Motor driven fluid pump

Disclosed is a motor driven fluid pump (e.g., water pump) including a pump body having a motor chamber and a pump chamber; a bearing supporting a rotary shaft of a motor which extends from motor chamber to pump chamber in pump body; a mechanical seal disposed between rotary shaft of the motor and pump body and blocking motor chamber from pump chamber; a bearing guide integrally fixed to rotary shaft of the motor between bearing and mechanical seal; a fluidproof plate fixed to pump body to overlap bearing guide, perpendicular to rotary shaft of the motor; and a leachate exhaust aperture and a vapor exhaust aperture which are formed through pump body to communicate with the space between fluidproof plate and mechanical seal.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Korean Patent Application No. 10-2010-0113167 filed Nov. 15, 2010, the entire contents of which application is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a motor driven fluid pump, and more particularly, to a structure of discharging vapor and liquid-state fluid (e.g., water) which pass through a mechanical seal in a fluid pump having a motor chamber and a pump chamber which are divided by the mechanical seal.

2. Description of Related Art

FIG. 1 shows a motor driven fluid pump of the related art which has a motor chamber 502 where a motor 500 is disposed and a pump chamber 506 where an impeller 504 that is operated by rotational force supplied from motor 500 is disposed, in which a mechanical seal 508 is provided between pump chamber 506 and motor chamber 502 to prevent fluid from permeating to motor chamber 502 from pump chamber 506.

In this configuration, cooling fluid may leak at several cubic centimeters (cc) per hour in a vapor state or a liquid state for lubrication, through mechanical seal 508 for the structure, which corrodes the bearing supporting the rotary shaft of motor 500 to the case and reduces insulation of motor 500.

Meanwhile, a specific leachate hole is provided to discharge the fluid leaking out of mechanical seal 508, as described above; however, the leachate hole may rather allow fluid to flow inside from the outside, such that motor 500 may become wet.

BRIEF SUMMARY OF THE INVENTION

The present invention has been made in an effort to provide a motor driven fluid pump in which a rotary shaft of a motor extends from a motor chamber to a pump chamber, the rotary shaft of the motor is supported by a bearing, the motor chamber and the pump chamber are divided by a mechanical seal, and which can make the insulation of the motor stable by preventing fluid leaking out of the pump chamber through the mechanical seal from flowing into the bearing and the motor chamber, and considerably improve durability by preventing corrosion of the bearing.

An exemplary embodiment of the present invention provides a motor driven fluid pump (e.g., water pump) including a pump body having a motor chamber and a pump chamber; a bearing supporting a rotary shaft of a motor which extends from the motor chamber to the pump chamber, in the pump body; a mechanical seal disposed between the rotary shaft of the motor and the pump body and blocking the motor chamber and the pump chamber; a bearing guide integrally fixed to the rotary shaft of the motor, between the bearing and the mechanical seal; a fluidproof (e.g., waterproof) plate fixed to the pump body to overlap the bearing guide, perpendicular to the rotary shaft of the motor; and a leachate exhaust aperture and a vapor exhaust aperture formed in the pump body to communicate with a space between the fluidproof plate and the mechanical seal.

In the motor driven fluid pump according to the exemplary embodiments of the present invention, a rotary shaft of a motor extends from a motor chamber to a pump chamber, the rotary shaft of the motor is supported by a bearing, the motor chamber and the pump chamber are divided by a mechanical seal, such that it is possible to make the insulation of the motor stable by preventing fluid leaking out of the pump chamber through the mechanical seal from flowing into the bearing and the motor chamber, and considerably improve durability by preventing corrosion of the bearing.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIGS. 2 to 4, a motor driven fluid pump according to an exemplary embodiment of the present invention includes a pump body5having a motor chamber1(or drive chamber) and a pump chamber3; a bearing9supporting a rotary shaft7of a motor which extends from motor chamber1to pump chamber3in pump body5; a mechanical seal11disposed between rotary shaft7of the motor and pump body5and blocking motor chamber1from pump chamber3(e.g., where the term “blocking” illustratively indicates a fluidic separation between the motor chamber1and pump chamber3); a bearing guide13integrally fixed to rotary shaft7of the motor between bearing9and mechanical seal11; a fluidproof plate15fixed to pump body5to overlap bearing guide13, perpendicular to rotary shaft7of the motor; and a leachate exhaust aperture17(forming a leachate exhaust hole) and a vapor exhaust aperture19(forming a vapor exhaust hole) which are formed through pump body5to communicate with the space between fluidproof plate15and mechanical seal11.

That is, mechanical seal11between pump chamber3and motor chamber1performs the basic sealing function that allows rotary shaft7of the motor to rotate and prevents fluid from pump chamber3from flowing to motor chamber1, a small amount of fluid passing through mechanical seal11is secondarily blocked by a sealed structure formed by fluidproof plate15and bearing guide13, and the fluid leaking in a vapor state is discharged outside through vapor exhaust aperture19and the fluid leaking in a liquid state is discharged through the leachate exhaust aperture17, such that fluid cannot permeate bearing9and the motor.

Bearing guide13, as shown in detail inFIG. 3, is formed in a ring shape covering the entire outer circumference of rotary shaft7of the motor to ensure airtightness and fluidproof plate15is formed in a ring shape with an outer circumference fixed to pump body5and an inner circumference spaced apart from rotary shaft7of the motor.

Bearing guide13is coupled to rotary shaft7of the motor by fitting or welding, or integrally formed with rotary shaft7of the motor such that fluid cannot flow between rotary shaft7of the motor and bearing guide13, and fluidproof plate15is spaced apart from rotary shaft7of the motor, but a side of fluidproof plate15is in contact with bearing guide13to prevent fluid from permeating.

In the exemplary embodiment, a protruding seal rib21is integrally formed on the surface opposite to bearing guide13of fluidproof plate15to seal bearing guide13.

That is, according to one example embodiment, it is more advantageous in improving airtightness and reducing friction to implement sealing between bearing guide13and fluidproof plate15by using seal rib21, than to implement sealing by directly contacting fluidproof plate15to bearing guide13, such that seal rib21is integrally formed on fluidproof plate15.

In one embodiment, seal rib21may be formed at bearing guide13and it is preferable to prepare for friction and ensure stronger airtightness by applying grease on seal rib21.

A plurality of air motion tips23alternately bending to both sides of fluidproof plate15is circumferentially formed on the inner circumference of fluidproof plate15.

Air motion tips23make the air flow on the inner circumference of fluidproof plate15, when rotary shaft7of the motor rotates with bearing guide13, such that they contribute to block or interfere with flow of fluid leaking from mechanical seal11to motor chamber1and discharge the fluid through vapor exhaust aperture19.

Fluidproof plate15may be fitted or thread-fastened in pump body5; however, in this embodiment, pump body5has a female thread25to thread-fasten fluidproof plate15by rotating it and a male thread27that is engaged with female thread25of pump body5is formed on the outer circumference of fluidproof plate15, such that fluidproof plate15is thread-fastened to pump body5.

Further, as shown in detail inFIG. 4, tool grooves29are formed at one side of fluidproof plate15to easily combine fluidproof plate15with pump body5by rotating the fluidproof plate.

In one embodiment, fluidproof plate15may be formed such that the outer circumference is fitted in pump body5and bearing guide13may also be fitted on rotary shaft7of the motor.

In the motor driven fluid pump having the configuration described above, according to an exemplary embodiment of the present invention, the impeller pumps the fluid up from pump chamber3, using the rotational force supplied from the motor in motor chamber1, mechanical seal11prevents the fluid in pump chamber3from leaking out of pump chamber3to motor chamber1while allowing rotary shaft7of the motor to freely rotate, the fluid leaking through mechanical seal11is blocked by the air flow generated by air motion tips23, led to vapor exhaust aperture19and leachate exhaust aperture17, and prevented again from permeating by the sealed structure between fluidproof plate15and bearing guide13, such that it is possible to prevent corrosion of bearing9above motor chamber1, ensure stable insulation of the motor, and ensure stable operability and durability of a motor driven fluid pump.