U.S. patent application number 17/017918 was filed with the patent office on 2020-12-31 for hybrid vehicle.
The applicant listed for this patent is KANZAKI KOKYUKOKI MFG. CO., LTD.. Invention is credited to Fumiaki ITO, Yoshitaka KOCHIDOMARI, Hiroshi SUGIMOTO, Hongkun WANG.
Application Number | 20200408293 17/017918 |
Document ID | / |
Family ID | 1000005080046 |
Filed Date | 2020-12-31 |
United States Patent
Application |
20200408293 |
Kind Code |
A1 |
SUGIMOTO; Hiroshi ; et
al. |
December 31, 2020 |
HYBRID VEHICLE
Abstract
A hybrid vehicle may include an engine, a drive wheel, a CVT for
driving the drive wheel by continuously changing an engine power,
an electric motor for driving the drive wheel, and a transaxle
mechanically linked to the drive wheel. The transaxle may include
an input shaft having first and second ends axially opposite each
other and a clutch interposed between the motor and the input
shaft. The first end of the input shaft is structured to receive
power from the CVT and the second end of the input shaft is
structured to receive power from the electric motor, The clutch,
the second end of the input shaft and a motor shaft serving as a
rotary axis of the motor are coaxially disposed.
Inventors: |
SUGIMOTO; Hiroshi;
(Amagasaki-shi, JP) ; KOCHIDOMARI; Yoshitaka;
(Amagasaki-shi, JP) ; WANG; Hongkun;
(Amagasaki-shi, JP) ; ITO; Fumiaki;
(Amagasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KANZAKI KOKYUKOKI MFG. CO., LTD. |
Amagasaki-shi |
|
JP |
|
|
Family ID: |
1000005080046 |
Appl. No.: |
17/017918 |
Filed: |
September 11, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15341452 |
Nov 2, 2016 |
10808813 |
|
|
17017918 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60K 2006/4833 20130101;
B60Y 2400/82 20130101; B60K 6/543 20130101; B60Y 2200/92 20130101;
B60K 2006/4816 20130101; B60K 6/48 20130101; B60W 2710/021
20130101; Y10S 903/909 20130101; B60K 6/36 20130101; B60K 6/387
20130101; B60K 6/405 20130101; Y10S 903/93 20130101; Y10S 903/916
20130101; F16H 37/021 20130101; B60K 2006/4808 20130101; B60K
2006/4825 20130101; B60K 6/40 20130101; B60W 10/06 20130101; B60Y
2300/42 20130101; F16H 2037/026 20130101; B60W 10/08 20130101; Y02T
10/62 20130101; B60K 6/52 20130101; B60Y 2300/43 20130101; B60W
10/02 20130101; Y10S 903/946 20130101 |
International
Class: |
F16H 37/02 20060101
F16H037/02; B60K 6/36 20060101 B60K006/36; B60K 6/48 20060101
B60K006/48; B60K 6/52 20060101 B60K006/52; B60K 6/40 20060101
B60K006/40; B60K 6/405 20060101 B60K006/405; B60K 6/543 20060101
B60K006/543; B60K 6/387 20060101 B60K006/387 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 4, 2015 |
JP |
2015-217151 |
Claims
1. A hybrid vehicle, comprising: an engine; a drive wheel; a CVT
for driving the drive wheel by continuously changing an engine
power; an electric motor for driving the drive wheel; and a
transaxle mechanically linked to the drive wheel; wherein the
transaxle comprises, an input shaft having first and second ends
axially opposite each other, the first end of the input shaft being
structured to receive power from the CVT and the second end of the
input shaft being structured to receive power from the electric
motor; and a clutch interposed between the motor and the input
shaft; wherein the clutch, the second end of the input shaft and a
motor shaft serving as a rotary axis of the motor are coaxially
disposed.
2. The hybrid vehicle according to claim 1, wherein the transaxle
comprises the electric motor, the clutch and the motor shaft being
assembled as a motor-and-clutch assembly, and a housing
incorporating the entire motor-and-clutch assembly.
3. The hybrid vehicle according to claim 1, further comprising, a
controller and a drive mode selection device; wherein when a motor
assist mode is selected by the drive mode selection device, the
controller operates the electric motor and engages the clutch.
4. The hybrid vehicle according to claim 3, wherein when a
regeneration mode is selected by the drive mode selection device,
the controller does not operate the electric motor and engages the
clutch.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation application based
on U.S. patent application Ser. No. 15/341,452 filed on Nov. 2,
2016, and the present application claims priority under Paris
Convention based on Japanese Patent Application No. 2015-217151,
filed on Nov. 4, 2015, the contents of both of which are hereby
incorporated by reference.
BACKGROUND
Field of the Invention
[0002] At least one embodiment of the present invention relates to
a hybrid vehicle.
[0003] There is a well-known conventional utility vehicle
(hereinafter referred to as "UTV") equipped with an engine, a rear
transaxle carrying rear drive wheels and incorporating a gear
transmission, and a continuously variable belt transmission
(hereinafter, referred to as "CVT") interposed between an engine
output shaft of the engine and an input shaft of the rear
transaxle. The UTV includes a front transaxle carrying front drive
wheels, and the rear transaxle includes a power take-off
(hereinafter, referred to as "PTO") shaft for transmitting power
outputted from the CVT to the front transaxle.
[0004] The UTV must have a high axle-driving torque to ensure a
good run-through performance on wildernesses, uneven grounds, muddy
places, and so on. On the contrary, it is desired to save fuel
consumption for driving the engine. Further, if the UTV is used for
hunting, the UTV is required to go slow and silent to approach a
quarry. However, a rotary speed of the engine must increase to some
degree to realize a low speed stage of the CVT, so that it is hard
for the UTV to be silent during its slow traveling.
[0005] Therefore, as disclosed by JP 2014-133489 A (hereinafter,
referred to as "D1"), some kinds of UTVs have been developed as
hybrid UTV, each of which has a motor that outputs a motor power
for assisting an engine power from the engine.
[0006] However, in the hybrid UTV of D1, the motor is assembled
with the CVT. Similarly, each of hybrid vehicle transmission
systems disclosed by JP 2014-083869 A (hereinafter referred to as
"D2") and JP 2015-000679 A (hereinafter referred to as "D3")
includes a CVT assembled with a motor.
[0007] Each of the CVTs disclosed by D1, D2 and D3 includes an
input pulley provided on a motor output shaft of the motor. An
engine output shaft is disposed coaxially to the motor output
shaft, and is provided thereon with a centrifugal clutch or a one
way clutch through which an engine power is transmitted to the
input pulley. Therefore, the CVT, especially, the input pulley and
its surroundings, must be complicated and expanded. Such a
complicated and expanded CVT with a motor causes a laborious work
of installing the CVT with the motor in association with an engine,
strictly limits a position of the CVT and the motor in the vehicle,
and increases costs for manufacturing the hybrid vehicle.
SUMMARY
[0008] In at least a first embodiment of the invention, a transaxle
for a hybrid vehicle comprises a motor, an input shaft, first and
second output shafts, and first and second clutches. The motor is
configured to output a motor power. The input shaft has first and
second ends axially opposite each other. The first end of the input
shaft is structured to receive an engine power from an engine of
the hybrid vehicle. The second end of the input shaft is structured
to receive the motor power from the motor. The first output shaft
is driven by power outputted from the input shaft so as to drive a
first drive wheel of the hybrid vehicle. The second output shaft is
driven by the motor power from the motor so as to drive a second
drive wheel of the hybrid vehicle. The second output shaft is
extended coaxially to the input shaft. The first clutch is
interposed between the motor and the input shaft. The second clutch
is interposed between the motor and the second output shaft. The
first clutch and the second clutch are coaxially disposed between
the second end of the input shaft and an axial end of the second
output shaft.
[0009] Therefore, even if the hybrid vehicle includes a
transmission, such as a CVT, interposed between the engine and the
input shaft of the transaxle, the transmission can be simplified
and minimized because the transaxle includes the motor.
[0010] In a first aspect of the transaxle, the motor comprises a
motor shaft serving as a rotary axis of the motor. The motor shaft
is axially offset from the input shaft and the second output shaft.
The transaxle further comprises a drive train interposed between
the motor shaft and the first and second clutches. The drive train
comprises a power distribution member disposed between the first
and second clutches. The first clutch is interposed between the
second end of the input shaft and the power distribution member.
The second clutch is interposed between the power distribution
member of the second output shaft.
[0011] Therefore, due to the axial offset of the motor from the
first and second clutches, the whole length of the transaxle in the
axial direction of the input shaft and the second output shaft can
be reduced, thereby minimizing the hybrid vehicle in this
direction, or expanding a free space in the hybrid vehicle sideward
from the transaxle in this direction. Further, due to the power
distribution member that distributes the motor power between the
first and second clutches, the transaxle needs no additional drive
train to drivingly connect the motor shaft to both the first and
second clutches, thereby reducing the number of component parts and
costs.
[0012] Alternatively, in a second aspect of the transaxle, the
motor comprises a motor shaft serving as a rotary axis of the
motor. The motor shaft comprises axially opposite end portions
serving as first and second motor output end portions for
outputting the motor power. The motor is disposed between the first
and second clutches so that the motor shaft is extended coaxially
to the input shaft and the second output shaft. The first clutch is
interposed between the second end of the input shaft and the first
motor output end portion of the motor shaft. The second clutch is
interposed between the second motor output end portion of the motor
shaft and the axial end of the second output shaft.
[0013] Therefore, due to the coaxial arrangement of the motor
between the first and second clutches, a portion of the transaxle
incorporating the motor and the first and second clutches is
minimized in the radial direction with respect to the axial line of
the input shaft and the second output shaft, thereby expanding a
free space for arranging various implements around the portion of
the transaxle incorporating the motor and the first and second
clutches. Further, the transaxle needs no additional component
member for constituting a drive train, such as a gear train,
drivingly connecting the motor to the first and second clutches,
thereby reducing the number of component members of the transaxle
and reducing costs.
[0014] In a third aspect of the transaxle, the transaxle comprises
a transmission interposed between the input shaft and the first
output shaft, and a transaxle casing comprising first and second
housings. The first housing incorporates the input shaft, the
transmission and the first output shaft. The motor and the first
and second clutches are assembled as a motor-and-clutch assembly.
The second housing incorporates the entire motor-and-clutch
assembly and the second output shaft, so that the second housing,
the motor-and-clutch assembly, and the second output shaft are
assembled as a motor unit. The transaxle comprising the motor unit
is configured such that the motor unit is detachable from the first
housing of the transaxle casing by detaching the second housing
from the first housing and by separating the first clutch from the
input shaft in the first housing.
[0015] Therefore, the motor unit including the motor-and-clutch
assembly can be easily detached from the transaxle only by
detaching the second housing from the first housing without
requiring disassembling the motor-and-clutch assembly, thereby
facilitating maintenance of the motor-and-clutch assembly in the
second housing, and the transmission in the first housing.
[0016] In the third aspect of the transaxle, the motor comprises a
motor shaft axially offset from the second output shaft. The
motor-and-clutch assembly comprises a drive train interposed
between the motor shaft and the first and second clutches so as to
transmit the motor power from the motor to the first and second
clutches.
[0017] Therefore, the motor unit of the transaxle has the
above-mentioned effects due to the axial offset of the motor from
the first and second clutches.
[0018] Alternatively, in the third aspect of the transaxle, in the
motor-and-clutch assembly, the motor is disposed between the first
and second clutches. The motor comprises a motor shaft disposed
coaxially to the second output shaft. The motor shaft has axially
opposite ends drivingly connected to the first and second clutches,
respectively.
[0019] Therefore, the motor unit of the transaxle has the
above-mentioned effects due to the coaxial arrangement of the motor
between the first and second clutches.
[0020] In a fourth aspect of the transaxle, the motor and the first
and second clutches are operatively connected to a controller and a
drive mode selection device provided in the hybrid vehicle. The
controller is configured such that, when a drive mode for the
hybrid vehicle is selected by the drive mode selection device, the
controller controls on/off operation of the engine in the hydraulic
vehicle and the motor in the transaxle and engagement/disengagement
operation of the first and second clutches in the transaxle so as
to realize the selected drive mode.
[0021] Therefore, the hybrid vehicle can travel in an optimal drive
mode corresponding to respective requirements, such as high-power
travel performance, economic travel, smooth starting acceleration,
and the like.
[0022] In the fourth aspect of the transaxle, the controller is
configured such that the engine and the motor are turned on, the
first clutch is disengaged, and the second clutch is engaged, when
the selected drive mode is to make the hybrid vehicle travel with
the first drive wheel driven by the engine power from the engine
and with the second drive wheel driven by the motor power from the
motor.
[0023] Therefore, the hybrid vehicle can travel off-road with high
power, i.e., the engine power driving the first drive wheel and the
motor power driving the second drive wheel, over wildernesses,
uneven grounds, muddy places, etc.
[0024] In the fourth aspect of the transaxle, the controller is
configured such that the engine is turned off, the motor is turned
on, the first clutch is disengaged, and the second clutch is
engaged, when the selected drive mode is to make the hybrid vehicle
travel with the second drive wheel driven by the motor power from
the motor.
[0025] Therefore, the hybrid vehicle can travel as an electric
vehicle such as to enable a silent and slow travel performance
appropriate for hunting or any other uses, and such as to reduce
fuel consumption for driving the engine.
[0026] In the fourth aspect of the transaxle, the controller is
configured such that the engine and the motor are turned on, the
first clutch is engaged, and the second clutch is disengaged, when
the selected drive mode is to make the hybrid vehicle travel with
the first drive wheel driven by the engine power from the engine
and the motor power from the motor.
[0027] Therefore, the hybrid vehicle can travel by the driving
power of the first drive wheel concentratedly receiving both the
engine power and the motor power, thereby performing a high-power
traction or a smooth starting acceleration.
[0028] In the fourth aspect of the transaxle, the controller is
configured such that the engine is turned on, the motor is turned
off, the first clutch is engaged, and the second clutch is
disengaged, when the selected drive mode is to make the hybrid
vehicle travel with the first drive wheel driven by the engine
power from the engine while the motor is rotated by the engine
power to generate electric power.
[0029] Therefore, the hybrid vehicle can automatically recover the
capacity of a battery for reserving electric power for driving the
motor during its travel with the first drive wheel driven by the
engine power.
[0030] In the fourth aspect of the transaxle, the controller is
configured such that the engine is turned on, the motor is turned
off, the first clutch is disengaged, and the second clutch is
engaged, when the selected drive mode is to make the hybrid vehicle
travel with the first drive wheel driven by the engine power from
the engine while the motor is rotated by a rotary force of the
second drive wheel to generate electric power.
[0031] Therefore, the conversion of the rotary force of the second
drive wheel to electric power by the motor functions as a
regeneration brake applied to the second drive wheel so as to
prevent the hybrid vehicle descending a slope (for example) from
being unexpectedly accelerated.
[0032] In at least a second embodiment of the invention, a motor
unit comprises a motor, first and second drive members, first and
second clutches, and a power distribution member. The motor is
configured to output a motor power. The first and second drive
members are coaxial to each other. The first and second clutches
are disposed between the first and second drive member. The power
distribution member is disposed between the first and second
clutches so as to be driven by the motor power. The first clutch is
interposed between the first drive member and the power
distribution member. The second clutch is interposed between the
second drive member and the power distribution member.
[0033] Therefore, the motor unit having the first and second drive
members is adaptable to a hybrid vehicle so that the first drive
member serves as an input shaft of a transaxle carrying a first
drive wheel, such as rear wheels, of the vehicle and driven by an
engine, and the second drive member serves as a drive shaft for
transmitting the motor power from the motor to a second drive
wheel, such as front wheels, of the vehicle.
[0034] In a first aspect of the motor unit, the motor, the power
distribution member and the first and second clutches are assembled
as a motor-and-clutch assembly. The motor unit further comprises a
housing incorporating the entire motor-and-clutch assembly.
[0035] Therefore, the motor unit including the motor-and-clutch
assembly can be easily handled as a unit which does not require
disassembling the motor-and-clutch assembly. If the housing is
detachably attachable to a transaxle housing incorporating a
transmission driven by an engine, a transaxle including the
transaxle housing can be easily adapted as a transaxle for a hybrid
vehicle only by attaching the housing of the motor unit to the
transaxle housing.
[0036] In a second aspect of the motor unit, the motor comprises a
motor shaft serving as a rotary axis of the motor. The motor shaft
is axially offset from the first and second drive members. The
motor unit comprises a drive train interposed between the motor
shaft and the first and second clutches. The drive train comprises
the power distribution member disposed between the first and second
clutches.
[0037] Therefore, the whole length of the motor unit in the axial
direction of the first and second drive members can be reduced,
thereby minimizing a vehicle equipped with the motor unit, or
expanding a free space in the vehicle sideward from the motor unit
in the axial direction of the first and second drive members.
[0038] In the second aspect of the motor unit, the motor, the drive
train and the first and second clutches are assembled as a
motor-and-clutch assembly. The motor unit comprises a housing
incorporating the entire motor-and-clutch assembly.
[0039] Therefore, the motor unit including the drive train has the
above-mentioned effects of the motor unit including the housing
incorporating the motor-and-clutch assembly, in addition to the
above-mentioned effect of the axial offset of the motor from the
first and second drive members via the drive train.
[0040] In a third aspect of the motor unit, the motor comprises a
motor shaft serving as a rotary axis of the motor. The motor is
disposed between the first and second clutches so that the motor
shaft is disposed coaxially to the first and second drive members
so as to serve as the power distribution member.
[0041] Therefore, due to the coaxial arrangement of the motor
between the first and second clutches, the motor unit is minimized
in the radial direction with respect to the axial line of the first
and second drive members, thereby expanding a free space for
arranging various implements around the motor unit. Further, the
motor unit needs no additional component member for constituting a
drive train for drivingly connecting the motor to the first and
second clutches, thereby reducing the number of component members
of the motor unit and reducing costs.
[0042] In the third aspect of the motor unit, the motor and the
first and second clutches are assembled as a motor-and-clutch
assembly. The motor unit further comprises a housing incorporating
the entire motor-and-clutch assembly.
[0043] Therefore, the motor unit in which the motor has the motor
shaft coaxial to the first and second drive members has the
above-mentioned effect of the motor unit including the housing
incorporating the motor-and-clutch assembly, in addition to the
above-mentioned clutch of the coaxial arrangement of the motor
between the first and second clutches.
[0044] These and other features and advantages of the invention
will appear more fully from the following detailed description of
embodiments of the invention with reference to the attached
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] Embodiments will now be described, by way of example only,
with reference to the accompanying drawings which are meant to be
exemplary, not limiting, and wherein like elements are numbered
alike in several Figures, in which:
[0046] FIG. 1 is a schematic side view of a hybrid vehicle equipped
with a transaxle according to a first embodiment.
[0047] FIG. 2 is a schematic plan view of the hybrid vehicle
equipped with the transaxle according to the first embodiment.
[0048] FIG. 3 is a skeleton diagram of a hybrid vehicle driving
system including the transaxle according to the first
embodiment.
[0049] FIG. 4 is a sectional plan view of the transaxle according
to the first embodiment.
[0050] FIG. 5 is a fragmentary sectional plan view of a portion of
the transaxle according to the first embodiment, incorporating a
motor and first and second clutches.
[0051] FIG. 6 is a skeleton diagram of a motor-and-clutch assembly
for the transaxle according to the first embodiment.
[0052] FIG. 7 is a skeleton diagram of a hybrid vehicle driving
system including the transaxle according to the first embodiment,
the transaxle being modified to include a motor unit including the
motor-and-clutch assembly.
[0053] FIG. 8 is a schematic plan view of a hybrid vehicle equipped
with a transaxle according to a second embodiment.
[0054] FIG. 9 is a skeleton diagram of a hybrid vehicle driving
system including the transaxle according to the second
embodiment.
[0055] FIG. 10 is a sectional plan view of the transaxle according
to the second embodiment.
[0056] FIG. 11 is a fragmentary sectional plan view of a portion of
the transaxle according to the second embodiment, incorporating a
motor and first and second clutches.
[0057] FIG. 12 is a skeleton diagram of a motor-and-clutch assembly
for the transaxle according to the second embodiment.
[0058] FIG. 13 is a skeleton diagram of a hybrid vehicle driving
system including the transaxle according to the second embodiment,
the transaxle being modified to include a motor unit including the
motor-and-clutch assembly.
[0059] FIG. 14 is a block diagram of a drive mode selection
system.
[0060] FIG. 15 is a table indicating control of an engine, the
motor and the first and second clutches according to selection of
drive mode.
[0061] FIG. 16 is a diagram of the hybrid vehicle showing power
flow in an AWD mode.
[0062] FIG. 17 is a diagram of the hybrid vehicle showing power
flow in an EV mode.
[0063] FIG. 18 is a diagram of the hybrid vehicle showing power
flow in an Assist mode.
[0064] FIG. 19 is a diagram of the hybrid vehicle showing power
flow in a First Regeneration mode.
[0065] FIG. 20 is a diagram of the hydraulic vehicle showing power
flow in a Second Regeneration mode.
DETAILED DESCRIPTION
[0066] Referring to FIGS. 1 and 2, a utility vehicle (UTV) 100 will
be described. UTV 100 includes a vehicle body frame 101 extended
between front and rear ends of UTV 100. Vehicle body frame 101 is
provided on a fore-and-aft intermediate portion thereof with a
platform 101a, and on a front portion thereof with a front cover
101b. A rear portion of vehicle body frame 101 extended rearward
from platform 101a is stepped to become higher than platform 101a.
The rear portion of vehicle body frame 101 is provided on a front
end thereof with seats 102, including a driver's seat 102, and is
provided thereon with a cargo bed 103 in rear of sears 102.
[0067] Right and left front wheels 104 are suspended from the front
portion of vehicle body frame 101, and right and left rear wheels
105 are suspended from the rear portion of vehicle body frame 101.
A steering wheel 106 for steering front wheels 104 is disposed at
an upper portion of front cover 101b.
[0068] An engine 120 is supported via elastic vibro-isolating
rubber by vehicle body frame 101 below cargo bed 103. Engine 120
has a lateral horizontal engine output shaft 120a. A front portion
of an automatic continuously variable belt transmission
(hereinafter referred to as "CVT") 121 is disposed laterally
sideward (in this embodiment, leftward) from engine 120 and is
drivingly connected to engine output shaft 120a so as to serve as a
main transmission.
[0069] CVT 121 includes an input pulley 122, an output pulley 123,
and a V-belt 124. Input pulley 122 is fixed to engine output shaft
120a. Output pulley 123 is fixed to an input shaft 3 of a reverser
gear transmission 4 in a rear transaxle casing 2. V-belt 124 is
looped over input pulley 122 and output pulley 123.
[0070] Each of input and output pulleys 122 and 123 is a dividable
pulley whose belt groove has a variable width depending on change
of a rotary speed of engine output shaft 120a. Therefore, effective
diameters of input and output pulleys 122 and 123 having V-belt 124
looped thereon are changed according to change of the rotary speed
of engine output shaft 120a, so as to change a speed ratio of CVT
121 between engine output shaft 120a and input shaft 3.
[0071] A transaxle 1 is disposed rearward from engine 120 and
laterally sideward (in this embodiment, rightward) from a rear
portion of CVT 121. In other words, CVT 121 is disposed laterally
sideward (in this embodiment, leftward) from engine 120 and
transaxle 1 juxtaposed front and rear.
[0072] Transaxle 1 includes a rear transaxle casing 2, input shaft
3, reverser gear transmission 4, a differential gear unit 5, a pair
of right and left first output shafts 6 serving as right and left
rear wheel driving output shafts, a second output shaft 7 serving
as a front wheel driving output shaft, an electric motor 8, a first
clutch 9 and a second clutch 10 (see FIG. 3).
[0073] Rear transaxle casing 2 incorporates reverser gear
transmission 4, motor 8, first clutch 9 and second clutch 10. Rear
transaxle casing 2 is supported via vibro-isolating rubber by
vehicle body frame 101. A power take-off (hereinafter referred to
as "PTO") shaft 14 is drivingly connected to second output shaft 7
in rear transaxle casing 2, and projects forward from rear
transaxle casing 2 so as to transmit power to front wheels 104.
[0074] UTV 100 is provided with a battery 190 serving as a power
source for motor 8. Battery 190 is disposed inside of front cover
101b on the front portion of vehicle body frame 101 so as to
balance UTV 100 in weight with engine 120 and transaxle 1 disposed
at the rear portion of UTV 100.
[0075] Therefore, UTV 100 having the center of gravity located at
the fore-and-aft middle portion thereof can escape from mud easily
even if rear wheel 105 is (or rear wheels 105 are) stuck in the
mud. In this regard, if battery 190 were also disposed at the rear
portion of UTV 100, UTV 100 would have its center of gravity biased
rearward to the rear portion of UTV 100, so that it would be hard
for UTV 100 to escape from mud when rear wheel 105 were stuck in
the mud.
[0076] Right and left first output shafts 6 are differentially
connected at proximal ends thereof to each other via differential
gear unit 5 in rear transaxle casing 2, and project at distal ends
thereof rightward and leftward from rear transaxle casing 2 so as
to be drivingly connected to respective rear wheels 105 via
respective universal joints 107 and propeller shafts 108.
[0077] A front transaxle casing 50 is supported by the front
portion of vehicle body frame 101 below front cover 101b. Front
transaxle casing 50 incorporates a differential gear unit 52. Right
and left front differential output shafts 51 are journalled by
right and left end portions of front transaxle casing 50, are
differentially connected at proximal ends thereof to each other via
differential gear unit 51 in front transaxle casing 50, and project
at distal ends thereof rightward and leftward from the right and
left end portions of front transaxle casing 50 so as to be
drivingly connected to respective front wheels 104 via respective
universal joints 109 and propeller shafts 110.
[0078] Right and left front wheels 104 have respective axles
connected to each other via a tie rod 53. Tie rod 53 is operatively
connected to steering wheel 106. Therefore, during rotation of
steering wheel 106, tie rod 53 is moved rightward or leftward so as
to rotate both of right and left front wheels 104 rightward or
leftward, thereby turning UTV 100 rightward or leftward.
[0079] A horizontal input shaft 52a of differential gear unit 52
projects rearward from front transaxle casing 50. On the other
hand, as mentioned above, PTO shaft 14 projects forward from rear
transaxle casing 2, and a propeller shaft 114 is extended coaxially
forward from PTO shaft 14 rotatably integrally with PTO shaft 14.
Propeller shaft 114 is drivingly connected to input shaft 52a via a
universal joint 111, a propeller shaft 112 and a universal joint
113.
[0080] UTV 100 serves as a typical four-wheel driving hybrid
vehicle, and transaxle 1 serving as a rear transaxle of UTV 100 is
configured to work well for a four-wheel driving hybrid vehicle.
Transaxle 1 will be described in detail with reference to FIGS. 3
to 5, on an assumption that CVT 121 is disposed leftward from
transaxle 1.
[0081] Rear transaxle casing 2 includes a main housing 2a, a gear
housing 2b, a motor housing 2c, a PTO housing 2d and a motor cover
2e.
[0082] Gear housing 2b is disposed between CVT 121 and main housing
2a. A left portion of main housing 2a and gear housing 2b are
joined to each other so as to define a rear wheel driving gear
chamber 17, in which reverser gear transmission 4 and differential
gear unit 5 are disposed.
[0083] Motor housing 2c is disposed opposite gear housing 2b with
respect to main housing 2a. A right portion of main housing 2a and
motor housing 2c are joined to each other so as to define a
motor-and-clutch chamber 18, in which motor 8 and first and second
clutches 9 and 10 are disposed. Further, a right portion of motor
housing 2c and PTO housing 2d are joined to each other so as to
define a front wheel driving gear chamber 19, in which a
later-discussed front wheel driving gear train 16 is disposed.
[0084] Reverser gear transmission 4 in rear wheel driving gear
chamber 17 in rear transaxle casing 2 serves as a transmission for
driving rear wheels 105 via differential gear unit 5 and right and
left first output shafts 6.
[0085] Reverser gear transmission 4 includes input shaft 3, a
gearshift shaft 4d, and a final pinion shaft 4g, which are extended
parallel to one another and to first output shafts 6. Reverser gear
transmission 4 includes a forward travel gear train and a reverse
travel gear train interposed between input shaft 3 and gearshift
shaft 4d, and includes a speed reduction gear train interposed
between gearshift shaft 4d and differential gear unit 5 via final
pinion shaft 4g.
[0086] In rear wheel driving gear chamber 17, a forward travel
driving gear 3a and a reverse travel driving gear 3b are formed (or
fixed) on input shaft 3.
[0087] A reverse travel driven gear 4c is fitted on gearshift shaft
4d rotatably relative to gearshift shaft 4d, and meshes with
reverse travel driving gear 3b via an idle gear 4i, so that reverse
travel driving gear 3b, idle gear 4i and reverse travel driven gear
4c constitute the reverse travel gear train interposed between
input shaft 3 and gearshift shaft 4d.
[0088] A forward travel driven gear 4b is fitted on reverse travel
driven gear 4b rotatably relative to reverse travel driven gear 4b
and gearshift shaft 4d, and directly meshes with forward travel
driving gear 3a, so that forward travel driving gear 3a and forward
travel driven gear 4b constitute the forward travel gear train
interposed between input shaft 3 and gearshift shaft 4d.
[0089] In rear wheel driving gear chamber 17, a shifter 4a is
fitted on gearshift shaft 4d so that shifter 4a is axially slidable
along gearshift shaft 4d and is unrotatable relative to gearshift
shaft 4d.
[0090] Forward travel driven gear 4b is formed with clutch teeth
4b1, and reverse travel driven gear 4c is formed with clutch teeth
4c1. Shifter 4a is formed with clutch teeth that can mesh with
clutch teeth 4b1, and with clutch teeth that can mesh with clutch
teeth 4c1. Shifter 4a slides along gearshift shaft 4d so as to be
selectively disposed at one of three positions consisting of a
forward travel position, a reverse travel position, and a neutral
position.
[0091] When shifter 4a is disposed at the forward travel position,
shifter 4a meshes with clutch teeth 4b1 and is separated from
clutch teeth 4c1, so that input shaft 3 is drivingly connected to
gearshift shaft 4d via the forward travel gear train including
gears 3a and 4b.
[0092] When shifter 4a is disposed at the reverse travel position,
shifter 4a meshes with clutch teeth 4c1 and is separated from
clutch teeth 4b1, so that input shaft 3 is drivingly connected to
gearshift shaft 4d via the reverse travel gear train including
gears 3b, 4i and 4c.
[0093] When shifter 4a is disposed at the neutral position, shifter
4a meshes with neither clutch teeth 4b1 nor clutch teeth 4c1, so
that gearshift shaft 4d is isolated from the rotary power of input
shaft 3 driven by engine 120 via CVT 121.
[0094] In rear wheel driving gear chamber 17, a gear 4e is fixed on
gearshift shaft 4d axially opposite shifter 4a with respect to
reverse travel driven gear 4c, and meshes with a gear 4f fixed on
final pinion shaft 4g. A final pinion 4h is fixed on final pinion
shaft 4g and meshes with a bull gear 5b serving as an input gear of
differential gear unit 5. Therefore, gears 4e and 4f, final pinion
4h and bull gear 5b constitute the speed reduction gear train
interposed between gearshift shaft 4d and differential gear unit
5.
[0095] In rear wheel driving gear chamber 17, differential gear
unit 5 includes a differential casing 5a on which bull gear 5b
serving as the input gear is fixed. Differential pinions 5c are
pivoted in differential casing 5a via a pivot axis perpendicular to
first output shafts 6. Proximal ends of right and left first output
shafts 6 are disposed in differential casing 5a, and are fixedly
provided thereon with respective differential side gears 5d.
Differential pinions 5c are disposed between differential side
gears 5d on respective right and left first output shafts 6 so that
each differential pinion 5c meshes with both differential side
gears 5d on right and left first output shafts 6.
[0096] A differential lock slider 5e is fitted on one of right and
left first output shafts 6 (in this embodiment, right first output
shaft 6). Differential lock slider 5e is axially slidable along
first output shaft 6 so as to shift between a differential locking
position to engage with differential casing 5a and a differential
unlocking position to disengage from differential casing 5a.
[0097] Motor-and-clutch chamber 18 includes a motor chamber section
18a mainly formed in motor housing 2c, a clutch chamber section 18c
mainly formed in the right portion of main housing 2a, and a gear
chamber section 18b formed in the right portion of main housing 2a
to extend between motor chamber section 18a and clutch chamber
section 18c.
[0098] Motor chamber section 18a is formed as a laterally axial
cylindrical chamber. Motor 8, including a rotor 8r and a stator 8s
surrounding rotor 8r, is disposed in motor chamber section 18a so
that an outer circumferential surface of stator 8s is tightly
fitted to an inner circumferential surface of motor housing 2c
defining motor chamber section 18a, so that stator 8s is fixed to
motor housing 2c. Motor 8 includes a laterally horizontal motor
shaft 8a serving as an axis of rotor 8r, i.e., a rotary axis of
motor 8.
[0099] Motor chamber section 18a is open at a right end of motor
housing 2c. A motor cover 2e is attached to the right end of motor
housing 2c so as to cover the right end opening of motor chamber
section 18a, thereby covering motor 8 fitted in motor chamber
section 18a. Motor cover 2e is fastened to motor housing 2c via a
bolt (not shown) or the like, so that motor cover 2e is detachable
from motor housing 2c.
[0100] A basal right end portion of motor shaft 8a is journalled by
motor cover 2e via a bearing. A left end portion of motor shaft 8a
projects leftward from rotor 8r of motor 8 so as to serve as a
motor output end portion 8b for outputting the motor power of motor
8. An utmost left end of motor shaft 8a is journalled by main
housing 2a via a bearing.
[0101] Therefore, only by detaching motor cover 2e from motor
housing 2c, motor chamber section 18a is open rightward, so that
motor 8 can be easily moved together with motor cover 2e outward
from motor chamber section 18a, thereby facilitating maintenance of
motor 8.
[0102] On the other hand, motor 8 can be inserted into motor
chamber section 18a easily via the right end opening of motor
chamber section 18a. When motor 8 reaches its proper axial position
in motor chamber section 18a, motor cover 2e comes to abut against
the right end of motor housing 2c so that motor cover 2e can be
fastened to motor housing 2c by bolts or the like, thereby
facilitating installation of motor 8 into rear transaxle casing
2.
[0103] Various kinds of motors, e.g., an SR (Switched Reluctance)
motor, an AC (alternate current) motor, a DC (direct current)
motor, and a PM (Permanent Magnet) motor, are adaptable as motor 8.
Any kind of motor having any capacity is selected as motor 8 in
correspondence to the kind, use and required performance of UTV
100.
[0104] In motor-and-clutch chamber 18, a motor output gear 11 is
fixed on motor output end portion 8b of motor shaft 8a. A
distribution gear 13 is disposed in clutch chamber section 18c, and
an idle gear 12 is disposed in gear chamber section 18b, so that
motor output gear 11 meshes with distribution gear 13 via idle gear
12. Motor output gear 11, idle gear 12 and distribution gear 13
constitute a motor gear train 15 drivingly connecting motor 8 to
first and second clutches 9 and 10.
[0105] Distribution gear 13 has an axial center through hole 13a
open at right and left ends thereof. A left clutch drum 9a is
disposed at a left side of distribution gear 13, i.e., closer to
CVT 121 in the lateral direction of transaxle 1, and a right clutch
drum 10a is disposed at a right side of distribution gear 13, i.e.,
opposite CVT 121 with respect to distribution gear 13 in the
lateral direction of transaxle 1.
[0106] A right end portion of left clutch drum 9a and a left end
portion of right clutch drum 10a are fitted into axial center
through hole 13a of distribution gear 13, so that left and right
clutch drums 9a and 10a are rotatably integrated with distribution
gear 13, i.e., unrotatable relative to distribution gear 13.
[0107] A right end portion of input shaft 3 is supported in left
clutch drum 9a via a bearing so as to be rotatable relative to left
clutch drum 9a, i.e., distribution gear 13. A left end portion of
second output shaft 7 disposed coaxially to input shaft 3 is
supported in right clutch drum 10a via a bearing so as to be
rotatable relative to right clutch drum 10a, i.e., distribution
gear 13.
[0108] A discoid clutch member 9b is disposed along a wall of main
housing 2a defining a left end of clutch chamber section 18c, and
is fixed on the right end portion of input shaft 3. Friction
members 9c are layered in left clutch drum 9a along the right end
portion of input shaft 3 so as to be interposed between left clutch
drum 9a and discoid clutch member 9b. Friction members 9c consist
of friction members fitted rotatably integrally to left clutch drum
9a and friction members fitted rotatably integrally to discoid
clutch member 9b.
[0109] A clutch actuator 9d with a solenoid is provided on discoid
clutch member 9b, and the solenoid of clutch actuator 9d is
disposed in the wall of main housing 2a. A wire 9e is extended from
the solenoid of clutch actuator 9d through the wall of main housing
2a, and is extended outward from rear transaxle casing 2 so as to
be connected to a later-discussed electronic control unit
(hereinafter referred to as "ECU") 180 (see FIG. 14) of UTV
100.
[0110] Therefore, left clutch drum 9a, discoid clutch member 9b,
friction members 9c, clutch actuator 9d and wire 9e constitute an
electromagnetic clutch serving as first clutch 9 interposed between
distribution gear 13 and input shaft 3.
[0111] When clutch actuator 9d acts to press friction members 9c
against one another, discoid clutch member 9b engages to left
clutch drum 9a so as to be rotatably integral with left clutch drum
9a so that first clutch 9 is engaged, or on-operated, thereby
enabling power to flow between distribution gear 13 and input shaft
3.
[0112] When clutch actuator 9d acts to separate friction members 9c
from one another, discoid clutch member 9b disengages from left
clutch drum 9a so as to be rotatable relative to left clutch drum
9a so that first clutch 9 is disengaged, or off-operated, thereby
isolating input shaft 3 from the rotary power of distribution gear
13 as the motor power from motor 8, or thereby isolating
distribution gear 13 and motor 8 from the rotary power of input
shaft 3 as the engine power from engine 120 via CVT 121.
[0113] Therefore, motor 8 is drivingly connected via motor gear
train 15, including gears 11, 12 and 13, to input shaft 3 for
driving rear wheels 105 only if first clutch 9 is engaged. During
the engagement of first clutch 9, if engine 120 is stationary and
motor 8 is turned on, the rotary power of distribution gear 13
driven by the motor power from motor 8 via motor gear train 15 is
transmitted to input shaft 3. During the engagement of first clutch
9, if engine 120 is driven and motor 8 is turned off, the engine
power from engine 120 is transmitted to motor 8 via motor gear
train 15 so as to rotate motor 8 for generating electric power.
[0114] A discoid clutch member 10b is disposed along a wall of
motor housing 2c defining a right end of clutch chamber section
18c, and is fixed on the left end portion of second output shaft 7.
Friction members 10c are layered in right clutch drum 10a along the
left end portion of second output shaft 7 so as to be interposed
between right clutch drum 10a and discoid clutch member 10b.
Friction members 10c consist of friction members fitted rotatably
integrally to right clutch drum 10a and friction members fitted
rotatably integrally to discoid clutch member 10b.
[0115] A clutch actuator 10d with a solenoid is provided on discoid
clutch member 10b, and the solenoid of clutch actuator 10d is
disposed in the wall of motor housing 2c. A wire 10e is extended
from the solenoid of clutch actuator 10d through the wall of motor
housing 2c, and is extended outward from rear transaxle casing 2 so
as to be connected to ECU 180 of UTV 100.
[0116] Therefore, right clutch drum 10a, discoid clutch member 10b,
friction members 10c, clutch actuator 10d, and wire 10e constitute
an electromagnetic clutch serving as second clutch 10 interposed
between distribution gear 13 and second output shaft 7.
[0117] When clutch actuator 10d acts to press friction members 10c
against one another, discoid clutch member 10b engages to right
clutch drum 10a so as to be rotatably integral with right clutch
drum 10a so that second clutch 10 is engaged, or on-operated,
thereby enabling power to flow between distribution gear 13 and
second output shaft 7.
[0118] When clutch actuator 10d acts to separate friction members
10c from one another, discoid clutch member 10b disengages from
right clutch drum 10a so as to be rotatable relative right clutch
drum 10a so that second clutch 10 is disengaged, or off-operated,
thereby isolating second output shaft 7 from the rotary power of
distribution gear 13 driven by the motor power from motor 8 and/or
the engine power from input shaft 3.
[0119] Therefore, distribution gear 13 is drivingly connected to
second output shaft 7 for driving front wheels 104 only if second
clutch 10 is engaged. During the engagement of second clutch 10, if
motor 8 is turned on, distribution gear 13 is driven by the motor
power from motor 8 via gears 11 and 12 so that the rotary power of
distribution gear 13 is transmitted to second output shaft 7 via
second clutch 10. During the engagement of second clutch 10, if
motor 8 is turned off, a rotary force of front wheels 104 can
backflow to motor 8 so as to rotate motor 8 (i.e., rotor 8r) to
generate electric power.
[0120] PTO housing 2d is joined to a right end portion of motor
housing 2c so that PTO housing 2d and a right portion of motor
housing 2c define a front wheel driving gear chamber 19 partitioned
from motor-and-clutch chamber 18 by a wall of motor housing 2c.
[0121] A right end portion of second output shaft 7 is disposed in
front wheel driving gear chamber 19, and a bevel gear 7a is fixed
(or formed) on the right end portion of second output shaft 7. A
rear end portion of PTO shaft 14 is also disposed in front wheel
driving gear chamber 19, and a bevel gear 14a is formed (or fixed)
on the rear end portion of PTO shaft 14. Bevel gears 7a and 14a
mesh with each other so as to constitute a front wheel driving gear
train 16.
[0122] In this embodiment, bevel gear 14a is diametrically larger
than bevel gear 7a so that front wheel driving gear train 16 serves
as a speed reduction gear train. Alternatively, bevel gears 7a and
14a may have the same diameter so as to constitute a constant
velocity gear train or bevel gear 7a may be diametrically larger
than bevel gear 14a so as to constitute a speed increasing gear
train.
[0123] Therefore, PTO shaft 14 for driving front wheels 104 is
driven only if second clutch 10 is engaged to transmit a rotary
power of distribution gear 13 to second output shaft 7.
[0124] During the engagement of second clutch 10, if motor 8 is
turned on, the rotary power of distribution gear 13 driven by the
motor power from motor 8 via gears 11 and 12 is transmitted to
second output shaft 7, front wheel driving gear train 16 and PTO
shaft 14.
[0125] During the engagement of second clutch 10, if engine 120 is
turned on and first clutch 9 is also engaged, the engine power from
engine 120 is transmitted to second output shaft 7, front wheel
driving gear train 16 and PTO shaft 14 via CVT 121, input shaft 3,
engaged first clutch 9, distribution gear 13 and engaged second
clutch 10.
[0126] Further, during the engagement of second clutch 10, if front
wheels 104 free from the engine power and the motor power receive a
rotary force from the ground such as to accelerate front wheels
104, the rotary force backflows to motor 8 via differential gear
unit 52 in front transaxle casing 50, PTO shaft 14, front wheel
driving gear train 16, second output shaft 7, engaged second clutch
10, and motor gear train 15. Motor 8 converts the backflowing
rotary force to electric power. The electric power regenerated by
motor 8 is reserved in buttery 190. Therefore, the regeneration
action of motor 8 functions as a brake for preventing front wheels
104 from being unexpectedly accelerated.
[0127] Since first and second clutches 9 and 10 are electromagnetic
clutches, whether friction members 9c or 10b of each of first and
second clutches 9 and 10 are pressed against one another or are
separated from one another, i.e., whether each of first and second
clutches 9 and 10 is engaged or disengaged, depends on whether the
solenoid of its clutch actuator 9d or 10d is excited or unexcited.
Alternatively, each of first and second clutches 9 and 10 may be a
hydraulic clutch or another kind of clutch.
[0128] Referring to FIG. 6, an assembly of motor 8, motor gear
train 15, first clutch 9 and second clutch 10 is defined as a
motor-and-clutch assembly 20. Therefore, transaxle 1 includes
motor-and-clutch assembly 20 disposed in motor-and-clutch chamber
18 formed by the right portion of main housing 2a and motor housing
2c of rear transaxle casing 2.
[0129] Referring to FIG. 7, transaxle 1 may be modified as a
transaxle 1A including a motor unit 30 including motor-and-clutch
assembly 20.
[0130] In this regard, transaxle 1A includes a rear transaxle
casing 2A. Rear transaxle casing 2A includes a main housing 2f,
gear housing 2b, a motor housing 2g, PTO housing 2d and motor cover
2e. Gear housing 2b, PTO housing 2d and motor cover 2e are
identical to those of rear transaxle casing 2 of transaxle 1.
[0131] Main housing 2f and gear housing 2b are joined to each other
so as to define a rear wheel driving gear chamber 17A incorporating
reverser gear transmission 4 and differential gear unit 5, similar
to rear wheel driving gear chamber 17 defined by joining main
housing 2a and gear housing 2b of rear transaxle casing 2.
[0132] The difference of main housing 2f from main housing 2a is
that a right end of main housing 2f defines a right end of rear
wheel driving gear chamber 17A. In other words, main housing 2f is
not formed with a right portion extended rightward from the right
end of rear wheel driving gear chamber 17A so as to define at least
a portion of a motor-and-clutch chamber 18A, in comparison with
main housing 2a, which is formed with the right portion extended
rightward from the right end of rear wheel driving gear chamber 17
so as to define the left portion of motor-and-clutch chamber 18,
including gear chamber section 18b and clutch chamber section
18c.
[0133] Motor housing 2g is formed therein with entire
motor-and-clutch chamber 18A in which motor 8, motor gear train 15
and first and second clutches 9 and 10 are entirely disposed,
except that motor cover 2e is attached to motor housing 2g to cover
the right end of motor 8.
[0134] On the contrary, regarding transaxle 1, motor housing 2c of
rear transaxle casing 2 is formed therein with only the right
portion of motor-and-clutch chamber 18 including motor chamber
section 18a. When main housing 2a and motor housing 2c are
separated from each other, motor-and-clutch chamber 18 has to be
divided into the left portion in main housing 2a and the right
portion in motor housing 2c, and motor-and-clutch assembly 20,
including motor 8, motor gear train 15, and first and second
clutches 9 and 10, has to be disassembled so as to separate second
output shaft 7 journalled by motor housing 2c from input shaft 3
journalled by main housing 2a.
[0135] Therefore, transaxle 1A includes motor unit 30. Motor unit
30 includes motor-and-clutch assembly 20 of motor 8, motor gear
train 15 and first and second clutches 9 and 10, and includes motor
housing 2g incorporating entire motor-and-clutch assembly 20. Motor
unit 30 is detachable from main housing 2f defining rear wheel
driving gear chamber 17A with neither dividing of motor-and-clutch
chamber 18A nor disassembling of motor-and-clutch assembly 20.
[0136] When motor unit 30 is attached to main housing 2a, a left
end portion of motor housing 2g is joined to the right end of main
housing 2f defining the right end of rear wheel driving gear
chamber 17A. In this regard, an input shaft 3A of transaxle 1A is
divided into a main shaft portion 3c and a clutch shaft portion 3d
at a portion thereof close to the right end of rear wheel driving
gear chamber 17A. In rear wheel driving gear chamber 17A, main
shaft portion 3c is formed (or fixedly provided) thereon with
forward travel driving gear 3a and reverse travel driving gear
3b.
[0137] A coupling sleeve 3e formed with inner splines is provided
on a right end portion of main shaft portion 3c. Clutch shaft
portion 3d is journalled by the left end portion of motor housing
2g via first clutch 9 so as to serve as the right end portion of
input shaft 3A to be drivingly connected to distribution gear 13
via first clutch 9.
[0138] Therefore, when the left end portion of motor housing 2g is
joined to the right end of main housing 2f, the left end of clutch
shaft portion 3d is spline-fitted into coupling sleeve 3e so as to
connect clutch shaft portion 3d to main shaft portion 3c via
coupling sleeve 3e unrotatably relative to main shaft portion 3c,
thereby completing input shaft 3A.
[0139] On the other hand, motor unit 30 incorporating entire
motor-and-clutch assembly 20 is easily detachable from mutually
joined main and gear housings 2f and 2b of rear transaxle casing 2A
defining rear wheel driving gear chamber 17A only by detaching gear
housing 2g from the right end of main housing 2f and by extracting
clutch shaft portion 3d from coupling sleeve 3e to separate clutch
shaft portion 3d from main shaft portion 3c.
[0140] Further, a right portion of motor housing 2g and PTO housing
2d are joined to each other so as to define front wheel driving
gear chamber 19 similar to that of rear transaxle casing 2. Second
output shaft 7 is extended between motor-and-clutch chamber 18A and
front wheel driving gear chamber 19.
[0141] The mechanical connection of second output shaft 7 to
distribution gear 13 via second clutch 10 can be kept regardless of
whether motor housing 2g is joined to main housing 2a or is
separated from main housing 2a. Therefore, motor unit 30 including
motor-and-clutch assembly 20 also serves as a PTO unit including
second output shaft 7, front wheel driving gear train 16 and PTO
shaft 14.
[0142] Referring to FIG. 8, UVT 100 may be equipped with an
alternative transaxle 21. In UTV 100, transaxle 21 includes a rear
transaxle casing 22 carrying right and left rear wheels 105 and
incorporating reverser gear transmission 4 and differential gear
unit 5.
[0143] Transaxle 21 includes input shaft 3 projecting outward (in
this embodiment, leftward) from rear transaxle casing 22 so as to
be drivingly connected to engine 120 via CVT 121. Also, transaxle
21 includes PTO shaft 14 projecting outward (in this embodiment,
forward) from rear transaxle casing 22 so as to be drivingly
connected to differential gear unit 52 in front transaxle casing 50
carrying front wheels 104.
[0144] In FIG. 8, the same reference numerals as those in FIGS. 1
and 2 designate respective component elements having identical or
similar functions or configurations to the corresponding component
elements in FIGS. 1 and 2 designated by the same reference
numerals.
[0145] Transaxle 21 will be described in detail with reference to
FIGS. 9 to 12. Description of the component elements designated by
the same reference numerals as those used in FIGS. 3 to 6 is
omitted because of the above-mentioned reason. Further, it is
assumed that rear transaxle casing 22 of transaxle 21 is provided
with CVT 121 at the left side thereof, and is provided with PTO
shaft 14 at the right portion thereof laterally opposite CVT 121,
similar to the above-mentioned assumption with regard to rear
transaxle casing 2 of transaxle 1.
[0146] Rear transaxle casing 22 includes a main housing 22a, a gear
housing 22b, a motor housing 22c, and a PTO housing 22d. Gear
housing 22b and PTO housing 22d are identical or similar to gear
housing 2b and PTO housing 2d of rear transaxle casing 2,
respectively.
[0147] Gear housing 22b and a left portion of main housing 22a are
joined to each other so as to define a rear wheel driving gear
chamber 24, in which input shaft 3, reverser gear transmission 4,
differential gear unit 5, and right and left first output shafts 6
are arranged in the same way as those in rear wheel driving gear
chamber 17 formed in gear housing 2b and the left portion of main
housing 2a of rear transaxle casing 2.
[0148] A right portion of motor housing 22c and PTO housing 22d are
joined to each other so as to define a front wheel driving gear
chamber 26, in which the right end portion of second output shaft
7, the rear end portion of PTO shaft 14, and front wheel driving
gear train 16 including bevel gears 7a and 14a are arranged in the
same way as those in front wheel driving gear chamber 19 formed in
the right portion of motor housing 2c and PTO housing 2d of rear
transaxle casing 2.
[0149] A right portion of main housing 22a and a left portion of
motor housing 22c are joined to each other so as to define a
laterally axial cylindrical motor-and-clutch chamber 25 therein.
Motor-and-clutch chamber 25 includes a left portion for
incorporating first clutch 9, a right portion for incorporating
second clutch 10, and an axially (laterally) middle portion for
incorporating an alternative electric motor 28 for transaxle 21.
The left and middle portions of motor-and-clutch chamber 25 are
formed by the right portion of main housing 22a, and the right
portion of motor-and-clutch chamber 25 is formed by the left
portion of motor housing 22c.
[0150] A main portion of motor 28, including a rotor 28r and a
stator 28s surrounding rotor 28r, is disposed in the middle portion
of motor-and-clutch chamber 25, so that an outer circumferential
surface of stator 28s is tightly fitted to an inner circumferential
surface of the middle portion of motor-and-clutch chamber 25. Motor
28 includes a motor shaft 28a serving as an axis of rotor 28r,
i.e., a rotary axis of motor 28.
[0151] Motor shaft 28a has axially opposite motor output end
portions 28b and 28c that project rightward and leftward from right
and left ends of rotor 28r, i.e., the main body of motor 28. Each
of motor output end portions 28b and 28c of motor shaft 28a
functions as a motor output shaft that outputs a motor power
outputted from motor 28.
[0152] In this regard, aforesaid motor 8 has only motor output end
portion 8b that is the left end portion of motor shaft 8a
projecting leftward from the main portion of motor 8 to serve as
the motor output shaft. The right end portion of motor shaft 8a
does not function as a motor output shaft but merely projects to be
journalled by motor cover 2e via the bearing.
[0153] Motor 28 is disposed between input shaft 3 and second output
shaft 7 so that motor shaft 28a serving as the rotary axis of motor
28 is extended coaxially to input shaft 3 and second output shaft
7.
[0154] The right end portion of input shaft 3 is disposed in the
left portion of motor-and-clutch chamber 25. In the left portion of
motor-and-clutch chamber 25, left clutch drum 9a is fixed on left
motor output end portion 28b of motor shaft 28a by spline-fitting,
and discoid clutch member 9b is fixed on the right end portion of
input shaft 3 by spline-fitting and is disposed along the left end
of motor-and-clutch chamber 25, so as to constitute first clutch 9
interposed between the right end portion of input shaft 3 and left
motor output end portion 28b of motor shaft 28a. First clutch 9
further includes friction members 9c, clutch actuator 9d and wire
9e, similar to those of first clutch 9 of transaxle 1.
[0155] The left end portion of second output shaft 7 is disposed in
the right portion of motor-and-clutch chamber 25. In the right
portion of motor-and-clutch chamber 25, right clutch drum 10a is
fixed on right motor output end portion 28c of motor shaft 28a by
spline-fitting, and discoid clutch member 10b is fixed on the left
end portion of second output shaft 7 by spline-fitting, and is
disposed along the right end of motor-and-clutch chamber 25, so as
to constitute second clutch 10 interposed between right motor
output end portion 28c of motor shaft 28a and the left end portion
of second output shaft 7. Second clutch 10 further includes
friction members 10c, clutch actuator 10d and wire 10e, similar to
those of second clutch 10 of transaxle 1.
[0156] Therefore, when motor housing 22c is detached from the right
portion of main housing 22a and is moved together with second
output shaft 7 and second clutch 10 away from the right portion of
main housing 22a, the right portion of motor-and-clutch chamber 25
formed by motor housing 22c is separated from the left and middle
portions of motor-and-clutch chamber 25 formed by main housing 22a,
and right clutch drum 10a having been spline-fitted on right motor
output end portion 28c is slid along right motor output end portion
28c and is separated from right motor output end portion 28c. In
this way, motor housing 22c, supporting second clutch 10, second
output shaft 7, and PTO shaft 14, can be easily removed from main
housing 22a, in which motor 28 and first clutch 9 are left in the
left and middle portions of motor-and-clutch chamber 25 formed by
main housing 22a.
[0157] Therefore, the middle and left portion of motor-and-clutch
chamber 25 in main housing 22a is open rightward, so that motor 28
can easily be removed from first clutch 9 and be withdrawn from
motor-and-clutch chamber 25 in main housing 22a, and first clutch 9
can be removed from the right end portion of input shaft 3 and be
withdrawn from motor-and-clutch chamber 25 in main housing 22a.
Also, motor housing 22c removed from main housing 22a has the right
portion of motor-and-clutch chamber 25 open leftward, so that
second clutch 10 can easily be removed from the left end portion of
second output shaft 7. Such easy detachment of motor housing 22c
from main housing 22a facilitates maintenance of motor 28 and first
and second clutches 9 and 10.
[0158] Referring to FIG. 12, an assembly of motor 28, first clutch
9 and second clutch 10 is defined as a motor-and-clutch assembly
40. Therefore, transaxle 21 includes motor-and-clutch assembly 40
disposed in motor-and-clutch chamber 25 formed by the right portion
of main housing 22a and motor housing 22c of rear transaxle casing
22.
[0159] Referring to FIG. 13, transaxle 21 may be modified as a
transaxle 21A including a motor unit 50 including motor-and-clutch
assembly 40. In this regard, transaxle 21A includes a rear
transaxle casing 22A. Rear transaxle casing 22A includes a main
housing 22f, gear housing 22b, a motor housing 22g and PTO housing
22d. Gear housing 22b and PTO housing 22d are identical to those of
rear transaxle casing 22 of transaxle 21.
[0160] Main housing 22f and gear housing 22b are joined to each
other so as to define a rear wheel driving gear chamber 24A
incorporating reverser gear transmission 4 and differential gear
unit 5, similar to rear wheel driving gear chamber 24 defined by
joining main housing 22a and gear housing 22b of rear transaxle
casing 22.
[0161] The difference of main housing 22f from main housing 22a is
that a right end of main housing 22f defines a right end of rear
wheel driving gear chamber 24A. In other words, main housing 22f is
not formed with a right portion extended rightward from the right
end of rear wheel driving gear chamber 24A so as to define at least
a portion of a motor-and-clutch chamber 25A, in comparison with
main housing 22a, which is formed with the right portion extended
rightward from the right end of rear wheel driving gear chamber 24
so as to define the left and middle portions of motor-and-clutch
chamber 25.
[0162] Motor housing 22g is formed therein with entire
motor-and-clutch chamber 25 in which motor 28 and first and second
clutches 9 and 10 are entirely disposed.
[0163] On the contrary, motor housing 22c of rear transaxle casing
22 is formed therein with only the right portion of
motor-and-clutch chamber 25. When main housing 22a and motor
housing 22c are separated from each other, motor-and-clutch chamber
25 has to be divided into the left and middle portions in main
housing 22a and the right portion in motor housing 22c, and
motor-and-clutch assembly 40, including motor 8 and first and
second clutches 9 and 10, has to be disassembled so as to separate
second output shaft 7 journalled by motor housing 22c from input
shaft 3 journalled by main housing 22a.
[0164] Therefore, transaxle 21A includes motor unit 50. Motor unit
50 includes motor-and-clutch assembly 40 of motor 8 and first and
second clutches 9 and 10, and includes motor housing 22g
incorporating entire motor-and-clutch assembly 40. Motor unit 50 is
detachable from main housing 22f defining rear wheel driving gear
chamber 24A with neither dividing of motor-and-clutch chamber 25A
nor disassembling of motor-and-clutch assembly 40.
[0165] When motor unit 50 is attached to main housing 22a, a left
end portion of motor housing 22g is joined to the right end of main
housing 22f defining the right end of rear wheel driving gear
chamber 24A. In this regard, transaxle 21A includes input shaft 3A
dividable into main shaft portion 3c and clutch shaft portion 3d at
its portion close to the right end of rear wheel driving gear
chamber 24A, similar to input shaft 3A of transaxle 1A as shown in
FIG. 6. The right end portion of main shaft portion 3c and the left
end portion of clutch shaft portion 3d are spline-fitted into
coupling sleeve 3e so as to complete entire input shaft 3A, when
motor unit 50 is attached to main housing 22f by attaching the left
end portion of motor housing 22g to the right end of main housing
22f.
[0166] On the other hand, motor unit 50 incorporating entire
motor-and-clutch assembly 40 is easily detachable from mutually
joined main and gear housings 22f and 22b of rear transaxle casing
22A defining rear wheel driving gear chamber 24A only by detaching
gear housing 22g from the right end of main housing 22f and by
extracting clutch shaft portion 3d from coupling sleeve 3e to
separate clutch shaft portion 3d from main shaft portion 3c.
[0167] Further, a right portion of motor housing 22g and PTO
housing 22d are joined to each other so as to define front wheel
driving gear chamber 26 incorporating the right end portion of
second output shaft 7, the rear end portion of PTO shaft 14, and
front wheel driving gear train 16, similar to that of rear
transaxle casing 22. Therefore, motor unit 50 including
motor-and-clutch assembly 40 also serves as a PTO unit including
second output shaft 7, front wheel driving gear train 16 and PTO
shaft 14.
[0168] Transaxle 21 (or 21A) shown in FIG. 9 to 11 (or 13) will be
compared with transaxle 1 (or 1A) shown in FIG. 3 to 5 (or 7) in
advantages regarding arrangement of its electric motor and first
and second clutches 9 and 10.
[0169] In motor-and-clutch assembly 40 installed in rear transaxle
casing 22 of transaxle 21 or motor unit 50 of transaxle 21A, motor
28 is disposed between first and second clutches 9 and 10, so that
motor shaft 28a serving as the rotary axis of motor 28 is disposed
coaxially to input shaft 3 (or 3A) and second output shaft 7 and
has left and right motor output end portions 28b and 28c fixed to
left and right clutch drums 9a and 10b, respectively, thereby also
serving as a power distribution member for distributing the motor
power between clutch drums 9a and 10a of first and second clutches
9 and 10, similar to distribution gear 13 of motor gear train 15 in
motor-and-clutch assembly 20. Therefore, transaxle 21 (or 21A) is
advantageous in reducing the number of component members such as to
reduce costs because no gear train such as motor gear train 15 is
needed to drivingly connect motor 28 to first and second clutches 9
and 10.
[0170] Further, due to the arrangement of motor 28 between first
and second clutches 9 and 10 coaxial to input shaft 3 (or 3A) and
second output shaft 7, the right portion of main housing 22a and
motor housing 22c defining motor-and-clutch chamber 25 (or motor
housing 22g defining motor-and-clutch chamber 25A) are minimized in
the radial direction of input shaft 3 (or 3A) and second output
shaft 7, thereby reducing costs for manufacturing rear transaxle
casing 22 (or 22A).
[0171] Further, such a minimization of the housing defining
motor-and-clutch chamber 25 (or 25A) is advantageous to expand a
free space around the housing. For example, if rear transaxle
casing 22 (or 22A) is arranged so as to extend rear wheel driving
gear chamber 24 (or 24A) in the fore-and-aft direction of UTV 100
so that first output shafts 6 are disposed rearward from input
shaft 3 (or 3A), transaxle 21 (or 21A) has a large free space along
the right end of rear wheel driving gear chamber 24 (or 24A) and
rearward from motor-and-clutch chamber 25 (or 25A). Such a large
free space can be used for arranging various implements around
transaxle 21 (or 21A).
[0172] On the contrary, transaxle 1 (or 1A) is advantageous in
reducing its width in the lateral direction of UTV 100. In this
regard, the axis of motor 8, i.e., motor shaft 8a, is offset from
the axis of first and second clutches 9 and 10 coaxial to input
shaft 3 (or 3A) and second output shaft 7. Therefore, transaxle 1
(or 1A) has a gap between input shaft 3 (or 3A) and second input
shaft 7, which is narrowed in the lateral direction of UTV 100
because only distribution gear 13 is disposed between first and
second clutches 9 and 10, in comparison with transaxle 21 (or 21A)
having motor 28 disposed between first and second clutches 9 and
10.
[0173] Such a minimization of transaxle 1 (or 1A) in the lateral
direction of UTV 100 contributes to minimization of entire UTV 100
in the lateral direction thereof or expansion of a free space
rightward or leftward from transaxle 1 (or 1A) in UTV 100 for
arranging implements around transaxle 1 (or 1A).
[0174] Motor-and-clutch assembly 20 installed in rear transaxle
casing 2 of transaxle 1 or motor unit 30 of transaxle 1A may
include an alternative drive train interposed between motor output
end portion 8b of motor shaft 8a and first and second clutches 9
and 10, instead of motor gear train 15, only if the drive train
drivingly connects first and second clutches 9 and 10 to motor
shaft 8a of motor 8 axially offset from input shaft 3 and second
output shaft 7.
[0175] For example, the alternative drive train may include pulleys
and a belt looped over the pulleys, or may include sprockets and a
chain looped over the sprockets. In such a case, one pulley or
sprocket may be fixed on motor output end portion 8b, and another
pulley or sprocket may be disposed between first and second
clutches 9 and 10 coaxially to input shaft 3 and second output
shaft 7 so as to be fixed to left and right clutch drums 9a and
10a. Therefore, the pulley or sprocket between first and second
clutches 9 and 10 serves as a power distribution member that
distributes the motor power between clutch drums 9a and 10b of
first and second clutches 9 and 10, similar to distribution gear
13.
[0176] Drive modes of UTV 100 equipped with transaxle 1 as
representative of transaxles 1, 1A, 21 and 21A will be described
with reference to FIGS. 14 to 20.
[0177] A drive mode selection switch 170 is disposed at a portion
of UTV 100 close to driver's seat 102 (see FIG. 1). Drive mode
selectin switch 170 is electrically connected to ECU 180. By
turning or rotating drive mode selection switch 170, one of drive
modes is selected, and an input signal corresponding to the
selected drive mode is inputted to ECU 180.
[0178] ECU 180 is electrically connected to engine 120, motor 8,
first clutch 9 and second clutch 10. As mentioned above, first and
second clutches 9 and 10 are electrically connected to ECU 180 via
respective wires 9e and 10e. Therefore, ECU 180 outputs command
signals about on/off operation of engine 120 and motor 8 and
engagement/disengagement operation of first and second clutches 9
and 10 based on the drive mode selection.
[0179] Information about the drive modes is stored in a memory of
ECU 180. The information about the drive mode means information
about decision of whether each of engine 120, motor 8, first clutch
9 and second clutch 10 is turned on or off (or is engaged or
disengaged) depending on which drive mode is selected.
[0180] FIGS. 14 to 20 are adapted on an assumption that engine 120,
motor 8 (or 28), first clutch 9, second clutch 10, front wheels 104
and rear wheels 105 are referred to as engine E, motor M, first
clutch C1, second clutch C2, front wheels F, rear wheels R,
respectively. Further, FIG. 15 is adapted on an assumption that
on-and-off operation of each of engine 120 and motor 8 (or 28) and
engagement-and-disengagement of each of first and second clutches 9
and 10 are referred to as "ON" and "OFF". Hereinafter, the drive
mode selection system will be described on the same assumption.
[0181] Referring to FIG. 14, when drive mode selection switch 170
is set at "AWD" (All Wheel Drive) position, UTV 100 is set in an
AWD mode such that UTV 100 travels by driving all drive wheels F
and R. This drive mode is appropriate to off-road travel of UTV 100
on wildernesses, uneven grounds, muddy places, and so on, because
such an off-road travel requires high torque of drive wheels F and
R.
[0182] To realize the AWD mode, referring to FIG. 15, engine E and
motor M are turned on (set in "ON"), first clutch C1 is disengaged
(set in "OFF"), and second clutch C2 is engaged (set in "ON").
[0183] Therefore, referring to FIG. 16, due to the turn-on of
engine E and the disengagement of first clutch C1, first output
shafts 6 does not receive the motor power from motor M but receives
the engine power from engine E via CVT 121, input shaft 3 (or 3A),
reverser gear transmission 4 and differential gear unit 5, thereby
driving rear wheels R by the engine power. In the meanwhile, due to
the turn-on of motor M, the disengagement of first clutch C1, and
the engagement of second clutch C2, second output shaft 7 does not
receive the engine power from engine E via input shaft 3 (or 3A)
but receives the motor power from motor M (via motor gear train 15
in transaxle 1 or 1A), thereby driving front wheels F by the motor
power.
[0184] In this regard, ECU 180 controls the rotary speed of motor M
in correspondence to a detected rotary speed of rear wheels R,
thereby diminishing a rotary speed difference between front wheels
F driven by the motor power and rear wheels R driven by the engine
power.
[0185] Preferably, during the engagement of second clutch C2 in the
AWD mode, the on/off operation of motor M is ondemand-controlled so
that motor M is turned off to make front wheels F free from any
driving power except that motor M is turned on to drive front
wheels F by the motor power only if a rotary speed reduction or
stopping of rear wheels R meaning that rear wheel R is (or rear
wheels R are) stuck is detected. Therefore, consumption of electric
power from battery 190 is reduced so as to prolong the life of
battery 190.
[0186] Referring to FIG. 14, when drive mode selection switch 170
is set at "EV" (Electric Vehicle) position, UTV 100 is set in an EV
mode such that UTV 100 travels by only the motor power from motor
M, i.e., UTV 100 functions as an electric vehicle. For example, for
hunting, UTV 100 needs to travel silently at a low speed. The EV
mode is appropriate to such a silent and slow travel of UTV 100,
which does not require a great driving power.
[0187] To realize the EV mode, referring to FIG. 15, engine E is
turned off (set in "OFF"), motor M is turned on (set in "ON"),
first clutch C1 is disengaged (set in "OFF"), and second clutch C2
is engaged (set in "ON").
[0188] Therefore, referring to FIG. 17, due to the turn-off of
engine E and the disengagement of first clutch C1, first output
shafts 6 receives neither the engine power from engine E nor the
motor power from motor M, thereby transmitting no driving power to
rear wheels R. In the meanwhile, due to the turn-on of motor M and
the engagement of second clutch C2, second output shaft 7 receives
the motor power from motor M (via motor gear train 15 in transaxle
1 or 1A), thereby driving front wheels F by the motor power. Since
the engine power is not used, no fuel for driving engine E is
consumed.
[0189] Referring to FIG. 14, when drive mode selection switch 170
is set at "Assist" position, UTV 100 is set in an assist mode such
that UTV 100 travels with the engine power from engine E assisted
by the motor power from motor M in driving rear wheels R. This
drive mode is appropriate to high-power traction travel of UTV 100
or starting acceleration of UTV 100. Especially, this drive mode
effects to solve a delayed acceleration because of the speed-shift
performance of CVT 121.
[0190] To realize the assist mode, referring to FIG. 15, engine E
and motor M are turned on (set in "ON"), first clutch C1 is engaged
(set in "ON"), and second clutch C2 is disengaged (set in
"OFF").
[0191] Therefore, referring to FIG. 18, due to the turn-on of
engine E and motor M and the engagement of first clutch C1, first
output shafts 6 receives both the engine power from engine E and
the motor power from motor M via input shaft 3 (or 3A), reverser
gear transmission 4 and differential gear unit 5, thereby driving
rear wheels R by the engine power and the motor power. In the
meanwhile, due to the disengagement of second clutch C2, second
output shaft 7 receives neither the engine power nor the motor
power, thereby leaving front wheels F free from a driving power.
Therefore, the great driving power as combination of the engine
power and the motor power is concentrated to rear wheels R so as to
generate a high traction force of rear wheels R.
[0192] To output a sufficient power for starting UTV 100, CVT 121
requires a rotary speed of engine E (i.e., engine output shaft
120a) more than a certain value, thereby delaying start of UTV 100.
However, by setting UTV 100 in the assist mode, due to the power
assistance by motor M, first output shafts 6 can receive the
sufficient driving power even when the rotary speed of engine E is
low. Therefore, UTV 100 set in the assist mode can be started and
accelerated without delay.
[0193] Referring to FIG. 14, when drive mode selection switch 170
is set at "Regeneration 1" position, UTV 100 is set in a first
regeneration mode such that UTV 100 travels by driving only rear
wheels R with the engine power from engine E while motor M is
rotated by the engine power from engine E so as to regenerate
electric power.
[0194] To realize the first regeneration mode, referring to FIG.
15, engine E is turned on (set in "ON"), motor M is turned off (set
in "OFF"), first clutch C1 is engaged (set in "ON"), and second
clutch C2 is disengaged (set in "OFF").
[0195] Therefore, referring to FIG. 19, due to the turn-on of
engine E and the engagement of first clutch C1, first output shafts
6 receives the engine power from engine E, and the engine power
from engine E is transmitted to turned-off motor M via input shaft
3 (or 3A) and first clutch C1 (and motor gear train 15 in transaxle
1 or 1A), thereby rotating motor M to function as a generator. The
electric power regenerated by motor M is reserved in battery 190 so
as to recover the capacity of battery 190 for enabling long-time
and long-distance travel of UTV 100.
[0196] Referring to FIG. 14, when drive mode selection switch 170
is set at "Regeneration 2" position, UTV 100 is set in a second
regeneration mode such that UTV 100 travels by driving only rear
wheels R with the engine power from engine E while motor M is
rotated by a rotation force of front wheels F so as to regenerate
electric power.
[0197] To realize the second regeneration mode, referring to FIG.
15, engine E is turned on (set in "ON"), motor M is turned off (set
in "OFF"), first clutch C1 is disengaged (set in "OFF"), and second
clutch C2 is engaged (set in "ON").
[0198] Therefore, referring to FIG. 20, due to the turn-on of
engine E, first output shafts 6 receives the engine power from
engine E. Due to the disengagement of first clutch C1 and the
turn-off of motor M, second output shaft 7 receives neither the
engine power nor the motor power. Therefore, during travel of UTV
100, rotation of front wheels F does not depend on a driving power
from PTO shaft 14 but depends on rotation of rear wheels R driven
by the engine power.
[0199] However, due to the engagement of second clutch C2, the
rotation of front wheels F generates a rotary force that backflows
to turned-off motor M, so that motor M functions as a regenerator
that converts the backflowing rotary force to electric energy. The
regeneration action of motor M functions as a rotational resistance
so as to prevent front wheels F from unexpectedly increasing their
rotary speed.
[0200] Therefore, the second regeneration mode is convenient for
UTV 100 when descending a slope. The braking performance of UTV 100
by applying the regeneration brake from motor M to front wheels F
is substantially equal to that by applying an engine brake from
engine E to front wheels F.
[0201] It is further understood by those skilled in the art that
the foregoing description is given to preferred embodiments of the
disclosed apparatus and that various changes and modifications may
be made in the invention without departing from the scope thereof
defined by the following claims.
[0202] While the description above refers to particular embodiments
of the present invention, it will be understood that many
modifications may be made without departing from the spirit
thereof. The accompanying claims are intended to cover such
modifications as would fall within the true scope and spirit of the
present invention.
[0203] The presently disclosed embodiments are therefore to be
considered in all respects as illustrative and not restrictive, the
scope of the invention being indicated by the appended claims,
rather than the foregoing description, and all changes which come
within the meaning and range of equivalency of the claims are
therefore intended to be embraced therein.
* * * * *