U.S. patent application number 15/649111 was filed with the patent office on 2017-10-26 for engine valve lifter anti-rotation device.
The applicant listed for this patent is Eaton Corporation. Invention is credited to Robert D. Hogan, James E. McCarthy, JR., Douglas J. Nielsen, Anthony Leon Spoor.
Application Number | 20170306810 15/649111 |
Document ID | / |
Family ID | 56406385 |
Filed Date | 2017-10-26 |
United States Patent
Application |
20170306810 |
Kind Code |
A1 |
Nielsen; Douglas J. ; et
al. |
October 26, 2017 |
ENGINE VALVE LIFTER ANTI-ROTATION DEVICE
Abstract
An engine roller lifter for use in a valve train of an internal
combustion engine includes a body, an anti-rotation device and a
clip. The body can have an outer peripheral surface configured for
sliding movement in a bore provided in the engine. The body can
define a receiving channel formed in the outer peripheral surface.
The body can further define a slot formed at the receiving channel.
The anti-rotation device can include a guide plug received in the
receiving channel of the body. The guide plug can extend outwardly
from the outer peripheral surface of the body. The guide plug can
be configured to locate into a bore slot defined in a cylinder head
of the internal combustion engine. The clip can be received by the
slot and captured the guide plug in the receiving channel.
Inventors: |
Nielsen; Douglas J.;
(Marshall, MI) ; Spoor; Anthony Leon; (Marshall,
MI) ; Hogan; Robert D.; (Marshall, MI) ;
McCarthy, JR.; James E.; (Kalamazoo, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Eaton Corporation |
Cleveland |
OH |
US |
|
|
Family ID: |
56406385 |
Appl. No.: |
15/649111 |
Filed: |
July 13, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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PCT/US2016/013409 |
Jan 14, 2016 |
|
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15649111 |
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62103387 |
Jan 14, 2015 |
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62104121 |
Jan 16, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01L 1/047 20130101;
F01L 1/146 20130101; F01L 2001/2427 20130101; F01M 9/104 20130101;
F01L 2307/00 20200501; F01L 1/245 20130101; F16B 19/02 20130101;
F01L 2305/00 20200501; F01M 9/00 20130101; F01L 2810/02 20130101;
F01L 2001/256 20130101; F16B 21/183 20130101 |
International
Class: |
F01L 1/245 20060101
F01L001/245; F01M 9/10 20060101 F01M009/10; F01L 1/14 20060101
F01L001/14; F01L 1/047 20060101 F01L001/047 |
Claims
1. An engine roller lifter for use in a valve train of an internal
combustion engine, the engine roller lifter comprising: a body
having an outer peripheral surface configured for sliding movement
in a bore provided in the engine, the body defining a receiving
channel formed in the outer peripheral surface, the body further
defining a slot formed at the receiving channel; an anti-rotation
device including a guide plug received in the receiving channel of
the body, the guide plug extending outwardly from the outer
peripheral surface of the body, the guide plug configured to locate
into a bore slot defined in a cylinder head of the internal
combustion engine; and a clip received by the slot and capturing
the guide plug in the receiving channel.
2. The engine roller lifter of claim 1 wherein the clip is a
C-clip.
3. The engine roller lifter of claim 2 wherein the guide plug
includes a first and a second lobed body portion.
4. The engine roller lifter of claim 3 wherein the first lobed body
portion is keyed in the receiving channel to preclude radial
movement of the guide plug.
5. The engine roller lifter of claim 4 wherein the second lobed
body portion extends radially outwardly beyond the outer peripheral
surface of the body.
6. The engine roller lifter of claim 5 wherein the second lobed
body portion includes a pair of parallel sidewalls. The engine
roller lifter of claim 6 wherein the guide plug is cold-formed.
8. The engine roller lifter of claim 7 wherein the guide plug
further includes an extension portion having a finger thereon, the
finger configured to prevent rotation of the C-clip.
9. The engine roller lifter of claim 1 wherein the body further
includes a groove and a connecting channel formed into the
peripheral surface, the body further including a transverse
passage, wherein oil collected in the groove flows to the
connecting channel and into the transverse passage to lubricate a
roller bearing disposed on the roller lifter.
10. An engine roller lifter for use in a valve train of an internal
combustion engine, the engine roller lifter comprising: a body
having an outer peripheral surface configured for sliding movement
in a bore provided in the engine, the body defining a receiving
channel formed in the outer peripheral surface; an anti-rotation
device including a guide plug having a first and second lobed body
portion, the first lobed body portion configured to be slidably
received in the receiving channel of the body in an installed
position, the second lobed body portion extending outwardly from
the outer peripheral surface of the body, the second lobed body
portion configured to locate into a bore slot defined in a cylinder
head of the internal combustion engine and inhibit rotation of the
guide plug and body; and a coupling arrangement that couples the
anti-rotation device at the receiving channel.
11. The engine roller lifter of claim 10 wherein the body further
includes a groove and a connecting channel formed into the
peripheral surface, the body further including a transverse
passage, wherein oil collected in the groove flows to the
connecting channel and into the transverse passage to lubricate a
roller bearing disposed on the roller lifter.
12. The engine roller lifter of claim 10 wherein the coupling
arrangement comprises a set screw.
13. The engine roller lifter of claim 10 wherein the coupling
arrangement comprises a clip received by a slot defined in the
body, the clip capturing the guide plug in the receiving
channel.
14. The engine roller lifter of claim 10 wherein the coupling
arrangement comprises annealing, wherein the body is locally
annealed in an area around the guide plug.
15. The engine roller lifter of claim 14 wherein a circumferential
edge area that defines an entrance to the channel is annealed and
shaped inwardly to close a circumference and trap the guide plug
within the channel.
16. The engine roller lifter of claim 10 wherein the coupling
arrangement comprises staking, wherein the guide plug is staked
relative to the body.
17. The engine roller lifter of claim 16 wherein the first lobed
body portion is axially compressed and expanded radially forming an
interference fit with the receiving channel of the body.
18. The engine roller lifter of claim 10 wherein the coupling
arrangement comprises resistance welding.
19. The engine roller lifter of claim 10 wherein the coupling
arrangement comprises laser welding.
20. An engine roller lifter for use in a valve train of an internal
combustion engine, the engine roller lifter comprising: a body
having an outer peripheral surface configured for sliding movement
in a bore provided in the engine, the body defining a receiving
channel formed in the outer peripheral surface, the body further
defining a slot formed at the receiving channel, a groove and a
connecting channel formed into the outer peripheral surface, the
body further including a transverse passage, wherein oil collected
in the groove flows to the connecting channel and into the
transverse passage to lubricate a roller bearing disposed on the
roller lifter; an anti-rotation device including a guide plug
having a first and second lobed body portion, the first lobed body
portion configured to be slidably received in the receiving channel
of the body in an installed position, the second lobed body portion
extending outwardly from the outer peripheral surface of the body,
the second lobed body portion configured to locate into a bore slot
defined in a cylinder head of the internal combustion engine and
inhibit rotation of the guide plug and body; and a clip received by
the slot and capturing the guide plug in the receiving channel.
21. An engine roller lifter for use in a valve train of an internal
combustion engine, the engine roller lifter comprising: a body
having an outer peripheral surface configured for sliding movement
in a bore provided in the engine, the body defining a receiving
channel formed in the outer peripheral surface; and an
anti-rotation device including a guide plug having a first body
portion and a second body portion, the first body portion formed in
a geometrical shape complementary for receipt into the receiving
channel, the guide plug being formed of a smart memory alloy
wherein subsequent to positioning of the guide plug into the
receiving channel, heat treating the engine roller lifter sets the
shape of the guide plug to retain the guide plug in an installed
position within the receiving channel such that the second body
portion extends outwardly from the outer peripheral surface of the
body, the second body portion configured to locate into a bore slot
defined in a cylinder head of the internal combustion engine and
inhibit rotation of the guide plug and body.
22. The engine roller lifter of claim 21 wherein the body further
defines a slot formed at the receiving channel, the engine roller
lifter further comprising: a clip received by the slot and
capturing the guide plug in the receiving channel.
23. The engine roller lifter of claim 22 wherein the clip is formed
of smart memory alloy such that heat treating sets the clip in the
slot.
24. The engine roller lifter of claim 21 wherein the body further
includes a groove and a connecting channel formed into the
peripheral surface, the body further including a transverse
passage, wherein oil collected in the groove flows to the
connecting channel and into the transverse passage to lubricate a
roller bearing disposed on the roller lifter.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International
Application No. PCT/US2016/013409 filed Jan. 14, 2016, which claims
the benefit of U.S. Patent Application No. 62/103,387 filed on Jan.
14, 2015 and U.S. Patent Application No. 62/104,121 filed on Jan.
16, 2015. The disclosures of the above applications are
incorporated herein by reference.
FIELD
[0002] The present disclosure relates generally to hydraulic lash
adjusting tappets of the type having a roller follower for
contacting a cam shaft in an internal combustion engine valve
train.
BACKGROUND
[0003] Roller lifters can be used in an engine valvetrain to reduce
friction and as a result provide increased fuel economy. In other
advantages, a roller lifter can open a valve quicker and for a
longer period of time than a flat tappet lifter. In this regard,
airflow can be attained quicker and longer increasing the ability
to create power.
[0004] The background description provided herein is for the
purpose of generally presenting the context of the disclosure. Work
of the presently named inventors, to the extent it is described in
this background section, as well as aspects of the description that
may not otherwise qualify as prior art at the time of filing, are
neither expressly nor impliedly admitted as prior art against the
present disclosure.
SUMMARY
[0005] An engine roller lifter for use in a valve train of an
internal combustion engine includes a body, an anti-rotation device
and a clip. The body can have an outer peripheral surface
configured for sliding movement in a bore provided in the engine.
The body can define a receiving channel formed in the outer
peripheral surface. The body can further define a slot formed at
the receiving channel. The anti-rotation device can include a guide
plug received in the receiving channel of the body. The guide plug
can extend outwardly from the outer peripheral surface of the body.
The guide plug can be configured to locate into a bore slot defined
in a cylinder head of the internal combustion engine. The clip can
be received by the slot and captured the guide plug in the
receiving channel.
[0006] According to additional features, the clip can include a
C-clip. The guide plug can include a first and second lobed body
portion. The first lobed body portion is keyed in the receiving
channel to preclude radial movement of the guide plug. The second
lobed body portion can extend radially outwardly beyond the outer
peripheral surface of the body. The second lobed body portion can
include a pair of parallel sidewalls. The guide plug can be
cold-formed. The guide plug can further include an extension
portion having a finger thereon. The finger can be configured to
prevent rotation of the C-clip. The body can further include a
groove and a connecting channel formed into the peripheral surface.
The body can further include a transverse passage. Oil collected in
the groove can flow to the connecting channel and into the
transverse passage to lubricate a roller bearing disposed on the
roller lifter.
[0007] An engine roller lifter for use in a valve train of an
internal combustion engine according to additional features of the
present disclosure can include a body, an anti-rotation device and
a coupling arrangement. The body can have an outer peripheral
surface configured for sliding movement in a bore provided in the
engine. The body can define a receiving channel formed in the outer
peripheral surface. The anti-rotation device can include a guide
plug having a first and second lobed body portion. The first lobed
body portion can be configured to be slidably received in the
receiving channel of the body in an installed position. The second
lobed body portion can extend outwardly from the outer peripheral
surface of the body. The second lobed body portion can be
configured to locate into a bore slot defined in a cylinder head of
the internal combustion engine and inhibit rotation of the guide
plug and body. The coupling arrangement can couple the
anti-rotation device at the receiving channel.
[0008] According to additional features, the body can further
include a groove and a connecting channel formed into the
peripheral surface. The body can further include a transverse
passage. Oil collected in the groove can flow to the connecting
channel and into the transverse passage to lubricate a roller
bearing disposed on the roller lifter.
[0009] In other features, the coupling arrangement can comprise a
set screw. In another configuration, the coupling arrangement can
comprise a clip received by a slot defined in the body. The clip
can capture the guide plug in the receiving channel. In other
configurations, the coupling arrangement can comprise annealing.
The body can be locally annealed in an area around the guide plug.
A circumferential edge area that defines an entrance to the channel
can be annealed and shaped inwardly to close a circumference and
trap the guide plug within the channel.
[0010] According to other configurations, the coupling arrangement
can comprise staking, wherein the guide plug can be staked relative
to the body. The first lobed body portion can be axially compressed
and expanded radially forming an interference fit with the
receiving channel of the body. In another configuration, the
coupling arrangement comprises resistance welding. In yet another
configuration, the coupling arrangement comprises laser
welding.
[0011] An engine roller lifter for use in a valve train of an
internal combustion engine includes a body and an anti-rotation
device. The body can have an outer peripheral surface configured
for sliding movement in a bore provided in the engine. The body can
define a receiving channel formed in the outer peripheral surface.
The anti-rotation device can include a guide plug having a first
body portion and a second body portion. The first body portion can
be formed in a geometrical shape complementary for receipt into the
receiving channel. The guide plug can be formed of a smart memory
alloy. Subsequent to positioning the guide plug into the receiving
channel, the engine roller lifter can be heat treated setting the
shape of the guide plug to retain the guide plug in an installed
position within the receiving channel. The second body portion
extends outwardly from the outer peripheral surface of the body.
The second body portion can be configured to locate into a bore
slot defined in a cylinder head of the internal combustion engine
and inhibit rotation of the guide plug and body.
[0012] According to other features, the body further defines a slot
formed at the receiving channel. A clip can be received by the
slot. The clip captures the guide plug in the receiving channel.
The clip can be formed of smart memory alloy such that heat
treating sets the clip in the slot. The body can further include a
groove and a connecting channel formed into the peripheral surface.
The body further includes a transverse passage. Oil collected in
the groove flows to the connecting channel and into the transverse
passage to lubricate a roller bearing disposed on the roller
lifter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present disclosure will become more fully understood
from the detailed description and the accompanying drawings,
wherein:
[0014] FIG. 1 is a roller lifter constructed in accordance to one
example of the present disclosure and shown in an exemplary Type V
valve train arrangement;
[0015] FIG. 2 is a side perspective view of a roller lifter
constructed in accordance to one example of prior art;
[0016] FIG. 3 is a front perspective view of the roller lifter of
FIG. 2 and shown with a retaining clip in exploded view;
[0017] FIG. 4 is a side perspective view of a roller lifter
including a roller lifter body and a guide plug constructed in
accordance to one example of the present teachings;
[0018] FIG. 5 is a detail perspective view of the guide plug of the
roller lifter of FIG. 4;
[0019] FIG. 6 is a schematic illustration of a guide plug according
to another example of the present disclosure;
[0020] FIG. 7 is a top view of a guide plug constructed in
accordance to another example of the present disclosure and shown
retained in a roller lifter body with a C-clip;
[0021] FIG. 8 is a side perspective view of the roller lifter body
of FIG. 7;
[0022] FIG. 9 is a side perspective view of the guide plug of FIG.
7; and
[0023] FIG. 10 is a detail view of an interface between the guide
plug and an opposing bore slot in a cylinder head of an engine.
DETAILED DESCRIPTION
[0024] With initial reference to FIG. 1, a roller lifter
constructed in accordance to one example of the present disclosure
is shown and generally identified at reference number 10. The
roller lifter 10 is shown as part of a Type V arrangement. It will
be appreciated that while the roller lifter 10 is shown in a Type V
arrangement, the roller lifter 10 may be used in other arrangements
within the scope of the present disclosure. In one non-limiting
example, the present teachings can also be applied to a fuel pump
actuator. In this regard, the features described herein associated
with the roller lifter 10 can be suitable to a wide variety of
applications. A cam lobe 12 indirectly drives a first end of a
rocker arm 14 with a push rod 16. It will be appreciated that in
some configurations, such as an overhead cam, the roller lifter 10
may be a direct link between the cam lobe 12 and the rocker arm 14.
A second end of the rocker arm 14 actuates a valve 20. As the cam
lobe 12 rotates, the rocker arm 14 pivots about a fixed shaft 22.
The roller lifter 10 is in contact with, and follows the cam 12
through a conventional roller bearing or roller follower 24, such
as a needle roller bearing type. Those skilled in the art will
appreciate that the present disclosure is not limited to any
particular roller follower design, or for example, whether the axle
of the roller is provide with needle bearings or merely a
bushing.
[0025] The roller lifter 10 is configured to reciprocate along its
axis within a lifter-receiving hole 26 formed in engine block 28. A
clearance 29 can be defined between the receiving hole 26 and the
roller lifter 10. As will become appreciated herein, pressurized
engine oil can flow from an engine oil passage P formed in the
engine block 28, around the clearance 29 and into a groove 44
formed around the roller lifter. The groove 44 can act as an oil
reservoir to provide lubrication for the roller follower 24.
[0026] With initial reference to FIGS. 2 and 3, a roller lifter 10A
according to one example of prior art is shown and will be
described. The roller lifter 10A generally includes a body 30A,
having a leakdown assembly 32A received within the body 30A. A
roller bearing 34A is rotatably mounted to the body 30A. An
anti-rotation assembly 36A includes a guide plug 38A and a
retaining clip 40A. The body 30A includes an outer peripheral
surface 42A configured for sliding movement in a bore (not
specifically shown) provided in an engine block or cylinder head of
an internal combustion engine. The body 30A includes a groove 50A
and a pair of concave recess portions 52A formed therein and inset
from the outer peripheral surface 42A. The guide plug 38A includes
a pair of cylindrical sections 54A that extend from a central body
portion 56A.
[0027] The retaining clip 40A generally includes a ring body 60A
having an anti-rotation protrusion 62A extending therefrom. The
anti-rotation protrusion 62A extends radially beyond the outer
peripheral surface 42A of the body 30A in an installed position.
The anti-rotation protrusion 62A is configured to locate or key in
a corresponding bore slot (not specifically shown) in the cylinder
head for inhibiting rotation of the roller lifter about a
longitudinal axis during operation. The retaining clip 40A can be
snap fit into the groove 50A to capture the guide plug 38A.
Specifically, the pair of cylindrical sections 54A can locate into
the corresponding concave recess portions 52A formed in the body
30A. In the assembled position, the pair of cylindrical sections
54A can protrude radially beyond the outer peripheral surface 42A
of the body 30A and key in the corresponding bore slot of the
cylinder head.
[0028] Turning now to FIGS. 4-6, the roller lifter 10 constructed
in accordance to one example of the present teachings will be
described. The roller lifter 10 generally includes a body 30,
having a leakdown assembly 32 received within the body 30. The
roller follower 24 (FIG. 1) is rotatably mounted to the body 30. An
anti-rotation device 36 includes a guide plug 38 secured to the
body 30 with at least one of a set screw 39 and/or a C-clip 40
(FIG. 6). The body 30 includes an outer peripheral surface 42
configured for sliding movement in a bore slot (see for example
bore slot 158, FIG. 10) provided in a cylinder head of an internal
combustion engine. A groove 44 is formed around the outer
peripheral surface 42. The body 30 includes a receiving channel 50
formed therein and inset from the outer peripheral surface 42
configured to receive the guide plug 38.
[0029] The guide plug 38 includes a first and a second lobed body
portion 52 and 54, respectively. The first lobed body portion 52 is
configured to be slidably received into the receiving channel 50 of
the body 30. The first lobed body portion 52 will key into the
channel 50 to preclude radial movement of the guide plug 38. A slot
60 is defined in the body 30 at the channel 50 for receiving the
C-clip 40. The C-clip 40 can retain the guide plug 38 within the
channel 50 and preclude axial movement of the guide plug 38.
[0030] The second lobed body portion 54 extends radially beyond the
outer peripheral surface 42 of the body 30 in an installed
position. The second lobed body portion 54 is configured to locate
or key in a corresponding bore slot (see for example bore slot 158,
FIG. 10) in the cylinder head for inhibiting rotation of the roller
lifter about a longitudinal axis during operation.
[0031] The body 30 includes a connecting channel 70 formed therein.
The connecting channel 70 can be inset from the outer peripheral
surface 42. The connecting channel 70 fluidly connects with a
transverse passage 74. Oil that leaks down around the peripheral
surface 42 of the body 30 (between the body 30 and the bore of the
engine block) can be captured into the groove 44. From the groove
44, oil can flow into the connecting channel 70, through the
transverse passage 74 to lubricate the roller bearing 34.
[0032] Turning now to FIGS. 7-10, a roller lifter 110 constructed
in accordance to another example of the present teachings will be
described. The roller lifter 110 generally includes a body 130,
having a leakdown assembly 132 received within the body 130. A
roller bearing (see FIG. 1) is rotatably mounted to the body 130.
An anti-rotation device 136 includes a guide plug 138 secured to
the body 130 with a C-clip 140 (FIG. 7). The body 130 includes an
outer peripheral surface 142 configured for sliding movement in a
bore (see for example bore slot 158, FIG. 10) provided in a
cylinder head or engine block of an internal combustion engine. The
body 130 includes a channel 150 formed therein and inset from the
outer peripheral surface 142 configured to receive the guide plug
138.
[0033] The guide plug 138 includes a first and a second lobed body
portion 152 and 154, respectively. The first lobed body portion 152
is configured to be slidably received into channel 150 of the body
130 in a direction generally upward as viewed in FIG. 8. The first
lobed body portion 152 will key into the channel 150 to preclude
radial movement of the guide plug 138. A slot 160 is defined in the
body 130 at the channel 150 for receiving the C-clip 140. The
C-clip 140 can retain the guide plug 138 within the channel 150 and
preclude axial movement of the guide plug 138. In one example, the
guide plug 138 is cold formed.
[0034] The second lobed body portion 154 extends radially beyond
the outer peripheral surface 142 of the body 130 in an installed
position. The second lobed body portion 154 can have a pair of
parallel sidewalls 156. The second lobed body portion 154 is
configured to locate or key in a corresponding bore slot 158 (FIG.
10) in a cylinder head 159 for inhibiting rotation of the roller
lifter about a longitudinal axis during operation. An extension
portion 162 can be formed on the guide plug 138. The extension
portion 162 can be the result of a forming process for the guide
plug 138 such as cold form material overflow. Explained further,
the dies used in cold forming can be designed to allow a bulge to
form at one end of the guide plug 138. The extension portion 162
can further include a finger 164 (FIG. 9) configured to prevent
rotation of the C-clip 140 that retains the guide plug 138 further
improving reliability.
[0035] The body 130 includes a connecting channel 170 and an outer
groove 172 (FIG. 8) formed therein. The connecting channel 170 and
the outer groove 172 can be inset from the outer peripheral surface
142. The connecting channel 170 fluidly connects the outer groove
172 with a transverse passage 174. Oil can flow between the
connecting channel 170 and the outer groove 172 and to the
transverse passage 174 to lubricate the roller bearing (see FIG.
1).
[0036] According to other features of the present disclosure,
additional coupling arrangements and/or joining techniques may be
provided for retaining the guide plug 138 within the channel 150 of
the body 130 of the roller lifter 110. In one example, the body 130
of the roller lifter 110 can be locally annealed in an area around
the guide plug 138. In some examples, once the metal of the guide
plug 138 is softened, it can be shaped or formed toward the guide
plug 138 to retain the guide plug 138 within the channel 150.
Additionally or alternatively, a circumferential edge area 180 that
defines an entrance to the channel 150 can be annealed and shaped
inwardly to close the circumference and trap the guide plug 138
within the channel 150.
[0037] In other examples, the guide plug 138 can be staked relative
to the body 130 of the roller lifter 110. When staking, the guide
plug 138 can attain an interference fit in the channel of the body
130. In one non-limiting example, the guide plug 138 can be
slidably inserted into the channel 150. Once inserted, a tool such
as a staking punch can be used to axially compress the guide plug
138. Axial compression can cause the outer surfaces of the first
lobed body portion 152 (and the second lobed body portion 154) to
expand radially forming an interference fit with the channel 150 of
the body 130. A permanent joint can result that retains the guide
plug 138 into the channel 150.
[0038] In other configurations, the guide plug 138 can be
resistance welded to the body 130 in the channel 150. Other welding
operations such as laser welding can be used as well to couple the
guide plug 138 to the body 130. It will be appreciated that the
additional joining techniques described above can be equally
applied to the other configurations disclosed herein such as to the
guide plug 38 and body 130 of roller lifter 10. Furthermore, in
some examples multiple joining techniques disclosed herein may be
used in concert to capture the guide plug to the body of the roller
lifter.
[0039] According to additional features of the present disclosure,
various components of the roller lifter, guide plug and/or clip can
be formed of shape or smart memory alloy (SMA). In general SMA's
are metals that can "remember" their original or parent shape.
SMA's are Martensitic crystal materials that can be molded, then
plastically deformed, and then heat treated to return to the
desired shape. Once inserted, the guide plug 138 can be heat
treated. As used herein, the terms "heat treated" and "heat
treating" are used to denote raising the temperature of the SMA
above the transition temperature to restore the SMA to its original
or parent shape. By way of non-limiting example, some SMA's include
nickel-titanium (Ni--Ti, or nitinol), copper, zinc and aluminum
alloy (Cu--Zn--Al); copper, aluminum and nickel (Cu--Al--Ni); iron,
manganese and silicon (Fe--Mn--Si). Other SMA's may be used within
the scope of the present disclosure.
[0040] In one configuration, with reference to the examples show in
FIGS. 7-9, the guide plug 138 may be formed of SMA. While the
following discussion will be made in reference to the guide plug
138, a guide plug may be formed of SMA having other similar
geometries within the scope of the present disclosure. It will be
appreciated that the guide plug may be originally formed or molded
in a shape consistent to the desired "installed" shape for the
given channel 150.
[0041] In one configuration, the guide plug 138 can be introduced
into the channel 150 of the body 130. In some examples the guide
plug 138 may be plastically deformed prior to insertion into the
channel 150. Elevating the temperature of the guide plug 138 causes
it to take its original shape. In this regard, heat treating sets
the shape of the guide plug 138 in an installed position within the
channel 150. It is appreciated that the roller lifter 110 and guide
plug 138 may be heated in concert causing the SMA guide plug 138 to
be set in an installed position within the channel 150. The guide
plug 138 can attain a tolerance or clearance fit relative to the
channel 150 in the installed position fixing the guide plug 138
into the channel 150. This example eliminates the requirement of a
supplemental retaining device (such as the c-clip 140). Moreover,
such a configuration eliminates the requirement of special tooling
for installation of the guide plug 138 as there is no press-fit
during installation.
[0042] In another example, the c-clip 140 may be formed of SMA.
Again, the c-clip 140 can be originally formed or molded in a shape
consistent to the desired "installed" shape relative to the body
130. A guide plug 138 can be introduced into the channel 150 of the
body 130 and the c-clip 140 (or other supplemental retaining
mechanism) subsequently located. The c-clip 140 can be heat treated
causing it to take its original shape attaining a fixed
relationship with the body 130 and securing the guide plug 138 in
the channel 150. Again, in some examples the whole assembly (roller
lifter 110, guide plug 138 and c-clip 140) may be heated together
with the understanding that the SMA components will react
appropriately to the heat treatment. It is further appreciated that
more than one piece may be formed of SMA. For example, the guide
plug 138 and the c-clip 140 may both be formed of SMA and arranged
in geometries to cooperatively "return" to their original shape in
a coupled relationship subsequent to heat treatment.
[0043] The foregoing description of the examples has been provided
for purposes of illustration and description. It is not intended to
be exhaustive or to limit the disclosure. Individual elements or
features of a particular example are generally not limited to that
particular example, but, where applicable, are interchangeable and
can be used in a selected example, even if not specifically shown
or described. The same may also be varied in many ways. Such
variations are not to be regarded as a departure from the
disclosure, and all such modifications are intended to be included
within the scope of the disclosure.
* * * * *