JPH0741908Y2 - Fuel pump - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a fuel pump suitable for use in, for example, pumping and supplying the fuel in a fuel tank to an automobile engine or the like,
In particular, the present invention relates to a fuel pump in which a fixed shaft is provided in a casing and an electric motor or the like is rotatably supported by the fixed shaft.

[Conventional technology]

As a fuel pump of this type according to the prior art, turbine type fuel pumps are shown in FIGS.

In the drawing, reference numeral 1 denotes a casing, which has a cylindrical casing body 2, a suction port 3A communicating with the fuel tank side, and a pump housing 3 for covering the lower end of the casing body 2 and an internal combustion engine. An upper cover 4 having a discharge port 4A communicating with the side and covering the upper end of the casing body 2
It consists of 5 is an axial direction 7 in the casing 1.
Of the fixed shaft 5, one end in the axial direction of the fixed shaft 5 is fixed to the pump housing 3 and the other end is fixed to the upper cover 4. A small-diameter step portion 5A for fitting the die retaining ring 16 is formed (see FIG. 4).

Reference numeral 6 denotes a pump portion for pumping fuel from the suction port 3A of the casing 1 to the discharge port 4A side, and the pump portion 6 is provided in the pump housing 3 and the pump chamber 7 provided in the pump housing 3. , And a turbine 8 rotatably supported by the fixed shaft 5.

Reference numeral 9 denotes an electric motor provided in the casing 1 for driving the pump portion 6 to rotate, and the electric motor 9 includes a stator 10 fixed to the casing 1 side and a sleeve 11 inserted into the fixed shaft 5. Armature 12 fixed to,
The armature 12 is composed of a commutator 13 which is located on the upper end side of the armature 12 and is fitted in the sleeve 11.
Twelve rotary cylinders 12A engage with the turbine 8 and rotate integrally.

Reference numeral 14 is a sleeve bearing (hereinafter referred to as a bearing) for rotatably supporting the armature 12 and the commutator 13 on the fixed shaft 5. The bearing 14 is located on the end side of the commutator 13 as shown in FIG. It is fitted in the sleeve 11, and its upper end surface 14A is in a state of slightly protruding from the upper end of the commutator 13. Also, the same sleeve bearing (not shown) is provided for the sleeve 11 located on the lower end side of the armature 12.
Is fitted.

15A, 15B and 15C are shims inserted through the fixed shaft 5, and the lower shim 15A is in sliding contact with the upper end surface 14A of the bearing 14 and the upper shim 15C.
Is in sliding contact with the C-shaped retaining ring 16. 16 is the 4th
As shown in the figure, a C-shaped retaining ring having an opening 16B between both circumferential ends 16A, 16A for press-fitting to the fixed shaft 5 and a shim sliding contact surface 16C on the lower side, The retaining ring 16 is press-fitted to the small-diameter step portion 5A of the fixed shaft 5 so as to face the upper end surface 14A of the bearing 14 via the shims 15A, 15B, 15C. A small gap (about 0.1 to 0.3 mm) is provided between the C-shaped retaining ring 16 and the upper shim 15C in order to reduce the sliding resistance with respect to the armature 12 or to absorb the manufacturing dimensional tolerance. ) Is formed.

Further, in the drawing, 17 and 17 are a pair of brushes (provided that one is not shown) provided on the upper cover 4 side and slidingly contacting the commutator 13 to drive the armature 12 by energization.
Is connected to an external power source via a cable 18.

In the fuel pump configured as described above, when a DC voltage is supplied to the brush 17 via the cable 18, the commutator 13 collects the current and applies the current to the coil of the armature 12 to rotate the armature 12. As a result, the pump unit 6
Is driven so that the fuel sucked from the suction port 3A can be discharged from the discharge port 4A through the inside of the casing body 2.

[Problems to be solved by the device]

By the way, in the above-mentioned conventional technique, the upper end surface 14A of the bearing 14 is
Located on top, the fixed shaft 5 has a plurality of shims 15A, 15B,
Insert 15C as shown in Fig. 4, and insert C-shaped retaining ring 1 from above.
By fitting 6 to the small diameter stepped portion 5A of the fixed shaft 5, the gap between the retaining ring 16 and the upper end surface 14A of the bearing 14 is adjusted by the shims 15A, 15B, 15C, and when the electric motor 9 rotates. The armature 12, the commutator 13 and the like are prevented from axially displacing with respect to the fixed shaft 5.

However, since the shims 15A, 15B, 15C are formed by using a means such as a press, burrs 19, 19, ... Are generated on the upper surface or the lower surface of the shims 15A, 15B, 15C as shown in FIG. Although it is easy to remove these burrs 19 by post-processing, these burrs 19 may actually remain on the end faces of the shims 15A, 15B, 15C.

Therefore, in the prior art, when the electric motor 9 rotates, the shim 15
A, 15B, 15C slide against each other, and each burr between shims 15A, 15B, 15C
When the 19 interfere with each other, the armature of the electric motor 9
12. The commutator 13 vibrates in the axial direction of the fixed shaft 5, and this vibration propagates to the fuel tank accommodating the fuel pump and resonates, causing a problem of generating abnormal noise outside.

The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention can prevent the armature and the commutator from vibrating in the axial direction of the fixed shaft, and can solve the problems such as generating abnormal noise to the outside. The fuel pump according to the present invention is provided.

[Means for Solving the Problems]

The feature of the configuration adopted by the present invention to solve the above-mentioned problems is that the protruding end surface of the sleeve bearing and the bottom surface of the retaining ring are provided with uneven portions, and the upper and lower shims of the shim have the respective This is because another concavo-convex portion that engages with the concavo-convex portion is provided, and a rotary sliding surface is formed on an intermediate shim located between the upper and lower shims.

[Action]

With the above configuration, among the shims, the upper shim engages with the retaining ring, the lower shim engages with the projecting side end surface (upper end surface) of the sleeve bearing, and the sleeve bearing is fixed to the fixed shaft together with the armature and commutator. When rotating with respect to each other, the lower shim rotates relative to the upper shim through the rotary sliding surface of the intermediate shim.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the embodiment, the same components as those of the prior art shown in FIGS. 3 and 4 described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 21 is a sleeve for rotatably supporting the armature 12, commutator 13 and the like with respect to the fixed shaft 5.
11 shows a sleeve bearing fitted in 11, the sleeve bearing
Although the reference numeral 21 is formed in substantially the same manner as the bearing 14 described in the prior art, the projection-side end surface (upper end surface) thereof is provided with uneven portions 21A radially arranged in the circumferential direction as shown in FIG. Then, the uneven portion 21A engages with the uneven portion 22A of the shim 22, which will be described later, and the shim 22 together with the commutator 13 etc.
It is designed to rotate against.

Reference numerals 22,23,24 denote shims which are located above the sleeve bearing 21 and which are inserted into the fixed shaft 5. The shims 22,23,24 are each formed in an annular shape with a predetermined plate thickness, and the lower shim 22 is provided. On the lower surface thereof, another uneven portion 22A that engages with the uneven portion 21A of the sleeve bearing 21 is formed. The intermediate shim 23 is subjected to deburring so that the upper and lower surfaces thereof become the rotary sliding surfaces 23A and 23B, and is formed into a uniform flat surface. Further, on the upper surface of the shim 24, another uneven portion 24A that engages with the uneven portion 25C of the snap ring 25 described later is formed on the upper surface thereof, and the uneven portion 24A is radially arranged in the circumferential direction of the shim 24. There is. In this case, the uneven portions 22A and 24A of the shims 22 and 24 are press-molded so as to crush burrs that are likely to occur on the end surfaces of the shims 22 and 24, and the upper surface of the shim 22 and the lower surface of the shim 24 are flat surfaces. Has become.

Further, 25 is located on the upper side of the shim 24, and the fixed shaft 5
Shows a C-shaped retaining ring that is fitted to the small-diameter stepped portion 5A from the outside in the radial direction. Although it has an opening 25B in its inner surface, an uneven portion 25A that engages with the uneven portion 24A of the shim 24 is radially formed on the lower surface thereof. As shown in FIG. 1, the retaining ring 25 restricts relative rotation of the shim 24 with respect to the retaining ring 25 in a state of being engaged with the uneven portion 24A of the shim 24. The shims 22, 23,
Among the 24, the intermediate shim 23 is prepared as a plurality of types of shims having different plate thicknesses, and the gap between the sleeve bearing 21 and the retaining ring 25 is adjusted by appropriately changing the plate thickness of the shim 23.

The fuel pump according to the present embodiment has the above-described structure, and its basic operation is not different from that of the conventional art.

However, in this embodiment, the uneven portions 21A and 25C are formed on the upper end surface of the sleeve bearing 21 and the lower surface of the C-shaped snap ring 25, respectively, and the lower shim 22 and the upper shim of the shims 22, 23 and 24 are formed. 24 is formed with other uneven portions 22A, 24A that engage with the uneven portions 21A, 25C, respectively, and an intermediate shim 23 is formed on the upper and lower surfaces, and the lower surface is a rotary sliding surface 23A,
Since it was formed flat so as to be 23B, the commutator 13
And the like are rotated with respect to the fixed shaft 5, the lower shim 22 integrally rotates with the sleeve bearing 21 via the uneven portions 21A, 22A, and the upper shim 24 is fitted to the fixed shaft 5. The C-shaped retaining ring 25 continues to be engaged via the uneven portions 24A and 25C, whereby the lower shim 22 is connected to the upper shim 24.
In contrast, it will rotate relative to the intermediate shim 23,
The lower shim 22, the sleeve bearing 21, the commutator 13 and the like can be smoothly rotated via one of the rotary sliding surfaces 23A, 23B of the shim 23.

Therefore, in the present embodiment, it is possible to effectively prevent the commutator 13 and the like from vibrating in the axial direction of the fixed shaft 5 due to interference between the shims 22, 23 and 24 when the commutator 13 and the like are rotated, and the commutator 13 and the like are externally connected via the fuel tank. It is possible to reliably reduce abnormal noise that leaks into the air, improve reliability, and so on.

Although the turbine type fuel pump has been described as an example in the above embodiment, the present invention is not limited to this, and may be applied to other fuel pumps such as a roller vane type fuel pump.

[Effect of device]

As described in detail above, according to the present invention, the upper shim is engaged with the snap ring, and the lower shim is engaged with the sleeve bearing.
Since the rotational sliding surface is formed on the intermediate shim, the lower shim can be smoothly rotated together with the sleeve bearing, commutator and the like through the intermediate shim with respect to the upper shim and the retaining ring. It is possible to effectively prevent these from vibrating in the axial direction of the fixed shaft, reliably reduce abnormal noise leaking from the fuel pump to the outside through the fuel tank, and improve the reliability.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention, FIG. 1 is an enlarged vertical sectional view showing an essential part of a fuel pump, FIG. 2 is an exploded perspective view of commutators, shims, etc., and FIG. 5 shows the prior art, FIG. 3 is a vertical sectional view of the fuel pump, FIG. 4 is an exploded perspective view of the commutator, shim, etc., and FIG. 5 is an enlarged vertical sectional view of the shim. 1 ... Casing, 2 ... Casing body, 3 ... Pump housing, 4 ... Top cover, 5 ... Fixed shaft, 5A ... Small diameter step, 6 ... Pump section, 9 ... Electric motor, 12 ... Armature, 13 ... Commutator, 21 ... Sleeve bearing, 21A, 22A, 24
A, 25C ... uneven parts, 22,23,24 ... shims, 23A, 23B ... rotary sliding surface, 25 ... C type snap ring.

Claims (1)

[Scope of utility model registration request] 1. A casing, a fixed shaft having axially opposite ends fixed to the casing, a pump driving armature slidably fitted on the fixed shaft, a commutator for supplying power to the armature, and the armature. And a sleeve bearing axially protruding from the commutator so as to rotatably support the commutator to the fixed shaft, and a plurality of shims that are located above the sleeve bearing and inserted into the fixed shaft. And a retaining ring which is located on the upper side of each of the shims and is fitted to the fixed shaft, and which restricts the armature and commutator together with the sleeve bearing from axially displacing through the shim. In the fuel pump, the uneven surface is provided on the protruding side end surface of the sleeve bearing and the lower surface of the retaining ring. Serial upper one of the shims, the other uneven portions respectively engaging the respective concave-convex portion is provided under the shim, upper,
A fuel pump characterized in that a rotary sliding surface is formed on an intermediate shim located between lower shims.