How do I install the eccentric bushing to achieve the desired 1mm offset?

Installation requires aligning the bushing's offset direction with the desired shaft adjustment. First, clean the housing bore and shaft, ensuring no burrs or debris. Apply a thin layer of anti-seize compound to the outer diameter. Insert the bushing into the housing by hand, then rotate it to the position where the offset points in the required direction. Use a soft mallet to seat it fully, avoiding excessive force. Secure with a set screw or retaining compound if necessary. Verify the adjustment by measuring the shaft position with a dial indicator; the 1mm offset should be achievable within ±0.01mm. For high-vibration applications, use a thread-locking adhesive on the set screw.

What is the maximum operating temperature for this SAE 660 bronze bushing?

SAE 660 bronze has a maximum continuous operating temperature of 260°C (500°F) in dry conditions. However, when used with grease or oil lubrication, the temperature limit is determined by the lubricant, typically 120°C for lithium-based greases. At temperatures above 150°C, the bronze's strength decreases by approximately 10% per 50°C rise. For applications exceeding 200°C, consider a high-temperature lubricant or a different material such as aluminum bronze. The bushing's thermal expansion coefficient is 18 µm/m·°C, which should be accounted for in tight-clearance assemblies.

Can this eccentric bushing be used in a rotating application where the outer ring is press-fitted?

Yes, but with caution. When press-fitted into a housing with an interference fit of 0.02-0.04mm, the outer ring is fixed, and the inner ring rotates with the shaft. The eccentricity then causes the shaft to orbit, which can create imbalance at high speeds. For rotating applications, limit the speed to 1500 rpm to avoid excessive vibration. Alternatively, use the bushing in a static adjustment mode where the shaft is locked after positioning. For dynamic applications, consider a concentric bushing or a balanced eccentric design. Always ensure proper lubrication to prevent fretting corrosion at the outer diameter.

Eccentric Bushing

25mm ID, 1mm Offset Eccentric Bushing for Precision Adjustment

This eccentric bushing features a 25mm inner diameter, 32mm outer diameter, and 20mm length, with a 1mm offset between the inner and outer bores. Manufactured from SAE 660 bronze, it provides a tensile strength of 240 MPa and a hardness of 70 HB. The bushing is designed for machine tool spindles, automotive steering columns, and industrial machinery where precise radial adjustment is required.

Length

20mm

Eccentricity (Offset)

1mm

Tolerance

0.02mm

Material

SAE 660 Bronze

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How Does a 1mm Offset Eccentric Bushing Solve Shaft Misalignment?

The eccentric bushing with 25mm ID, 32mm OD, and 20mm length is a precision component that allows radial adjustment of a shaft by 1mm. The offset between the inner and outer diameters creates an eccentricity that, when rotated, shifts the shaft position. This is critical in machine tool spindles where thermal expansion or wear can cause misalignment. The SAE 660 bronze construction offers a tensile strength of 240 MPa and a yield strength of 140 MPa, ensuring durability under cyclic loads. The 0.02mm tolerance on the inner diameter guarantees a close fit with shafts ground to h6 tolerance, minimizing vibration and wear.

Typical applications include automotive steering columns, where the bushing compensates for manufacturing tolerances in the steering rack, and industrial machinery such as printing presses, where precise roller alignment is essential for print quality. The self-lubricating properties of SAE 660 bronze, with a friction coefficient of 0.08 against steel, reduce maintenance intervals by up to 50% compared to plain carbon steel bushings. The 20mm length provides sufficient bearing surface area to handle radial loads up to 3.5 kN, making it suitable for medium-duty applications.

Compared to standard concentric bushings, this eccentric version eliminates the need for shims or adjustable mounts, simplifying assembly and reducing part count. The 1mm offset is ideal for applications requiring fine adjustment without excessive eccentricity, which can cause imbalance in high-speed rotating equipment. For higher offset requirements, custom sizes are available, but the 1mm version offers a balanced solution for most alignment tasks. The bushing's outer diameter of 32mm fits standard housings with H7 tolerance, ensuring interchangeability.

SAE 660 bronze with 240 MPa tensile strength for high load capacity
1mm eccentricity allows precise radial adjustment without shims
0.02mm tolerance ensures minimal vibration and long service life

Core Technical Features and Quantified Advantages

STEP 1

SAE 660 Bronze Construction with 240 MPa Tensile Strength

The bushing is cast from SAE 660 bronze, which provides a tensile strength of 240 MPa and a yield strength of 140 MPa. This material offers excellent wear resistance and conformability, making it suitable for applications with shock loads. The bronze's self-lubricating properties reduce the need for external lubrication, extending maintenance intervals by up to 50% compared to steel bushings.

STEP 2

1mm Eccentricity for Precise Radial Adjustment

The 1mm offset between the inner and outer diameters allows the shaft position to be adjusted radially by rotating the bushing. This eliminates the need for shims or adjustable mounts, reducing assembly time by up to 30%. The eccentricity is ground to a tolerance of ±0.01mm, ensuring accurate and repeatable adjustments in machine tool spindles and automotive steering systems.

STEP 3

0.02mm Tolerance on Inner Diameter for Minimal Vibration

The inner diameter is machined to a tolerance of 0.02mm, providing a close fit with shafts ground to h6 tolerance. This reduces vibration and noise in high-speed applications, such as printing press rollers operating at up to 3000 rpm. The tight tolerance also minimizes wear, extending the bushing's service life to over 10,000 hours under normal load conditions.

STEP 4

20mm Length for Load Capacity up to 3.5 kN

The 20mm length provides a bearing surface area of 1570 mm², allowing the bushing to support radial loads up to 3.5 kN at a pressure of 2.2 MPa. This makes it suitable for medium-duty industrial machinery, including conveyors and packaging equipment. The length is optimized for applications where space is limited but load capacity is critical.