Rotary shafts – gudgeons – housings – and flexible couplings for ro – Overload release coupling – Torque transmitted via frictional engagement of planar...
Reexamination Certificate
2001-07-24
2003-06-24
Binda, Greg (Department: 3679)
Rotary shafts, gudgeons, housings, and flexible couplings for ro
Overload release coupling
Torque transmitted via frictional engagement of planar...
C464S068800
Reexamination Certificate
active
06582312
ABSTRACT:
INCORPORATION BY REFERENCE
The disclosure of Japanese Patent Application No. 2000-226654 filed on Jul. 27, 2000, including the specification, drawings and abstract, is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a torque fluctuation absorbing apparatus having a structure for reducing misalignment of a torque limiter during assembling of the apparatus, and also relates to a method for assembling the torque fluctuation absorbing apparatus while reducing misalignment of the torque limiter when it is mounted in the apparatus.
2. Description of Related Art
A torque fluctuation absorbing apparatus is coupled to and between an engine crankshaft and an input shaft of a driven-side assembly (e.g., a transmission of a hybrid vehicle which houses a motor) so as to reduce engine torque fluctuations.
FIG.
9
and
FIG. 10
show a known example of torque fluctuation absorbing apparatus. The torque fluctuation absorbing apparatus
1
includes a flywheel
10
coupled to a crankshaft
2
of an engine, a damper assembly
20
disposed in a torque transmission path between the flywheel
10
and a driven-side input shaft
3
, and a torque limiter
30
disposed in a torque transmission path between the flywheel
10
and the damper assembly
20
. The damper assembly
20
has a pair of drive plates
21
, a driven plate
22
, and spring dampers
24
. The torque limiter
30
has a pair of linings
31
and a damper cover
32
, and is adapted to slip when receiving a predetermined or larger amount of torque.
The pair of linings
31
are secured to both faces of an outer peripheral portion of one of the drive plates
21
(or a member fixed to the drive plate
21
). The pair of linings
31
are sandwiched between the damper cover
32
and the flywheel
10
. When a torque that is equal to or larger than a predetermined value is applied to the torque limiter
30
, slippage occurs on surfaces of the linings
31
that are in contact with the damper cover
32
and the flywheel
10
. The drive plates
21
and the driven plate
22
are rotatable relative to each other in a circumferential direction thereof. Also, small amounts of radial clearances are provided between a bush
23
disposed between the drive plate
21
and the driven plate
22
, and the drive plates
21
and the driven plate
22
, respectively, whereby the drive and driven plates
21
,
22
rattle in the radial directions. In order to allow or accommodate rattling and assembling errors, a radial clearance d is provided between an outer periphery of the drive plate
21
(or a member secured thereto) and an inner periphery of the flywheel
10
.
A procedure of assembling the known torque fluctuation absorbing apparatus
1
is as follows: (1) a hub
22
a
of the driven plate
22
of the damper assembly
20
and the crankshaft
2
are aligned with an engine assembly by using a jig
50
, as shown in
FIG. 10
, (2) the damper cover
32
is bolted to the flywheel
10
, and the damper cover
32
and the flywheel
10
sandwich the linings
31
secured to the drive plate
21
to thereby support the damper assembly
20
, and (3) the engine assembly is assembled with a driven-side assembly, and these assemblies are thus fixed to each other.
The known apparatus, however, has following problems.
In the presence of the radial clearance between the drive plate and the driven plate as described above, the drive plate may be disposed eccentrically within the range of the clearance with respect to the flywheel, even with the driven plate being properly aligned with the engine assembly by using the jig upon assembling of the torque fluctuation absorbing apparatus with the engine assembly. As a result, the linings of the torque limiter secured to the drive plate may be out of alignment with respect to the flywheel in the radial directions. If the torque limiter is assembled eccentrically with the engine assembly, the following and/or other problems may occur when the engine is rotated, after assembling of the engine assembly with the driven-side assembly, to an angular point where the radial clearance between the drive plate and the driven plate disappears. For example, 1) the rotation of the input shaft of the driven-side assembly may become unstable or fluctuating due to the eccentric arrangement of the drive and driven plates, and torsional stress may be applied to a bearing
60
that supports the input shaft of the driven-side assembly, resulting in a reduction in the service life of the bearing
60
, 2) the service life of a bushing
61
(or a needle bearing) that is in sliding contact with the driven-side input shaft during rotation thereof may be shortened, and 3) the performance of an oil seal
62
that is in sliding contact with the driven-side input shaft may deteriorate.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a structure and a method (an assembling method) for reducing misalignment of a torque limiter during assembling of a torque fluctuation absorbing apparatus.
To accomplish the above and/or other objects, there is provided according to one aspect of the invention a torque fluctuation absorbing apparatus provided between a crankshaft of an engine and a driven-side input shaft, comprising: (1) a flywheel coupled to the crankshaft, (2) a damper assembly disposed in a torque transmission path between the flywheel and the driven-side input shaft, the damper assembly including a pair of drive plates, a driven plate and at least one spring damper, and (3) a torque limiter disposed in a torque transmission path between the flywheel and the damper assembly, the torque limiter including a pair of linings that are adapted to slip when receiving at least a predetermined amount of torque. In this apparatus, the torque limiter further includes a lining support plate to which the linings are fixed, and the linings are interposed between the pair of the drive plates. In fabricating this apparatus, the drive plates and the linings are centered with each other and assembled into a damper-torque limiter assembly, while the lining support plate is centered with respect to the flywheel, such that the damper-torque limiter assembly is fixed at the lining support plate to the flywheel. With this arrangement, the drive plates, the linings, and the flywheel are brought into concentric relationship with each other, thus effectively preventing the torque limiter from being eccentrically positioned with respect to the engine assembly during assembling of the apparatus.
According to a second aspect of the invention, there is provided a torque fluctuation absorbing apparatus including the flywheel, the damper assembly and the torque limiter as described above, in which the linings of the torque limiter are fixed to one of the drive plates of the damper assembly, and the torque limiter includes a pair of damper covers between which the linings are interposed. In fabricating this apparatus, the drive plates and the damper covers are centered with each other and assembled into a damper-torque limiter assembly, while the damper covers are centered with respect to the flywheel, such that the damper-torque limiter assembly is fixed at the damper covers to the flywheel.
According to a third aspect of the invention, there is provided a torque fluctuation absorbing apparatus including the flywheel, the damper assembly and the torque limiter as described above, in which the linings of the torque limiter are fixed to one of the drive plates, and the linings are interposed between the flywheel and a damper cover that forms a part of the torque limiter, while the flywheel includes a flywheel main body and a flywheel plate that are fastened to each other. In fabricating this apparatus, the drive plates, the linings and the damper cover are centered with respect to the flywheel main body, and are assembled together to provide an assembly of the flywheel main body, the damper assembly and the torque limiter. After the engine is assembled with the drive-side input shaft, the assembly of
Adachi Masatoshi
Hata Hiroshi
Kojima Masahiro
Nakane Mototaka
Saeki Tomohiro
Binda Greg
Pillsbury & Winthrop LLP
Toyota Seiki Jidosha Kabushiki Kaisha
LandOfFree
Torque fluctuation absorbing apparatus having structure for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Torque fluctuation absorbing apparatus having structure for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Torque fluctuation absorbing apparatus having structure for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3148587