PROBLEM TO BE SOLVED: To provide an electric actuator capable of recovering a brake fluid scraped out by piston slide movement, preventing the infiltration of the brake fluid into a ball screw mechanism, and ensuring a desired service life in a structure in which a screw shaft of the ball screw mechanism abuts on a piston of a hydraulic cylinder and directly deforms integrally with the piston.SOLUTION: An electric actuator is configured so that a through-hole 11 and a bag hole 12 are formed for accommodating a screw shaft 10 in a housing 2a, a hydraulic cylinder 21 is fitted and inserted into the through-hole 11, a reservoir groove 24 is formed in a bottom of an inner circumferential surface of the through-hole 11 along an axial direction to range from an opening portion of the through-hole 11 beyond a fitted and inserted portion of the hydraulic cylinder 21 so as to recover a brake fluid, and an oil absorption material 25 formed of a polymeric material having high oil absorption properties is buried in this reservoir groove 24. It is, therefore, possible for the brake fluid scraped out from the hydraulic cylinder 21 to flow along the inner circumferential surface of the through-hole 11 to be recovered in the reservoir groove 24, and thereby prevents the infiltration of the brake fluid into a ball screw mechanism 8.
【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を回収し、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、貫通孔11の開口部から油圧シリンダ21の嵌挿部を越えて、軸方向に沿って当該貫通孔11の内周面の底部にブレーキ液を回収するための溜り溝24が形成され、この溜り溝24に高吸油性の高分子材からなる吸油材25が埋設されているので、油圧シリンダ21から掻き出されたブレーキ液が貫通孔11の内周面に沿って流動して溜り溝24で回収され、ボールねじ機構8への浸入するのを防止できる。【選択図】図1
ELECTRIC ACTUATOR
電動アクチュエータ
2016-01-28
Patent
Electronic Resource
Japanese
ELECTRIC ACTUATOR AND ELECTRIC ACTUATOR MANUFACTURING METHOD
European Patent Office | 2018
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