1.Clarify application requirements
This is the first step in choosing a ball screw, and you need to know clearly what scenario the equipment will be used for and the specific working conditions.
- Determine the specific application scenario of the equipment: clarify what type of machine or equipment the ball screw will be used for, such as machine tools, robots, medical equipment, etc.
- Analyze motion requirements (stroke, speed, acceleration): determine the required motion distance, maximum running speed and acceleration requirements, which directly affect the selection of the ball screw.
- Determine working environment conditions: Understand the environment under which the equipment will work, such as temperature range, humidity, whether there is dust, whether anti-corrosion is required, etc.
2.Calculate load conditions
Load is a key factor in choosing a ball screw, and different load requirements correspond to different specifications of products.
- Determine the axial load size: Calculate the axial force applied to the ball screw during operation, including static (fixed) and dynamic (moving) loads.
- Calculate possible radial forces: Although the ball screw mainly bears axial forces, there are often radial forces in practical applications and it is necessary to evaluate its size to ensure that the appropriate support method is selected.
- Assess impact loads and instantaneous overload conditions: Consider possible sudden forces during equipment operation or overload conditions in a short period of time.
3.Determine the accuracy requirements
Different applications have different accuracy requirements, and the accuracy level directly affects the price of the ball screw.
- Analyze the positioning accuracy required for the application: Determine the position accuracy required for the equipment, which determines the accuracy level selection of the ball screw.
- Determine the acceptable cumulative error range: Whether the accumulated error in long distance motion is within the acceptable range, which affects the lead accuracy selection of the ball screw.
- Evaluate the degree of impact of reverse clearance on the system: Understand whether the gap during reverse movement will affect system performance, which determines whether pre-pressure and pre-pressure degree are required.
4.Determine the ideal guide
The lead is the distance the nut moves when the ball screw rotates for one turn, which directly affects the transmission ratio and efficiency.
- Choose the right lead according to speed and torque requirements: Large leads provide high speeds but require greater torque, while small leads are the opposite.
- Consider the self-locking requirement (if any): Some applications require the system to remain unchanged when the system is shut down, and it is necessary to consider whether the self-locking characteristic is required.
- Balancing transmission efficiency and control accuracy: The efficiency of large leads is high but the control accuracy may be reduced, and a balance point needs to be found between the two.
5.Choose the right prepressure method
Pre-pressing is a technology to eliminate gaps in ball screw systems and is very important for improving accuracy and rigidity.
- Determine the prepressure degree based on rigid requirements: high rigidity requires a large prepressure, but excessive excessiveness will affect life.
- Consider the balance of life and prepressure: Increased prepressure will reduce service life and need to be balanced according to the application.
- Choose double-nut or single-nut differential pre-pressure: Different pre-pressure methods have different characteristics and need to be selected according to space and performance requirements.
6.Determining the type of construction
Ball Screws are available in a variety of structure types, each with its own advantages and disadvantages.
- Choose internal or external recirculation structure: internal recirculation structure is compact but complex, external recirculation is simple but large, need to choose according to space and performance requirements.
- Determine the ideal nut form: e.g., flange type for ease of installation, cylindrical type for small size, choose according to the installation method.
- Consider mounting space constraints: Evaluate the available space within the equipment to ensure that the selected Ball Screw can be properly mounted.
7.Calculate service life
The service life of the ball screw is directly related to the reliability and maintenance cost of the equipment.
- Calculate life expectancy according to industry standards: Use standard formulas to calculate the life expectancy of a ball screw under a given load.
- Consider the operating cycle and frequency: high frequency use will accelerate wear and increase the life requirements accordingly.
- Balanced lifespan vs. cost requirements: Longer lifespan usually means higher costs and a balance point needs to be found.
8.Confirm the installation and support method
Proper installation and support are crucial to the performance of the ball screw.
- Select the support method according to the rigidity requirements: if the fixed-fixed support provides the highest rigidity but has thermal expansion restrictions, the fixed-support is more flexible.
- Consider the effects of thermal expansion: Thermal expansion significantly affects accuracy in long-distance applications and requires appropriate compensation measures.
- Choose the appropriate installation and fixing method: including bearing type, fastening method, etc. to ensure system stability.
9.Consider special needs
Some application environments have special requirements and require specially designed ball screws.
- Evaluate sealing and protection requirements: In dusty or humid environments, a special sealing design is required to protect the ball screw.
- Determine lubrication method and cycle: Determine the appropriate lubrication method and maintenance cycle according to the frequency of use and environment.
- Consider noise control requirements: Noise can be a problem in high-speed applications and may require specially designed low-noise models.
- Confirm whether special characteristics are required: such as dust protection, corrosion protection, vacuum environment applicability, etc. These usually require special materials or treatment.
10.Performance and cost balance
Ultimately, we need to find a balance between technical requirements and economics.
- Comparison of product performance of different manufacturers: Products of the same specifications may have quality and performance differences between different manufacturers.
- Evaluate standard models and custom solutions: Standard models are low in cost but may not fully meet the needs, while custom solutions can be accurately matched but cost high.
- Balancing technical needs and budget restrictions: On the premise of meeting basic technical requirements, consider budget restrictions and choose the optimal solution.
- Consider the cost of post-maintenance and replacement: In addition to the initial purchase cost, post-maintenance costs such as maintenance difficulty and availability of spare parts should also be considered.