GB2161221A

GB2161221A - Flexible chamber pump

Info

Publication number: GB2161221A
Application number: GB08514865A
Authority: GB
Inventors: Jost Schlesiger
Original assignee: Feluwa Schlesiger and Co KG
Current assignee: Feluwa Schlesiger and Co KG
Priority date: 1984-06-13
Filing date: 1985-06-12
Publication date: 1986-01-08
Also published as: JPS6155182U; GB8514865D0; NL8501621A; DE3443768C2; FR2566055A1; DE3443768A1; GB2161221B; JPH0353029Y2; FR2566055B1

Abstract

There is disclosed a flexible hose type pump arrangement which comprises a housing (12), a hose-actuation chamber (24) defined in the housing (12) and communicable successively with a source of pressurised fluid and suction (3), and a flexible hose (13) arranged in the housing (12) so as to be surrounded by the actuation chamber (24) and communicating at one end with a suction inlet (16) of the housing for admitting a fluid medium to be pumped by the pump arrangement and at its other end communicating with a pressure outlet (17) of the housing for delivering pumped fluid medium. The hose (13) exerts a pumping action on the fluid medium upon successive application of pressure and suction to the actuation chamber (24). The wall thickness of the hose (13) increases in a direction from the suction inlet (16) to the pressure outlet (17), and the actuation chamber (24) is sufficiently large to permit generally radial expansion of the hose during a fluid suction stroke caused by application of suction to the actuation chamber (24). In a flexible hose type pump arrangement of the above type, the flexible hose can be stressed considerably more than is possible with known constructions. <IMAGE>

Description

SPECIFICATION Hose-piston Pump The invention relates to a hose-piston pump with which the displacement chamber is formed by a hose, in particular a double hose filled with liquid in the intermediate space, and by two non-return valves, and the space surrounding the hose body has an application liquid moved by a driven piston or a hydraulic pump, and a supply container is provided with a non-return valve for the application liquid.

Diaphragm-displacement pumps in which a hydraulic material to be conveyed is pumped between an inlet valve and an outlet valve arranged in a housing into a chamber at higher pressure are known in different embodiments. Pumps with a flat, circular diaphragm can generally only be used for low outputs. In addition there are piston pumps with a hose diaphragm wherein a single hose or even a double hose is used. Even with these diaphragm pumps until now large outputs can not be achieved.

The amount delivered is due merely to the fact that the individual hose or the double hose is compressed for supplying the amount of liquid to be pumped. There is practically no noticeable space on the outer circumference of the hose or the double hose which would make possible a noticeable widening of the hose. In addition the hoses are unevenly loaded because of their uniform thickness.

Their working life is not sufficient.

It is-the aim of the invention to produce a diaphragm-piston pump with at least one hose of the type mentioned at the beginning forming the displacement chamber, with which, in the case of a substantially increased amount of material to be delivered, the hose or the hoses have a greater stability or longer service life. The diaphragm-piston pump of the type described is characterised according to the invention by the fact that the hose, especially each hose of a double hose, is made to be tapered as regards its wall thickness, and that the hose housing has an outer space substantially widened over the thickness of a hose wall.

By a construction of the hose diaphragm-piston pump of this type, it is possible to stress the hose diaphragm considerably more than up till now.

Under the effect of the piston pump, the hose or the double hose can be extended over its normal position so that - seen in the longitudinal section it can assume more or less the shape of an ellipse.

At the sametimethe hose or the double hose can be greatly compressed. Therefore a very high delivery volume is obtained for the through-passing liquid to be pumped. The volume to be supplied can, for example, reach double the value with respect to a hose pump with which the hose for the pump supply path is basically only compressed. At the same time the tapering construction of the wall thickness of the hose causes a greater elasticity in the hose structure. The result of this is that the hose or the double hose is stressed with the greatest possible care. Thus there is a greater stability and service life.

Advantageously the hose is constructed so that it has a cylindrical outer circumference, whereby the inner circumference of the hose extends conically outwards radially to the inlet side of the displacement chamber. The hose is therefore thicker as regards wall thickness at the outlet end than at the inlet end. Thus a greater durability of the hose is achieved. The outlet end is the pressure side.

According to the high stress on the pressure-side end, in particular with highly viscous material to be conveyed, the conical hose has its greatest wall thickness. On the whole the hose is stressed relatively uniformly over its length.

According to a further feature of the invention, the inner diameter of the hose housing can be approximately one and a half times to two times the outer diameter of the individual hose or the outer hose in the case of the double hose. Thus the hose has the possibility of comparatively great expansion. In this way a volume of material increasing up to two fold is obtained with respect to diaphragm pumps with which the hose is in practice only compressed for supplying.

The invention makes further provision for the hoses in the clamping region to be made to be reinforced. In addition the hose should be shaped at the clamping ends to extend outwards at a sharp angle and/or curved with respect to the hose axis.

The end rim ring can extend in the transverse plane to the hose axis. In this way it is possible that the hose can be deformed only in the middle region of its length, and the end areas of the hoses are kept free from tension by the deformation.

According to a further feature of the invention, the outer chamber of the hose housing is connected by means of a leakage valve and a ventilation valve to the supply container. In this way it can be ensured by simple means that the chamber receiving the application liquid remains full of the application liquid during operation of the pump. This leads to an optimum service life of the hose pump.

Advantageouslythe leakage valve is arranged on the outside of the hose housing.This means that the leakage valve is located outside the stream of the application liquid and works independently thereof.

In addition the leakage valve can project by means of a sensing device into the outer chamber of the hose housing. It has proved to be advantageous to shape the leakage valve in such a way that it has two oppositely directed non-return valves. These work in dependence on a possible low pressure in the chamber of the application liquid for the direct flowing-after of this.

In addition, between the outer space of the hose housing and the application chamber of the pump, there can be arranged a closing mechanism which projects into the outer chamber of the hose housing and is under spring pressure. This prevents an excessive widening of the hose structure.

In the presence of a double hose there is appropriately provided a safety device against hose breakage or an indicating device for a break in the hose. For this purpose, the hose break safety device can be capacitively controlled and this is obtained by means of an electrode which engages into the intermediate space in the double hose.

The invention is described in detail by means of an embodiment shown in the drawings.

Fig. 1 shows schematically and in longitudinal section a double hose-piston pump of the invention.

Fig. 2 shows another embodiment of the hose pump of Fig. 1.

Figs. 3 and 4 show respectively in longitudinal section and in cutaway portion advantageous embodiments of the hoses in the clamping region.

The hose-piston pump 1 is composed of the displacement part 2 for supplying the amount of liquid under pressure, and a piston drive device 3.

The latter has a cylinder 4, a piston 5, a piston rod 6 and a drive means 7. By means of a connecting rod, an eccentric 8 driven by a motor drives the piston rod 6, and the piston 5 in the cylinder 4 backwards and forwards, whereby the application liquid 10 is provided in front of the piston.

The displacement part 2 has a hose housing 12 in which is arranged a double hose 13. The delivery area 14 is sealed at both ends by non-return valves 15 and 16 working against the delivery direction. In the valve housing of the non-return valves there are cams 17 with cross pieces for the ball valves 18 which limit the valve lift of the balls and catch these concentrically so that the balls can again go back concentrically to their seat.

The displacement liquid 10 is connected by means of a line 20 to a chamber 21 of the displacement part 2 and a supply container 22 by means of prestressed non-return valves 23. Into the outer chamber 24 of the hose housing 12 projects a valve disc 25 which engages with the seat 26, is guided by pins 27 and is under the effect of springs 28. The displacement part 2 has a leakage valve 30 and a ventilation valve 31. A line 32 leads from the leakage valve 30, and a line 33 from the ventilation valve 31 to the supply container 22.

The hoses 35 and 36 of the double hose 13 are made to taper in wall thickness, and the tapering certainly extends in the direction of the inlet valve 16. Both the outer circumference and the inner circumference of each hose can have a conical shape, whereby the wall thickness becomes greater towards the outlet end. Advantageously the tapering of the wall thickness of the hoses is so provided that the hoses have a cylindrical outer circumference, with the inner surface of the hose extending conically towards the inlet side of the displacement chamber 14, so that the wall thickness becomes smaller towards the inlet side. Thus an increased elasticity is obtained for the hose movement during widening out and converging.

The intermediate space between the hoses 35 and 36 is filled with a liquid 37.

The hose housing 12 is so constructed that there is an outer chamber 24 which represents a considerable widening and makes possible a widening of the hose outwardly to a considerable extent. The widening should substantially exceed at least the wall thickness of one hose. Generally the inner diameter of the hose housing 12 can be approximately one and a half times to twice the outer diameter of the hose or the outer hose in the case of a double hose. Thus together with the increased elasticity of the hose or the hose structure, there is the guarantee that the hose structure can widen out to a considerable extent during the suction stroke. During the pressure stroke the hose structure is compressed approximately up to the middle of the hose. Thus there is obtained an amount of considerable size to be pumped through the hose.The amount can be approximately double with respect to hosediaphragm pumps in which the hose structure is basically only compressed.

The leakage valve 30 is arranged on the outside of the hose housing 12 and is connected to the supply container 22 by means of the line 32. In the housing 39 it has two oppositely working non-return valves 40 and 41 which are under the effect of springs 42 and 43. Valve 21 is provided with a sensing device 44 which projects into the outer chamber 24 of the hose housing 12.

The ventilation valve 31 has a double function.

The air which collects at the highest point of the hydraulic chamber 24 is discharged through this valve, and the hydraulic oil which would lead to overfilling of the outer chamber 24 is conveyed with the aid of the valve 31 into the supply container 22.

The valve 31 is constructed as a spring-loaded ball valve 46,47 and is so conceived that it always allows through the same amount of air or oil, independently of the counter pressure. This is achieved by the ball valves being sealed once at the bottom and once at the top. The line 33 connects the ventilation valve 31 to the supply container 22.

The double hose 13 is provided with a hose break safety device 48 or an indicating device for a break in a hose. For this purpose a capacitive control device with an electrode 49 can be provided and when the nature of the liquid in the intermediate space 37 changes, an indicating device or an acoustic signal device is activated.

If a low pressure occurs in the chambers 24 containing the application liquid due to leakage, the widening double hose 13 presses the valve 41 by means of the sensor 44. Then application liquid is drawn out of the supply container by means of the line 32 and the valve 40 until the chambers 24 and 21 are again completely filled with the application liquid. If the nominal pressure of the application liquid is exceeded, the excess pressure valve 23 is activated. So much application liquid is delivered into the supply container until the set maximum pressure is again reached. 50 designates a bypass valve in the bypass line 51 which is closed during operation of the pump.

Because of the increased amount of throughput, the double hose-piston pump is very powerful.

simple in construction and stabie, and guarantees a long service life.

Fig. 2 shows a hose-piston pump in which the valves 15a, 16a are constructed and used as float ball valves. Therefore the balls 18a are lighter in weight than water or the liquid to be delivered. The valve bodies are advantageously large volume components. Supplyihg of the liquid is effected from the top to the bottom. The other construction of the hose-piston pump corresponds to that of Fig.

1.

Fig. 3 and Fig. 4 show advantageous embodiments of the clamping ends of the hoses.

The hoses 35 and 36 - seen in the longitudinal section -- are shaped to run outwards at a sharp angle to the hose axis at their clamping ends 35a, 35b and 36a, 36b. The sharp angles are preferably in the range of 40 to 50 , preferably 450. The hose ends can also be curved and outwardly extending, as is shown with the lower clamping ends of Fig. 4. The end rim rings 53, 54 can be connected to the steep or curved bath of the hoses extending in the transverse plane to the hose axis. Advantageously the clamping ends of the hoses are made to be reinforced and stiffened, e.g. are made bigger than usual as regards wall thickness.The hoses are pressed by the type of design of the clamping ends so that deformation occurs only in the middle region of their length, and the end areas of the hoses are kept completely free from levelling, the occurrence of impact stresses and the like.

Thus, as will be evident from the above description of preferred embodiments with reference to the drawings, there is disclosed herein a flexible hose type pump arrangement which comprises a housing (12), a hose-actuation chamber (24) defined in the housing (12) and communicable successively with a source of pressurised fluid and suction (3), and a flexible hose (13) arranged in the housing (12) so as to be surrounded by the actuation chamber (24) and communicating at one end with a suction inlet (16) of the housing for admitting a fluid medium to be pumped by the pump arrangement and at its other end communicating with a pressure outlet (17) of the housing for delivering pumped fluid medium. The hose (13) exerts a pumping action on the fluid medium upon successive application of pressure and suction to the actuation chamber (24). The wall thickness of the hose (13) increases in a direction from the suction inlet (16) to the pressure outlet (17), and the actuation chamber (24) is sufficiently large to permit generally radial expansion of the hose during a fluid suction stroke caused by application of suction to the actuation chamber (24). In a flexible hose type pump arrangement of the above type, the flexible hose can be stressed considerably more than is possible with known constructions.

Claims

1. A flexible hose type pump arrangement comprising: a housing; a hose-actuation chamber defined in said housing and communicable successively with a source of a pressurised fluid and suction; and a flexible hose arranged in said housing so as to be surrounded by said actuation chamber and communicating at one end with a suction inlet of the housing, for admitting a fluid medium to be pumped by the pump arrangement and at its other end communicating with a pressure outlet of the housing for delivering pumped fluid medium, the hose exerting a pumping action on the fluid medium upon successive application of pressure and suction to the actuation chamber:: in which the wall thickness of the hose increases in a direction from said suction inlet to said pressure outlet, and the actuation chamber is sufficiently large to permit generally radial expansion of the hose during a fluid suction stroke caused by application of suction to the actuation chamber.

2. Hose-piston pump in which the displacement chamber is formed by a hose, in particular a double hose filled with liquid in the intermediate space, and by two non-return valves, and the space surrounding the hose body has an application liquid moved by a driven piston, and a supply container with a non-return valve is provided for the application liquid, characterised in that the hose, especially each hose of a double hose (13), is made to be tapered in its wall thickness, and in that the hose housing (12) has an outer chamber (24) substantially widened over the thickness of a hose wall.

3. Hose-piston pump according to claim 1, characterised in that the hose has a cylindrical outer circumference, wherein the inner circumference of the hose extends conically outwards radially to the inlet side of the displacement chamber (14).

4. Hose-piston pump according to claim 2 or 3, characterised in that the inner diameter of the hose housing (12) is approximately one and a half to double the outer diameter of the hose structure (13).

5. Hose-piston pump according to one of claims 1 to 4, characterised in that the hoses (35, 36) at the clamping ends (35a, 36a; 35b, 36b) are shaped to extend outwardly at a sharp angle to the hose axis, e.g. in the range of 40" two 50".

6. Hose-piston pump according to one of claims 1 to 4, characterised in that the hoses at the clamping ends are provided to extend outwardly and curved (35c, 36c).

7. Hose-piston pump according to one of claims 1 to 6, characterised in that the end rim ring (53, 54) connected to the steep or curved path of the hose extends in the transverse plane to the hose axis.

8. Hose-piston pump according to one of claims 1 to 7, characterised in that the hoses are made to be reinforced and stiffened in the clamping region, e.g.

with a greater wall thickness.

9. Hose-piston pump according to one of claims 1 to 8, characterised in that the outer chamber (24) of the hose housing (12) is connected by means of a leakage valve (30) and a ventilation valve (31) to the supply container (22).

10. Hose-piston pump according to one of claims 1 to 9, characterised in that the leakage valve (30) is arranged on the outside of the hose housing, and in that the leakage valve (30) projects by means of a sensing device (44) into the outer chamber (24) of the hose housing, and is arranged neither directly nor indirectly in the main oil stream of the connection (20) and hence works independently of the oil stream.

11. Hose-piston pump according to one of claims 1 to 10, characterised in that the leakage valve (30) has two oppositely working non-return valves (40, 41).

12. Hose-piston pump according to one of claims 1 to 11, characterised in that between the outer chamber (24) of the hose housing and the application chamber (21) of the pump (3) there is arranged a closure valve (25) projecting into the outer ciamber (24) and under spring pressure (28).

13. Hose-piston pump according to one of claims 1 to 12, characterised in that the valve housings (15, 16) which close the displacement chamber (14) have limiting cams (17) with cross pieces, adapted to the shape of the ball valve (18).

14. Hose-piston pump according to one of claims 1 to 13, characterised in that the intermediate space between the hoses (35, 36) filled with a liquid (37) is provided with a hose break safety device (48) with capacitive control means (49).

15. Hose-piston pump according to one of claims 1 to 14, characterised in that the valves (15a) and (16a) are constructed as float ball valves so that raw sewage can be delivered.