Motive force transmission device and production method therefor

Patent metadata

Field	Value
Publication number	US-10220702-B2
Application number	US-201515119219-A
Country	US
Kind code	B2
Filing date	Jan 14, 2015
Priority date	Mar 27, 2014
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

Abstract

A power transfer unit for transferring power from a front wheel side to a rear wheel side comprises: a hollow transfer input shaft which is coupled to an engine and through which a right-side front-wheel axle is penetrated; a transfer output shaft disposed to extend in a direction orthogonal to the transfer input shaft; a transfer drive gear provided on an outer periphery of the transfer input shaft; and a transfer driven gear provided on an outer periphery of the transfer output shaft and meshed with the transfer drive gear. It further comprises a damper mechanism configured to absorb a fluctuation in torque input from an engine side into the transfer input shaft. The damper mechanism is disposed such that an intermediate portion and a left end-side portion thereof overlap the transfer driven gear in an extension direction of the transfer output shaft, in top plan view.

First claim

The invention claimed is:

1. A power transfer unit for transferring power from a front wheel side to a rear wheel side of a vehicle, or from the rear wheel side to the front wheel side of the vehicle, comprising:
a transfer input shaft coupled to a power source;
a transfer output shaft disposed to extend in a direction orthogonal to the transfer input shaft;
a transfer drive gear provided on an outer periphery of the transfer input shaft;
a transfer driven gear provided on an outer periphery of the transfer output shaft and meshed with the transfer drive gear; and
a damper mechanism configured to absorb a fluctuation in torque input from a power source side into the transfer input shaft, wherein
the damper mechanism is disposed such that at least a part thereof overlaps the transfer driven gear in a front-rear direction of the vehicle,
the damper mechanism is provided in a space between an outer periphery of an axle penetrated through the transfer input shaft and an inner periphery of the transfer input shaft.

2. The power transfer unit as recited in claim 1 , wherein
the transfer input shaft comprises:
a first shaft member configured to receive an input of torque from the power source side; and
a second shaft member disposed to extend axially from one end of the first shaft member and coupled to the first shaft member in a circumferentially relatively rotatable manner, and wherein

the transfer drive gear is provided on an outer periphery of the second shaft member, and
the damper mechanism comprises:
an inner tube disposed to extend axially from the one end of the first shaft member at a position radially inside the second shaft member and integrally coupled to the first shaft member;
an outer tube coupled to an inner peripheral surface of the second shaft member integrally with the second shaft member; and
an elastic member interposed between the inner tube and the outer tube.

3. The power transfer unit as recited in claim 2 , wherein a coupling region between the first shaft member and the second shaft member is provided with a restriction section configured to restrict an occurrence of a situation where the first and second shaft members are relatively rotated beyond a given reference angle.

4. The power transfer unit as recited in claim 3 , wherein the first shaft member and the second shaft member are coupled together in the coupling region by spline engagement, and configured such that a given reference amount of gap is defined between corresponding ones of spline teeth of the first shaft member and spline teeth of the second shaft member, in a rotation direction thereof, and, when the first shaft member and the second shaft member are relatively rotated by the reference angle, the corresponding spline teeth of the first and second shaft members come into contact with each other to thereby form the restriction section.

5. The power transfer unit as recited in claim 4 , wherein
the outer tube has a first fitting portion provided in an outer peripheral surface thereof, and
the second shaft member has a second fitting portion provided in the inner peripheral surface thereof, and wherein
the first and second fitting portions are mutually fitted to thereby integrally couple the outer tube and the second shaft member together, in such a manner as to allow the restriction section to be provided in the coupling region between the first and second shaft members, when the first shaft member is integrally coupled to the inner tube of the damper mechanism including the outer tube.

6. A method for producing the power transfer unit as recited in claim 5 , comprising:
a first coupling step of mutually fitting the first and second fitting portions to thereby integrally couple the outer tube and the second shaft member together; and
a second coupling step of, after the first coupling step, integrally coupling the first shaft member and the inner tube of the damper mechanism including the outer tube, in such a manner as to provide the restriction section in the coupling region between the first and second shaft members.

7. The power transfer unit as recited in claim 3 , wherein
the outer tube has a first fitting portion provided in an outer peripheral surface thereof, and
the second shaft member has a second fitting portion provided in the inner peripheral surface thereof, and wherein
the first and second fitting portions are mutually fitted to thereby integrally couple the outer tube and the second shaft member together, in such a manner as to allow the restriction section to be provided in the coupling region between the first and second shaft members, when the first shaft member is integrally coupled to the inner tube of the damper mechanism including the outer tube.

8. A method for producing the power transfer unit as recited in claim 7 , comprising:
a first coupling step of mutually fitting the first and second fitting portions to thereby integrally couple the outer tube and the second shaft member together; and
a second coupling step of, after the first coupling step, integrally coupling the first shaft member and the inner tube of the damper mechanism including the outer tube, in such a manner as to provide the restriction section in the coupling region between the first and second shaft members.

9. A power transfer unit for transferring power from a front wheel side to a rear wheel side of a vehicle, or from the rear wheel side to the front wheel side of the vehicle, comprising:
a transfer input shaft coupled to a power source;
a transfer output shaft disposed to extend in a direction orthogonal to the transfer input shaft;
a transfer drive gear provided on an outer periphery of the transfer input shaft;
a transfer driven gear provided on an outer periphery of the transfer output shaft and meshed with the transfer drive gear; and
a damper mechanism configured to absorb a fluctuation in torque input from a power source side into the transfer input shaft, wherein
the damper mechanism is disposed such that at least a part thereof overlaps the transfer driven gear in a front-rear direction of the vehicle, and is provided on the outer periphery of the transfer input shaft,
a differential gear unit is disposed to one side of the damper mechanism in the axial direction of the transfer input shaft, and the transfer drive gear is disposed to the other side of the damper mechanism, and
the transfer drive gear is disposed to be meshed with the transfer driven gear at a position offset toward the other side of the damper mechanism with respect to a central axis of the transfer output shaft.

10. The power transfer unit as recited in claim 9 , wherein the damper mechanism is disposed such that an outwardmost periphery thereof is located radially inwardly with respect to an inwardmost periphery of the transfer drive gear.

11. The power transfer unit as recited in claim 10 , wherein
the damper mechanism comprises:
an inner tube coupled to an outer peripheral surface of the transfer input shaft integrally with the transfer input shaft;
an outer tube coupled to an inner peripheral surface of the transfer drive gear integrally with the transfer drive gear; and
an elastic member interposed between the inner tube and the outer tube, and wherein

the transfer input shaft has a first engagement portion provided in the outer peripheral surface thereof,
the transfer drive gear has a second engagement portion provided in the inner peripheral surface thereof, and
the first and second engagement portions are mutually coupled in a circumferentially relatively rotatable manner to provide a restriction section configured to restrict an occurrence of a situation where the first

Assignees

• Mazda Motor

Inventors

• Ohkawa Yuzo
• Mito Eiji
• Hidaka Seiji

Classifications

• F16D3/12

  specially adapted for accumulation of energy to absorb shocks or vibration (by making use of fluid elements F16D3/80) · CPC title

• B60Y2400/48

  Vibration dampers, e.g. dual mass flywheels · CPC title

• F16D3/50

  with the coupling parts connected by one or more intermediate members (F16D3/16 takes precedence) · CPC title

• B60K17/344 Primary

  having a transfer gear · CPC title

• F16F15/126

  consisting of at least one annular element surrounding the axis of rotation · CPC title