{
  "$type": "site.standard.document",
  "description": "Provided is a power transmission shaft to achieve enhancement of a static torsional strength of a smooth portion. The power transmission shaft according to the present invention includes a torque-transmission teeth portion (2) formed on an outer peripheral surface on an end portion side, and a…",
  "path": "/patents/1012512",
  "publishedAt": "2011-06-01T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B60K17/22",
    "NTN TOYO BEARING CO LTD [JP]"
  ],
  "textContent": "Provided is a power transmission shaft to achieve enhancement of a static torsional strength of a smooth portion. The power transmission shaft according to the present invention includes a torque-transmission teeth portion (2) formed on an outer peripheral surface on an end portion side, and a smooth portion (3) formed on the outer peripheral surface adjacent to the torque-transmission teeth portion (2) so as to have a stepwise reduced diameter. A ratio of a minimum diameter (D3min) of the smooth portion (3) to a minimum diameter (D2min) of the torque-transmission teeth portion (2) is set to 0.9 or more and 1.02 or less. Further, the torque-transmission teeth portion (2) and the smooth portion (3) undergo heat treatment so as to from a heat-treated hardened layer (4) . The heat-treated hardened layer (4) is formed to increase in depth from a side of the torque transmission teeth portion (2) to a side of the smooth portion (3) . At least a minimum diameter portion (3a) of the smooth portion (3) undergoes full hardening for forming the heat-treated hardened layer (4) from a surface to an axis (X) .",
  "title": "POWER TRANSMISSION SHAFT, DRIVE SHAFT, AND PROPELLER SHAFT"
}