PROBLEM TO BE SOLVED: To provide an electric actuator which prevents the intrusion of a brake fluid which is scooped out by the slide movement of a piston into a ball screw mechanism, and is secured in a desired life, in a structure in which a screw shaft of the ball screw mechanism abuts on the piston of a hydraulic cylinder, and is directly displaced integrally with the piston.SOLUTION: In an electric actuator, a penetration hole 11 and a bag hole 12 for accommodating a screw shaft 10 are formed at a housing 2a, a hydraulic cylinder 21 is inserted into the penetration hole 11, a sealing device 26 is arranged between the hydraulic cylinder 21 and a ball screw mechanism 8, the sealing device 26 is composed of a telescopic cover in which the sealing device 26 can be elongated and contracted, a cross section U-shaped fixed part 26a and a flat abutment part 26b which abuts on a drive shaft 7 in a center part are arranged at an outside diameter part, a telescopic part 26c which is thinned in thickness thinner than the other region is arranged between the abutment part 26b and the fixed part 26a, the fixed part 26a is fit into an annular groove 27 which is formed in the penetration hole 11, and the ball screw mechanism 8 is sealed into the hydraulic cylinder 21.SELECTED DRAWING: Figure 5
【課題】ボールねじ機構のねじ軸が油圧シリンダのピストンに当接して直接ピストンと一体的に変位する構造において、ピストンの摺動によって掻き出されたブレーキ液のボールねじ機構への浸入を防止して所望の寿命を確保した電動アクチュエータを提供する。【解決手段】ハウジング2aにねじ軸10を収容するための貫通孔11と袋孔12が形成され、貫通孔11に油圧シリンダ21が嵌挿されると共に、油圧シリンダ21とボールねじ機構8との間に密封装置26が設けられ、密封装置26が伸縮自在なカバーからなり、外径部に断面コの字状の固定部26aと、中心部に駆動軸7に当接する平坦状の当接部26bと、当接部26bと固定部26a間に、他の部位よりも薄肉に形成された伸縮部26cを備え、貫通孔11に形成された環状溝27に固定部26aが嵌合され、ボールねじ機構8が油圧シリンダ21に対して密封されている。【選択図】図5
ELECTRIC ACTUATOR
電動アクチュエータ
2016-02-08
Patent
Electronic Resource
Japanese
ELECTRIC ACTUATOR AND ELECTRIC ACTUATOR MANUFACTURING METHOD
European Patent Office | 2018
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