Ground Ball Screws vs. Conventional Screws: Which is Better?

In the field of mechanical transmission, the screw is a key transmission element, and its performance directly affects the efficiency and precision of the equipment. This article will make a detailed comparison between the ground ball screw and the traditional screw in terms of structural principle, performance characteristics, application field, etc., and analyze which one is more suitable for different usage requirements.

1. Basic Structure and Working Principle

1.1 Ground Ball Screw

The ground ball screw, also known as rolling screw or spherical screw, is a precision-machined steel ball that circulates between the screw and the nut to achieve transmission. Specifically, when the drive shaft rotates, the screw transmits linear motion to the nut part through the steel ball and drives the load to move.
This design gives the ground ball screw the following characteristics:
High efficiency: Since the rolling friction of the steel ball is much smaller than the sliding friction of the traditional screw, the energy loss of the ground ball screw is less, and the transmission efficiency can reach more than 90%.
High precision: The strict manufacturing process ensures that the gap between the screw and the nut is extremely small, thereby improving the positioning and repeatability accuracy.
Long life: High-quality materials and surface treatment technology give the ground ball screw a long service life.

1.2 Traditional Lead Screw

The traditional lead screw, also known as the sliding lead screw, mainly relies on the helical pair (direct contact between the lead screw and the nut) to achieve linear motion. When the rotational force is applied to the lead screw, the nut moves along the axial direction, thereby driving the load.
Its main features include:
Simple structure: The design of the traditional lead screw is relatively simple and the manufacturing cost is low.
Strong load-bearing capacity: In the case of large loads, the traditional lead screw may have more advantages.
Complex maintenance: Due to the existence of sliding friction, it is easy to wear and heat, and the lubrication requirements are high.

2. Performance Comparison

2.1 Efficiency Comparison

The working efficiency of the ground ball screw is much higher than that of the traditional lead screw. The nature of rolling friction enables the former to convert up to more than 90% of the driving force into useful work, while the traditional lead screw has a large energy loss due to the existence of sliding friction, and the transmission efficiency is usually between 70%-80%.

2.2 Accuracy and Stability

In terms of accuracy and stability, the ground ball screw also has advantages. Its small gap design ensures a high repeatability and is suitable for application scenarios with strict requirements on position accuracy. At the same time, due to the rolling shock absorption effect of the steel ball, the ground ball screw has good vibration resistance and can maintain stable performance under dynamic loads.
In contrast, the sliding friction of traditional screws easily leads to cumulative errors, especially in precision machining and high-frequency operations, and its positioning accuracy may be difficult to meet the requirements. In addition, the heat generated during the sliding process may cause thermal deformation, further affecting the operating stability.

2.3 Life and Maintenance

In terms of service life, the life of the ground ball screw under the same working conditions is much longer than that of the traditional screw due to the use of high-quality materials and surface hardening. At the same time, its excellent self-lubricating performance reduces the dependence on external lubricants and reduces the maintenance frequency and cost.
Although the manufacturing cost of traditional screws is relatively low and the structure is simple, due to its frequent lubrication and higher wear rate, the total cost of ownership (TCO) after long-term use may not be lower than that of ground ball screws.

3. Application Scenarios

3.1 Application Fields of Ground Ball Screws

Due to their high efficiency, precision and long life, ground ball screws are widely used in the following fields:
Industrial robots: scenarios that require high-precision positioning and fast response.
CNC machine tools (CNC): require strict motion control to ensure machining accuracy.
Automated assembly lines: efficient transmission helps improve production efficiency.
Aerospace equipment: reliable performance under extreme working conditions is essential.

3.2 Application Areas of Traditional Screws

Although they have been replaced by ground ball screws in many aspects, traditional screws still have certain advantages in the following application scenarios:
Low-speed and high-load equipment: such as certain types of cranes or agricultural machinery.
Projects with limited budgets: low initial investment, suitable for occasions with non-precision requirements.
Simple mechanical equipment: simple structure and easy maintenance, suitable for small-scale production.

Summary

Ground ball screws have occupied an increasingly important position in modern industry due to their efficient transmission, high-precision positioning and long service life. Especially in areas with high performance requirements, it is almost the best choice. Although the traditional screw technology is relatively old, it still plays an irreplaceable role in specific application scenarios.