U.S. patent application number 17/267087 was filed with the patent office on 2022-02-17 for rotor for camshaft phaser and camshaft phaser.
This patent application is currently assigned to Schaeffler Technologies AG & Co. KG. The applicant listed for this patent is Schaeffler Technologies AG & Co. KG, Peng WANG. Invention is credited to Peng Wang.
Application Number | 20220049633 17/267087 |
Document ID | / |
Family ID | |
Filed Date | 2022-02-17 |
United States Patent
Application |
20220049633 |
Kind Code |
A1 |
Wang; Peng |
February 17, 2022 |
Rotor for Camshaft Phaser and Camshaft Phaser
Abstract
The present disclosure relates to a rotor for a camshaft phaser.
A balance groove is formed inside the end face of one axial side of
the rotor and inside the end face of the other axial side of the
rotor. A through-hole penetrating through the rotor in an axial
direction is formed in the rotor, and the balance grooves at the
two sides of the rotor are in communication with each other by the
through-hole. The rotor can balance gaps between the rotor and two
end covers, so that the amount of engine oil leaking from the gaps
of an oil chamber can be maintained at a low level, and the
probability of hard contact between the rotor and the end covers is
reduced, thus also reducing the wear between the rotor and the end
covers.
Inventors: |
Wang; Peng; (Shanghai,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WANG; Peng
Schaeffler Technologies AG & Co. KG |
Shanghai
Herzogenaurach |
|
CN
DE |
|
|
Assignee: |
Schaeffler Technologies AG &
Co. KG
Herzogenaurach
DE
|
Appl. No.: |
17/267087 |
Filed: |
August 22, 2018 |
PCT Filed: |
August 22, 2018 |
PCT NO: |
PCT/CN2018/101769 |
371 Date: |
February 9, 2021 |
International
Class: |
F01L 1/344 20060101
F01L001/344 |
Claims
1. A rotor for a camshaft phaser, comprising: a first balance
groove formed on a first end face of a first axial side of the
rotor; a second balance groove formed on a second end face of a
second axial side of the rotor; at least one through-hole
penetrating through the rotor in an axial direction; and, the first
balance groove and the second balance groove are in fluid
communication with each other via the at least one through-hole;
and, each of the first and second balance grooves are arranged with
spacing relative to a periphery of the rotor.
2. The rotor of claim 1, wherein a first total volume of the first
balance groove is equal to a second total volume of the second
balance groove.
3. The rotor of claim 1, wherein a minimum spacing between the
first balance groove and a periphery of the rotor is greater than
or equal to 3 mm.
4. The rotor of claim 1, wherein the rotor further comprises a
cylindrical main body and a plurality of rotor blades protruding
from the main body, and the first balancing groove includes a
circumferential groove formed in the main body.
5. The rotor of claim 4, wherein the circumferential groove extends
continuously for 360 degrees.
6. The rotor of claim 4, wherein the first balance groove further
comprises a radial groove extending outwards one of the plurality
of rotor blades in a radial direction from the circumferential
groove, and the radial groove is in fluid communication with the
circumferential groove.
7. The rotor of claim 4, wherein the at least one through-hole
includes a plurality of through-holes evenly distributed in a
circumferential direction within the circumferential groove.
8. The rotor claim 6, wherein the at least one through-hole
includes a through-hole formed in the radial groove.
9. The rotor of claim 1, wherein the rotor is formed by powder
metallurgy.
10. The rotor of claim 1, wherein the rotor is a component of a
camshaft phaser.
11. A camshaft phaser, comprising: a stator configured with
radially inwardly extending protrusions; a rotor having: a first
balance groove formed on a first end face of a first axial side of
the rotor, the first balance groove; and, a second balance groove
formed on a second end face of a second axial side of the rotor; at
least one through-hole penetrating through the rotor in an axial
direction, the first balance groove and the second balance groove
in fluid communication with each other via the at least one
through-hole; and, radially outwardly extending blades; and, a
first end cover; and, a second end cover; and, the first and second
end covers, the blades, and the protrusions configured to form a
first oil chamber and a second oil chamber; and, the first oil
chamber configured receive engine oil to rotate the rotor in a
first rotational direction relative to the stator, defining a first
working state; and, the second oil chamber configured to receive
engine oil to rotate the rotor in a second rotational direction
relative to the stator, defining a second working state; and, in
the first working state: the first balance groove is configured to
receive engine oil from the second balance groove via the at least
one through-hole to move the rotor in a first axial direction; and,
the second balance groove is configured to receive engine oil from
the second balance groove via the at least one through-hole to move
the rotor in a second axial direction.
12. The camshaft phaser of claim 11, wherein: the first end cover
forms a first gap with the first end face; the second end cover
forms a second gap with the second end face; and, in the first
working state: the first balance groove is configured to receive
engine oil from the second gap via the second balance groove and
the at least one through-hole; and, the second balance groove is
configured to receive engine oil from the first gap via the second
balance groove and the at least one through-hole.
13. The camshaft phaser of claim 11, wherein in the second working
state: the first balance groove is configured to receive engine oil
from the second balance groove via the at least one through-hole;
and, the second balance groove is configured to receive engine oil
from the second balance groove via the at least one
through-hole.
14. The camshaft phaser of claim 13, wherein: the first end cover
forms a first gap with the first end face; the second end cover
forms a second gap with the second end face; and, in the second
working state: the first balance groove is configured to receive
engine oil from the second gap via the second balance groove and
the at least one through-hole; and, the second balance groove is
configured to receive engine oil from the first gap via the second
balance groove and the at least one through-hole.
15. The camshaft phaser of claim 11, wherein a first total volume
of the first balance groove is equal to a second total volume of
the second balance groove.
16. The camshaft phaser of claim 11, wherein the first and second
balance grooves are arranged on a cylindrical main body of the
rotor.
17. The camshaft phaser of claim 16, wherein the first and second
balance grooves each include a circumferential groove.
18. The camshaft phaser of claim 17, wherein the circumferential
groove extends continuously for 360 degrees.
19. A rotor for a camshaft phaser, comprising: a first balance
groove formed on a first end face of a first axial side of the
rotor; a second balance groove formed on a second end face of a
second axial side of the rotor; at least one through-hole
penetrating through the rotor in an axial direction; and, the first
balance groove and the second balance groove are in fluid
communication with each other via the at least one through-hole;
and, a plurality of blades having: a first side configured to
receive engine oil to move the rotor in a first rotational
direction, defining a first working state; and, a second side
configured to receive engine oil to move the rotor in a second
rotational direction, defining a second working state; and, in the
first working state: the first balance groove is configured to
receive engine oil from the second balance groove via the at least
one through-hole to move the rotor in a first axial direction; and,
the second balance groove is configured to receive engine oil from
the first balance groove via the at least one through-hole to move
the rotor in a second axial direction.
20. The rotor of claim 19, wherein each of the first and second
balance grooves include a circumferential groove and a radial
groove, the radial groove extending within one of the plurality of
blades from the circumferential groove.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. National Phase of PCT
Application PCT/CN2018/101769 filed on Aug. 22, 2018, the entire
disclosure of which is incorporated by reference herein.
TECHNICAL FIELD
[0002] The present disclosure relates to a rotor for a camshaft
phaser and the camshaft phaser.
BACKGROUND
[0003] A variable valve timing system is an important part for
guaranteeing engine performance, which can adjust the opening and
closing of a valve of an engine as required, thereby enabling the
engine to obtain expected power output, fuel consumption and
emissions.
[0004] In the prior art, the variable valve timing system mainly
comprises a camshaft phaser and a camshaft connected with the
camshaft phaser, and the camshaft is connected to the valve of the
engine through a valve mechanism. In general, a plurality of oil
chambers are formed in the camshaft phaser by an end cover, a rotor
and a stator (the stator and the end cover are relatively fixed),
engine oil at different pressures can be fed into the plurality of
oil chambers to enable the rotor to rotate relative to the stator
and the end cover, thereby driving the camshaft to regulate the
opening and closing of the valve through the rotor.
[0005] As shown in FIG. 1a and FIG. 1b, the camshaft phaser in the
prior art comprises a stator 10, a rotor 20, two end covers 30 and
40, a seal assembly 50 and a locking assembly 60.
[0006] Specifically, the stator 10 comprises a cylindrical stator
body 101 and a plurality of stator protrusions 102 (four shown in
the figure) protruding towards a radial inner side from the stator
body 101. A plurality of teeth 103 distributed in a circumferential
direction C are formed on a radial outer side of the stator body
101 for being engaged with transmission components such as chains
and the like.
[0007] The rotor 20 is arranged on the radial inner side of the
stator 10 and can rotate relative to the stator 10. The rotor 20
includes a cylindrical rotor main body 201 and a plurality of rotor
blades 202 (four shown in the figure) protruding towards the radial
outer side from the rotor main body 201. The plurality of rotor
blades 202 and the plurality of stator protrusions 102 are
alternately arranged in the circumferential direction C, so that
each rotor blade 202 is located between two adjacent stator
protrusions 102. In this way, a space between the two adjacent
stator protrusions 102 is divided into two oil chambers A and B
which are independent of each other by the rotor blade 202 located
between the two stator protrusions 102.
[0008] The two end covers 30 and 40 are fixed on the stator 10 from
the two axial sides through fixing parts, so that the two end
covers 30 and 40, the stator 10 and the rotor 20 form the oil
chambers A and B in a surrounding way.
[0009] The seal assemblies 50 are arranged at the end faces of the
radial outer sides of the rotor blades 202 and abut against the
stator body 101, and each seal assembly 50 includes a seal lip 501
and a leaf spring 502 abutting against the seal lip 501 from the
radial inner side for isolating the two oil chambers A and B
separated by the rotor blade 202 from each other.
[0010] The locking assembly 60 is arranged at a stator protrusion
102 and the end cover 40 and can lock the rotation of the rotor 20
relative to the stator 10, and the locking of the locking assembly
60 can be released when the rotor 20 is required to rotate relative
to the stator 10.
[0011] In the camshaft phaser with the structure in the prior art,
the rotor 20 is in plane contact (plane-to-plane contact) with the
end covers 30 and 40 in the axial direction X, this plane contact
must have a certain gap, thereby ensuring that the rotor 20 can
rotate relative to the end covers 30 and 40. In addition, it is
necessary to ensure the seal between the rotor 20 and the end
covers 30 and 40 while ensuring that the rotor 20 can rotate
relative to the end covers 30 and 40; consequently, on the one
hand, the amount of engine oil in the adjacent oil chambers A and B
leaking from the gaps between the rotor 20 and the end covers 30
and 40 needs to be controlled at a low level; and on the other
hand, the external leakage needs to be prevented.
[0012] However, in the actual working process, the rotor 20 is
closer to a certain side (the left side or right side in FIG. 1a)
of the two sides of the axial direction X for most of time due to
various reasons (such as bending moment produced by the chains or
belts, axial displacement of the camshaft, geometric error of the
rotor and the like), thus causing the unbalance (inequality) of the
gap between the rotor 20 and the end cover 30 and the gap between
the rotor 20 and the end cover 40, and then resulting in the
problems as follows:
1. Due to the fact that the amount of leakage is in direct
proportion to the third power of the gap, when the gap between the
rotor 20 and the end cover 30 and the gap between the rotor 20 and
the end cover 40 are unbalanced, the amount of leakage between the
oil chambers and amount of external leakage are undesirably
increased; 2. Due to the fact that hard contact is likely to occur
between the rotor 20 and the end cover 30 or between the rotor 20
and the end cover 40 at the side with the smaller gap, large
friction is likely to produce between the rotor 20 and the end
cover 30 or between the rotor 20 and the end cover 40, and the
rotor 20 and the end covers 30 and 40 are likely to wear.
SUMMARY
[0013] The present disclosure is provided based on the defects in
the prior art. An objective of the present disclosure is to provide
a rotor for a camshaft phaser, which can balance gaps between the
rotor and end covers at two sides as much as possible, thereby
reducing both the amount of engine oil in an oil chamber of the
camshaft phaser leaking from the gaps and reducing wear between the
rotor and the end covers. Another objective of the present
disclosure is to provide a camshaft phaser including the rotor for
a camshaft phaser.
[0014] In order to achieve the objectives of the present
disclosure, the present disclosure adopts the following technical
solutions.
[0015] The disclosure provides a rotor for the camshaft phaser as
follows: a balance groove is formed inside the end face of one
axial side of the rotor and in an end face of the other axial side
of the rotor respectively there is spacing between the balance
groove and the periphery of the rotor. A through-hole penetrating
through the rotor in an axial direction is formed in the rotor, and
the balance groove inside the end face of one axial side of the
rotor and the balance groove inside the end face of the other axial
side of the rotor are in communication with each other by the
through-hole.
[0016] In an example embodiment, a total volume of the balance
groove inside the end face of one axial side of the rotor is equal
to that of the balance groove inside the end face of the other
axial side of the rotor.
[0017] In an example embodiment, the minimum spacing between each
balance groove and the periphery of the rotor is greater than or
equal to 3 mm.
[0018] In an example embodiment, the rotor comprises a cylindrical
rotor main body and a plurality of rotor blades protruding towards
the radial outer side from the rotor main body, and each balance
groove comprises a circumferential groove part which is formed in
the rotor main body and extends in the circumferential
direction.
[0019] In an example embodiment, the circumferential groove part
continuously extends on the whole circumference in the
circumferential direction.
[0020] In an example embodiment, each balance groove further
comprises a radial groove part outward extending to the rotor blade
in a radial direction from the circumferential groove part, and the
radial groove part is in communication with the circumferential
groove part.
[0021] In an example embodiment, there are a plurality of
through-holes which are evenly distributed in the circumferential
groove part in the circumferential direction.
[0022] In an example embodiment, the through-holes include the
through-holes formed in the radial groove part.
[0023] In an example embodiment, the rotor is formed by powder
metallurgy.
[0024] The present disclosure further provides a camshaft phaser as
follows. The camshaft phaser includes a rotor for a camshaft phaser
in any one of the technical solutions.
[0025] By adoption of the technical solution, the disclosure
provides a rotor for a camshaft phaser and the camshaft phaser
including the rotor. The balance grooves communicating with each
other by the through-holes are formed inside the end faces of the
two axial sides of the rotor respectively. In this way, in the
working process of the rotor, engine oil in the balance grooves at
the two sides of the axial direction may flow to the balance groove
at the side with a smaller gap from the balance groove at the side
with a larger gap, thereby balancing the gaps between the rotor and
two end covers; the amount of the engine oil in the oil chambers
leaking from the gaps can be maintained at a low level, and the
probability of hard contact between the rotor and the end covers is
lowered, thus reducing both the amount of the engine oil in the oil
chambers of the camshaft phaser leaking from the gaps and wear
between the rotor and the end covers. In addition, due to the
existence of the balance grooves and the through-holes, the mass
and cost of the rotor are reduced.
BRIEF DESCRIPTION OF DRAWINGS
[0026] FIG. 1a is an axial section schematic diagram of a camshaft
phaser in the prior art. FIG. 1b is a schematic diagram of a
structure of a camshaft phaser in FIG. 1a viewed from one side of
the axial direction, with an end cover at one side of the axial
direction omitted.
[0027] FIG. 2a is a schematic diagram viewed from one axial side of
a rotor of a camshaft phaser according to a first embodiment of the
present disclosure. FIG. 2b is a schematic diagram viewed from one
axial side of a rotor of a camshaft phaser according to a second
embodiment of the disclosure.
LIST OF REFERENCE SYMBOLS
[0028] 10 stator [0029] 101 stator body [0030] 102 stator
protrusion [0031] 103 tooth [0032] 20 rotor [0033] 201 rotor main
body [0034] 202 rotor blade [0035] 203 balance groove [0036] 203c
circumferential groove part [0037] 203r radial groove part [0038]
204 through-hole [0039] 30,40 end cover [0040] 50 seal assembly
[0041] 501 lip seal [0042] 502 leaf spring [0043] 60 locking
assembly [0044] A,B oil chamber. [0045] X axial direction [0046] C
circumferential direction [0047] L minimum spacing
DETAILED DESCRIPTION OF EMBODIMENTS
[0048] The following describes the technical solutions of the
present disclosure with reference to the accompanying drawings of
the specification. A camshaft phaser according to the present
disclosure has a substantially cylindrical shape as a whole. Unless
otherwise specified, the axial, radial and circumferential
directions of the present disclosure refer to the axial, radial and
circumferential directions of the camshaft phaser (rotor)
respectively.
[0049] Specifically, a basic structure of the camshaft phaser
according to the present disclosure is same as that of the camshaft
phaser in the prior art shown in the FIG. 1a and FIG. 1b, the
difference between them is that a structure of a rotor of the
camshaft phaser according to the present disclosure is different
from that of a rotor of a camshaft phaser in the prior art. The
following mainly describes a specific structure of the rotor of the
camshaft phaser according to the present disclosure.
The First Embodiment
[0050] As shown in FIG. 2a, the camshaft phaser according to the
first embodiment of the present disclosure comprises a rotor 20.
The rotor 20 comprises a cylindrical rotor main body 201 and a
plurality of rotor blades 202 (four shown in the figure) protruding
towards the radial outer side from the rotor main body 201.
[0051] Specifically, in this embodiment, balance grooves 203 (only
the balance groove 203 inside the end face of one axial side of the
rotor 20 is shown in the figure) with the same shape and same size
are respectively formed inside the end face of one axial side of
the rotor 20 and the end face of the other axial side of the rotor
20, so that a total volume of the balance groove 203 inside the end
face of one axial side of the rotor 20 is equal to that of the
balance groove 203 inside the end face of the other axial side of
the rotor 20.
[0052] Taking the balance groove 203 located inside the end face of
one axial side of the rotor 20 as an example for description, the
balance groove 203 comprises a circumferential groove part 203c
which is formed in the rotor body 201 and extends in a
circumferential direction C, preferably, the circumferential groove
part 203c continuously extends on the whole circumference. The
circumferential groove part 203c is spaced apart from both outer
periphery and inner periphery of body 201 by same spacing
(corresponding to the minimum spacing L) of 4 mm.
[0053] In this embodiment, the balance grooves 203 respectively
located inside the end face of one axial side of the rotor 20 and
inside the end face of the other axial side of the rotor 20 are in
communication with each other through four round through-holes 204
which penetrate through the rotor 20 in the axial direction, so
that engine oil can circulate between the balance grooves 203 at
the two sides of the axial direction by the through-holes 204.
Specifically, the four through-holes 204 are evenly distributed in
the circumferential groove parts 203c in the circumferential
direction C, and openings of all the through-holes 204 are located
at the bottoms of the circumferential groove parts 203c.
[0054] The above describes that the rotor 20 of the camshaft phaser
according to the first embodiment of the present disclosure differs
from the specific structure in the prior art, the following
describes the working principle of the balance grooves 203 and the
through-holes 204 of the rotor 20.
[0055] In the working process of the camshaft phaser, there is
always the internal leakage of the engine oil in the oil chambers
from the gaps between the rotor 20 and the end covers, so the
engine oil will flow in the camshaft phaser all the time. On the
side where the gap between the rotor 20 and the end cover is
larger, the flowing resistance of the engine oil in the larger gap
is small, so that the pressure drop is small, and the oil pressure
is greater than that of the engine oil in the smaller gap on the
other side. Accordingly, the engine oil may flow to the side with
the smaller gap from the side with the larger gap by the
through-holes 204, the engine oil flowing to the smaller gap can
generate thrust in the balance groove 203, thereby enlarging the
smaller gap until the gaps at the two sides of the rotor 20
approach a balanced state (equality). In other words, a thrust
generated by the balance grooves 203 can increase the probability
that the rotor 20 is in a more balanced position, and the thrust
generated by the balance grooves 203 at least can increase the
opportunity or time when the rotor 20 is in the equilibrium
position. The gaps between the rotor 20 and the two end covers are
balanced through the thrust generated in the balance grooves 203,
the amount of the engine oil in the oil chambers leaking from the
gaps can be maintained at a low level, and the probability of hard
contact between the rotor and the end covers is lowered, thus
reducing both the amount of the engine oil in an oil chamber of the
camshaft phaser leaking from the gaps and wear between the rotor
and the end covers.
The Second Embodiment
[0056] As shown in FIG. 2b, a basic structure of a rotor 20 of the
camshaft phaser according to the second embodiment of the present
disclosure is approximately same as that of the rotor 20 of the
camshaft phaser according to the first embodiment of the present
disclosure, the difference between them is that, in the second
embodiment, a balance groove 203 of the rotor 20 further includes a
radial groove part 203r, and the number and forming positions of
through-holes 204 are different.
[0057] Specifically, in this embodiment, the balance groove 203
also include the radial groove parts 203r outward extending to the
rotor blade 202 from a circumferential groove part 203 in a radial
direction, and the radial groove part 203r is in communication with
the circumferential groove part 203c. The minimum spacing L between
the whole balance groove 203 and the periphery of the rotor 20 is
the spacing between the radial groove part 203r and the periphery
of the root of the rotor blade 202, which is 3 mm.
[0058] Furthermore, in this embodiment, the rotor 20 not only
includes six round through-holes 204 formed in the circumferential
groove parts 203c, but also includes two round through-holes 204
formed in the radial groove parts 203r.
[0059] In addition, the working principle of the balance grooves
203 and the through-holes 204 in the second embodiment is same as
those in the first embodiment, which is not described in detail
herein.
[0060] The disclosure further provides a camshaft phaser. The
camshaft phaser includes a rotor 20 for the camshaft phaser with
the structure.
[0061] Although the technical solutions of the present disclosure
have been described in detail in the specific embodiments, it
should be noted that:
1. Although the number and shapes of the through-hole 204 have been
described in the specific embodiments, the present disclosure is
not limited to this. In the present disclosure, the number and
shapes of the through-hole 204 may be changed as required. In
addition, the position of the through-hole 204 may be adjusted at
will as long as the normal work of an oil line and a locking
assembly in the rotor 20 is not affected. 2. Although the specific
embodiments describe that the balance groove 203 includes the
circumferential groove part 203c and/or the radial groove part
203r, the present disclosure is not limited to this. The balance
groove 203 may include other groove parts in any shapes. In
addition, the balance groove 203 may be formed in such a way that
the balance groove 203 covers areas as much as possible as long as
the balance groove 203 are sufficiently spaced from the periphery
of the rotor 20. 3. Although specific embodiments describe that the
minimum spacing L between the balance grooves 203 and the rotor 20
are 4 mm and 3 mm, the present disclosure is not limited to this.
In the present disclosure, it is sufficient that the minimum
spacing L is greater than or equal to 3 mm. In addition, the
spacing between the balance grooves 203 and the periphery of the
rotor 20 can be equally distributed. 4. The rotor 20 can be formed
by powder metallurgy. In addition, in the process of manufacturing
the rotor 20 with the structure, a mold can be adjusted to
facilitate implementation. Additional machining is not needed.
Furthermore, due to the existence of the balance groove 203 and the
through-hole 204, manufacturing materials of the rotor 20 are
reduced, the cost is lowered, and the mass of the molded rotor 20
is reduced.
* * * * *