Power plants – Pressure fluid source and motor – Having distinct cooling or lubricating structure
Reexamination Certificate
1999-12-28
2001-05-22
Ryznic, John E. (Department: 3745)
Power plants
Pressure fluid source and motor
Having distinct cooling or lubricating structure
C417S366000
Reexamination Certificate
active
06233930
ABSTRACT:
TECHNICAL FIELD
The present invention relates to an improvement of a power steering apparatus integrally having an electric motor, a hydraulic pump being driven by the electric motor, and a controlling device for controlling the electric motor, in which steering is assisted by oil pressure generated by the hydraulic pump.
BACKGROUND ART
A hydraulic pump for feeding an operating fluid to a hydraulically operating equipment such as a hydraulic actuator (control valve) or the like provided in a power steering apparatus of automobile, and an electric motor for driving the hydraulic pump are constructed as shown in
FIG.1
, for example. The hydraulic pump
1
of this power steering apparatus comprises a pump housing
12
and covering body
16
for covering a portion of the pump housing
12
. A controlling device housing
6
in which a controlling device for controlling the electric motor
4
is contained is disposed between the pump housing
12
and electric motor
4
.
A portion
60
which produces heat by a large current inside the controlling device housing
6
is provided on the electric motor
4
side of the controlling device housing
6
and radiates heat to ambient by heat radiation structure such as a fin or the like provided on a surface of the controlling device housing
6
.
Here, when a structure for transmitting heat from a heat-producing member to another member for radiating heat is employed, in order to enhance the thermal conductivity, the following methods are conceivable: increasing a clamping torque of bolts for attaching and clamping the heat-producing member and other member; enhancing a degree of intimate contact between the heat-producing member and other member by enhancing surface quality of adhered surfaces therebetween; applying a material having a high thermal conductivity such as a silicon grease or the like onto the adhered surfaces of the heat-producing member and other member; and sandwiching a sheet having a high thermal conductivity between the heat-producing member and other member.
On the other hand, in order to secure a water-resistance for preventing water from being impregnated between the heat-producing member and other member, there are the following methods: sandwiching a rubber packing between the heat-producing member and other member; applying a liquid packing between the heat-producing member and other member; and applying an O-ring for sealing between the heat-producing member and other member.
However, temperature of an engine room in which the hydraulic pump
1
, electric motor
4
, and controlling device housing
6
containing the controlling device of the power steering apparatus are provided is increased by heat generated by the engine. Therefore, the heat radiation method to ambient by the heat radiation structure such as the fin or the like is employed, the heat radiation efficiency is lowered, and there is an adverse possibility that temperature of the heat-producing portion
60
inside the controlling device housing
6
exceeds acceptable temperature.
In the case of the method for enhancing thermal conductivity, it is difficult to control dimensions of the connected portions of the heat-producing member and other member, and there is a problem that the method for enhancing thermal conductivity is not compatible with the method for securing water-resistance.
It is an object of the present invention to provide a power steering apparatus capable of efficiently radiating heat generated inside the controlling device, capable of allowing heat-radiation design without being influenced by ambient condition, and capable of allowing replacement to members having low heat-resistance.
It is another object of the invention to provide a power steering apparatus capable of stably radiating heat generated inside a controlling device, having an excellent water-resistance against outside, in which the dimensions for fitting is easily controlled.
DISCLOSURE OF THE INVENTION
A power steering apparatus according to the present invention integrally comprising an electric motor, a hydraulic pump driven by the electric motor, and a controlling device which is disposed between the electric motor and hydraulic pump and which controls the electric motor, in which steering is assisted by oil pressure generated by the hydraulic pump, is characterized in that a radiating body for radiating a heat generated by the controlling device is disposed between the controlling device and hydraulic pump, so that the heat generated by the controlling device is radiated to the hydraulic pump.
In the power steering apparatus of the present invention, it integrally comprises the electric motor, the hydraulic pump driven by the electric motor, and the controlling device which is disposed between the electric motor and hydraulic pump which controls the electric motor, and steering is assisted by oil pressure generated by the hydraulic pump. The radiating body disposed between the controlling device and hydraulic pump radiates the heat generated by the controlling device to the hydraulic pump. Therefore, it is possible to efficiently radiate a heat generated inside the controlling device, the heat radiation can be designed without being influenced by ambient condition, and it is possible to be replaced by members having low heat-resistance.
An another power steering apparatus according to the present invention is characterized in that the radiating body is a sheet for transmitting the heat, held between the controlling device and hydraulic pump.
In the power steering apparatus of the present invention, the radiating body is a sheet which is held between the controlling device and hydraulic pump and which transmits the heat. Therefore, it is possible to efficiently radiate a heat generated inside the controlling device, the heat radiation can be designed without being influenced by ambient condition, and it is possible to be replaced by members having low heat-resistance.
An another power steering apparatus according to the present invention is characterized in that the controlling device and hydraulic pump have fitting configurations, a cross section of the fitting configurations is approximately circular in shape, and a convex portion and concave portion of the fitting configurations provide a space for clamping an O-ring therebetween.
In the power steering apparatus of the present invention, it integrally comprises the electric motor, the hydraulic pump driven by the electric motor, and the controlling device which is disposed between the electric motor and hydraulic pump and which controls the electric motor, and steering is assisted by oil pressure generated by the hydraulic pump. The radiating body disposed between the controlling device and hydraulic pump radiates the heat generated by the controlling device to the hydraulic pump. Further, the controlling device and hydraulic pump have fitting configurations, a cross section of the fitting configurations is approximately circular in shape, and a convex portion and concave portion of the fitting configurations provide a space for clamping the O-ring therebetween. Therefore, it is possible to stably radiate a heat generated inside the controlling device, and since the O-ring is clamped between the convex portion and concave portion of the fitting configurations, water-resistance against outside is excellent, and it is easy to control the dimensions for fitting.
An another power steering apparatus according to the present invention is characterized in that the controlling device is contained inside a housing connected to the hydraulic pump, the housing and hydraulic pump have fitting configurations, a cross section of the fitting configurations is approximately circular in shape, and a convex portion and concave portion of the fitting configurations provide a space for clamping an O-ring therebetween.
In the power steering apparatus of the present invention, it integrally comprises the electric motor, the hydraulic pump driven by the electric motor, and the controlling device which is disposed between the electric motor
Goto Yoshihiro
Hamasaki Yoshiaki
Matsuoka Hirofumi
Darby & Darby
Koyo Seiko Co. Ltd.
Ryznic John E.
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