# US 11,444,505 B2 · Sealing structure of electric-machine-shaft extension end > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,444,505 B2 - Document ID: US11444505B2 - Status: Granted - Kind: B2 - Application number: 15/733,636 - Filed: 2018-11-06 - Published: 2021-02-04 - Granted: 2022-09-13 - Earliest claimed: 2018-03-26 - Assignees: Jing-Jin Electric Technologies Co., Ltd. - Applicants: Jing-Jin Electric Technologies Co., Ltd. - Inventors: Zhengqiang Pei; Ping Yu; Haitao Jin; Pengfei Liu - Web page: https://patentgrep.com/patent/US11444505B2 ## CPC - F16J 15/324: Arrangements for lubrication or cooling of the sealing itself - H02K 5/124: Sealing of shafts - H02K 5/173: using bearings with rolling contact, e.g. ball bearings - Y02A 30/14: Extreme weather resilient electric power supply systems, e.g. strengthening power lines or underground power cables - F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE ## Abstract The present disclosure relates to the field of shaft sealing, and particularly relates to a sealing structure of an electric-machine-shaft extension end. The sealing structure of an electric-machine-shaft extension end includes an electric-machine end cap and an electric-machine-shaft extension end, the electric-machine-shaft extension end is mounted to the electric-machine end cap via a bearing, a double-oil-seal structure is provided between the electric-machine end cap and the electric-machine-shaft extension end, the double-oil-seal structure includes an oil-seal seat that is connected to the electric-machine end cap and an outer-side oil seal and an inner-side oil seal that are provided inside the oil-seal seat, the outer-side oil seal and the inner-side oil seal are provided face to face, and are interference-fitted to the oil-seal seat, and an oil storing chamber and an oil-seal spacer ring contained inside the oil storing chamber are provided between the outer-side oil seal and the inner-side oil seal. ## Claims ### Claim 1 A sealing structure of an electric-machine-shaft extension end, comprising: an electric-machine end cap; and an electric-machine-shaft extension end, and the electric-machine-shaft extension end being mounted to the electric-machine end cap via a bearing, wherein a double-oil-seal structure is provided between the electric-machine end cap and the electric-machine-shaft extension end, the double-oil-seal structure comprises an oil-seal seat that is connected to the electric-machine end cap and an outer-side oil seal and an inner-side oil seal that are provided inside the oil-seal seat, the outer-side oil seal and the inner-side oil seal are provided face to face, and are interference-fitted to the oil-seal seat, and an oil storing chamber and an oil-seal spacer ring contained inside the oil storing chamber are provided between the outer-side oil seal and the inner-side oil seal, wherein the oil-seal seat is detachably connected to the electric-machine end cap, the oil-seal seat is provided with an oil injecting hole for injecting oil into the oil storing chamber and an external oil discharging hole for discharging oil from the oil storing chamber to exterior, and the oil injecting hole and the external oil discharging hole are individually blocked by a plug, and wherein the oil-seal spacer ring is provided with a through hole in a radial direction that corresponds to the oil injecting hole and the external oil discharging hole, and the through hole is used as a channel for injecting oil into the oil storing chamber and discharging oil from the oil storing chamber. ### Claim 2 (depends on 1) The sealing structure of an electric-machine-shaft extension end according to claim 1, wherein the electric-machine end cap and the oil-seal seat are of an integral structure. ### Claim 3 (depends on 1) The sealing structure of an electric-machine-shaft extension end according to claim 1, wherein the oil-seal seat is provided with a breather hole that is in communication with the oil storing chamber, and a water-proof breather valve is provided inside the breather hole. ### Claim 4 (depends on 1) The sealing structure of an electric-machine-shaft extension end according to claim 1, wherein the inner-side oil seal is positioned axially by using a retaining shoulder provided at an inner-side end of the oil-seal seat, and the outer-side oil seal is positioned axially by using a retaining ring that is connected to the oil-seal seat. ### Claim 5 (depends on 1) The sealing structure of an electric-machine-shaft extension end according to claim 1, wherein a mudguard ring located on an outer side of the outer-side oil seal is nested to the electric-machine-shaft extension end. ### Claim 6 (depends on 1) The sealing structure of an electric-machine-shaft extension end according to claim 1, wherein the electric-machine end cap is provided with an internal oil discharging hole for, when the inner-side oil seal fails, introducing an oil inside the oil storing chamber into an inner cavity of an electric machine. ### Claim 7 (depends on 1) The sealing structure of an electric-machine-shaft extension end according to claim 1, wherein lips of the outer-side oil seal and the inner-side oil seal contact closely the electric-machine-shaft extension end.