U.S. patent application number 13/973371 was filed with the patent office on 2014-02-27 for hybrid variable external gear pump.
This patent application is currently assigned to MAGNA POWERTRAIN. The applicant listed for this patent is Liping Wang, Matthew Williamson. Invention is credited to Liping Wang, Matthew Williamson.
Application Number | 20140056732 13/973371 |
Document ID | / |
Family ID | 50148134 |
Filed Date | 2014-02-27 |
United States Patent
Application |
20140056732 |
Kind Code |
A1 |
Wang; Liping ; et
al. |
February 27, 2014 |
HYBRID VARIABLE EXTERNAL GEAR PUMP
Abstract
A pump comprising a housing having a first cavity and a second
cavity, where the first cavity has a first motor and a pump element
located therein. The first cavity is also connected to an external
gear connected to the outside of the housing for receiving rotation
power from a vehicle engine. The second cavity has a second motor
that selectively connects to the pump element in the first cavity
to provide toque.
Inventors: |
Wang; Liping; (Markham,
CA) ; Williamson; Matthew; (Richmond Hill,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Wang; Liping
Williamson; Matthew |
Markham
Richmond Hill |
|
CA
CA |
|
|
Assignee: |
MAGNA POWERTRAIN
Concord
CA
|
Family ID: |
50148134 |
Appl. No.: |
13/973371 |
Filed: |
August 22, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61692070 |
Aug 22, 2012 |
|
|
|
Current U.S.
Class: |
417/319 ;
417/410.4 |
Current CPC
Class: |
F04C 2240/45 20130101;
F04C 14/00 20130101; F04C 2210/206 20130101; F04C 2/18 20130101;
F04C 14/185 20130101 |
Class at
Publication: |
417/319 ;
417/410.4 |
International
Class: |
F04C 14/00 20060101
F04C014/00 |
Claims
1. An electric gear oil pump comprising: a housing having a first
cavity and a second cavity and an inlet and an outlet; a drive gear
connected to the housing; a first motor in the first cavity; a
primary shaft extending through the first cavity, said primary
shaft being connected to both the drive gear and the first motor,
wherein the first motor and the drive gear supply torque to the
primary shaft; a pump element connected to and rotatable with the
primary shaft for pumping fluid through the inlet and the outlet of
the housing; a second shaft extending through the second cavity,
the second shaft has second shaft gear configured to selectively
engage the pump element in order to input torque to the primary
shaft and pump element when the drive gear is not supplying torque
to the primary shaft; and a second motor contained in the second
cavity and selectively drives the second shaft.
2. The electric gear oil pump of claim 1 further comprising: a
clutch member connected between the drive gear and the primary
shaft, wherein the drive gear selectively supplies torque to the
primary shaft from an engine in one direction when the clutch
member is engaged and the drive gear is disconnected from the
primary shaft when the clutch member is disengaged.
3. The electric gear oil pump of claim 2 further comprising a lead
screw connected between the second shaft and the second shaft gear,
wherein the lead screw causes the second shaft gear to slide in a
linear direction in the second cavity when the second motor is
energized, thereby engaging the second shaft gear with the pump
element.
4. The electric gear oil pump of claim 1 further comprising a lead
screw connected between the second shaft and the second shaft gear,
where in the lead screw causes the second shaft gear to slide in a
linear direction in the second cavity when the second motor is
energized, thereby engaging the second shaft gear with the pump
element.
5. The electric gear oil pump of claim 1 further comprising single
controller contained in the housing, wherein the single controller
is configured to control the operation of the first and second
pumps.
6. The electric gear oil pump of claim 1 further comprising: a
first failsafe spring located proximal the first end of the second
shaft; a second failsafe spring located proximal the second end of
the second shaft, wherein the first failsafe spring and second
failsafe spring move the second shaft gear to a full displacement
position if there is failure of the first motor and the second
motor.
7. The electric gear oil pump of claim 1 further comprising: a
first seal coupled to the second shaft; a second seal coupled to
the second shaft, wherein the second shaft gear is located between
the first seal and the second seal and the first seal and second
seal allow the second shaft gear to contact the pump member and
prevent fluid from entering the second cavity from the first
cavity.
8. An electric gear oil pump comprising: a housing having a first
cavity and a second cavity and an inlet and an outlet; a drive gear
connected to the housing; a first motor in the first cavity; a
primary shaft extending through the first cavity with one end
connected to the drive gear and a second end connected to the first
motor, wherein the first motor supplies torque to the primary
shaft; a clutch member connected between the drive gear and the
primary shaft, wherein the drive gear selectively supplies torque
to the primary shaft from an engine in one direction when the
clutch member is engaged and the drive gear is disconnected from
the primary shaft when the clutch member is disengaged; a pump
element rotatable with the primary shaft for pumping fluid through
the inlet and the outlet of the housing; a second shaft extending
through the second cavity, the second shaft has a second shaft gear
configured to selectively engage the pump element in order to input
torque to the primary shaft and pump element when the drive gear is
not supplying torque to the primary shaft; and a second motor
contained in the second cavity and selectively drives the second
shaft.
9. The electric gear oil pump of claim 8 further comprising a lead
screw connected between the second shaft and the second shaft gear,
wherein the lead screw causes the second shaft gear to slide in a
linear direction in the second cavity when the second motor is
energized, thereby engaging the second shaft gear with the pump
element.
10. The electric gear oil pump of claim 8 further comprising single
controller contained in the housing, wherein the single controller
is configured to control the operation of the first and second
pumps.
11. The electric gear oil pump of claim 8 further comprising: a
first failsafe spring located proximal the first end of the second
shaft; a second failsafe spring located proximal the second end of
the second shaft, wherein the first failsafe spring and second
failsafe spring move the second shaft gear to a full displacement
position if there is failure of the first motor and the second
motor.
12. The electric gear oil pump of claim 8 further comprising: a
first seal coupled to the second shaft; a second seal coupled to
the second shaft, wherein the second shaft gear is located between
the first seal and the second seal and the first seal and second
seal allow the second shaft gear to contact the pump member and
prevent fluid from entering the second cavity from the first
cavity.
13. An electric gear oil pump comprising: a housing having a first
cavity and a second cavity and an inlet and an outlet; a first BLDC
motor located in the first cavity; a primary shaft having a first
end and a second end; an external gear coupled to the first end of
the primary shaft; a one way clutch coupling the external gear and
the primary shaft such that the external gear can rotate the
primary shaft in a first direction and wherein the BLDC motor is
coupled to the second end of the primary shaft and selectively
rotates the primary shaft in an opposite direction and the one way
clutch prevents such rotation from being transferred to the
external gear; a second step motor located in the second cavity; a
second shaft having a first end rotatably supported in the housing
and a second end coupled to the step motor; a first failsafe spring
located proximal the first end of the second shaft; a first seal
coupled to the second shaft; a second seal coupled to the second
shaft; a second shaft gear coupled to the second shaft and located
between the first seal and the second seal; a second failsafe
spring located proximal the second end of the step motor shaft; a
controller coupled to the BLDC motor and to the step motor; and a
cover coupled to the motor portion.
14. The electric gear oil pump of claim 13 further comprising a
lead screw connected between the second shaft and the second shaft
gear, wherein the lead screw causes the second shaft gear to slide
in a linear direction in the second cavity when the second motor is
energized, thereby engaging the second shaft gear with the pump
element.
15. The electric gear oil pump of claim 13 further comprising
single controller contained in the housing, wherein the single
controller is configured to control the operation of the first and
second pumps.
16. The electric gear oil pump of claim 13 further comprising: a
first failsafe spring located proximal the first end of the second
shaft; a second failsafe spring located proximal the second end of
the second shaft, wherein the first failsafe spring and second
failsafe spring move the second shaft gear to a full displacement
position if there is failure of the first motor and the second
motor.
17. The electric gear oil pump of claim 13 further comprising: a
first seal coupled to the second shaft; a second seal coupled to
the second shaft, wherein the second shaft gear is located between
the first seal and the second seal and the first seal and second
seal allow the second shaft gear to contact the pump member and
prevent fluid from entering the second cavity from the first
cavity.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/692,070, filed Aug. 22, 2012.
FIELD OF THE INVENTION
[0002] The present disclosure relates generally to an improved
pump, and more particularly, to an improved hybrid variable
external gear pump for use in a transmission for a vehicle such as
an automobile, truck, van, utility, industrial equipment, fleet,
cargo or the like.
BACKGROUND OF THE INVENTION
[0003] Many transmissions, engines, transfer cases and other power
transferring devices are equipped with oil pumps for lubrication or
other pressurized fluid supply. Internal oil pumps are typically
continuously driven. While known arrangements are fairly simple to
construct, continuously, mechanically driving the pump may not be
the most efficient way of operating the vehicle, let alone even
possible in some electric vehicle applications. During certain
modes of vehicle operation, the input shaft driving the pump may
rotate at relatively high speed thereby producing relatively high
fluid flow at a time when relatively low or no fluid flow is
required. The energy to drive the pump during these modes of
operation is not providing value and may be considered inefficient
waste.
[0004] It is generally known to have a variable displacement vane
pump for use in a transmission in a vehicle. One particular example
is disclosed in U.S. Pat. No. 4,342,545, to Schuster, the entire
contents of which are incorporated herein by reference thereto.
Variable displacement pumps are generally known in transmission
control systems, however, these prior art devices have generally
been of the gerotor or sliding ring type in which the control
thereof is maintained by a spring. It is also generally known in
electric vehicle applications to provide two pumps--a mechanical
pump driven by a power take off from the engine and an electric
motor-driven pump for use when the engine is not running. This adds
significant expense and complexity as well additional potential
failure modes and control issues. There is also known an externally
mounted electric fluid pump for pumping fluid within a power
transmission device as disclosed in US Patent Application
Publication Number 2010/0290934A1, the entire contents of which are
incorporated herein by reference thereto.
[0005] Despite the long known solutions, there remains a
significant need to provide an improved variable displacement vane
pump capable of providing improved performance and gains in
efficiency and packaging of the pump. In spite of the long known
solutions, there remains a significant need to provide an improved
variable displacement pump that can overcome the problems of the
known art.
SUMMARY OF THE INVENTION
[0006] A pump comprising a housing having a first cavity and a
second cavity. A primary shaft extending through the first cavity
having a first end and a second end with a first motor in the
cavity coupled to a second end of the primary shaft. A drive gear
coupled to the first end of the primary shaft by a one way clutch
coupling the drive gear and the primary shaft such that the drive
gear can rotate the primary shaft in a first direction. The first
motor is coupled to the second end of the drive shaft and can
rotate the drive shaft in an opposite direction. The one way clutch
prevents such rotation from being transferred to the drive
gear.
[0007] A second shaft extends through the second cavity and is
connected to a second motor located in the second cavity. The
second shaft has a first end rotatably supported in the housing and
a second end coupled to the second motor. The second cavity also
has a first failsafe spring located proximal to the first end of
the second shaft and a second failsafe spring located proximal to
the second end of the step motor shaft. A first seal and a second
seal with a second shaft positioned gear between the seals, are
coupled to the step motor shaft for contacting and providing torque
to a pump element in the first cavity.
[0008] Further areas of applicability of the present invention will
become apparent from the detailed description provided hereinafter.
It should be understood that the detailed description and specific
examples, while indicating the preferred embodiment of the
invention, are intended for purposes of illustration only and are
not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention will become more fully understood from
the detailed description and the accompanying drawings,
wherein:
[0010] FIG. 1 is a perspective view of an exemplary embodiment of
an outer rotor drive and pump according to the present
disclosure;
[0011] FIG. 2 is an alternate perspective view of the outer rotor
drive and pump of FIG. 1;
[0012] FIG. 3 is a further alternate perspective view of the outer
rotor drive of FIG. 1;
[0013] FIG. 4 is a partial, perspective view of the exemplary
embodiment of the outer rotor drive and pump of FIG. 1 according to
the present disclosure;
[0014] FIG. 5 is an exploded perspective view of the exemplary
embodiment of the outer rotor drive and pump of FIG. 1 according to
the present disclosure;
[0015] FIG. 6 is an alternate exploded perspective view of the
exemplary embodiment of the oil pump of FIG. 1 according to the
present disclosure;
[0016] FIG. 7 is a perspective view of the second shaft gear of the
second motor of pump of FIG. 6 according to the present disclosure;
and
[0017] FIG. 8 is an exploded perspective view of the second gear of
the second motor of pump of FIG. 7 according to the present
disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The following description of the preferred embodiment(s) is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0019] Referring in general to all of the Figures, the present
disclosure and teachings described herein provide for an oil pump
10 and oil pump operating system for use with a cooling system in a
transmission or engine. The oil pump 10 is design so it can be
driven using multiple sources. The oil pump 10 includes a housing
11 having a pump portion 12 and a motor portion 14 that is coupled
to the pump portion 12 at one end 16 of the pump portion 12. The
interiors of the pump and motor portions have a first cavity 18 and
second cavity 19, which are both generally cylindrically shaped and
aligned side-by-side as shown in the Figures. The first cavity 18
is connected to an inlet 13 and outlet 15 disposed through the
housing 11. Fluid such as oil or transmission fluid enters the
housing 11 through the inlet 13 and exits an outlet 15. The
movement of fluid through the housing 11 is caused by a pump
element 31 positioned in the first cavity 18. The pump element 31
in the present embodiment of the invention is a gerotor formed on
the primary shaft 30.
[0020] The motor portion 14 is closed at an opposite end using a
housing cover 20. The motor portion 14 includes a first motor 22 in
the first cavity 18 and a second motor 24, (a generally smaller,
step motor), located in the second cavity 19. The first motor 22
and second motor 24 are coupled to a controller 26 located between
the first motor 22 and second motor 24 and the end of the motor
portion and the housing cover 20.
[0021] In one exemplary embodiment as shown in the Figures, the oil
pump 10 of the present disclosure preferably includes only a single
controller 26 for controlling both the first motor 22 and second
motor 24, the controller 26 being located at an end of the motor
portion 14. In the exemplary embodiment shown in the Figures,
locating the controller 26 at the one end of the motor portion 14
of the oil pump 10 and co-locating the motors as disclosed allows
for one controller to manage the two motors to thereby provide a
lower cost controller and lower cost oil pump. In one alternate
embodiment, it is contemplated that two controllers are used
wherein each controller controls a single motor. In a further
alternative embodiment, it is contemplated that two controllers are
used wherein each controller controls a single motor and includes a
backup controller for the other motor to provide redundancy.
[0022] In one exemplary aspect, the oil pump 10 is driven using
power take off from the engine using an external gear 28 coupled to
the power take off. The external gear 28 is coupled to the power
take off from one of the engine or the transmission and is driven
thereby to cause rotation of the oil pump 10. The external gear 28
is coupled to a primary shaft 30 located in the first cavity 18 in
pump portion 12 of the pump 10 using a fastener 32, such as the
screw shown in the Figures, or other known and appropriate coupling
device.
[0023] The external gear 28 of the pump 10 includes a one way
clutch 34. The one way clutch 34 is configured so that rotation of
the external gear 28 in one direction will be transferred directly
to the primary shaft 30, and causes it to rotate directly with the
external gear 28. The pump element 31 is connected to the primary
shaft 30 and rotates in response to torque inputted from the
external gear 28 or torque inputted from the first motor 22 or the
second motor 24. Rotation of the external gear 28 in the opposite
direction does not cause rotation of the primary shaft 30. More
significantly, rotation of the primary shaft 30 does not cause
rotation of the external gear 28 because the one way clutch
mechanism is designed to only allow forces to be transferred from
the external gear 28 to the primary shaft 30 and not from the
primary shaft 30 to the external gear 28.
[0024] Accordingly, in one mode of operation of the oil pump 10,
such as when the engine is operating in a start/stop mode, (also
known as a start and go mode or application), the engine is stopped
when the vehicle is stopped and there is no demand from the
operator for the vehicle engine to run. When the engine is stopped,
the engine and transmission do not rotate and there is no operating
power take off from the engine or transmission that can cause the
external gear 28 to rotate. Therefore the oil pump 10 cannot be
driven by the external gear 28. In this mode, the oil pump 10 is
operated by the first motor 22, which is a brushless direct current
("BLDC") motor using power, such as electricity, to cause the first
motor 22 to rotate and thereby rotate the primary shaft 30 and pump
element 31. In this mode, the one way clutch prevents rotation of
the shaft from being transferred to the external gear 28 and back
into the power take off mechanism and/or the engine and
transmission. The BLDC motor can be of any known or appropriate
type and preferably has a power rating of between about 50W and
80W, sufficient to drive the pump 10 in the start and go mode or
application.
[0025] As shown in the Figures, the second motor 24, of the oil
pump 10 and its control, is a step motor located in the end near
the first motor 22 and in the second cavity 19 of the motor portion
14 aligned with the pump portion. The second motor 24 is coupled to
a second shaft 36. The second shaft 36 includes a bearing 38 for
supporting rotation of the second shaft 36 within the second cavity
19. The second shaft 36 has a second shaft gear 37 that engages
with the pump element 31 in order to apply torque from the second
motor 24 to the pump element 31 through the second shaft gear 37.
The second shaft gear 37 has seals 39, 39' on either side that
prevent fluid from leaking from the first cavity 18 to the second
cavity 19. The seals 39, 39' are optional and it is within the
scope of the invention for some embodiments to allow fluid to flow
into the second cavity 19. The second motor 24 is preferably a
three phase stepper motor (having an operating range of
approximately 3W-4W that operates to change the displacement of the
pump and to the force balance of the second shaft 36 with bearing
38. The use of the second motor 24 changes the displacement of the
pump and thereby reduces the torque for operating the pump at the
cold start. In one embodiment, the second motor 24 preferably
includes an over molded motor winding with an integrated bus bar
and also includes smart control implemented in the controller 26 to
keep high accuracy of control and high dynamic regulation
function.
[0026] In one exemplary embodiment as shown in the Figures, the oil
pump 10 further include an oil flow for cooling portions of the
controller 26, or MOSFETS of the step motor and/or the BLDC motor.
In one alternate exemplary embodiment, it is contemplated that the
arrangement of the controller 26 and the motors 22, 24 of the oil
pump 10 of the present disclosure further includes a robust,
low-cost Bx_By flux position sensor integrated in PCB of the
controller 26. With the arrangement of the oil pump 10 and motors
22, 24 of the present disclosure, the first motor 22 and controller
26 may be used to generate regeneration energy during operation of
the oil pump 10 when the engine reduces speed, such as when the
vehicle is slowing down and there is a lower demand for oil pumping
within the transmission and engine and the transmission continues
to rotate and drive the external gear 28 of the oil pump 10 and the
motors 22, 24 can be used to generate electricity that can be
stored for later use. In one exemplary embodiment, upon operation
of the second motor 24, failsafe spring(s) 40, 40' move the second
shaft gear 37 coupled to the second shaft 36 to a full displacement
position if there is issue in the electrical controller 26. The
conversion of rotational movement of the second motor 24 to linear
movement of the second shaft gear 37 is accomplished using a lead
screw 42 or mated threads formed between a gear support 41 and the
surface of the second shaft 36. FIG. 8 shows how the second shaft
gear 37 is press fit onto the gear support, that is connected to
one of the seals 39'. The gear support 41 is used to connect the
seals 39, 39' and second shaft gear 37 onto the second shaft
36.
[0027] The oil pump, its motors and the controller can be operated
using any known or appropriate communications protocol including,
but not limited to, CAN or LIN communication protocols.
[0028] The description of the invention is merely exemplary in
nature and, thus, variations that do not depart from the gist of
the invention are intended to be within the scope of the invention.
Such variations are not to be regarded as a departure from the
spirit and scope of the invention.
* * * * *