Description

1. Product Overview

This Precision CNC Machined 45# Steel Ball Screw Floating Bearing Block (commonly known as FK-series floating support unit) is a critical component for linear motion systems. Designed with an integrated helical spring, it provides continuous axial preload to eliminate backlash and thermally compensates for ball screw expansion during high-speed operation. Manufactured from high-grade C45 (SAE 1045) medium carbon steel and finished with a black oxide coating, this block ensures superior wear resistance, structural rigidity, and corrosion protection in demanding industrial environments.

2. CNC Machining Specifications & Parameter Table

Below are the standard manufacturing capabilities and specifications we offer for this custom precision part. Our facility is equipped with 5-axis CNC milling centers and turning centers to meet high-tolerance industrial demands.

3. Material Analysis: Why 45# Steel (C45)?

Choosing the correct raw material is vital for this floating support block because it bears both torque and axial loads.

• Why 45# Steel (C45)? This medium-carbon structural steel offers an ideal balance between strength (tensile strength ≥ 600MPa), toughness, and machinability. It is significantly more rigid than aluminum, which prevents micro-vibrations that could otherwise affect the precision of the ball screw and positioning system.

• Black Oxide Finish (表面发黑): This chemical conversion coating does not add significant thickness to the part, ensuring it does not interfere with the tight inner bore tolerances. It effectively protects the steel against rust, reduces light reflection (better for visual inspection), and helps absorb and retain lubricating oil during operation.

4. Application Scenarios

This ball screw floating bearing block is widely applied in industries where precise linear translation and high-speed movement are critical:

• CNC Machine Tools: As the floating-side bearing support for X, Y, Z axes, ensuring smooth motion even during prolonged high-speed milling or grinding.

• Industrial Robotics & Automation: Used in servo-driven robot arms, gantry loaders, and transfer systems to prevent binding caused by slight alignment errors during assembly.

• Semiconductor & Electronics Manufacturing: Employed in precision wafer handling equipment and high-speed PCB drilling machines where vibration dampening is essential.

• Packaging & Medical Machinery: Provides reliable, backlash-free linear movement for automated packaging and laboratory analyzer systems.

5. Tolerance Capability & Quality Control

Our CNC machining services maintain strict precision standards.

• Critical Tolerances: The most critical feature is the inner bearing mounting hole. We can achieve an H7 tolerance (typically +0.010mm to +0.018mm depending on diameter). This is essential because any out-of-tolerance bore will squeeze the angular contact bearing, causing friction and premature failure.

• Geometric Tolerances (GD&T): We guarantee parallelism ≤ 0.02mm between the square base mating face and the top flange face. This ensures the block sits perfectly flat on the machine bed, preventing misalignment stress on the screw shaft.

• Inspection: All critical dimensions are verified 100% using CMM (Coordinate Measuring Machines) and professional bore gauges, with detailed QC reports provided upon request.

6. Manufacturing Difficulties & Solutions

This component poses significant challenges for standard CNC workshops. Here is how we resolve them:

• Challenge 1: Concentricity of the Spring Cavity & Bearing Bore. The inner spring resting groove and the inner bearing bore must be machined on the exact same center line.

  • Our Solution: We use 4-axis CNC turning-milling centers to complete these inner features in a single clamping operation, eliminating the cumulative errors caused by multiple setups.

• Challenge 2: Machining Deformation. The thin-walled structure around the spring cavity can easily deform when the side clamping holes (set screws) are drilled and tapped.

  • Our Solution: We apply a rough machining and stress-relieving heat treatment step before the final precision finishing process, ensuring the steel releases internal stresses before the final cut.

• Challenge 3: Thread Perpendicularity. The side set-screw holes must be perfectly perpendicular to the bearing outer ring.

  • Our Solution: We utilize high-rigidity tapping machines and special spring-loaded guide bushings to guarantee an 90° angle and high thread finish.

7. Frequently Asked Questions (FAQ)

Q1: What is the difference between this “Floating” block and a standard Fixed block?
A: A “Fixed” block (e.g., BK series) anchors both sides of a bearing without axial movement. This “Floating” block (FK series) contains a spring. When the ball screw heats up and expands during operation, this spring compresses to absorb the thermal expansion, preventing the screw from bending or binding.

Q2: Can you make this support block in Aluminum instead of steel?
A: Yes, we can machine it in Aluminum 6061 or 7075 with an anodized finish. However, please note that aluminum provides less rigidity. For heavy-duty machine tools, we always recommend 45# steel; for lightweight automation arms or aluminum processing machines, Al 6061 is an excellent choice.

Q3: Do I need to purchase the bearings separately, or do you supply them too?
A: We typically machine the housing only. However, we can source and press-fit standard angular contact bearings (e.g., 7200 series) into the block and ship it as a complete, fully assembled sub-assembly upon your request.

Q4: What is your MOQ (Minimum Order Quantity)?
A: Because this is a custom CNC machined part, we do not have a strict MOQ. We welcome prototype orders from 1-5 pcs for your R&D testing, and we offer competitive bulk pricing for quantities over 50 pcs.

Q5: How do you ensure the spring provides the correct axial preload?
A: The spring’s compression force is determined by the depth of the machined spring groove and the flange thickness. We follow your specific CAD design prints precisely. If your design has pre-set spring lengths, we can also adjust the machining depth to match your pre-calculated load requirement.