Drive force transmission apparatus

{
  "publication_number": "US9334926B2",
  "country": "US",
  "kind": "B2",
  "title": "Drive force transmission apparatus",
  "abstract": "In a drive force transmission apparatus, when an input shaft is rotated in a normal rotational direction, a rotational force of the input shaft is transmitted to an output shaft through a one-way clutch to rotate the output shaft at a rotational speed, which is the same as a rotational speed of the input shaft. At this time, an input side sub-shaft is freed from an output side sub-shaft. In contrast, when the input shaft is rotated in a reverse rotational direction, the rotational force of the input shaft is transmitted to the output shaft through an input gear, a first gear, the input side sub-shaft, a two-way clutch, the output side sub-shaft, a second gear and an output gear. At this time, the output shaft is freed from an intermediate shaft.",
  "claims": [
    "1. A drive force transmission apparatus comprising: an input shaft that is rotatable in each of a normal rotational direction and a reverse rotational direction, which are opposite to each other; an output shaft that is rotatable by a rotational force transmitted from the input shaft, wherein the output shaft is rotated in the normal rotational direction at a rotational speed, which is the same as a rotational speed of the input shaft when the input shaft is rotated in the normal rotational direction, and the output shaft is rotated in the reverse rotational direction at a decreased rotational speed, which is decreased from a rotational speed of the input shaft, when the input shaft is rotated in the reverse rotational direction; an input transmitting member that is fixed to the input shaft and is rotatable integrally with the input shaft; an input side sub-shaft that has an axis, which is different from an axis of the input shaft; a first transmitting member that is fixed to the input side sub-shaft and is rotatable integrally with the input side sub-shaft when rotation is transmitted from the input transmitting member to the first transmitting member; an output side sub-shaft that has an axis, which is different from an axis of the output shaft; a second transmitting member that is fixed to the output side sub-shaft and is rotatable integrally with the output side sub-shaft; an output transmitting member that is fixed to the output shaft and is rotatable integrally with the output shaft when rotation is transmitted from the second transmitting member to the output transmitting member; a one-way rotational force transmitting member that is placed between the input shaft and the output shaft, wherein the one-way rotational force transmitting member transmits a rotational force from the input shaft to the output shaft when the input shaft is rotated in the normal rotational direction, and the one-way rotational force transmitting member frees the output shaft to enable rotation of the input shaft relative to the output shaft when the input shaft is rotated in the reverse rotational direction; and a two-way rotational force transmitting member that is placed between the input side sub-shaft and the output side sub-shaft, wherein the two-way rotational force transmitting member transmits a rotational force from the input side sub-shaft to the output side sub-shaft, and the two-way rotational force transmitting member frees the input side sub-shaft to enable rotation of the output side sub-shaft relative to the input side sub-shaft upon application of a rotational force from the output side sub-shaft, wherein: the rotational force of the input shaft is transmitted to the output shaft through the one-way rotational force transmitting member when the input shaft is rotated in the normal rotational direction; and the rotational force of the input shaft is transmitted to the output shaft through the input transmitting member, the first transmitting member, the input side sub-shaft, the two-way rotational force transmitting member, the output side sub-shaft, the second transmitting member and the output transmitting member when the input shaft is rotated in the reverse rotational direction.",
    "2. The drive force transmission apparatus according to claim 1, further comprising an idler coupler member that couples between the input shaft and the output shaft in a manner that enables relative rotation between the input shaft and the output shaft through a predetermined angular range.",
    "3. The drive force transmission apparatus according to claim 2, wherein: the idler coupler member is a coupling, which includes: an input rotor fixed to the input shaft; an intermediate rotor fixed to an intermediate shaft that is placed between the input shaft and the output shaft; a projection, which is provided in one of the input rotor and the intermediate rotor; and a stopper, which is provided in the other one of the input rotor and the intermediate rotor, and to which the projection is contactable; relative rotation between the input rotor and the intermediate rotor is enabled within a predetermined play angle until the projection contacts the stopper; when the projection contacts the stopper, a rotational force of the input shaft is transmittable to the intermediate shaft; the one-way rotational force transmitting member is placed between the intermediate shaft and the output shaft; the one-way rotational force transmitting member transmits a rotational force from the intermediate shaft to the output shaft when the intermediate shaft is rotated in the normal rotational direction; and the one-way rotational force transmitting member frees the output shaft to enable rotation of the intermediate shaft relative to the output shaft when the intermediate shaft is rotated in the reverse rotational direction.",
    "4. The drive force transmission apparatus according to claim 3, wherein: the predetermined play angle of the coupling is set to satisfy a relationship of: θ≧ Z×λ 2−λ1 where: θ denotes the predetermined play angle: λ1 denotes a switching angle that is required to change an operational state of the one-way rotational force transmitting member from a freed state, in which the one-way rotational force transmitting member frees the output shaft upon rotation of the input shaft in the reverse rotational direction, to a drive force transmitting state, in which the one-way rotational force transmitting member transmits the rotational force from the input shaft to the output shaft upon rotation of the input shaft in the normal rotational direction; λ2 denotes a switching angle that is required to change an operational state of the two-way rotational force transmitting member from a drive force transmitting state, in which the two-way rotational force transmitting member transmits the rotational force from the input side sub-shaft to the output-side sub-shaft, to a freed state, in which the two-way rotational force transmitting member frees the input side sub-shaft upon the application of the rotational force from the output side sub-shaft; and Z denotes an input side speed change ratio, which is a ratio of the number of rotations of the input shaft per unit time over the number of rotations of the input side sub-shaft per unit time.",
    "5. The drive force transmission apparatus according to claim 4, wherein the coupling includes urging means for urging the input rotor against the intermediate rotor in the reverse rotational direction to return the projection to a location, at which the predetermined play angle is provided between the projection and the stopper when rotation of the input shaft in the normal rotational direction is stopped or is changed to the rotation in the reverse rotational direction."
  ],
  "description_excerpt": "The present invention relates to a drive force transmission apparatus.\n\nA drive force transmission apparatus drives a subject mechanism, which is connected to an output shaft of the drive force transmitting apparatus, by transmitting rotation of an input shaft, which is driven with a drive force of, for example, an electric motor, to the output shaft at a rotational speed that is the same, decreased or increased relative to a rotational speed of the input shaft. In a typical drive force transmission apparatus, an input-to-output speed ratio (also referred to as a speed change ratio), which is a ratio between a rotational speed of the input shaft and a rotational speed of the output shaft, and an output characteristic of a transmitted torque, which is transmitted from the input shaft to the output shaft, are constant regardless of the rotational direction of the input shaft. However, in some cases, it is required to provide different output characteristics between the normal rotation and the reverse rotation or between forward movement and backward movement of an actuator, which serves as the subject mechanism.\n\nFor example, a loading and unloading lift requires the low speed and high torque at the time of lifting up and requires the high speed without requiring a torque at the time of lifting down. A winch requires the low speed and high torque at the time of winding up (pulling in) and requires the high speed without requiring a torque at the time of winding out (letting out).",
  "cpc": [
    "F16H 1/20",
    "F02D 15/02",
    "F16H 3/003",
    "Y10T 74/19614"
  ],
  "ipc": [
    "F16H 1/20",
    "F02D 15/02",
    "F16H 3/00",
    "F16H 57/00"
  ],
  "assignees": [
    "Denso Corp"
  ],
  "inventors": [
    "Yuuya Takahashi",
    "Yasuyoshi Suzuki",
    "Hiroki Ozaki",
    "Masaru Irie",
    "Yoshiyasu Inoue",
    "Takashi Kawasaki"
  ],
  "filing_date": "2012-01-16",
  "publication_date": "2016-05-10",
  "grant_date": "2016-05-10",
  "priority_date": "2011-03-22",
  "application_number": "US-201214005366-A",
  "family_id": "45563476",
  "cited_by_count": 4,
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}