JP2003239740A - Cooling water pump device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance pump efficiency and engine output by restraining rotation resistance and frictional resistance of an impeller to be low. <P>SOLUTION: In this cooling water pump device for engine, a shaft 71 and the impeller 72 of a cooling water pump 70 are separated from each other, permanent magnets 77 and 80 are fixed to a face in which the shaft 71 and the impeller 72 are opposite to each other, and rotation of the shaft 71 is transmitted to the impeller 72 by attraction of the permanent magnets 77 and 80 thereby rotating and driving the impeller 72. In this device, the shaft 71 and the impeller 72 are partitioned by a partition wall 75, and balls (support members) 81 for rotatably supporting the impeller 72 are interposed between the partition wall 75 and the impeller 72. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine cooling water pump device for circulating cooling water in various parts of an engine.

[0002]

2. Description of the Related Art As a cooling water pump for circulating cooling water in various parts of an engine, one in which an impeller is directly connected to an end of a shaft is generally used. In such a cooling water pump, a mechanical seal or the like is used as a shaft sealing means, but since this mechanical seal is pressed against the seat ring by a spring, friction loss is inevitably generated.

By the way, in general, the friction loss is not so large as to cause a problem, but in a small engine having a small displacement, the friction loss of a mechanical seal or the like may not be negligible.

Further, in the cooling water pump, a structure is adopted in which a boss is provided on the suction side of the impeller in order to fix the impeller to the end portion of the shaft, and this boss serves as resistance against the inflow of the cooling water into the impeller. There is a problem that the pump efficiency is reduced.

Therefore, the shaft of the cooling water pump and the impeller are separated, permanent magnets are fixed to the surfaces of the shaft and the impeller facing each other, and the rotation of the shaft is transmitted to the impeller by the attractive force of the permanent magnet. There has been proposed a structure in which the shaft is driven to rotate, which eliminates the need for a shaft sealing means.

[0006]

However, in the conventional cooling water pump device adopting the above-mentioned structure, since the means for rotatably supporting the impeller is not provided, the rotation resistance of the impeller is large, and the impeller is permanent. Since the impeller is pressed against the other member by the attraction force of the magnet, the frictional resistance is increased, and there is a problem that the pump efficiency is lowered and the horsepower loss of the engine is increased.

The present invention has been made in view of the above problems, and an object of the present invention is to reduce the rotational resistance and frictional resistance of an impeller to improve pump efficiency and engine output. It is to provide a pump device.

[0008]

In order to achieve the above object, the invention according to claim 1 separates a shaft of a cooling water pump and an impeller, and fixes a permanent magnet on the surfaces of the shaft and the impeller facing each other. In a cooling water pump device for an engine that transmits the rotation of a shaft to an impeller by the attractive force of the permanent magnet to drive the impeller to rotate, the shaft and the impeller are partitioned by a partition wall, and the partition wall and the impeller are separated from each other. A supporting member for rotatably supporting the impeller is interposed between the two members.

A second aspect of the invention is characterized in that, in the first aspect of the invention, the supporting member is formed of a ball.

According to a third aspect of the invention, in the first aspect of the invention, the supporting member is constituted by a shaft supported by the partition wall.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the opposite end surface of the impeller support portion of the shaft is exposed from the partition wall, and the shaft is positioned in the partition wall direction by the end surface. It is characterized by

According to a fifth aspect of the invention, in the third aspect of the invention, the shaft is fitted and inserted into a hole formed in the shaft center portion of the impeller, and between the impeller and the shaft in the hole. The feature is that a ball is provided.

Therefore, according to the present invention, since the separated shaft and impeller are separated by the partition wall, a shaft sealing means such as a mechanical seal is not required, and a ball provided between the partition wall and the impeller. Since the structure in which the impeller is rotatably supported by such support members is adopted, the rotational resistance of the impeller is suppressed to a low level, and the thrust force acting on the impeller due to the attractive force of the permanent magnet is received by the support member. Since there is no sliding contact with the wall, the frictional resistance generated between the impeller and the support member is also minimized, which improves pump efficiency and engine output.

Further, since it is not necessary to fix the impeller to the shaft, it is not necessary to provide a boss on the suction side of the impeller, and the cooling water can be smoothly introduced into the impeller without any resistance, which also improves the pump efficiency. Planned.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side view of a scooter type motorcycle 1 in which a head pipe 2 is located in the front upper portion of the vehicle body of the scooter type motorcycle 1 shown in the figure, and a steering shaft 3 is provided in the head pipe 2. It is inserted rotatably. A steering wheel 4 is attached to the upper end of the steering shaft 3, and a front fork 5 is attached to the lower end of the steering shaft 3, and a front wheel 6 is rotatably attached to the lower end of the front fork 5. It is supported.

A down tube 7 extends obliquely downward from the head pipe 2 toward the rear of the vehicle body, and is bent and extends substantially horizontally toward the rear of the vehicle body. From this, a pair of left and right back stays 8 branch off and extend obliquely upward toward the rear of the vehicle body.

By the way, the head pipe 2, the down tube 7 and the like at the front of the vehicle body are covered with a front cover 9 made of resin, and the rear half of the front cover 9 constitutes a leg shield 10 also made of resin. There is.

Further, a seat 1 is provided behind the handle 4.
1 is arranged, and a low-floor foot step 12 is provided between the seat 11 and the handle 4. A radiator 13 is arranged in a space diagonally below and in front of the foot step 12.

A unit swing type engine 14 as a power unit is provided behind the foot step 12 and below the seat 11.

The unit swing type engine 14 is
It is located on the left side of the vehicle body, and this is the engine 1 as a drive source.
5 and a transmission case 16 including a V-belt type automatic transmission (not shown) and a speed reduction mechanism are integrally formed. The transmission case 16 extends from the left side of the vehicle body of the engine 15 to the rear side of the vehicle body, and the rear wheel is provided at the rear end thereof. 17 is rotatably supported.

An air cleaner 18 is arranged on the left side of the engine 15, and an intake pipe 19 extending from the upper portion of the air cleaner 18 rises upward and is bent toward the rear of the vehicle body. Is attached. An intake pipe 21 extending from the carburetor 20 to the rear of the vehicle body is bent downward and connected to the intake system of the engine 15.

On the other hand, the exhaust pipe 22 extending from the exhaust system in the lower part of the engine 15 is extended on the right side of the vehicle body toward the rear of the vehicle body, and an exhaust muffler 23 is attached to the end thereof.

Further, the cooling water pipes 24 and 25 extending substantially horizontally from the radiator 13 arranged in the front of the engine 15 toward the rear of the vehicle body are provided with the engine 1 as shown in the drawing.
Connected to 5.

The unit swing type engine 14 having the above construction is supported by an engine suspension bracket 26 fixed to the back stay 8 via links 27 so as to be vertically swingable, and its rear end is a rear wheel 17. At the same time, it is supported by the back stay 8 via the rear cushion 28.

On the other hand, a portion of the vehicle body below the seat 11 is covered with a resinous vehicle body cover 29, and the unit swing type engine 14 in the vehicle body cover 29 is covered.
A storage box 30 having an open upper surface is arranged above and a fuel tank 31 is arranged behind it. Here, the storage box 30 is for storing the helmet 32, and the front half of the bottom wall of the storage box 30 is formed into a curved arc shape according to the outer shape of the helmet 32. The sheet 11 is placed on the storage box 30.
Is supported, and the front end of the seat 11 pivots up and down around a hinge (not shown) to open and close the storage box 30.

Details of the structure of the engine 15 will be described with reference to FIGS. 2 and 3. 2 and 3 are longitudinal sectional views of the engine.

The engine 15 is a water-cooled 4-cycle single-cylinder DOHC engine, and its cylinder 33 and cylinder head 34 are tilted substantially horizontally forward. Specifically, as shown in FIG. 2, an axial center line (hereinafter, referred to as a cylinder axis line) M of the bore 35 formed in the cylinder 33 is
Inclining upward with respect to the horizontal line H by an angle θ,
Offset ε downward with respect to crank center O. It should be noted that the angle θ is set to a value that allows the oil to return from the lowest portion of the chain chamber 36 shown in FIG. 3 in the DOHC engine 15.

A piston 37 is slidably fitted in a bore 35 formed in the cylinder 33, and the piston 37 is connected to a crankshaft 39 via a connecting rod 38. Here, the crankshaft 39 is rotatably disposed in a crankcase 40 that is integral with the transmission case 16 in the direction perpendicular to the plane of FIG. 2 (the vehicle width direction), and is arranged on the web 39a of the crankshaft 39. The large end of the connecting rod 38 is connected by a crank pin 41,
The small end of the connecting rod 38 is connected to the piston 37 via a piston pin 42. In addition, the reciprocating linear motion of the piston 37 in the cylinder bore 35 is
Is converted into rotary motion of the crankshaft 39 via.

In addition, intake passages 43 are formed in the upper and lower portions of the cylinder head 34 attached to the end surface of the cylinder 33, respectively.
An exhaust passage 44 is formed, the intake pipe 21 is connected to the intake passage 43, and the exhaust pipe 22 is connected to the exhaust passage 44. The intake port and the exhaust port, which are the openings of the intake passage 43 and the exhaust passage 44 to the combustion chamber S, are opened and closed at appropriate timings by the intake valve 45 and the exhaust valve 46, respectively. Gas exchange is done. A spark plug 48 is screwed onto the cylinder head 34, and the electrode portion of the spark plug 48 faces the top of the combustion chamber S.

Here, in the engine 15, a DOHC (twin cam) type is adopted as a valve operating mechanism for driving the intake valve 45 and the exhaust valve 46 to open and close. The structure and operation of this valve operating mechanism will be described below. To do.

The intake valve 45 and the exhaust valve 46 are
Valve guides 49, 5 press-fitted into the cylinder head 34
0 are slidably inserted and supported respectively, and these are always urged toward the closing side by valve springs 51 and 52.

Rocker arms 53 and 54 are rotatably supported on the upper and lower portions of the cylinder head 34 by rocker shafts 55 and 56, respectively.
The tips of 3, 54 are in contact with the tops of the intake valve 45 and the exhaust valve 46, respectively. And the cylinder head 3
An intake cam shaft 57 and an exhaust cam shaft 58, which extend in the vehicle width direction (the direction perpendicular to the paper surface of FIG. 2), are rotatably supported near the rocker arms 53 and 54 at the upper and lower portions of 4, respectively.
The intake cam 57a and the exhaust cam 5 formed integrally with these
8a are in contact with the back surfaces of the rocker arms 53 and 54, respectively. The intake cam shaft 57 and the exhaust cam shaft 58 are covered by a head cover 59 attached to the cylinder head 34.

By the way, as shown in FIG. 3, chain sprockets 60 and 61 having the same diameter are attached to the respective ends of the intake cam shaft 57 and the exhaust cam shaft 58 by bolts 62 and 63, respectively. An endless cam chain 65 is wound around the chain sprockets 60 and 61 and a small-diameter chain sprocket 64 attached to one end of the crankshaft 39. In FIG. 3, 66 is a chain tensioner for applying a predetermined tension to the cam chain 65, and 67 and 68 are chain guides for preventing the cam chain 65 from swinging.

While the engine 15 is being driven, the rotation of the crankshaft 39 is 1 / g through the chain sprocket 64, the cam chain 65 and the chain sprockets 60 and 61.
It is decelerated to 2 and transmitted to the intake cam shaft 57 and the exhaust cam shaft 58, respectively.
8 is rotationally driven. Then, the intake cam 57a and the exhaust cam 58a formed on the intake cam shaft 57 and the exhaust cam shaft 58, respectively.
Rocker arms 53 and 54 at appropriate timings
The rocker arms 53 and 54 are rotated about the rocker shafts 55 and 56, respectively, and the intake valve 4 is pressed.
5 and the exhaust valve 46 are pushed open, the required gas exchange is performed in the cylinder bore 35 as described above.

Next, the operation of the engine 15 will be described.

When the engine 15 is started, the piston 3
7 is drawn by the intake negative pressure generated in the intake stroke that descends diagonally in the cylinder bore 35, and the fresh air is the air cleaner 1.
8 is sucked into the air cleaner 8, and the sucked fresh air is purified by the air cleaner 18 and then introduced into the carburetor 20 through the intake pipe 19. In the carburetor 20, an air-fuel mixture having a predetermined air-fuel ratio (A / F) is formed by mixing the atomized fuel into the fresh air flowing through the carburetor 20, and the air-fuel mixture is taken by the intake pipe 21 and the cylinder head 34. Passage 43
And through the intake valve 45 in the open state into the cylinder bore 35. The exhaust valve 46 is closed during the intake stroke.

Then, the piston 37 moves to the bottom dead center (BDC).
The intake valve 4
5 is closed, the mixture is compressed in the cylinder bore 35 by the piston 37, which causes the piston 37 to reach the top dead center (TD).
Immediately before reaching C), it is ignited and burned by the spark plug 48. Then, the high pressure generated by the combustion of the air-fuel mixture shifts the piston 37 to the explosion (work) stroke in which it descends in the cylinder bore 35, and the exhaust valve 46 opens in the exhaust stroke in which the piston 37 rises past the bottom dead center. Then, high-temperature and high-pressure exhaust gas is discharged into the exhaust passage 44 of the cylinder head 34, and the exhaust gas is discharged into the atmosphere through the exhaust pipe 22 and the exhaust muffler 23.

Thereafter, the same process is repeated and the engine 15 is continuously operated. As described above, the reciprocating linear motion of the piston 37 in the cylinder bore 35 is converted into the rotational motion of the crankshaft 39 by the connecting rod 38. The rotation of the crankshaft 39 passes through a V-belt type automatic transmission (not shown) and a reduction mechanism, which are built in the transmission case 16, and the rear wheel 1
7 is transmitted. As a result, the rear wheels 17 are rotationally driven, and the scooter type motorcycle 1 is caused to travel at a predetermined speed.

Next, details of the cooling pump device of the engine 15 will be described with reference to FIGS. 4 is a longitudinal sectional view of the engine showing the cooling water path, FIG. 5 is a right side view in which a part of the engine is broken, FIG. 6 is a sectional view taken along the line AA of FIG. 5, and FIG. 7 is a front view of the impeller. Is.

As shown in FIGS. 5 and 6, the engine 15
On one end surface (right end surface) of the head cover 59, a cooling water pump 70 is attached coaxially with the exhaust cam shaft 58 by a bolt 69. Here, the cooling water pump 70
Is configured to include a shaft 71 and an impeller 72 that are arranged coaxially with the exhaust cam shaft 58, and they are separated from each other. As shown in FIG. 7, the impeller 72 has 6
The blade 72a is provided.

By the way, as shown in FIG. 6, a pump cover 74 is attached to the bolt housing 69 on the pump housing 73.
And a partition wall 75 made of magnetic metal is sandwiched between the two. The partition wall 75 separates the shaft 71 and the impeller 72, and the outer periphery thereof is sealed by a seal member 76.

The shaft 71 is rotatably inserted into and supported by the pump housing 73, and one end of the shaft 71 projecting out of the pump housing 73 is connected to one end of the exhaust cam shaft 58 by a concave-convex fitting. A disk-shaped plate 71a is integrally formed at the other end facing the inside. Then, for example, an N-pole permanent magnet 77 is fixed to the surface of the plate 71a facing the partition wall 75, and a recess 71b formed in the center of the plate 71a.
The ball 78 is housed in the partition wall 7
5 is engaged with a conical recess 75a formed in the central portion of No. 5. Therefore, the entire shaft 71 is axially received by the partition wall 75 via the balls 78.

On the other hand, the impeller 72 has a scroll chamber 7 defined by a partition wall 75 inside a pump cover 74.
The S-pole permanent magnet 80 is fixed to the surface (back surface) of the impeller 72 facing the partition wall 75. The impeller 72 is provided with a plurality of balls 81 arranged on the back side thereof and forming a thrust bearing.
It is rotatably supported while being centered on the partition wall 75 via the, and is axially received by the partition wall 75 via the ball 81.

Further, the pump cover 74 is integrally formed with a cooling water passage 74a for guiding the cooling water to the impeller 72 in the axial direction. The cooling water passage 74a is provided from the outlet side of the radiator 13. The extending cooling water pipe 24 (see FIG. 1) is connected. And the scroll chamber 79
One end of a cooling water pipe 82 arranged on the right side of the engine 15 is connected to the outlet 79a of the.

On the other hand, as shown in FIG. 4, the intake passage 43, the exhaust passage 44, and the spark plug 48 of the cylinder head 34.
A water jacket 83 is formed around the
A water jacket 84 is formed around the cylinder bore 35 of the cylinder 33. The exhaust-side lower portion of the water jacket 83 formed in the cylinder head 34 communicates with the exhaust-side lower portion of the water jacket 84 formed in the cylinder 33.

A circular hole-shaped cooling water inlet 83a that opens into the water jacket 83 is formed on the side of the cylinder head 34 on the intake side (upper side), and this cooling water inlet 83a is formed. The other end of the cooling water pipe 82 is connected. Further, a circular hole-shaped cooling water outlet 84a opening to the water jacket 84 is formed on the side portion on the intake side (upper side) of the cylinder 33.
One end of the cooling water pipe 25 (see FIG. 1) is connected to a, and the other end of the cooling water pipe 25 is connected to the radiator 13 (see FIG. 1).
(See) entrance.

In the cooling device having the cooling water path as described above, the cooling water from the radiator 13 is introduced into the vicinity of the intake passage 43 of the cylinder head 34, and then the water jacket 83 of the cylinder head 34 is exhausted. Flow downward toward the cylinder 3 from the bottom of the exhaust passage 44.
3 is introduced to the exhaust side of the water jacket 84 and returned to the radiator 13 from the intake side of the cylinder 33.

That is, when the engine 15 is started and the exhaust cam shaft 58 is rotationally driven as described above, the shaft 71 of the cooling water pump 70 connected to the exhaust cam shaft 58 is rotationally driven at the same speed. However, since the rotation of the shaft 71 is transmitted to the impeller 72 by the attractive force of the permanent magnets 77 and 80 fixed to the shaft 71 and the impeller 72, the impeller 72 is rotationally driven. still,
At this time, the shaft 71 and the impeller 72 form the permanent magnet 7
The attraction of 7,78 attracts each other,
The thrust force acting on the shaft 71 in the right direction of FIG. 6 is received by the partition wall 75 via the ball 78, and the thrust force acting on the impeller 72 in the left direction of FIG.
It is received by the partition wall 75 through 1.

When the impeller 72 is rotationally driven as described above, the cooling water having a low temperature cooled in the radiator 13 passes through the cooling water pipe 24 and the pump cover 7
The cooling water passage 74a of No. 4 sucks the impeller 72 of the cooling water pump 70 in the axial direction. Then, the cooling water is pressurized by the impeller 72 and is discharged from the outlet 79 a of the scroll chamber 79.
To the cooling water pipe 82, and is first introduced into the cylinder head 34 from the cooling water inlet 83a formed on the intake side of the cylinder head 34.

In the cylinder head 34, the cooling water having a low temperature flows through the water jacket 83 from the intake side (upper side) to the exhaust side (lower side), first cooling the vicinity of the intake passage 43, and then the exhaust side. Flows downward to cool the vicinity of the spark plug 48 and the exhaust passage 44. In this way, the high-temperature cooling water that has flowed through the water jacket 83 of the cylinder head 34 from the intake side to the exhaust side and cooled each portion is exhausted from the water jacket 84 of the cylinder 33 from the lower portion of the exhaust passage 44 of the cylinder head 33. Is introduced into the water jacket 84 to cool the water around the cylinder bore 35 of the cylinder 33 in the process of flowing from the exhaust side to the intake side (from below to above). Finally, the cooling water is the cooling water outlet 84a formed on the side portion of the cylinder 33.
Is discharged from the cylinder 33 to the outside of the cylinder 33, returned to the radiator 13 through the cooling water pipe 25, cooled by heat exchange with the traveling wind in the radiator 13, and thereafter continuously flows through the same cooling water path as described above. And cools each part of the engine 15.

As described above, in the cooling water pump 70 according to the present invention, the separated shaft 71 and impeller 7 are separated.
Since the partition wall 75 and 2 are separated from each other, a shaft seal means such as a mechanical seal is not required, and the partition wall 75 and the impeller 7 are not necessary.
The ball 81 provided between the impeller 72 and
Since the structure that rotatably supports is adopted, the impeller 7
The rotation resistance of 2 is kept low and the permanent magnet 7
The thrust force acting on the impeller 72 by the suction force of 7, 78 is received by the partition wall 75 via the ball 81, and the frictional resistance generated between the impeller 72 and the ball 81 is also minimized, which results in pump efficiency. And the engine output is improved.

Further, in the cooling water pump 80, since it is not necessary to fix the impeller 72 to the shaft 71, it is not necessary to provide a boss on the suction side of the impeller 72, and the cooling water can smoothly flow into the impeller 72 without resistance. The flow loss is suppressed to a low level, which also improves the pump efficiency.

In the present embodiment, the cooling water pump 70
Although the exhaust cam shaft 58 is used for driving, the intake water cam shaft 57 may of course drive the cooling water pump 70.

By the way, in the present embodiment, since the shaft 71 of the cooling water pump 70 is connected to the exhaust cam shaft 58 by the concave and convex fitting, the cooling water pump 70 is formed as a unit and integrated with the engine 15. However, if such a structure is not adopted, the shaft 71 may be attached to the bolt 8 as shown in FIG.
5 can be directly attached to the exhaust cam shaft 58.

Further, in the above embodiment, the shaft 71
The balls 78 and 81 are used as support members for rotatably supporting the impeller 72 with respect to the partition wall 75.
As shown in FIG. 9, insert the shaft 86 into the center of the partition wall 75 as an Al die-cast or resin molded product, and insert the shaft 86 into the hole 72b formed in the axial center of the impeller 72. Alternatively, a structure in which the impeller 72 is rotatably supported by a shaft 86 may be adopted. Where axis 8
The end surface on the opposite side of the impeller support portion 6 is also exposed from the partition wall 75, and one end of the shaft 71 in the partition wall direction abuts on this end surface to position the shaft 71.
In this case, if the shaft 86 is made of a material having high wear resistance such as SUS, the partition wall 75 does not need to have wear resistance. or,
Since both ends of the shaft 86 are exposed, the shaft 86 as a single item
Is inserted into the partition wall 75, which simplifies the structure of the partition wall 75.

Alternatively, as shown in FIG. 10, the impeller 72
A ball 87 may be interposed between the impeller 72 of the hole 72b formed in the shaft and the shaft 86, and the shaft 71 may be brought into contact with the end surface of the shaft 86 via the ball 78. If so, the rotational resistance of the shaft 71 and the impeller 72 can be further reduced.

[0058]

As is apparent from the above description, according to the present invention, the shaft of the cooling water pump and the impeller are separated,
In a cooling water pump device for an engine, wherein a permanent magnet is fixed to opposite surfaces of the shaft and an impeller, and the attraction force of the permanent magnet transmits the rotation of the shaft to the impeller to drive the impeller to rotate. And a partition wall, and a support member that rotatably supports the impeller is provided between the partition wall and the impeller, so that rotation resistance and friction resistance of the impeller are suppressed to a low level, and pump efficiency and engine output are improved. The effect that can be achieved is obtained.

[Brief description of drawings]

FIG. 1 is a side view of a scooter type motorcycle.

FIG. 2 is a vertical sectional view of an engine.

FIG. 3 is a longitudinal sectional view of the engine.

FIG. 4 is a longitudinal sectional view of the engine showing a cooling water path.

FIG. 5 is a right side view in which a part of the engine is cut away.

6 is a cross-sectional view taken along the line AA of FIG.

FIG. 7 is a front view of the impeller.

FIG. 8 is a view similar to FIG. 6 showing another embodiment of the cooling water pump device according to the present invention.

FIG. 9 is a view similar to FIG. 6 showing another embodiment of the cooling water pump device according to the present invention.

FIG. 10 is a view similar to FIG. 6 showing another embodiment of the cooling water pump device according to the present invention.

[Explanation of symbols]

15 engine 70 Cooling water pump 71 shaft 72 Impeller 72a feather 72b hole 75 partition wall 77,80 Permanent magnet 81 ball (support member) 86 shaft (support member) 87 balls

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F16C 19/32 F16C 19/32 F16D 7/02 F16D 7/02 C F16H 49/00 F16H 49/00 A

Claims (5)

[Claims] 1. A shaft of a cooling water pump and an impeller are separated, permanent magnets are fixed to opposite surfaces of the shaft and the impeller, and the rotation of the shaft is transmitted to the impeller by the attractive force of the permanent magnet. In an engine cooling water pump device that rotationally drives, while partitioning the shaft and the impeller with a partition wall,
A cooling water pump device for an engine, wherein a support member that rotatably supports the impeller is provided between the partition wall and the impeller. 2. The engine cooling water pump device according to claim 1, wherein the support member is formed of a ball. 3. The engine cooling water pump device according to claim 1, wherein the support member is constituted by a shaft supported by the partition wall. 4. The engine cooling water according to claim 3, wherein an end surface of the shaft opposite to the impeller support portion is exposed from the partition wall, and the shaft is positioned in the partition wall direction by the end surface. Pump device. 5. The ball according to claim 3, wherein the shaft is fitted and inserted into a hole formed in a shaft center portion of the impeller, and a ball is provided between the impeller and the shaft in the hole. Engine cooling water pump device.