CN1140484A - pump piston - Google Patents

Abstract

The pump piston (1) is formed by a cup-shaped body (2). The piston (1) reciprocates in the piston cylinder to pump liquid. The side wall (3) of the piston (1) is configured such that the side wall (3) can expand during a discharge stroke of the pump, sealing against the piston cylinder. The side wall (3) may taper from the base (4) to the free end (6), or may have helical cuts (7, 8, 9) from the free end (6) to the adjacent base (4), which cuts are inclined radially outwards and away from the free end (6), or may have vertical cuts (20) which are substantially tangential to the inner surface of the cup (2).

Description

pump piston

The invention relates to pistons for pumps and in particular for water pumps.

The piston of the pump reciprocates along the piston cylinder and requires a seal between the piston cylinder wall and the side wall of the piston. This seal usually takes the form of a piston ring disposed around the outer wall of the piston. The present invention seeks to provide a piston with integral sealing means.

In one broad form, the invention comprises a pump piston adapted to pump (pump) liquid in a piston cylinder comprising:

A cup-shaped body of flexible (resilient) material having a side wall extending from a base and terminating in a flange at a free end, wherein said side wall is constructed such that the side wall is released ( expands during the discharge) stroke, thereby sealing against the piston cylinder.

In another form, the invention comprises a pump piston adapted to pump liquids comprising:

a cup-shaped body of flexible material having a side wall extending from the base and terminating in a flange at the free end; and

at least one cut extending through the material of the side wall, which originates at the flange of the side wall and spirals around the side wall towards the bottom of the cup to form a seal which moves radially outwardly during the release stroke, So that it is sealed against the piston cylinder.

The invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a perspective view of a piston according to one embodiment of the invention;

Fig. 2 shows a cross-sectional view of the middle part of the piston shown in Fig. 1;

Figure 3 shows a partial cross-sectional view of the side wall of the piston shown in Figure 1;

Figure 4 shows a side view of the piston shown in Figure 1;

Figure 5 shows a plan view of the embodiment shown in the previous drawings showing the movement of the seal arm enlarged;

Figure 6 shows the same sectional view as Figure 3, but during the pumping stroke;

Figure 7 shows a further embodiment of the invention;

Figure 8 shows a cross-sectional view of another embodiment of the present invention;

Figure 9 shows a perspective view of another embodiment of the present invention;

Figure 10 shows a plan view of the piston shown in Figure 9;

Figure 11 shows a double-acting piston according to another embodiment of the present invention;

An implement for cutting the helical incision is schematically shown at 12, and

FIG. 13 shows a further view of the appliance shown in FIG. 12 .

The piston (1) of the pump, as shown in Figures 1 to 6, consists of a cup (2) with side walls (3) starting from the bottom (4). A central hole (5) passes through the bottom (4) to accommodate the drive rod (not shown); causing the piston to reciprocate in the piston cylinder. Around the flange (6) of the side wall (3) are provided three cutouts (7, 8 and 9) which extend completely through the side wall (3). Each cutout (7, 8 and 9) spirals from the flange (6) to the adjacent bottom (4), as shown in Figures 2 and 4, and as shown in Figure 3, these cutouts (7, 8 and 9) Outwardly and towards an angle away from the flange (6), it may be at any suitable angle other than the one shown in Figures 3 and 6.

In use, the cutouts (7, 8 and 9) form sealing valves (10, 11 and 12) which rotate radially outwards away from the piston (1) during the discharge stroke of the pump as shown in Figures 5 and 6, which is Due to the effect of the axial vector (13) and radial vector (14) of the fluid pressure. The notched surface (15) of the piston door (10) slides over the notched surface (16) of the side wall (3) to form a seal.

As shown in FIGS. 1 and 5 , the flaps overlap each other, which contributes to their flexibility and thus their sealing action. The cutouts 7a-7b extend about 160° around the piston (1), while the lowest point 7b is about 45° behind the highest point 8a of the next cutout 8a-8b. Repeat this pattern around the piston (1), preferably the angle of these cuts is about 5°. But any suitable stagger or overlap may be used, depending on the materials of construction.

The present invention is applicable to the double-acting piston (17) shown in Fig. 7, wherein the structure of the valve is the same as the previous embodiment.

Another embodiment is shown in Figure 8, where the piston (18) has side walls (19) that taper (pointer) towards the flange (6). The material of construction is chosen to be sufficiently flexible to allow the side walls to expand outwardly during the pumping stroke to seal against the piston cylinder wall.

A variation of the piston of Fig. 8 is shown in Figs. 9 and 10, in which vertical cuts (20) are machined in several places around the side wall (19). These cutouts (20) are substantially tangential to the inner surface (21) of the side wall (19). The valves (22) thus formed slide radially outwards transversely to each other and form a seal between the piston cylinders and themselves during the pumping or releasing stroke.

The double-acting piston cylinder (23) is shown in Figure 11, and its construction is the same as that of Figures 9 and 10.

Depending on the material of construction, for example, the material can be any suitable plastic like high density polypropylene, and there can be any number of cuts, from 1, 2, etc., to achieve the seal, as long as the valves show the required degree of flexibility That's it.

The apparatus for making the helical cuts of the pistons shown in FIGS. 1 to 7 is shown in FIGS. 12 and 13 . The appliance includes a cutting blade holder (23) having several blades (24). The piston centering pin (25) is located in the center of these blades. Piston blank (26) is slidably mounted on the centering pin (25), and centering pin then fits in the center hole (5) of piston blank (26). The piston blank (26) is rotated in the direction of arrow 27, while the blade (24) cuts the helical cuts (7, 8 and 9).

It should be understood that modifications and changes to the foregoing embodiments can be made by those skilled in the art without departing from the scope and spirit of the invention.

Claims (11)

1. piston that is suitable for the pump of pumping liquid in piston cylinder, it comprises:

A goblet of being made by flexible material, this goblet have one from the bottom extension and at the sidewall of free end with the flange ending; Wherein above-mentioned sidewall is so constructed, so that this sidewall dilates during discharging stroke, seals thereby pasting piston cylinder.

2. the piston of a pump, it comprises:

A goblet of being made by flexible material, this goblet have one from the bottom extension and at the sidewall of free end with the flange ending; And

The otch that at least one material that penetrates sidewall extends, it originates in the flange of sidewall and spirals towards hypanthial bottom around sidewall, forms seal arrangement, and sealing device radially outward during discharging stroke moves, thereby is pasting the piston cylinder sealing.

3. according to the piston of the pump of claim 2, wherein, at least one otch radially outward and tilt towards leaving hypanthial free-ended direction.

4. according to the piston of the pump of claim 3, wherein, at least one otch radially outward and with about 5 ° angle and to leave hypanthial free-ended direction and tilt.

5. according to the piston of the pump of any one in the claim 2 to 4, wherein have many otch, these otch are staggered around sidewall, form the valve of adjacent overlap joint.

6. according to the piston of the pump of claim 5, wherein there are 3 otch.

7. piston that is suitable for the pump of pumping liquid in piston cylinder, it comprises:

A goblet of being made by flexible material, this goblet have from the bottom extension and at the sidewall of free end with the flange ending; Wherein, above-mentioned sidewall toward the flange taper, so that sidewall dilates, thereby is pasting the piston cylinder sealing from the bottom during discharging stroke.

8. according to the piston of the pump of claim 7, it further comprises a plurality of axial cut-outs, and these otch are around hypanthial circumference, and extend the bottom from flange toward adjacency, and tangent with inside surface of side wall basically.

9. the piston of the pump of any one in requiring according to aforesaid right, wherein the material of structure is a high density poly propylene.

10. according to any one the piston of pump of aforementioned claim, wherein this piston is a double action.

11. with reference to the accompanying drawings Fig. 1 to 6 basically, Fig. 7, Fig. 8, Fig. 9 and 10, or the piston of the described pump of Figure 11.

Images