motion
- Low friction
- Excellent repeatability
Flexible Curved Motion
The HCR guide enables accurate circular motion without requiring custom cam systems or expensive rotary bearings.
Selection Recommendations
Choose HCR25A when:
✓ Payload is below 500 kg
✓ Moderate moment loads are present
✓ Circular or arc motion is required
✓ High positioning accuracy is needed
✓ Equipment size must remain compact
Consider HCR35A or larger models when:
✓ Heavy tooling is mounted
✓ Large cantilever loads exist
✓ High-speed indexing systems are used
✓ Significant moment loads exceed 0.3 kN·m per block
Conclusion
The THK HCR25A provides an excellent balance between compact size and load capacity.
Key specifications include:
- Dynamic Load Rating (C): 19.9 kN
- Static Load Rating (C₀): 34.4 kN
- Moment Capacity (MA/MB): 0.307 kN·m
- Moment Capacity (MC): 0.344 kN·m
- Available Radii: 500 mm, 750 mm, 1000 mm
- Block Size: 36 × 70 × 82 mm
For most automated rotary tables, inspection equipment, semiconductor machinery, and circular transfer systems, the HCR25A offers sufficient load capacity while maintaining THK's renowned motion accuracy and durability.