Transfer for vehicle

Patent metadata

Field	Value
Publication number	US-10145472-B2
Application number	US-201615348518-A
Country	US
Kind code	B2
Filing date	Nov 10, 2016
Priority date	Nov 26, 2015
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

A transfer includes: an input shaft; an output shaft; a high-low switching mechanism; an output member whose output destination is different from output destination of the output shaft; a clutch for transmitting a power to the output member; a first transmitting mechanism for transmitting movement of an internally threaded member to the clutch; and a drum cam having a cam groove. The cam groove includes a first inclined section that causes the high-low switching mechanism to be switched between a high-speed gear stage and a low-speed gear stage, and a second inclined section that causes the first transmitting mechanism to be switched between (i) a separated position in which the first transmitting mechanism is separated from the clutch and (ii) a contact position in which the first transmitting mechanism is in contact with the clutch, while the high-speed gear stage is established in the high-low switching mechanism.

First claim

What is claimed is:

1. A transfer for a vehicle, said transfer comprising:
an input shaft and an output shaft disposed on a common axis and coaxial with each other;
a high-low switching mechanism configured to change a speed of rotation inputted to said input shaft, by selectively establishing a high-speed gear stage and a low-speed gear stage, and to transmit the rotation to said output shaft;
an output member whose output destination is different from output destination of said output shaft;
a clutch configured to adjust a part of a power transmitted to said output shaft, and to transmit the adjusted part of the power to said output member;
an electric motor;
a screw mechanism which is supported by said output shaft, and which includes an externally threaded member and an internally threaded member that are in thread engagement with each other, such that a rotatable threaded member that is one of said externally threaded member and said internally threaded member is rotatable by said electric motor, and such that said internally threaded member is moved along the common axis when said rotatable threaded member is rotated by said electric motor;
a first transmitting mechanism configured to transmit movement of said internally threaded member to said clutch;
a fork shaft disposed on a parallel axis that is parallel to the common axis and axially movable along the parallel axis;
a drum cam which is connected to said rotatable threaded member, and which is rotatable about the common axis, said drum cam having a cam groove provided in an outer circumferential surface thereof;
a second transmitting mechanism including a cam engaging member that is engaged in said cam groove of said drum cam, and configured to cause said fork shaft to be axially moved along the parallel axis through said cam engaging member when said drum cam is rotated about the common axis;
a fork provided in said fork shaft and configured to transmit axial movement of said fork shaft along the parallel axis, to said high-low switching mechanism; and
a locking member which is configured, when said fork shaft is positioned in a high-speed-gear-stage establishing position that causes said high-low switching mechanism to establish the high-speed gear stage, to be removably engaged in a recessed portion provided in said fork shaft for restricting the axial movement of said fork shaft from the high-speed-gear-stage establishing position along the parallel axis,
wherein said cam groove of said drum cam includes:
a first inclined section configured, when said drum cam is rotated about the common axis with said cam engaging member being engaged within said first inclined section, to cause said fork shaft to be moved along the parallel axis whereby said high-low switching mechanism is switched between the high-speed gear stage and the low-speed gear stage by the axial movement of said fork shaft, which is transmitted to said high-low switching mechanism through said fork; and
a second inclined section configured, when said drum cam is rotated about the common axis with said cam engaging member being engaged within said second inclined section, to cause said first transmitting mechanism to be switched between (i) a separated position in which said first transmitting mechanism is separated from said clutch and (ii) a contact position in which said first transmitting mechanism is in contact with said clutch, while the high-speed gear stage is established in said high-low switching mechanism, such that said screw mechanism is moved, by rotation of said electric motor, along said common axis, whereby said first transmitting mechanism is separated from or is brought into contact with said clutch while said folk shaft is in the high-speed-gear-stage establishing position.

2. The transfer according to claim 1 , wherein said locking member is forced toward said fork shaft by a locking spring, such that said locking member is removed from said recessed portion of said fork shaft when said high-low switching mechanism is switched from the high-speed gear stage to the low-speed gear stage by said first inclined section of said cam groove, and such that said locking member is engaged in said recessed portion of said fork shaft when said first transmitting mechanism is switched from the separated position to the contact position by said second inclined section of said cam groove.

3. The transfer according to claim 1 , wherein said output shaft is rotatably held, at one of axially opposite end portions thereof which is located on a side of said drum cam, by an output-shaft supporting bearing which is located radially inside said drum cam within an axial length of said drum cam.

4. The transfer according to claim 1 ,
wherein said drum cam as well as said rotatable threaded member is rotatable by said electric motor,
wherein said first inclined section of said cam groove extends in a direction inclined with respect to a circumferential direction of said drum cam, and
wherein said cam engaging member is moved along the parallel axis by a distance larger than a distance by which said internally threaded member is moved relative to said externally threaded member along the common axis, when said drum cam and said rotatable threaded member are rotated about the common axis by said electric motor, during engagement of said cam engaging member within said first inclined section of said cam groove.

5. The transfer according to claim 1 , wherein said internally threaded member is in thread engagement with said externally threaded member through a plurality of balls.

6. The transfer according to claim 1 , wherein said second transmitting mechanism includes a waiting mechanism that is configured to transmit movement of said cam engaging member along the common axis, to said fork shaft through a spring member.

7. The transfer according to claim 1 ,
wherein said externally threaded member and said internally threaded member of said screw mechanism are movable along the common axis relative to said output shaft that holds said screw mechanism, and
wherein the other of said externally threaded member and said internally threaded member is an unrotatable threaded member that is held by a non-rotating member of said transfer and is unrotatable relative to said non-rotating member.

8. The transfer according to claim 1 ,
wherein said clutch includes a pressing-force receiving portion such that said clutch is placed in slipping state or engaged state when said pressing-force receiving portion receives a pressing force which is based on the movement of said internally threaded member and which is applied through a pressing portion of said first transmitting mechanism,
wherein said cam groove provided in said outer circumferential surface of said drum cam further includes a circumferentially central section which extends in a circumferential direction of said drum cam and which is located between said first inclined section and said second inclined section of said cam groove in said circumferential direction,
wherein said first inclined section of said cam groove extends from one of circumferentially opposite ends of said circumferentially central section, in a direction inclined with respect to said circumferentially central section extending in said circumferential direction, said first inclined section having a circumferentially distal end that is distant from said circumferentially central section by a first distance in an axial direction of said drum cam,
wherein said second inclined section of said cam groove extends from the other of circumferentially opposite ends of said circumferentially central section, in a direction inclined with respect to said circumferentially central section extending in said circumferentia

Assignees

• Toyota Motor Co Ltd

Inventors

• Imafuku Mizuki

Classifications

• B60K17/34

  for driving both front and rear wheels, e.g. four wheel drive vehicles · CPC title

• F16H25/2204

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• B60K2023/0816

  for varying front-rear torque distribution with a central differential · CPC title

• F16H63/18

  the final actuating mechanism comprising cams · CPC title

• F16H2063/3079

  Shift rod assembly, e.g. supporting, assembly or manufacturing of shift rails or rods; Special details thereof · CPC title