Flexspline protective structure and robot arm mechanism using same

{
  "publication_number": "US9109685B2",
  "country": "US",
  "kind": "B2",
  "title": "Flexspline protective structure and robot arm mechanism using same",
  "abstract": "A flexspline protective structure includes a first rotation member, a second rotation member and a plurality of fixing members. The second rotation member is sleeved on the first rotation member. The plurality of fixing members fix the first rotation member and the second rotation member together and are capable of breaking off in the event of jamming or other mischance to enable the second rotation member to rotate freely relative to the first rotation member. The disclosure presents a robot arm mechanism equipped with the flexspline protective structure.",
  "claims": [
    "1. A robot arm mechanism, comprising: a first arm; a second arm; a reducer comprising: a flexspline fixed to the first arm and a rigid gear engaging with the flexspline; and a flexspline protective structure, comprising: a first rotation member fixed to the rigid gear; a second rotation member sleeved on the first rotation member; and at least one fixing member fixedly connecting the first rotation member and the second rotation member together, wherein the at least one fixing member is capable of breaking off to enable the second rotation member to rotate relative to the first rotation member freely when the second rotation member suffers an undue amount of torsion or an unexpected collision.",
    "2. The robot arm mechanism of claim 1, wherein the flexspline protective structure further comprises a plurality of rolling members rotatably received between the first rotation member and the second rotation member.",
    "3. The robot arm mechanism of claim 2, wherein the first rotation member and the second rotation member are both annular, the first rotation member defines a first groove around the peripheral surface thereof, the second rotation member defines a second groove around the inner surface thereof, and the plurality of rolling members are contained between the first groove and the second groove.",
    "4. The robot arm mechanism of claim 1, wherein the first rotation member and the second rotation member are both annular, the first rotation member comprises a first fixing portion axially formed on an end thereof, the second rotation member comprises a second fixing portion axially formed on an end thereof, the second fixing portion is sleeved on the first fixing portion, and the at least one fixing member fixedly mounted the first rotation member and the second rotation member.",
    "5. The robot arm mechanism of claim 4, wherein the first fixing portion defines a plurality of first fixing holes uniformly arranged along the periphery thereof, the second fixing portion defines a plurality of second fixing holes along the periphery thereof uniformly, the plurality of first fixing holes communicate with the plurality of the second fixing holes respectively; the at least one fixing member comprises a plurality of fixing members, the plurality of fixing members extend through the plurality of first fixing holes and the second fixing holes respectively.",
    "6. The robot arm mechanism of claim 4, wherein the reducer further comprises a bearing, the flexspline comprises a containing portion and a flange formed on an end of the containing portion, the containing portion comprises a plurality of first teeth separately formed around the outer periphery wall thereof, the rigid gear comprises a periphery inner wall and a plurality of second teeth separately formed around the inner wall, the rigid gear is sleeved on the containing portion via the inner wall, the second teeth engages with the first teeth, the bearing is sleeved on the containing portion between the flange and the rigid gear, the outer ring of the bearing is fixed to the flange, and the inner ring of the bearing is fixed to the rigid gear.",
    "7. The robot arm mechanism of claim 6, wherein a recess is recessed from an end of the first rotation member, the first fixing portion surrounds the recess, and the first rotation member is partially sleeved on the rigid gear.",
    "8. The robot arm mechanism of claim 1, the reducer further comprises a driver partially received in and fixedly connected to the flexspline, the first rotation member is rotatably sleeved on the driver.",
    "9. The robot arm mechanism of claim 8, wherein the driver is a wave generator, the at least one fixing member is made of ceramic materials."
  ],
  "description_excerpt": "1. Technical Field\n\nThe present disclosure relates to a flexspline protective structure and a robot arm mechanism use the flexspline protective structure.\n\n2. Description of Related Art\n\nA robot arm mechanism may include a first mechanical arm, a second mechanical arm, a reducer and a transmission assembly. The reducer is connected to the transmission assembly, and both of the reducer and the transmission assembly are received in the first mechanical arm and the second mechanical arm. The first mechanical arm is rotatably connected to the second mechanical arm via the reducer and the transmission assembly. A flexspline of the reducer is vulnerable to become damaged when the second mechanical arm is subjected to an unexpected collision or an undue amount of torsion. A flexspline protective structure is needed to protect the flexspline of the reducer. A flexspline protective structure of related art includes an electric motor, a transmission shaft controlled by the electric motor, and a connecting member. When the robot arm mechanism is subjected to an external force, the flexspline protective structure drives the transmission assembly away from the reducer, thereby preventing damage to the flexspline. However, such a flexspline protective structure has a complicated structure, and low rigidity.\n\nTherefore, there is room for improvement in the art.\n\nThe components in the drawings are not necessarily drawn to scale, the emphasis instead placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.",
  "cpc": [
    "F16H 49/001",
    "B25J 19/065",
    "B25J 9/1025",
    "F16B 2200/63",
    "F16D 9/06",
    "F16H 35/10",
    "Y10T 403/11",
    "Y10T 74/20329"
  ],
  "ipc": [
    "B25J 17/00",
    "B25J 19/06",
    "B25J 9/10",
    "F16D 9/06",
    "F16H 35/10",
    "F16H 49/00"
  ],
  "assignees": [
    "Hongfujin Precision Industry Shenzhen Co Ltd",
    "Hon Hai Precision Industry Co Ltd"
  ],
  "inventors": [
    "Xiao-Ming Xu",
    "Chia-Peng Day",
    "Zhen-Xing Liu"
  ],
  "filing_date": "2012-04-02",
  "publication_date": "2015-08-18",
  "grant_date": "2015-08-18",
  "priority_date": "2011-09-16",
  "application_number": "US-201213437129-A",
  "family_id": "47879377",
  "cited_by_count": 0,
  "citations": [
    "US4347715A",
    "WO1985000315A1",
    "CN200992719Y",
    "EP2085631A1",
    "US20090253521A1",
    "US8191439B2",
    "TW201109139A",
    "CN201560447U",
    "CN102085667A"
  ]
}