KR20020076526A - lubricating device of fuel pump in the LPG vehicles - Google Patents

Abstract

PURPOSE: An apparatus for lubricating a fuel pump for an LPG(liquefied petroleum gas) vehicle is provided to perform the cooling operation of a rotational shaft and bearing of a motor, coil windings, and diaphragm assembly with performing the lubricating operation, thereby increasing product life. CONSTITUTION: An apparatus for lubricating a fuel pump for an LPG vehicle is composed of a motor part(A) having a rotor(34) engaged with a rotational shaft(32) and a stator(33) for applying the rotational force to the rotor, an eccentric cam installed at the lower end of the rotational shaft of the motor part(A), a rod for switching the circular motion to the linear motion, and a diaphragm assembly(27) for performing the pumping operation by the linear motion of the rod. The diaphragm assembly(27) divides the pumping part(B) with an LPG fuel chamber and oil lubricant chamber. A circulating screw(37) is installed at the rotational shaft in the motor part and splashes the oil lubricant contained in the pumping part. An elastic member(39) is installed at the upper portion of the circulating screw to elastically support the circulating screw.

Description

Lubricating device of fuel pump in the LPG vehicles}

The present invention relates to a fuel pump for an LPI vehicle, and more particularly, a pumping operation of fuel by a diaphragm assembly that is interlocked with a rotation driving unit of a motor driving unit, and lubricating oil that is interlocked with a rotating shaft of the motor unit and stored in the pumping unit. The present invention relates to a lubrication device for an LPG vehicle fuel pump equipped with a circulation screw scattered from the upper side to perform cooling and lubrication of the motor driving unit.

In general, a vehicle fuel pump is classified into an in-line fuel pump installed on a fuel pipe and an in-tank fuel pump mounted in a fuel tank. Most fuel tanks are in-tank.

Figure 1 shows a representative structure of the in-tank fuel pump, the configuration of the fuel pump is divided into a pumping unit (A) and a motor unit (B) for driving the pump inside the motor housing (1) The pumping part A is provided on the fuel inlet 2 side which is the lower part of the housing 1, and the motor part B is located on the fuel outlet 3 side which is the upper part of the housing 1.

Pumping unit (A) is a configuration in which the impeller (5a) mounted on the rotating shaft (5) inside the pump case (4), the motor portion (B) armature (6) mounted on the rotating shaft (5), Correspondingly, the magnet 7 is provided on the inner circumferential surface of the housing 1. The relief valve 8 and the terminal 9 are provided in the upper surface of the housing 1, and the check valve 10 is provided in the fuel discharge port 3. As shown in FIG. The symbol F represents fuel.

In the in-tank fuel pump for a vehicle configured as described above, when electric power is supplied through the terminal 9, the armature 6 is rotated to rotate the rotary shaft 5, which is press-fit and fixed to the armature 6, so that the fuel is rotated by the impeller. (F) is sucked through the fuel inlet (2) is supplied to the fuel supply pipe side through the fuel outlet (7).

Such a vehicle fuel pump naturally performs lubrication on the motor because the fuel is discharged while passing through the motor unit while the fuel is filled in the fuel pump even without a separate lubrication device for the motor.

However, the liquid fuel of Liquified Petroleum Gas (hereinafter referred to as LPG) has almost no viscosity, so it is difficult to apply the vane or impeller method to the pumping part. There is a problem that the pump part is damaged in the process of cavitation phenomenon and the pressure fluctuation and bubble bursting locally.

In addition, LPG fuel has a problem in that the temperature in the fuel tank is changed due to the heat generated from the motor portion, the LPG fuel is changed to a gaseous state.

In addition, since LPG fuel itself does not have lubricity, there is a problem in that the driving part of the motor is worn.

The object of the present invention devised in view of the various problems as described above is to exclude the vane or impeller method to pump the liquid fuel by the stroke change by the drive member driven by the eccentrically rotating shaft.

Another object of the present invention is to be suitable for cooling the heat generated in the motor portion of the fuel pump.

Another object of the present invention is to prevent wear of the drive portion of the motor.

1 is a cross-sectional view of a fuel pump of a fuel tank built-in type for a conventional gasoline vehicle.

Figure 2 is a fuel supply configuration of a typical LPG vehicle fuel pump.

Figure 3 is a cross-sectional view of the fuel pump for an LLP vehicle to which an embodiment of the present invention is applied.

<Description of Symbols for Main Parts of Drawings>

21; Pump case 22; Motor case

23; Fuel outlet 27; Diaphragm assembly

31; Motor housing 32; Axis of rotation

33; Stator 34; Rotor

37; Circulating screw 39; Coil spring

40; Lubrication channel

A; Motor part B; Pumping part

F; LPG fuel O; lubricant

The present invention for achieving the above object is a rotor coupled to the rotating shaft inside the case, and a motor unit consisting of a stator for applying a rotational force to the rotor; A pumping part having a diaphragm assembly for supplying LPG fuel by converting the rotational motion of the motor part into a linear motion; The pumping part is partitioned into an LPG fuel chamber and a lubricating oil chamber with the diaphragm assembly as a diaphragm, and the motor part is equipped with a circulating screw on the rotating shaft for interlocking with the rotating shaft to scatter the lubricant contained in the pumping part to the upper side of the motor part. An upper portion of the circulation screw is characterized in that to install an elastic member for elastically supporting the circulation screw so as to interlock with the rotary shaft.

Preferably, the case is provided with a plurality of lubrication flow paths so that the lubricating oil that is scattered can be recovered to the pumping part and circulated when descending.

This preferred embodiment of the present invention will be described in more detail based on the accompanying drawings.

2 is a fuel supply configuration diagram of an LPG vehicle fuel pump applying a liquid LPG fuel injection method, and FIG. 3 is a cross-sectional view of an LPG vehicle fuel pump to which an embodiment of the present invention is applied.

As shown, a fuel supply device to which a conventional LPG vehicle fuel tank is applied is maintained in a liquid state by LPG fuel being pumped by the pump 12 mounted on the fuel tank 11 to shut off the regulator unit 13. It is supplied to the injector 16 of the engine 15 via 14. The injector 16 injects the appropriate fuel in accordance with the operating conditions of the engine and the fuel conditions, and the injected and remaining fuel is fuel tank 11 through the pressure sensor 17 and the pressure regulator 18 of the regulator unit 13. ) Is recovered.

In the fuel pump according to the embodiment of the present invention, as shown in FIG. 3, the configuration of the pump is divided into the motor part A and the pumping part B, so that the lower fuel intake port 22 inside the pump case 21 is provided. The pumping part B is formed in the side of the motor, and the motor part A is formed in the inner upper fuel discharge port 23 side of the motor case 22.

The rotating shaft 32 is press-fitted and fixed in the center of the motor housing 31 inside the motor case 22. The stator 33 is provided on the outer peripheral surface of the rotating shaft 32, and the rotor is provided on the inner peripheral surface of the housing 31. 34 is attached and fixed, and is interlocked with the rotating shaft 32.

Since the motor case 22 is formed of a small heat transfer material such as plastic, heat dissipation is blocked as much as possible into the tank.

An eccentric cam 24 is mounted at the lower end of the rotating shaft 32, and a rod 25 that is linearly interlocked by the eccentric cam 24 is elastically supported by the spring 26 at the outer circumference of the eccentric cam 24. It is installed in a state supported by the diaphragm assembly 27.

The fuel inlet 22 is connected to the fuel outlet 23 by a fuel passage 28 formed through the outer wall of the pump case 21 and the motor case 22, and the fuel inlet 22 is a check valve 29 LPG fuel flowing into the fuel inlet 22 is filled in the outer side of the diaphragm assembly 27 and is discharged to the fuel outlet port 23 through the fuel passage 28.

The inside of the diaphragm assembly 27 is filled with lubricating oil (O), the roll shaft (36) is mounted on the rotary shaft (32) above the lowermost mounted eccentric cam (24), and the roll bearing (36). At the upper side of the rotating oil (37) to the upper side of the motor portion (A), the circulating screw (37) for lubricating and cooling the motor (A) is mounted, and the upper end of the rotating shaft (32) has a ball bearing ( 38) is mounted, and the coil spring 39 is interposed between the circulation screw 37 and the ball bearing 38. In addition, a plurality of lubricating oil passages 40 are formed in the pump case 21, and reference numeral 41 denotes a vent hole.

The lubrication and cooling action of the LPG vehicle fuel pump according to the present invention configured as described above will be described.

The motor unit A, which is specifically applied in the embodiment of the present invention, is applied to a brushless DC motor which does not have a problem in that carbon melts in LPG fuel even when used for a long time, and is variably controlled according to the speed of the internal combustion engine and is unnecessary. Remove the motor drive load.

The heat generating portion of the fuel pump is a portion in which the coil of the motor is wound, the rotation shaft 32 portion, and the diaphragm assembly 27 portion in which the stroke is continuously changed, and a bearing supporting the shaft 32 when driven for a long time. Since there is a problem that wear occurs in the portion, in the present invention, in order to simultaneously realize the cooling action of the heat-generating portion and the lubrication of the bearing portion as described above, the inner space of the motor and the LPG fuel (F) are not filled. This is to circulate the lubricant O in the inner space of the diaphragm 26.

When an electric signal is applied to the motor unit A, the rotor 34 is rotated and the rotating shaft 32 is rotated so that the eccentric circular motion of the eccentric cam 24 mounted at the lower end of the rotating shaft 32 is loaded (25). The diaphragm assembly 27 repeats the forward and backward pumping operation as it is converted into a linear reciprocating motion. By the pumping operation of the diaphragm assembly 27, the fuel F is raised upward along the fuel passage 28 and supplied to the engine through the fuel outlet 23.

When the rotating shaft 32 rotates, the circulating screw 37 which is elastically supported in the downward direction by the coil spring 39 is interlockedly rotated, and the lubricating oil in the spiral direction of the screw is rotated by the rotation of the circulating screw 37. ) Ascends and is continuously lifted upward by the coil spring 39 mounted on the rotating shaft 32 in contact with the circulation screw 37 so as to be scattered as shown in the figure above the motor part A. It rises above the motor part A through the space between the inner wall of the 21 and the rotating shaft 32, and is scattered on the upper part of the motor part A. As shown in FIG.

The lubricating oil O thus raised passes through the rotating shaft 32 and the bearing parts 36 and 38, and the lubricating oil O scattered and lowered flows on the outer circumferential surface of the inner stator 33 of the motor. Therefore, the lubricating oil is to perform the cooling and lubricating action in the course of passing through each component of the motor portion (A), the lubricating oil (O) is passed through the lubricating oil passage 40 during the scattering or falling. On the other hand, the cooling of the lubricating oil (O) is made by the liquid fuel (F) pumped on the opposite side of the diaphragm assembly (27).

Through the vent hole 41 drilled on the upper end of the motor case 22, the pressure of the lubricating oil chamber is maintained at the same pressure as the gas phase pressure (= liquid pressure), thereby preventing the overload on the diaphragm assembly 27, thereby providing a pure motor. The pumping pressure is generated by the driving of the unit (A).

As described above, according to the lubrication apparatus of the LPG vehicle fuel pump according to the present invention, in the state where the LPG fuel pump is divided into the fuel chamber and the lubricating oil chamber, the lubricating oil is scattered on the upper side of the motor part by the rotating shaft of the motor during pumping operation. By doing so, cooling of the rotating shaft of the motor and the bearing, the coil winding part and the diaphragm assembly, etc. are performed, and the bearing part is lubricated to prolong the life of the parts and improve the performance of the product.

Claims (2)

A motor unit comprising a rotor having a rotating shaft coupled to the inner side of the motor case and a stator for providing a rotational force to the rotor, an eccentric cam mounted at the lower end of the rotating shaft of the motor unit inside the pump case, and installed to be external to the eccentric cam. A pumping portion having a rod for converting a circular motion of the linear motion into a linear motion, and a diaphragm assembly configured to perform a popping operation by the linear motion of the rod; The pumping unit is partitioned into an LPG fuel chamber and a lubricating oil chamber with the diaphragm assembly as a barrier. The motor unit is equipped with a rotating screw that rotates in coordination with the rotary shaft to disperse the lubricant contained in the pumping unit to the upper side of the motor unit, Lubricating device of the fuel pump for an LLP vehicle, characterized in that the upper portion of the circulation screw to install an elastic member for elastically supporting the circulation screw so as to interlock with the rotary shaft. The method of claim 1, The pump case is a lubrication device of the fuel pump for an LLP vehicle, characterized in that a plurality of lubricating oil passages for lubricating oil to be recovered to the pumping unit is formed.