Sealing structure

Abstract

This invention provides a seal structure. A needle bar 12 is guided by a tubular needle bar receiving members 29 and 30 and reciprocatingly and displaceably driven in the axial direction. Needle bar seal members 33 and 34 comprise outer peripheral base parts 40, oil seal parts 50, and dust seal parts 52, and are fitted to the needle bar receiving members 29 and 30 by the outer peripheral base part 40. A contact face 53 supporting the axial displacements of the needle bar receiving members 29 and 30 is formed on the outer peripheral base part 40. Thus, the outer peripheral base part 40 can be prevented from being axially displaced relative to the needle bar receiving members 29 and 30. As a result, even if the needle bar seal members 33 and 34 are fitted to a needle bar 12 reciprocatingly and displaceably driven, the needle bar seal members 33 and 34 can be securely prevented from coming out of the needle bar receiving members 29 and 30.

Description

technical field [0001] The invention relates to a sealing structure of a drive shaft that moves back and forth along the axis. Background technique [0002] FIG. 9 is a sectional view showing a part of the structure related to the needle bar 2 of the sewing machine 1 in the prior art. Fig. 10 is an exploded perspective view showing a part of the structure related to the needle bar 2 of the sewing machine 1 in the prior art. The conventional technology is described in Japanese Unexamined Patent Application Publication No. 2004-105516. The oil leakage preventing device of the sewing machine 1 described in JP-A-2004-105516 includes: a needle bar 2 for reciprocating movement along the axis direction; a needle bar support member 3 for moving the needle bar 2 along the axis direction; Guide; needle bar sealing member 4, used to scrape off the lubricating oil supplied to the needle bar 2. The inner peripheral surface 4 a of the needle bar sealing member 4 is connected to the out...

AI Technical Summary

Problems solved by technology

Because the needle bar seal member 4 is attached to the needle bar 2, the needle bar seal member 4 wears due to sliding friction as it is used, reducing the effect of scraping the lubricating oil from the needle bar 2.

In this case, it is necessary to replace the needle bar sealing member 4 with a new needle bar sealing member 4, but since the needle bar sealing member 4 is bonded to the needle bar supporting member 3 by an adhesive, it is necessary to remove the adhesive. agent, difficult to replace

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