U.S. patent application number 12/150370 was filed with the patent office on 2009-10-29 for pump drive cartridge assembly.
Invention is credited to Chris M. De Minco, Jared I. Meeker.
Application Number | 20090269226 12/150370 |
Document ID | / |
Family ID | 41215199 |
Filed Date | 2009-10-29 |
United States Patent
Application |
20090269226 |
Kind Code |
A1 |
De Minco; Chris M. ; et
al. |
October 29, 2009 |
Pump drive cartridge assembly
Abstract
An anti-rotation sleeve for a high-pressure piston compression
pump includes a sleeve having a generally cylindrical elongated
shape and extending longitudinally along a central axis from a
first end to a second end and features that provide orientation and
that limit radial movement integrated in an inner diameter of the
sleeve. The first end of the sleeve attaches to a base of the pump
and the second end slidably engages a lifter body. The lifter body
includes corresponding features that provide orientation and that
limit radial movement integrated in an outer diameter of the lifter
body. By providing an anti-rotation sleeve a relatively simple pump
drive cartridge assembly that integrates all pump drive components
into a one integral part is enabled. Hence, lower manufacturing and
assembly costs, reduced manufacturing and assembly cycle times, and
easier packaging conditions are obtained.
Inventors: |
De Minco; Chris M.; (Honeoye
Falls, NY) ; Meeker; Jared I.; (Rochester,
NY) |
Correspondence
Address: |
DELPHI TECHNOLOGIES, INC.
M/C 480-410-202, PO BOX 5052
TROY
MI
48007
US
|
Family ID: |
41215199 |
Appl. No.: |
12/150370 |
Filed: |
April 28, 2008 |
Current U.S.
Class: |
417/437 |
Current CPC
Class: |
F04B 1/0408 20130101;
F04B 1/0439 20130101 |
Class at
Publication: |
417/437 |
International
Class: |
F04B 19/00 20060101
F04B019/00 |
Claims
1. An anti-rotation sleeve for a fuel pump, comprising: a sleeve
having a generally cylindrical elongated shape and extending
longitudinally along a central axis from a first end to a second
end; and at least one feature that provides orientation and that
limits radial movement integrated in said sleeve; wherein said
first end of the sleeve attaches to a base of said fuel pump;
wherein said second end of the sleeve slidably engages a lifter
body; and wherein said lifter body includes at least one feature
that mates with said at least one sleeve feature to provide
orientation and to limit radial movement of said lifter body
relative to said sleeve.
2. The anti-rotation sleeve of claim 1, wherein said at least one
sleeve feature includes one of a flat surface or a projection; and
wherein said at least one lifter body feature includes the other of
said flat surface or said projection, thereby limiting radial
movement of said lifter body relative to said sleeve.
3. The anti-rotation sleeve of claim 1, wherein said sleeve houses
a reciprocating plunger and spring assembly of said pump.
4. The anti-rotation sleeve of claim 1, wherein said first end is
retained to said base of said pump such that radial movement of
said sleeve relative to said base is prevented.
5. The anti-rotation sleeve of claim 1, further comprising a
plurality of holes incorporated in said sleeve, wherein said holes
enable oil passage into and out of said sleeve.
6. The anti-rotation sleeve of claim 1, wherein an inner diameter
of said sleeve at said second end receives an outer diameter of
said lifter body.
7. The anti-rotation sleeve of claim 1, wherein an outer diameter
of said sleeve at said second end receives an inner diameter of
said lifter body.
8. The anti-rotation sleeve of claim 1, wherein an axial length of
said sleeve is adjustable to an engine-mounting requirement.
9. The anti-rotation sleeve of claim 1, wherein said at least one
sleeve feature includes one of a longitudinal groove or a
projection; and wherein said at least one lifter body feature
includes the other of said longitudinal groove or said projection,
thereby limiting radial movement of said lifter body relative to
said sleeve.
10. The anti-rotation sleeve of claim 1, wherein a push rod extends
between said lifter body and a plunger of said pump to transmit a
linear vertical reciprocating motion of said lifter body to said
plunger of said pump.
11. The anti-rotation sleeve of claim 1, wherein a plunger of said
pump is in contact with said lifter body to transmit a linear
vertical reciprocating motion of said lifter body to said pump.
12. The anti-rotation sleeve of claim 1, wherein said sleeve
integrates all pump drive components of said pump into a single
integral part.
13. A pump drive cartridge assembly of a fuel pump, comprising: a
lifter body including a camshaft follower; an anti-rotation sleeve
connecting said lifter body to a base of said pump, said sleeve
slidably receiving said lifter body and said sleeve housing a
reciprocation plunger and spring assembly of said pump; and at
least one feature disposed in one of said lifter body or said
anti-rotation sleeve that provides orientation and that prevents
radial movement of said lifter body relative to said sleeve;
wherein said camshaft follower transmits a rotational motion and
lift provided by a camshaft lobe to a linear vertical reciprocating
motion of said lifter body, said linear vertical reciprocating
motion driving said pump.
14. The pump drive cartridge assembly of claim 13, wherein said
plunger is in contact with said lifter body transmitting said
linear vertical reciprocating motion.
15. The pump drive cartridge assembly of claim 13, further
including a push rod that extends between said lifter body and said
plunger of said pump to transmit a linear vertical reciprocating
motion of said lifter body to said plunger.
16. The pump drive cartridge assembly of claim 13, wherein said
camshaft follower is a roller follower.
17. The pump drive cartridge assembly of claim 13, wherein said
lifter body axially slides within said sleeve.
18. The pump drive cartridge assembly of claim 13, wherein said at
least one feature disposed in one of said lifter body or said
anti-rotation sleeve includes a pair of flat surfaces positioned
radially across from each other for providing orientation and
preventing radial movement of said lifter body relative to said
sleeve.
19. The pump drive cartridge assembly of claim 13, wherein said at
least one feature disposed in one of said lifter body or said
anti-rotation sleeve includes a projection extending from one of
said lifter body or said anti-rotation sleeve and a mating groove
formed in the other of said lifter body or said anti-rotation
sleeve, wherein said projection axially moves in said groove for
providing orientation and preventing radial movement of said lifter
body relative to said sleeve.
20. A pump assembly of a direct injection fuel system, comprising:
a pump including a reciprocating plunger and spring assembly
extending a base of said pump; a camshaft lobe; and a pump drive
cartridge assembly arranged between said pump and said camshaft
lobe to transmit the rotational motion and lift of said camshaft
lobe to a linear vertical reciprocating motion required to drive
said pump; wherein said pump drive cartridge assembly defines
features that provide orientation and that prevent radial movement
of said pump relative to said camshaft lobe.
21. The pump assembly of claim 20, wherein said pump drive
cartridge assembly includes: a lifter body including a roller
follower; and an anti-rotation sleeve connecting said lifter body
to said base of said pump, said sleeve slidably receiving said
lifter body opposite from said roller follower and said sleeve
housing said reciprocation plunger and spring assembly of said
pump; wherein said features that provide orientation and that
prevent radial movement of said pump relative to said camshaft lobe
are integrated in said lifter body and said anti-rotation
sleeve.
22. The pump assembly of claim 20, wherein said pump drive
cartridge assembly includes oil passages that minimize the
reciprocating weight of said pump drive cartridge and enable
adequate lubrication of interfaces between said pump drive
cartridge assembly and said camshaft lobe.
Description
TECHNICAL FIELD
[0001] The present invention relates to direct injection internal
combustion engines; more particularly, to high-pressure mechanical
fuel pumps used in high-pressure direct injection fuel systems; and
most particularly, to a pump drive cartridge assembly.
BACKGROUND OF THE INVENTION
[0002] It has become generally known in the art of internal
combustion engine design to use high-pressure mechanical fuel pumps
in direct injection fuel systems. In known direct injection fuel
systems, a high-pressure fuel injection pump typically disposed in
the engine compartment close to the injector fuel rail is arranged
to supply fuel from a pumping chamber to associated injectors
located downstream of the pumping chamber.
[0003] Traditionally, high-pressure mechanical fuel pumps require a
camshaft follower, such as a flat foot follower or a roller
follower, operated by a dedicated camshaft lobe on a rotating jack
shaft, to transmit the rotational motion and lift of the camshaft
lobe to a linear motion required to drive a typical piston
compression pump. A high-pressure fuel pump may generate fuel
system pressure approaching 100 atmospheres or more.
[0004] These high fuel pressures generate high loads in the system
and require a robust pump and pump drive design. Based on the
design of the internal combustion engine and/or the pump placement,
the assembly of the pump and lifter assembly becomes cumbersome and
costly, especially when roller followers are used, and alignment of
the roller follower and a camshaft is required.
[0005] Typically, a lifter engages a camshaft lobe via the camshaft
follower end, which preferably includes a roller. Unless suitably
constrained by an anti-rotation guide, a roller follower lifter may
rotate axially in its bore during reciprocation, thereby
undesirably misaligning its roller follower from the associated
camshaft lobe.
[0006] Lifter anti-rotation guides in the prior art are often
integrated in the engine block adjacent to the lifter bore. A
locating feature in the guide aperture, such as a longitudinal
groove or undercut, receives a mating feature in the lifter to
prevent the lifter from rotating about its longitudinal axis during
reciprocation. Machining of such locating features is cost and
labor intensive. Other prior art lifter anti-rotation guides
utilize secondary anti-rotation attachments of locator features
that are attached to the engine following lifter installation and,
therefore, add another step to the assembly process.
[0007] What is needed in the art is to simplify the assembly
process of a high-pressure direct injection fuel system and to
reduce the total number of parts of such system.
[0008] It is a principal object of the present invention to provide
a cartridge assembly that integrates all pump drive components in
one integral part.
[0009] It is a further object of the invention to simplify engine
block machining by eliminating secondary anti-rotation attachments
or locator features.
SUMMARY OF THE INVENTION
[0010] The present invention successfully addresses the
shortcomings of the prior art by providing in a first aspect of the
invention a cartridge pump drive assembly that includes an
anti-rotation sleeve and that integrates all pump drive components
in one integral part.
[0011] The anti-rotation sleeve extends from the base of a
high-pressure pump, around a reciprocating plunger and spring
assembly, over a push rod assembly (if one is required for driving
the pump), and to a lifter body above a lifter engine bore. The
inner pump shaft may be extended as needed or a simple lower cost
push rod may be used to connect the pump plunger to the lifter body
as needed). The anti-rotation sleeve engages an end of the lifter
body but is designed to allow the lifter body to slide up and down
within the anti-rotation sleeve based on the drive motion created
by a camshaft lobe profile thereby transmitting the vertical
reciprocating motion to the pump. The sleeve may be made out of a
lightweight polymer or drawn from thin sheet steel and may be
designed to minimize the reciprocating weight and to reduce engine
friction. The anti-rotation sleeve may be designed to allow
additional spring packaging to support the lifter body and push rod
reciprocating mass.
[0012] All drive components are self-contained within the
anti-rotation sleeve thereby resisting separation during shipping
or assembly. A simple press/snap fit or other engagement technique
may be used at the pump end and a captive ring, snap fit or other
engagement technique may be used at the sliding end. If a roller
lifter is used and anti-rotation is required, the sleeve can be
pinned or retained to the upper pump body and undercuts can be
provided on the top of the lifter body or a sliding pin device can
be utilized.
[0013] By using the anti-rotation sleeve in accordance with the
invention, a relatively simple single piece cartridge assembly is
provided utilizing relatively low cost modifications. The pump
drive cartridge assembly in accordance with the invention minimizes
engine assembly steps, total number of parts, and installation
time. Existing manufacturing and assembly techniques can be used to
implement the anti-rotation sleeve in accordance with the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will now be described, by way of
example, with reference to the accompanying drawings, in which:
[0015] FIG. 1 is a cross-sectional view of a pump assembly, in
accordance with a first embodiment of the invention;
[0016] FIG. 2 is a cross-sectional view taken along line 2-2 in
FIG. 1, in accordance with the first embodiment of the
invention;
[0017] FIG. 3 is a cross-sectional view taken along line 3-3 in
FIG. 2, in accordance with the first embodiment of the
invention;
[0018] FIG. 4 is a cross-sectional view taken along line 4-4 in
FIG. 2, in accordance with the first embodiment of the invention;
and
[0019] FIG. 5 is a cross-sectional view of a pump assembly, in
accordance with a second embodiment of the invention.
[0020] Corresponding reference characters indicate corresponding
parts throughout the several views. The exemplification set out
herein illustrates preferred embodiments of the invention, in one
form, and such exemplification is not to be construed as limiting
the scope of the invention in any manner.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Referring to FIG. 1, a pump assembly 100 includes a
high-pressure pump 110, a camshaft lobe 120, and a pump drive
cartridge assembly 130 arranged between pump 110 and lobe 120. The
pump drive cartridge assembly 130 includes an anti-rotation sleeve
132 that extends from a base 112 of high-pressure pump 110 to a
lifter body 134 above an engine lifter bore 114. Cartridge assembly
130 houses a reciprocating plunger 136 and spring 138 assembly, and
extends partially over a push rod 142. Lifter body 134 engages
camshaft lobe 120 via a camshaft follower, for example, a roller
follower 144 as shown in FIG. 1 that is attached to one end of
lifter body 134. Roller follower 144 transmits the rotational
motion and lift of camshaft lobe 120 to a linear vertical motion of
lifter body 134 required to drive pump 110, which may be a typical
high-pressure piston compression pump. Pump assembly 100 is
suitable for various engine-mounting applications and may be
installed to an engine block 116 through an engine interface, for
example, through an oil manifold assembly plate 118 or a suitable
bracket.
[0022] Lifter body 134 includes a push rod seat 146 that receives
push rod 142. Push rod 142 extends between lifter body 134 and
plunger 136 to transmit the linear vertical reciprocating motion of
lifter body 134 to plunger 136 of pump 110. While push rod 142 is
shown to have parallel axial extending walls, it may be possible to
use a tapered push rod that includes a larger diameter inserted in
lifter body 134 and that includes a smaller diameter at the pump
side. It may also be possible to utilize a push rod 142 that is
crowned at the end where it contacts plunger 136.
[0023] Lifter body 134 has a generally cylindrical elongated shape.
Lifter body 134 has roller follower 144 attached at one end and
receives push rod 142 through an open opposite end. The open end of
lifter body 134 is received by and slidably attached to sleeve 132.
Lifter body 134 may include openings 135 as oil passages that
enable oil drainage and adequate lubrication of the roller follower
144/camshaft lobe 120 interface. Shown in FIG. 1 is a lifter body
134 that extends longitudinally along axis 140 for a relatively
long distance.
[0024] Anti-rotation sleeve 132 has a generally cylindrical
elongated shape and extends longitudinally along a central axis 140
from a first end 148 to a second end 152. First end 148 is designed
to be received by base 112 of pump 110. Sleeve 132 may be attached
to base 112 of pump 110 by a typical engagement technique; for
example, by a simple press/snap fit or crimp fit mechanism. If
roller follower 144 is used as shown in FIG. 1 and anti-rotation is
required, sleeve 132 may be pinned or otherwise retained to base
112 of pump 110 to keep roller 144 properly aligned with its mating
camshaft lobe. Second end 152 of sleeve 132 is designed to receive
and engage lifter body 134 such that lifter body 134 is able to
slide up and down within sleeve 132 based on the drive motion
created by the profile of camshaft lobe 120. Therefore the inner
diameter of sleeve 132 at second end 152 is designed to receive the
outer diameter of lifter body 134. When inserted, lifter body 134
and sleeve 132 overlap in axial direction for a distance. Sleeve
132 may be attached to lifter body 134 by an engagement technique,
such as a captive ring or a press/snap fit mechanism. In accordance
with the invention, it is also possible that the sleeve and body be
designed so that an outer diameter of sleeve 132 receives an inner
diameter of lifter body 132. If roller follower 144 is used as
shown in FIG. 1 and anti-rotation is required, undercuts may be
provided on the top of lifter body 134 as illustrated in FIGS. 2-4
or a sliding pin device may be utilized as in traditional valve
train roller lifter systems.
[0025] Anti-rotation sleeve 132 may be formed from a relatively
light weight polymer material or steel and may be designed with
several holes 154 as oil passages incorporated that allow splash
lubrication into and out of pump drive cartridge assembly 130 to
minimize the reciprocating weight of assembly 130 while enabling
adequate lubrication of the interfaces of pump assembly 100. The
axial length of sleeve 132 can be adjusted to various engine
mounting requirements.
[0026] All pump drive components, such as plunger 136 and spring
138 assembly, push rod 142, lifter body 134, and camshaft follower,
for example, a roller follower 144 as shown in FIG. 1, are self
contained within anti-rotation sleeve 132, such that these parts
cannot become separated during shipping or during assembly. Sleeve
132 may be attached to pump 110 prior to shipping and/or prior to
assembly into engine lifter bore 114, such that pump assembly 100
is shipped and/or installed as a single integral part.
[0027] Referring to FIGS. 2 through 4, cross-sectional views are
taken in various directions where lifter body 134 and anti-rotation
sleeve 132 overlap. In this overlapping area, several features that
provide orientation and that prevent radial movement of lifter body
134 relative to anti-rotation sleeve 132 may be included. As
illustrated in FIGS. 2 and 3, both lifter body 134 and
anti-rotation sleeve 132 may have corresponding flat surfaces 156
and 158, respectively, incorporated. Flat surface 156 and 158 are
positioned where anti-rotation sleeve 132 engages lifter body 134
and prevent axial rotation of lifter body 134 relative to
anti-rotation sleeve 132. Flat surface 156 and 158 are also
orientation guides that simplify the assembly process of pump
assembly 100. Tolerances between the two flat surfaces 156 and 158
and length of the two flat surfaces 156 and 158 are dimensioned to
allow axial movement of lifter body 134 within anti-rotation sleeve
132. As shown in FIG. 2, a pair of flat surfaces 156 positioned
across from each other and a pair of flat surfaces 158 may be
formed in lifter body 134 and anti-rotation sleeve 132,
respectively. To further limit the axial position possibilities of
the body relative to the sleeve, it may also be possible to form
only one flat surface 156 and only one corresponding flat surface
158 in lifter body 134 and anti-rotation sleeve 132, respectively.
Flat surface 156 of lifter body 134 may be formed as an undercut as
illustrated in FIG. 3.
[0028] Referring to FIG. 4, in addition to flat surfaces 156 and
158, a pair of sliding pin features 160 may be included as
anti-rotation feature in pump drive cartridge assembly 130. Sliding
pin features 160 are positioned perpendicular to flat surfaces 156
and 158. It may be possible to include only one sliding pin feature
160 to prevent axial rotation of lifter body 134 relative to sleeve
132. It may further be possible to include only sliding pin
features 160 and not flat surfaces 156 and 158.
[0029] Sliding pin feature 160 may include a projection 162, such
as a pin, formed to extend from the inner diameter of sleeve 132
and a groove 164 formed in the outer diameter of lifter body 134
receiving the projection 162. Projection 162 and groove 164 are
dimensioned such that projection 162 is able to slide axially up
and down within groove 164 based on the drive motion created by the
profile of camshaft lobe 120 shown in FIG. 1. Groove 164 limits the
radial movement of projection 162, and therefore the radial
movement of the body relative to the sleeve. Furthermore,
projection 162 and groove 164 are designed such that lifter body
134 can be connected with sleeve 132 by a press/snap fit
technique.
[0030] Referring now to FIG. 5, a pump assembly 200 includes a
high-pressure pump 210, a camshaft lobe 220, and a pump drive
cartridge assembly 230 arranged between pump 210 and lobe 220. The
pump drive cartridge assembly 230 includes an anti-rotation sleeve
232 that extends from a base 212 of high-pressure pump 210 to a
lifter body 234 above an engine lifter bore 214, and houses a
reciprocating plunger 236 and spring 238 assembly. Contrary to pump
assembly 100 shown in FIG. 1, pump assembly 200 does not include a
push rod, such as push rod 142, and plunger 236 directly contacts
roller follower 244. Lifter body 234 engages camshaft lobe 220 via
a camshaft follower, for example, a roller follower 244 as shown in
FIG. 5 that is attached to one end of lifter body 234. Roller
follower 244 transmits the rotational motion and lift of a camshaft
lobe to a linear motion of lifter body 234 required to drive pump
210, which may be a typical high-pressure piston pump. Pump
assembly 200 is suitable for various engine-mounting applications
and may be installed to an engine block 216 through an engine
interface, for example, through an oil manifold assembly plate 218
or a suitable bracket.
[0031] Lifter body 234 has a generally cylindrical elongated shape.
Lifter body 234 has roller follower 244 attached at one end and
receives plunger 236 through an opposite open end. The open end of
lifter body 234 is received by and slidably attached to sleeve 232.
Lifter body 234 may include openings 235 that enable oil drainage.
A c-clip 266 or other attachment feature attaches lifter body 234
to plunger 236. The attachment feature can be used to transmit the
vertical reciprocating motion of lifter body 234 to pump 210. Shown
in FIG. 5 is a lifter body 234 that extends longitudinally along
axis 240 for a relatively long distance.
[0032] Anti-rotation sleeve 232 may be designed similar to
anti-rotation sleeve 132 shown in FIG. 1 and may connect pump 210
and lifter body 234. Anti-rotation sleeve 232 may engage lifter
body 234 including features providing orientation and anti-rotation
similar to anti-rotation sleeve 132 as shown in FIGS. 2-4.
[0033] The axial length of anti-rotation sleeves 132 and 232 shown
in FIGS. 1 and 2, respectively, may be adapted according to the
industry and customer needs. The axial length of lifter bodies 134
and 234 shown in FIGS. 1 and 2, respectively, may also be adapted
according to the industry and customer needs. Accordingly, a design
of pump assembly 200 is possible, where sleeve 232 has a larger
diameter and a shorter axial length than illustrated in FIG. 5 to
accommodate a spring 238 that is wider and shorter. Such sleeve 232
may engage a lifter body 234 that has a shorter axial length than
shown in FIG. 5.
[0034] By providing an anti-rotation sleeve, such as sleeves 132
and 232 shown in FIGS. 1 and 5, respectively, a relatively simple
pump drive cartridge assembly, such as assemblies 130 and 230 shown
in FIGS. 1 and 5, respectively, that integrates all pump drive
components into a one integral part is enabled. Hence, lower
manufacturing and assembly costs, reduced manufacturing and
assembly cycle times, and easier packaging conditions are
obtained.
[0035] While the invention has been described by reference to
various specific embodiments, it should be understood that numerous
changes may be made within the spirit and scope of the inventive
concepts described. Accordingly, it is intended that the invention
not be limited to the described embodiments, but will have full
scope defined by the language of the following claims.
* * * * *