JP2504042B2 - In-tank fuel pump - Google Patents

Description

The present invention relates to cooling of brushes and / or bearings of an in-tank fuel pump arranged in a fuel tank.

“Prior Art” Conventionally, in-tank fuel pumps have a pair of brushes arranged in parallel with the motor shaft and a main fuel passage has bearings arranged in the center of the in-tank fuel pump in order to reduce size. Is arranged at a position eccentric to the outer radial direction.

However, since the main flow path is arranged independently of the position where the bearing and the brush are arranged, the fuel is likely to stay around the bearing and the brush. Therefore, the cooling effect due to the fuel is not obtained very much, and the bearing rusts due to the moisture in the fuel.Therefore, a hole communicating from the brush and the bearing to the outside is provided, and the fuel is retained outside the fuel pump by leaking it to the fuel tank. It was preventing. However, by leaking the fuel to the outside, the discharge amount of the fuel pump decreases, and especially when the pressure inside the fuel pump becomes high, the leakage of the fuel to the outside increases, so that the brush and / or the bearing are not leaked to the outside without leaking the fuel to the outside. Distribution is required.

"Object of the Invention" The present invention has been made to solve the above problems, and while maintaining the miniaturization of the in-tank fuel pump,
An object of the present invention is to satisfactorily cool the brush and / or the bearing without leaking the fuel used for cooling the brush and / or the bearing to the outside of the fuel pump.

"Means and Actions for Solving Problems" In order to achieve the above, according to the first aspect of the invention, the discharge hole forming a part of the main flow path of the fuel is located at a position eccentric to the bearing in the outer radial direction, It is formed so as to open in the direction. Then, a brush that comes into contact with the planar commutator configured by a plane perpendicular to the motor shaft direction is arranged parallel to the motor shaft.

Furthermore, between the bearing holding member that holds the bearing and the cover member that covers the bearing holding member,
An auxiliary channel communicating with the main channel is formed. Then, in the bearing holding member, a bearing cooling flow passage for guiding the fuel from between the motor shaft and the bearing to the auxiliary flow passage is formed.

According to the above configuration, a part of the fuel fed through the motor section flows between the motor shaft and the bearing to cool the bearing, and then joins the main channel through the bearing cooling channel and the auxiliary channel. Therefore, the bearing can be cooled well. Further, since the fuel that has cooled the bearing does not leak to the outside of the in-tank fuel pump, it is possible to prevent a decrease in fuel discharge amount and improve pump efficiency.

Further, since the fuel that has cooled the bearing merges with the main flow path through the bearing cooling flow path and the auxiliary flow path and is discharged, it is possible to prevent the fuel from staying around the bearing. Therefore, it is possible to prevent the rust of the bearing due to the water contained in the accumulated fuel.

Moreover, since the auxiliary flow path communicating with the main flow path is formed between the bearing holding member and the cover member, the cover member can be assembled to the bearing holding member and the auxiliary flow path can be formed. Therefore, since the step of forming the auxiliary flow path does not occur, it is possible to suppress an increase in the manufacturing cost of the in-tank fuel pump and cool the bearing satisfactorily.

Also, while arranging the brush parallel to the motor shaft,
The discharge hole and a pair of brushes are formed around the bearing by forming the discharge hole, which forms part of the main fuel flow path, at a position that is eccentric from the bearing in the outer diameter direction and that opens toward the motor axis. Therefore, the in-tank fuel pump can be downsized.

In the second aspect of the invention, the essential parts of the first aspect of the invention are made the same, and the bearing holding member is provided with a brush cooling flow passage for guiding the fuel to the auxiliary flow passage through the periphery of the brush.

With this configuration, a part of the fuel fed through the motor section flows through the brush cooling flow path to cool the brush and joins the main flow path through the auxiliary flow path, so that the in-tank fuel pump is small in the radial direction. While maintaining the efficiency, without leaking the fuel that has cooled the brush to the outside of the in-tank fuel pump,
The brush can be cooled well. Further, since the fuel that has cooled the brush does not leak to the outside of the in-tank fuel pump, it is possible to prevent a decrease in fuel discharge amount and improve pump efficiency.

According to a third aspect of the invention, the essential parts of the first and second aspects of the invention are the same, and the bearing holding member has a bearing cooling flow passage for guiding the fuel to the auxiliary flow passage from between the motor shaft and the bearing, and a portion around the brush. And a brush cooling channel for guiding the fuel to the auxiliary channel.

With this configuration, a part of the fuel fed through the motor section flows between the motor shaft and the bearing to cool the bearing, and then flows through the bearing cooling flow passage to join the auxiliary flow passage, and other fuel Part of the flows through the brush cooling channel to cool the brush and join the auxiliary channel. Then, the fuel that has joined the auxiliary passage merges with the main passage. Therefore, the bearing and the brush can be satisfactorily cooled while maintaining the radial miniaturization of the in-tank fuel pump. Further, since the fuel that has cooled the brush does not leak to the outside of the in-tank fuel pump, it is possible to prevent a decrease in fuel discharge amount and improve pump efficiency.

Also, since both cooling flow paths share the auxiliary flow path,
There is no need to form a new auxiliary flow path. Therefore, it is possible to suppress an increase in the manufacturing cost of the in-tank fuel pump and cool the brush and the bearing satisfactorily.

[Example] Next, an example of the present invention will be described with reference to Figs.

As shown in FIG. 1, the vehicle in-tank fuel pump is composed of a pump portion 1, a discharge portion 2 and a motor portion 3 which are housed in a single fuel pump housing 19. The pump portion 1 provided at the lower end of the fuel pump housing 19 forms a pump chamber 4 between a pump cover 6 and a pump casing 17, and a turbine type impeller 14 is housed in the pump chamber 4. There is. Although not shown, the pump chamber 4 has a C shape, and the fuel sucked from the suction port 7 at one end is pumped to the discharge opening 5 by the impeller 14. Impeller 14
A large number of grooves 15 are radially provided in the. A motor shaft 16 is rotatably supported by a pump casing 17 by a bearing 8, and an impeller 14 is fixed to the motor shaft 16. The motor unit 3 includes an armature 24 and a field magnet 25. As shown in FIG. 2, a stopper 27 made of a non-magnetic material and a spring piece 26 having both ends bent are inserted between two field magnets 25 which are formed in an arc shape.
The fuel passage 28 is formed between the spring piece 26 and the armature 24. As shown in FIG. 1, the surface commutator 29 of the armature 24 has a bearing holding member.
A brush 12 held by 10 is in axial contact.

As shown in FIGS. 1 and 3, the housing member of the discharge part 2 is divided into a bearing holding member 10 and a cover member 11, and the space between the cover member 11 having the discharge port 13 and the bearing holding member 10 is divided. A gap (auxiliary flow path) 20 is formed in.
The periphery of the bearing 18 held by the bearing holding member 10 and the gap 20 communicate with each other through a flow path (bearing cooling flow path) 10a. Also, the pigtail 12a of the brush 12
The bearing holding member 10, which is drawn out in a direction perpendicular to the longitudinal direction of the brush, is provided with an opening 10c having a partially opened shape so that the pigtail 12a can move up and down. This opening (brush cooling flow path) 10c is a gap between the inside of the pump and the bearing holding member 10 and the covering member 11.
It forms a flow path that communicates with 20. Bearing holding member
A discharge hole 10b is formed in 10 and a discharge hole 11a is formed in the cover member 11. The discharge hole 11a is provided with a mushroom-shaped check valve 22. The check valve 22 is a discharge port.
This is a method of closing the discharge hole 11a by the internal pressure of the pipe connected to 13.

The material for the bearing holding member 10 and the covering member 11 is preferably glass fiber-containing polybutylene terephthalate or polyacetal. The material of the pump cover 6, the impeller 14 and the pump casing 17 is preferably glass fiber-containing phenol resin or PPS. The material of the fuel pump housing 19 is iron.

A brush spring 30 is provided above the brush 12, and a pressing plate 31 that presses the spring 30 is fixed to the bearing holding member 10. The holding plate 31 is provided with a hole 31a. A plate terminal 32 is attached to the cover member 11, the brush 12 is connected to the plate terminal 32 via the pigtail 12a, and is further connectable to an on-vehicle power storage device (not shown) via the plate terminal. The lower surface of the motor shaft 16 is received by the thrust receiver 33.

[Operation] In the above configuration, when the armature 24 is energized via the surface commutator 29, the brush 12, the pigtail 12a, and the plate terminal 32, it interacts with the two field magnets 25 and together with the motor shaft 16. It rotates and the impeller 14 is rotated by the motor shaft 16. As the impeller 14 rotates, the fuel sucked into the pump chamber 4 from the suction port 7 is discharged from the discharge opening 5, and the space between the armature 24 and both magnets 25 and between both magnets 25.
Through the fuel passage 28 between them, and is further pressure-fed to the discharge holes 10b, 11a forming part of the main flow path of the fuel, pushing up the check valve 22 and discharged from the discharge port 13 to a fuel injection device for an internal combustion engine (not shown). It

A part of the fuel pumped by the impeller 14 is part of the motor shaft 16
And the bearing 18, and while smoothly cooling the bearing 18, passes smoothly through the flow path 10a to reach the gap 20. Another part of the fuel passes through the opening 10c and reaches the gap 20 while cooling the brush 12. Then, the fuel flowing through the gap 20 passes through the discharge holes 10b, 11a and is discharged from the discharge port 13 to the fuel injection device for the internal combustion engine, so that all the fuel pumped by the impeller 14 is effectively discharged from the discharge port 13. To be done.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a fuel pump according to an embodiment of the present invention,
2 is a cross-sectional view of the motor section shown in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line AA of FIG. 1 ... Pump part, 2 ... Discharge part, 3 ... Motor part, 4 ...
... Pump chamber, 6 ... Pump cover, 10 ... Bearing holding member, 10a ... Flow path, 10c ... Opening part, 11 ... Cover member, 12 ... Brush, 14 ... Impeller, 16 ... Motor Axis, 17
…… Pump casing, 18 …… Bearing, 19 …… Fuel pump housing, 20 …… Gap.

Claims (3)

(57) [Claims] 1. A fuel pump housing, a pump portion provided at one end side in the fuel pump housing, a motor portion provided at an intermediate portion in the fuel pump housing, and driving the pump portion, the fuel An in-tank fuel pump comprising: a discharge portion provided on the other end side in the pump housing, the discharge portion having a discharge port for discharging fuel fed from the pump portion through the motor portion in a motor axial direction of the motor portion, The discharge unit includes a bearing that rotatably supports the motor shaft, a bearing holding member that is disposed on the other end side of the fuel pump housing to hold the bearing, the discharge port is formed, and the bearing is provided. A cover member for covering the holding member, and the bearing holding member formed at the position eccentric to the bearing in the outer diameter direction. And a discharge hole opening in the axial direction of the motor, wherein the motor section has a planar commutator configured by a plane orthogonal to the axial direction of the motor, and contacts the planar commutator. The pair of brushes are held by the bearing holding member in parallel with the motor shaft, and further, the discharge hole and the discharge port constitute a main flow path of fuel to be fed through the motor unit. An auxiliary flow path communicating with the main flow path is formed between the cover member and the bearing holding member that guides fuel to the auxiliary flow path from between the motor shaft and the bearing. An in-tank fuel pump, characterized in that a bearing cooling flow path is formed. 2. A fuel pump housing, a pump portion provided at one end side in the fuel pump housing, a motor portion provided at an intermediate portion in the fuel pump housing, and driving the pump portion, the fuel An in-tank fuel pump comprising: a discharge portion provided on the other end side in the pump housing, the discharge portion having a discharge port for discharging fuel fed from the pump portion through the motor portion in a motor axial direction of the motor portion, The discharge unit includes a bearing that rotatably supports the motor shaft, a bearing holding member that is disposed on the other end side of the fuel pump housing to hold the bearing, the discharge port is formed, and the bearing is provided. A cover member for covering the holding member, and the bearing holding member formed at the position eccentric to the bearing in the outer diameter direction. And a discharge hole opening in the axial direction of the motor, wherein the motor section has a planar commutator configured by a plane orthogonal to the axial direction of the motor, and contacts the planar commutator. The pair of brushes are held by the bearing holding member in parallel with the motor shaft, and further, the discharge hole and the discharge port constitute a main flow path of fuel to be fed through the motor unit. An auxiliary flow path communicating with the auxiliary flow path is formed between the cover member and the bearing holding member, and a brush cooling flow path for guiding the fuel to the main flow path through the brush periphery. An in-tank fuel pump characterized by being formed. 3. A fuel pump housing, a pump portion provided at one end side in the fuel pump housing, a motor portion provided at an intermediate portion in the fuel pump housing, and driving the pump portion, the fuel. An in-tank fuel pump comprising: a discharge portion provided on the other end side in the pump housing, the discharge portion having a discharge port for discharging fuel fed from the pump portion through the motor portion in a motor axial direction of the motor portion, The discharge unit includes a bearing that rotatably supports the motor shaft, a bearing holding member that is disposed on the other end side of the fuel pump housing to hold the bearing, the discharge port is formed, and the bearing is provided. A cover member for covering the holding member, and the bearing holding member formed at the position eccentric to the bearing in the outer diameter direction. And a discharge hole opening in the axial direction of the motor, wherein the motor section has a planar commutator configured by a plane orthogonal to the axial direction of the motor, and contacts the planar commutator. The pair of brushes are held by the bearing holding member in parallel with the motor shaft, and further, the discharge hole and the discharge port constitute a main flow path of fuel to be fed through the motor unit. An auxiliary flow path that communicates with the main flow path is formed between the cover member and the bearing holding member that guides fuel to the auxiliary flow path from between the motor shaft and the bearing. An in-tank fuel pump comprising: a bearing cooling flow passage; and a brush cooling flow passage that guides fuel to the auxiliary flow passage through the periphery of the brush.