Linear electromechanical actuator

{
  "publication_number": "US9520756B2",
  "country": "US",
  "kind": "B2",
  "title": "Linear electromechanical actuator",
  "abstract": "The present invention relates to an electromechanical actuator comprising a housing, an electric motor, a roller drive and a rotor rotation angle sensing unit received in said housing. The rotor of the electromechanical actuator is mounted within the housing and configured to rotate in bearing supports. Openings for supplying and removing lubricant are arranged in the housing in the vicinity of the bearing supports, the opening allowing to replace lubricant without disassembling the actuator, thus simplifying maintenance and operation.",
  "claims": [
    "1. A linear electromechanical actuator comprising: a housing, an electric motor comprising a stator fixed to an inner surface of the housing, and a rotor, the rotor being rotatably mounted within the housing on at least one bearing support; a roller drive comprising an internally threaded cylinder having an inner space, an output shaft comprising a threaded portion and slidably mounted within said cylinder, and threaded rollers mounted within said cylinder to engage between the inner thread of the cylinder and the threaded portion of the output shaft, wherein the rotor of the electric motor is formed by fixing magnets to the outer surface of the roller drive cylinder, and wherein the housing is provided with at least one closeable opening for supplying lubricant into the internal space of said internally threaded cylinder and to said at least one bearing support, and at least one closeable opening for draining the lubricant from said at least one bearing support and from the internal space of said internally threaded cylinder, and threaded sealing plugs configured to be mounted in said closeable openings in order to close them.",
    "2. A linear electromechanical actuator comprising: a housing, an electric motor comprising a stator fixed to an inner surface of the housing, and a rotor, the rotor being rotatably mounted within the housing on first bearing support and second bearing support; a roller drive comprising an internally threaded cylinder having an inner space, an output shaft comprising a threaded portion and slidably mounted within said cylinder, and threaded rollers mounted within said cylinder to engage between the inner thread of the cylinder and the threaded portion of the output shaft, wherein the rotor of the electric motor is formed by fixing magnets to the outer surface of the roller drive cylinder, wherein the actuator housing is provided with a closeable opening for supplying lubricant into the internal space of said threaded cylinder, a closable opening for supplying lubricant to said second bearing support, and a closeable opening for draining the lubricant from said second bearing supports and from the internal space of said threaded cylinder, wherein said first bearing support comprises a sealed radial bearing, wherein an enclosure of the housing receiving the electric motor is sealed by a lip seal mounted on the internally threaded cylinder and by a sealing ring mounted on the sealed radial bearing, and the actuator further comprising a rotor rotation angle sensing unit mounted within the housing and comprising a shaft of the sensing unit, the shaft being hollow cylindrical shaft and having at least one through radial channel, wherein the at least one through radial channel is adapted to communicate with the closeable opening for supplying lubricant into the internal space of said threaded cylinder and to said first bearing support.",
    "3. The actuator according to claim 2, wherein said second bearing support comprises two adjacent radial-thrust bearings.",
    "4. The actuator according to claim 2, wherein the rotor of the electric motor is formed by the internally threaded cylinder fixedly connected to the shaft of the sensing unit so that the inner space of the shaft communicates with the inner space of the threaded cylinder.",
    "5. The actuator according to claim 4, wherein the first bearing support of the rotor is mounted on the shaft of the sensing unit, while the second bearing support of the rotor is mounted on the internally threaded cylinder.",
    "6. The actuator according to claim 2, further comprising a lip seal mounted on the shaft of the sensing unit to seal an enclosure of the housing receiving the sensing unit.",
    "7. The actuator according to claim 2, wherein said closeable openings are provided with thread.",
    "8. The actuator according to claim 2, further comprising threaded sealing plugs configured to be mounted in said closeable openings in order to close them."
  ],
  "description_excerpt": "The present invention relates to linear actuators, in particular to a linear electromechanical actuator comprising a roller drive.\n\nLinear electromechanical actuators comprising a roller drive are known to utilize for controlling various machines and mechanisms. U.S. Pat. No. 5,491,372 (Erhart) discloses a bidirectional electrically powered linear actuator comprising a housing assembly, an electric motor and a roller drive, wherein said electric motor and said roller drive are received within the housing to engage with each other. The roller drive comprises a threaded cylinder, threaded rollers and an output shaft. The electric motor comprises a stator and a rotor, wherein the rotor of the electric motor comprises said threaded cylinder of the roller drive. The electric motor involves bidirectional linear movement of the output shaft. The working surfaces of the known actuator are lubricated by applying a lubricant to said surfaces during actuator assembly. In order to replace spent lubricant with fresh lubricant, the actuator need to be disassembled and the output shaft with threaded rollers need to be removed from the housing, which requires dismantling the actuator and leads to a lengthy downtime.\n\nIt is a general object of the present invention to simplify the process of replacing lubricant in a linear electromechanical actuator, to reduce downtime of such actuator and to simplify usage thereof.",
  "cpc": [
    "H02K 7/06",
    "F16H 2025/204",
    "F16H 2025/2075",
    "F16H 2025/2078",
    "F16H 25/2015",
    "F16H 25/2252",
    "F16H 57/0408",
    "F16H 57/0497",
    "H02K 11/21",
    "H02K 15/50",
    "H02K 33/16",
    "H02K 7/083"
  ],
  "ipc": [
    "H02K 11/00",
    "H02K 5/20",
    "H02K 7/06",
    "H02K 33/16",
    "H02K 7/08"
  ],
  "assignees": [
    "Joint Stock Co Diakont"
  ],
  "inventors": [
    "Mikhail Evgenievich Fedosovsky",
    "Vadim Igorevich Dunaev",
    "Evgeny Valerievich Mysov"
  ],
  "filing_date": "2015-05-28",
  "publication_date": "2016-12-13",
  "grant_date": "2016-12-13",
  "priority_date": "2015-05-08",
  "application_number": "US-201514724144-A",
  "family_id": "54288509",
  "cited_by_count": 12,
  "citations": [
    "US3021730A",
    "USRE32222E",
    "US5491372A",
    "US6084326A",
    "US20050155444A1",
    "WO2005096472A1",
    "US20060101929A1",
    "US20100084230A1",
    "US20080297010A1",
    "DE102009009395A1",
    "US20130112104A1",
    "US8601952B2",
    "EP2685609A1",
    "DE102012105709A1",
    "US20150263587A1"
  ]
}