Quick-Change Bearing Assembly for Machine Tool Spindle Exchange
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing machine tool spindle mounting systems require recentering of spindles each time they are replaced, which is time-consuming and inefficient.
Innovation Solution
A quick-change bearing assembly featuring a ferrous metal tubular sleeve with a frusto-conical outer surface and a bronze tubular bearing with an annular vertical surface, along with an interlock mechanism, allows spindles to be exchanged without recentering, using a nut to engage the frusto-conical surfaces and a pin to prevent axial movement, and lubricant distribution grooves for efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional spindle mounting systems are used with shims for centering, then the spindle can be centered with respect to the body opening, but each time the spindle is removed or replaced, the reinstalled or replacement spindle must be recentered
Solution Approach 1:
The mounting system is segmented into three distinct components: the body with body opening, the tubular sleeve with frusto-conical outer surface that remains in the body opening, and the tubular bearing that interfaces with the spindle. This segmentation allows the sleeve to remain as a permanent centered component while only the bearing and spindle are removed and replaced, eliminating the need to recenter the entire assembly.
Solution Approach 2:
The tubular sleeve is pre-mounted in the body opening with its frusto-conical outer surface already engaged against the frusto-conical inner surface of the body opening. This preliminary centering action is performed once during initial assembly, and the sleeve maintains this centered position permanently, serving as a pre-established reference for subsequent spindle replacements.
2Reliability
If a tubular sleeve with frusto-conical surface and nut engagement is used, then the sleeve can be securely mounted in the body opening, but the complexity of the bearing assembly increases
Solution Approach 1:
The frusto-conical surfaces provide asymmetric geometric engagement between the sleeve and body opening. The conical geometry creates a self-centering effect and prevents radial movement, while the asymmetric shape allows for simple axial engagement through the nut and washer assembly without requiring complex multi-directional fastening mechanisms.
Solution Approach 2:
The frusto-conical surfaces utilize curved geometry to achieve secure mounting. The conical shape provides continuous surface contact between the sleeve and body opening, distributing loads evenly and creating a stable, self-aligning connection that is more reliable than flat surface engagement while remaining structurally simple.
3Stability of the object's composition
If an interlock mechanism is added between sleeve and bearing, then relative movement between sleeve and bearing is prevented, but the device complexity increases
Solution Approach 1:
The interlock mechanism merges the sleeve and bearing into a single functional unit that moves together as an assembly. The interlocking features (such as keys, splines, or interlocking flanges) combine the rotational and axial positioning functions into one integrated mechanism, preventing relative movement between the two components while maintaining a relatively simple overall structure.
Data Source
Figure 1~6
Figure 7~13
Figure 14~21
AI summary
The present invention provides an improvement for use in a machine tool having a spindle (51) mounted in a body opening (30) for axial and rotative movement relative to a body (31). The improvement includes a bearing assembly (25) that permits spindles (Sl , S2, S3, ...) to be quickly exchanged while obviating the need to recenter a replacement spindle with respect to the opening after the original spindle has been initially center therein. The improved bearing assembly (25) broadly includes: a ferrous tubular sleeve (29) mounted in the body opening, the sleeve having an outer surface (40) arranged to face toward a portion (31 ) of the body that surrounds the opening and having an inner surface (36, 39) arranged to face toward a penetrant portion of the spindle; and a tubular bearing (46) arranged within the sleeve, the tubular bearing having an outer surface (51 ) arranged to face the sleeve inner surface and having an inner surface (50) arranged to face the spindle penetrant portion.