Abstract: A swing mechanism for a construction machine having a grease bath seal. A grease bath can be disposed on a vehicular base carrier of the machine, and can be coupled with a swing frame. The grease bath seal can then act to prevent intrusion of pollutants or other foreign materials into the grease bath. The seal may act to prevent intrusion of pollutants or other foreign materials over an extended amount of time and can be arranged in such as manner as to improve the durability and tightness of a seal member.

Abstract: A swinging pinion on the side of an upper swing structure is meshed with a ring gear which is provided on and around the inner periphery of an inner ring on the side of a vehicular base carrier. A grease bath is provided on the inner side of the inner ring and under a swing frame. A center joint is located in an opening which is provided in the swing frame at the center of swinging motions of the upper swing structure. The grease bath is formed by bath-forming walls around an central top plateau wall which is connected the center joint on the inner peripheral side. An annular seal member of resilient material is interposed between the top plateau wall of the grease bath and the lower side of the swing frame. The annular seal member is formed in a height which is larger than the width of spacing between the top plateau wall and the swing frame. At one side, the seal member is detachably fixed either on the side of the swing frame or on the side of the top plateau wall section.