Patent ID: 11885403
Assignee: HARMONIC DRIVE SYSTEMS INC.
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A lubricant sealing structure that prevents a lubricant from leaking out, from an interior of a device provided with a first member and a second member that rotate relative to one another about a central axis, through a gap portion between the first and second members, the lubricant sealing structure comprising:
a first surface portion of the first member and a second surface portion of the second member, between which the gap portion is formed;
an oil seal that is secured to the first surface portion and that seals the gap portion while slidably being in contact with the second surface portion;
an oil-repellent surface that is formed on at least one of the first surface portion and the second surface portion, and that is positioned at a side of the interior of the device with respect to the oil seal and is apart from the oil seal so as not to come into contact therewith; and
an oil film formation surface formed on at least one of a distal-end surface portion of the oil seal that comes into contact with the second surface portion and a site on the second surface portion with which the distal-end surface portion comes into contact,
the oil-repellent surface being provided with a surface texture in which first fine grooves having a groove width and a groove depth are formed at prescribed intervals so as to achieve an oil-repelling effect with respect to the lubricant,
the oil film formation surface being provided with a surface texture in which second fine grooves having a groove width depth are formed at prescribed intervals so as to achieve an oil film formation effect,
wherein
the gap portion has a first gap portion and a second gap portion, the second gap portion being narrower than the first gap portion;
the second gap portion is located at a side of the interior of the device with respect to the first gap portion in which the oil seal is accommodated;
in at least one of the first and second surface portions, the oil-repellent surface is formed on a surface portion extending from a position located at a site further toward the interior of the device than the second gap portion to the second gap portion and is formed on a surface portion forming the second gap portion; and
wherein
the first fine grooves extend in a circumferential direction centered on the central axis, and
the second fine grooves extend in a direction along the central axis.