U.S. patent application number 13/741008 was filed with the patent office on 2013-08-01 for hydraulic power steering pump having wet type motor with open type magnet.
This patent application is currently assigned to Youngshin Precision Co., LTD. The applicant listed for this patent is Youngshin Precision Co., LTD. Invention is credited to In Sang KIM, Hyunkwon LEE, Gi Woong NAM.
Application Number | 20130195697 13/741008 |
Document ID | / |
Family ID | 48870386 |
Filed Date | 2013-08-01 |
United States Patent
Application |
20130195697 |
Kind Code |
A1 |
KIM; In Sang ; et
al. |
August 1, 2013 |
HYDRAULIC POWER STEERING PUMP HAVING WET TYPE MOTOR WITH OPEN TYPE
MAGNET
Abstract
Disclosed is a hydraulic power steering pump including a wet
type motor with an open type magnet, the hydraulic power steering
pump including: a housing; a gear pump module supported at one side
of the housing and pressurizing a fluid; and a motor module
supported at the other side of the housing and providing driving
force to the gear pump module, the motor module including a stator
that is supported by the housing and receives electric current
based on supplied power, and a rotor that includes a motor rotation
shaft rotated by the stator and a permanent magnet generating
magnetic force, and an outer side of the permanent magnet being
supported by the motor rotation shaft to have an exposed portion
exposed toward the stator.
Inventors: |
KIM; In Sang; (Gyeongju-si,
KR) ; LEE; Hyunkwon; (Jeonju-si, KR) ; NAM; Gi
Woong; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Youngshin Precision Co., LTD; |
Gyeongju-si |
|
KR |
|
|
Assignee: |
Youngshin Precision Co.,
LTD
Gyeongju-si
KR
|
Family ID: |
48870386 |
Appl. No.: |
13/741008 |
Filed: |
January 14, 2013 |
Current U.S.
Class: |
417/410.4 |
Current CPC
Class: |
H02K 11/33 20160101;
F04C 11/008 20130101; F04C 15/008 20130101; H02K 1/30 20130101;
F04C 15/0049 20130101; F04C 2/18 20130101; H02K 7/14 20130101; H02K
5/12 20130101; H02K 1/278 20130101 |
Class at
Publication: |
417/410.4 |
International
Class: |
F04C 11/00 20060101
F04C011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 30, 2012 |
KR |
10-2012-0009019 |
Claims
1. A hydraulic power steering pump comprising a wet type motor with
an open type magnet, the hydraulic power steering pump comprising:
a housing; a gear pump module supported at one side of the housing
and pressurizing a fluid; and a motor module supported at the other
side of the housing and providing driving force to the gear pump
module, the motor module comprising a stator that is supported by
the housing and receives electric current based on supplied power,
and a rotor that comprises a motor rotation shaft rotated by the
stator and a permanent magnet generating magnetic force, and an
outer side of the permanent magnet being supported by the motor
rotation shaft to have an exposed portion exposed toward the
stator.
2. The hydraulic power steering pump according to claim 1, wherein
the rotor is arranged within flow of a fluid.
3. The hydraulic power steering pump according to claim 1, wherein
the rotor comprises a yoke holder coupled to the motor rotation
shaft, a yoke supported by the yoke holder, and the permanent
magnets plurally arranged outside the yoke, and the yoke holder
comprises a permanent magnet holder to support one end of each
permanent magnet along a lengthwise direction of the motor rotation
shaft.
4. The hydraulic power steering pump according to claim 3, wherein
the yoke holder comprises ribs that divide the yoke holder in a
circumferential direction to separate the permanent magnets from
each other if the permanent magnets are arranged in the
circumferential direction of the yoke holder.
5. The hydraulic power steering pump according to claim 3, further
comprising a separation preventing cab member comprising a skirt
surrounding the other end of the permanent magnet along the
lengthwise direction of the motor rotation shaft so that each
permanent magnet coupled to the yoke can be prevented from
separation in the circumferential direction.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Korean Patent
[0002] Application No. 10-2012-0009019, filed on Jan. 30, 2012 in
the Korean Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND
[0003] 1. Field
[0004] Apparatuses and methods consistent with the exemplary
embodiments relate to a hydraulic power steering pump having a wet
type motor with an open type magnet, and more particularly to a
hydraulic power steering pump having a wet type motor with an open
type magnet, in which the wet type motor is improved in a structure
of a rotor.
[0005] 2. Description of the Related Art
[0006] A vehicle is a modern representative transport unit into
which a lot of parts are assembled. In such a vehicle, a steering
wheel is typically turned so that a driver can control a vehicle's
going direction. Thus, a wheel connected to the steering wheel is
turned and therefore a driver steers the vehicle. Among many parts
of the vehicle, a steering device allows a driver to steer the
vehicle in a direction as s/he desires.
[0007] The steering device includes a hydraulic power steering
device with a pump for supplying hydraulic pressure to assist force
given by a driver to turn the steering wheel given by a driver so
that the driver can easily turn the steering wheel.
[0008] The hydraulic power steering device (hereinafter, referred
to as a `steering device`) uses a power steering gear to distribute
the hydraulic pressure supplied from the hydraulic power steering
pump installed in the middle of a steering linkage connected to the
steering wheel, and uses an output shaft to apply the distributed
hydraulic pressure to a steerage wheel (a front wheel or a rear
wheel), so that a driver can slightly and quickly steer the vehicle
with small force. That is, the steering device serves to reduce
force needed for a driver to control the steering wheel, and
prevent a shock from being transferred from a road surface to the
steering wheel via the front wheel.
[0009] The steering device is typically configured with an input
transfer device that generates steering torque and transferring the
steering torque or changing the direction of the steering torque, a
distribution device that generates steering assistant force or
decreases the steering assistant force, and an output device that
properly converts input torque and displacement or changes the
direction of the steering torque. Here, the input transfer device
includes steering linkage such as a steering wheel, a drag link, a
middle shaft, etc., the distribution device includes a hydraulic
power steering pump, a control valve, etc., and the output device
includes a steering gear having a power cylinder or the like, a tie
rod, an end, etc.
[0010] Meanwhile, the hydraulic power steering pump is generally
classified into two according to driving methods. One is to receive
motive power from an engine, and the other is to drive the
hydraulic power steering pump by a separate electric motor without
receiving the motive power from the engine. Recently, an
electric-driving hydraulic power steering pump for operating the
hydraulic power steering pump has been preferred only when it is
needed to pursue more efficient and environmentally-friendly
vehicle.
[0011] A hydraulic power steering pump system including the
electric-driving hydraulic power steering pump has a little
different structure from a conventional engine-driving hydraulic
power steering pump. The hydraulic power steering pump includes an
electric motor for providing power, a pump assembly for
pressurizing a fluid by rotation of an electric motor, a housing
for supporting the electric motor and the pump assembly and storing
and guiding the fluid, and a controller for controlling the
electric motor based on an angle of the steering wheel or the like,
pressure of the hydraulic power steering pump, etc.
[0012] The hydraulic power steering pump sucks oil through a
sucking hose as the engine or electric motor is driven to rotate
the pumping gear, and discharges the pressurized oil. Also, a
steering pump is generally coupled with a flux control valve for
controlling the amount of oil discharged. That is, a discharging
amount per unit time is increased or decreased in proportion to a
rotation number of the engine since the steering pump has a
constant discharging amount per its rotation. Further, the
hydraulic power steering pump is provided with a relief valve
capable of adjusting the maximum level of fluid pressure not to be
higher than necessary.
[0013] Recently, more and more hydraulic power steering pumps
driven by the electric motor have been developed in light of fuel
efficiency improvement and environmentally-friendly trend. Further,
a wet type motor through which operating fluid passes is more
preferable in consideration of cooling or the like.
[0014] As a related art, there is an example of Korean Patent
Publication No. 2006-5340 (2006 Jan. 17).
[0015] A driving motor 12 of the related art shown in FIG. 1
includes a rotor 36, a shaft 38 coupled to the rotor 36, and a
stator 40 arranged around the rotor 36. Here, the rotor 36 has a
structure that a metal cover fully surrounds an internal permanent
magnet, thereby causing problems of deteriorating magnetic
properties of the permanent magnet, increasing costs of
manufacturing molding or the like, and lowering economical
efficiency due to manufacture, assembly, etc.
SUMMARY
[0016] One or more exemplary embodiments may provide an aspect of
the present invention is to provide a hydraulic power steering pump
having a wet type motor with an open type magnet, in which a
coupling structure of a permanent magnet arranged in the rotor is
improved to enhance magnetic properties of the permanent magnet and
thus enhance the efficiency of the motor.
[0017] Another exemplary embodiment provides a hydraulic power
steering pump having a wet type motor with an open type magnet, in
which a coupling structure of a permanent magnet is simplified to
reduce costs of molding or the like and thus improve economical
efficiency.
[0018] Still another exemplary embodiment provides a hydraulic
power steering pump having a wet type motor with an open type
magnet, which has a simple structure to simplify processes for
manufacture, assembly, etc.
[0019] According to an aspect of another exemplary embodiment, a
hydraulic power steering pump including a wet type motor with an
open type magnet is provided including: a housing; a gear pump
module supported at one side of the housing and pressurizing a
fluid; and a motor module supported at the other side of the
housing and providing driving force to the gear pump module, the
motor module including a stator that is supported by the housing
and receives electric current based on supplied power, and a rotor
that includes a motor rotation shaft rotated by the stator and a
permanent magnet generating magnetic force, and an outer side of
the permanent magnet being supported by the motor rotation shaft to
have an exposed portion exposed toward the stator.
[0020] The rotor may be arranged within flow of a fluid.
[0021] The rotor may include a yoke holder coupled to the motor
rotation shaft, a yoke supported by the yoke holder, and the
permanent magnets plurally arranged outside the yoke, and the yoke
holder includes a permanent magnet holder to support one end of
each permanent magnet along a lengthwise direction of the motor
rotation shaft.
[0022] The yoke holder may include ribs that divide the yoke holder
in a circumferential direction to separate the permanent magnets
from each other if the permanent magnets are arranged in the
circumferential direction of the yoke holder.
[0023] The hydraulic power steering pump may further include a
separation preventing cab member including a skirt surrounding the
other end of the permanent magnet along the lengthwise direction of
the motor rotation shaft so that each permanent magnet coupled to
the yoke can be prevented from separation in the circumferential
direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The above and/or other aspects will become apparent and more
readily appreciated from the following description of exemplary
embodiments, taken in conjunction with the accompanying drawings,
in which:
[0025] FIG. 1 is an exploded perspective view of a hydraulic power
steering pump having a motor according to an exemplary
embodiment,
[0026] FIG. 2 is a partially cut-open perspective view of FIG.
1,
[0027] FIG. 3 is an exploded perspective view of a rotor in FIG. 1,
and
[0028] FIG. 4 is a cross-section view of FIG. 3.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0029] Hereinafter, exemplary embodiments of a hydraulic power
steering pump having a wet type motor with an open type magnet will
be described with reference to FIGS. 1 to 4.
[0030] FIG. 1 is an exploded perspective view of a hydraulic power
steering pump having a motor according to an exemplary embodiment,
FIG. 2 is a partially cut-open perspective view of FIG. 1, FIG. 3
is an exploded perspective view of a rotor in FIG. 1, and FIG. 4 is
a cross-section view of FIG. 3.
[0031] According to an exemplary embodiment, a hydraulic power
steering pump 100, which generates hydraulic pressure for assisting
torque of a steer wheel for a vehicle, is a gear type pump among
various types of pump. As shown in FIGS. 1 and 2, the hydraulic
power steering pump 100 includes a housing 110 accommodating a
working fluid and having a partition wall member 117 for
partitioning a space, a cap 190 coupled to one side of the housing
110 and sealing up the housing 110, a housing cover 180 coupled to
and sealing up the other side of the housing 110, a gear pump
module 130 accommodated between the housing 110 and the cap 190 and
pressurizing the working fluid as being coupled to the partition
wall member 117, a sucking fluid shock absorber 195a, 195b storing
the working fluid sucked by the gear pump module 130 and decreasing
pulsation of the sucked fluid, and a pressurized shock absorber 132
provided in the gear pump module 130 and decreasing the pulsation
of the pressurized fluid discharged from the gear pump module
130.
[0032] For reference, upward and downward directions in FIGS. 1 and
2 will be respectively defined as up and down directions, as
necessary.
[0033] The housing 110 forms most of an outer appearance of the
hydraulic power steering pump 100, and is hard enough to support
and accommodate various elements. The housing 110 may be made of
steel materials, or may be cast with aluminum alloy to be
lightweight.
[0034] The housing 110 includes the partition wall member 117 for
partitioning an inner space thereof into upper and lower spaces. A
gear pump module accommodating unit 113 is formed above the
partition wall member 117 and accommodates the gear pump module
130, and a motor module accommodating unit 115 is formed below the
partition wall member 117 and accommodates the motor module
150.
[0035] Also, the partition wall member 117 is formed with a
discharging hole 119 at one side thereof, through which the
pressurized working fluid for giving assisting force to the
steering wheel is discharged from the hydraulic power steering pump
100. Alternatively, the discharging hole 119 may be formed at a
necessary position of the housing 110.
[0036] Further, the partition wall member 117 is formed with a
shaft hole 117a penetrating the center thereof so that torque of
the motor module 150 can be transmitted to the gear pump module
130, a central sucking channel 117c formed so that the working
fluid can flow from the second sucking fluid shock absorber 195b to
the gear pump module 130, and a vertical sucking channel 117b
formed to guide the fluid introduced from the sucking hole 193 to
flow from the first sucking fluid shock absorber 195a to the second
sucking fluid shock absorber 195b.
[0037] The motor module 150 includes a wet type motor accommodated
in a second sucking fluid shock absorber 195b and being in contact
with the working fluid.
[0038] Further, the hydraulic power steering pump 100 may include a
driving circuit module 170 that applies electric power to the motor
module 150, controls the motor module 150 to be driven, transmits
and receives various signals to and from an engine control means
(not shown), and transmits and receives signals from and to a
sensor. The driving circuit module 170 includes a driving circuit
member 175 having a printed circuit board (PCB) or the like for
communication and control of various signals, and a driving circuit
module supporting member 173 supporting the driving circuit member
175 and coupled to the housing 110 so that the driving circuit
member 175 can be isolated from the working fluid.
[0039] Further, the reference numeral of `177` indicates a wiring
entrance via which an electric wire, a cable, etc. connected to the
driving circuit module 170 or the motor module 150 can enter or
exit.
[0040] The gear pump module 130 includes the gear pump housing 110,
a gear pump cover 133 sealing up the gear pump housing 110, and a
pumping unit 135 provided in the gear pump housing 110 and
pressurizing the sucked working fluid toward the engaged pumping
gear 135a. The gear pump module 130 includes a pump module holding
member 139a having a bolt for coupling the gear pump module 130
with the partition wall member 117, and a relief valve 138
discharging a high pressurized working fluid pressurized by the
pumping unit 135 toward a low pressure portion if discharging
pressurized working fluid pressure reaches some degree. Here, the
high pressure working fluid of the pressurized shock absorber 132,
discharged from the relief valve 138, may be discharged to a first
sucking fluid shock absorber 195a where a low pressure working
fluid is stored.
[0041] The gear pump housing 110 includes the pumping unit 135
accommodated in a pumping-unit accommodating portion 136 to
pressure a low-pressure working fluid up to a high-pressure working
fluid.
[0042] The pumping unit 135 includes the pumping gears 135a engaged
to each other to pressurize the low-pressure working fluid into the
high-pressure working fluid, the gear housing 110 supporting the
pair of pumping gears 135a at opposite ends, and a relatively long
gear pump rotation shaft 137 and a relatively short gear pump
rotation short shaft 137b which are coupled to a motor rotation
shaft 151 and allow the pumping gears 135a to turn.
[0043] The pressurized shock absorber 132 is a space formed in a
vertically lengthwise direction along a partial circumferential
direction of the gear pump internal housing 131d. The cross-section
of the pressurized shock absorber 132 is narrowing along a flowing
direction of the working fluid from a discharging area of the
pumping unit 135 to the discharging direction of the gear pump
module 130.
[0044] Although it is not shown, the pressurized shock absorber 132
may for example have a `U`-shaped cross-section in the discharging
area of the pumping unit 135, and be approximate to a circle as the
`U`-shaped cross-section is tapering along the flowing direction of
the working fluid discharged from the gear pump module 130.
[0045] Thus, the cross-section becomes wider in such a narrow
channel, i.e., a shock absorber sucking hole (not shown), and
becomes narrower again in direction toward a narrow channel, i.e.,
a shock absorber discharging hole (not shown), thereby forming the
pressurized shock absorber 132 so that the pulsation of the
pressurized and discharged working fluid can be effectively reduced
via the pressurized shock absorber 132.
[0046] The sucking fluid shock absorber 195a, 195b includes a first
sucking fluid shock absorber 195a provided as a space among the
partition wall member 117, the cap 190 and the gear pump module
130, and a second sucking fluid shock absorber 195b provided as a
space among the partition wall member 117, the housing cover 180
and the motor module 150. That is, the maximum space as possible
may be formed so that the pulsation generated in the working fluid
as the working fluid sucked and pressurized by the pumping gear
135a flows can be absorbed in the working fluid itself.
[0047] The cap 190 is coupled to a top of the housing 110 so as to
prevent the working fluid filled in the first sucking fluid shock
absorber 195a from leaking. The cap 190 is formed with the sucking
hole 193 at one side thereof to guide the working fluid introduced
from a tank (not shown) storing the working fluid to the hydraulic
power steering pump 100. Alternatively, the sucking hole 193 may be
formed in the housing 110 as necessary. The cap 190 may be molded
with a material such as a plastic compound to reduce weight.
[0048] With this configuration, an effect on reducing the pulsation
due to the channel of the hydraulic power steering pump 100
according to an exemplary embodiment will be schematically
described.
[0049] First, the hydraulic power steering pump 100 of a gear type
repetitively increases and decreases the discharging amount due to
characteristics of the pumping gear 135a, and the increase/decrease
of the discharging amount causes the pulsation of the hydraulic
power steering pump 100. Meanwhile, the pulsation of the
discharging side causes the pulsation of the sucking side. To
prevent the pulsation of the sucking or discharging side, a large
space is provided in the channel for sucking or discharging the
working fluid so that the working fluid stored in the large space
can reduce the pulsation. Further, the channels narrower than such
a large space are formed in front and back of the storage space and
thus prevent the pulsation from being transferred to another
channel.
[0050] That is, the working fluid in the narrow sucking hole 193 is
guided toward a large storage space, i.e., toward the first sucking
fluid shock absorber 195a while being sucked in the pumping unit
135, and guided by a plurality of narrow vertical sucking channels
117b formed in the partition wall member 117 toward a large space,
i.e., toward the second sucking fluid shock absorber 195b.
[0051] Further, the fluid stored in the second sucking fluid shock
absorber 195b is pressurized in the pumping unit 135 via the
central sucking channel 117c penetrating the center region of the
partition wall member 117, guided to the relatively large space,
i.e., to the pressurized shock absorber 132 via a relatively narrow
shock absorber sucking hole (not shown), and guided to the
discharging hole 119 of the hydraulic power steering pump 100 via
the narrow discharging hole 119, the cross-section of which gets
narrower, thereby acting as the pressurized working fluid. That is,
the volume of the channel for the working fluid is enlarged so that
the expanded working fluid can prevent the pulsation at the
discharging to sucking sides.
[0052] Thus, the pulsation of the working fluid sucked into or
discharged from the pumping unit 135 can be effectively reduced
through the sucking fluid shock absorber 195a, 195b and the
pressurized shock absorber 132. Also, the sucking fluid shock
absorber 195a, 195b may fully use a space formed by the pump
housing, the cap 190 and the housing cover 180, and the pressurized
shock absorber 132 is formed in the pump housing 110 so that the
hydraulic power steering pump 100 can be formed more compactly.
[0053] The motor module 150 is coupled to and supported by the
motor module accommodating unit 115 of the housing 110. The motor
module 150 includes a stator 153 provided to receive electric
current based on external electric power and supported by the
housing 110, and a rotor 155 provided rotatably corresponding to
the stator 153, coupled to the partition wall member 117 in the
middle region of the housing 110, and having the permanent magnet
161 and the motor rotation shaft 151. The permanent magnet 161
includes an exposed portion 161a at the outside thereof exposed
toward the stator 153.
[0054] The stator 153 is the same as a general motor module 150,
and thus detailed descriptions thereof will be avoided as
necessary.
[0055] The rotor 155 includes a yoke holder 157 coupled to the
motor rotation shaft 151, a yoke 159 having a first side coupled to
the yoke holder 157 and a second side coupled to a separation
preventing cab member 163, and the permanent magnet 161.
[0056] The yoke holder 157 is coupled to the motor rotation shaft
151, and on an upper side thereof includes a yoke coupling portion
157c recessed to couple with the yoke 159 and a permanent magnet
holder 157a to be engaged with the permanent magnet 161,
respectively. The yoke coupling portion 157c and the permanent
magnet holder 157a may have various shapes corresponding to the
shapes of the yoke 159 and the permanent magnet 161. Further, as
necessary, adhesive or the like may be used to be coupled to the
yoke coupling portion 157c and the permanent magnet holder
157a.
[0057] Meanwhile, the yoke holder 157 may be provided with ribs
157b formed between the permanent magnets 161 so that the plurality
of permanent magnets 161 coupled in a circumferential direction can
be separated and divided in the circumferential direction. As
necessary, the ribs 157b may form an inclination portion inclined
to the motor rotation shaft 151 so that the fluid can flow through
a gap between the rotor 155 and the stator 153 as the rotor 155
rotates. Thus, the flow of the fluid is caused between the stator
153 and the rotor 155 to thereby effectively dissipating heat
generated in the motor module 150.
[0058] Further, the separation preventing cab member 163 is
provided to hold the upper sides of the yoke 159 and the permanent
magnet 161 after the yoke 159 and the permanent magnet 161 are
coupled to the yoke holder 157. In this case, the separation
preventing cab member 163 includes a skirt 163a bent down from a
top plate thereof so as to surround the upper end of the permanent
magnet 161 or as necessary the upper end of the yoke 159. Thus, an
inside of the permanent magnet 161 may be coupled to the yoke 159
by adhesive or the like, an outer lower end of the permanent magnet
161 may be supported by the permanent magnet holder 157a (refer to
`K3` in FIGS. 3 and 4), an outer upper end of the permanent magnet
161 may be supported by the skirt 163a (refer to `K1` in FIGS. 3
and 4), an outer middle region of the permanent magnet 161 may form
an exposed portion 161a exposed toward the rotor 155 (refer to `K2`
in FIGS. 3 and 4).
[0059] A process of manufacturing the motor module 150 with this
configuration according to an exemplary embodiment will be
described with reference to FIGS. 3 and 4.
[0060] First, the yoke holder 157 is coupled to the motor rotation
shaft 151. As described above, the yoke holder 157 is formed with
the permanent magnet holder 157a, the rib 157b and the yoke
coupling portion 157c.
[0061] Next, the yoke 159 is coupled onto the upper side of the
yoke coupling portion 157c recessed in the yoke holder 157.
[0062] After coupling the yoke 159, adhesive or the like is applied
to the region for coupling with the yoke 159 and then the plurality
of permanent magnets 161 is coupled to the permanent magnet holder
157a. The plurality of permanent magnets 161 may be arranged to be
spaced apart from each other by the ribs 157b in the
circumferential direction.
[0063] Next, the separation preventing cab member 163 is coupled to
the upper sides of the permanent magnet 161 and the yoke 159 so
that the permanent magnet 161 can be firmly supported in the yoke
holder 157 by the end of the permanent magnet 161 surrounded with
the skirt 163a without being separated in the circumferential
direction or in an upward direction.
[0064] Thus, both ends of the permanent magnet 161 are not
separated in a radial direction or in a lengthwise direction by the
permanent magnet holder 157a and the skirt 163a, respectively, and
at the same time the middle region of the permanent magnet may form
the exposed portion 161a exposed in the circumferential
direction.
[0065] Here, data comparison between the related art and the
present embodiment is as follows.
[0066] The following [Table 1] shows experimental data under the
condition that the permanent magnet of the rotor is fully
surrounded according to the related art and experimental data under
the condition that the permanent magnet of the rotor is exposed
according to an exemplary embodiment.
TABLE-US-00001 TABLE 1 Volt- Effi- Torque Speed Output Input
Current age ciency N-m rpm kW W A V % Related 0.600 2235 0.140
220.5 17.60 12.31 63.7 art 1.200 1098 0.138 384.4 34.54 11.13 35.9
Present 0.600 3193 0.202 270.14 20.16 13.40 74.7 embodi- 1.200 2816
0.352 462.21 34.91 13.24 76.2 ment Note
[0067] As shown in [Table 1], under the same condition that a
constant torque of 0.600 N-m is generated, the related art shows
the efficiency of 63.7% but the present embodiment shows 74.2%,
which shows that the efficiency of the present embodiment is
increased by about 16%. Likewise, under the same condition that a
torque is 1.2 N-m, the related art shows the efficiency of 35.9%
but the present embodiment shows 74.7%, which shows that the
efficiency of the present embodiment is significantly increased as
compared with that of the related art.
[0068] Thus, on the contrary to the related art, the permanent
magnet 161 provides the maximum exposed portion 161a as possible,
and thus magnetic force generated by the permanent magnet 161 or
the like is not interfered to thereby enhance magnetic properties
and improve the efficiency of the motor. Also, the permanent magnet
is not fully surrounded, so that the structure for supporting the
permanent magnet can become simpler and more convenient, thereby
lowering molding costs or the like. In addition, the simple
structure may cause the number of parts to be reduced, thereby
simplifying manufacture, assembly, etc. and raising economical
efficiency.
[0069] According to an exemplary embodiment, there is provided a
hydraulic power steering pump having a wet type motor with an open
type magnet, in which a coupling structure of a permanent magnet
arranged in a rotor is improved to enhance magnetic properties of
the permanent magnet to thereby increase efficiency of a motor, a
structure of coupling the permanent magnet is simplified to lower
costs of manufacturing molding or the like and thus raise
economical efficiency, and the simple structure causes processes of
to be simplified.
[0070] Although a few exemplary embodiments have been shown and
described, it will be appreciated by those skilled in the art that
changes may be made in these exemplary embodiments without
departing from the principles and spirit of the invention, the
scope of which is defined in the appended claims and their
equivalents.
* * * * *