A submersible pump assembly having an electric motor and a pump coupled therewith which are accommodated in a housing and having a filter on its underside before the suction opening of the pump. The filter is formed by a pot of elastically yieldable material surrounding the suction opening of the pump, and forms the lower part of the pump housing and it is provided with filter openings. By the appropriate shaping and/or selection of material an elastic return force is achieved which suffices to carry the weight of the entire assembly or to lift it in the case of deformations.
What is claimed is
1. A submersible electric motor-pump assembly having a suction inlet and discharge outlet, and provided with a housing having an electric motor and pump coupled thereto, and adapted to be submersible in a fluid to be pumped, comprising:
2. A submersible electric motor-pump assembly having a suction inlet and discharge outlet, and provided with a housing of rigid material having an electric motor and pump coupled thereto, and adapted to be submersible in a fluid to be pumped, comprising:
3. The submersible electric motor-pump assembly according to claim 1, wherein said element is a pot shaped to form a cup-shaped, yieldable cage like device having passage slots at intervals about its side wall which permit the passage of said fluid to said pump suction inlet.
4. The submersible electric motor-pump assembly according to claim 2, wherein said element is a cup-shaped, yieldable pot or cage like device having passage slots at intervals about its side wall which permit the passage of said fluid to said pump suction inlet.
5. The submersible electric motor-pump assembly according to claim 2, wherein said element comprises an elastic material of high abrasion resistance.
6. The submersible electric motor-pump assembly according to claim 5, wherein said material is rubber.
7. The submersible electric motor-pump assembly according to claim 1, wherein said element comprises an elastic material of high abrasion resistance.
8. The submersible electric motor-pump assembly according to claim 7, wherein said material is rubber.
BACKGROUND OF THE INVENTION
This invention relates to a submersible electric motor-pump assembly, that is to say a pump assembly comprising an electric motor and a pump coupled thereto and accommodated in a common housing, such as are used for example, predominantly on building sites for the draining of trenches.
Such submersible motor-pump assembly is usually provided on the suction side of the pump, before its suction opening, with a filter which is intended primarily to prevent the possibility of constituents contained in the water, which cannot be conveyed by the pump, from entering the pump. Since the suction opening of the pump is ordinarily arranged on the underside of the pump, as a rule the filter forms the lowermost part of the motor-pump housing. Therefore, in rough work on building sites it is subjected to heavy loading and consequently is easily damaged or destroyed. Since as a rule, high dropping security is also required for such pumps, the filter is ordiniarily manufactured from the same or similar rigid material as the motor-pump housing, so that damage to this housing can easily occur in the case of impacts. High mechanical strength of the filter is also not able to prevent the occurrence of damage or destruction to the bearings or their mountings, caused by falling or impacts especially during transport, Finally, the known filters are subjected to heavy wear on account of the mineral admixtures of the conveyed liquid.
SUMMARY OF THE INVENTION
The invention is based upon the problem of producing an embodiment of a submersible motor-pump assembly in which the above described disadvantages and drawbacks are avoided and not only is damage or destruction to the filter and its rapid wear prevented, but also security against impact is achieved for the entire motor-pump assembly. To solve this problem, in a submersible motor-pump assembly of the initially described kind, there is provided an electric motor and a pump coupled therewith which are accommodated in one common housing having a filter on its underside before the suction opening of the pump. The invention provides that the filter is formed by a pot of elastically yieldable material forming a lower part of the pump housing, surrounding the suction opening of the pump and provided with filter openings. The strength and elastic return force of the pot suffice, by reason of appropriate shaping and/or selection of material, to carry the weight of the entire assembly and to lift it in the case of elastic deformation. Such a lower housing pot can consist, for example, of rubber or a rubber-like material or even of a suitable plastic of adequate abrasion resistance. By reason of such a formation, not only does it largely prevent damage or destruction to the filter, but it also takes up impacts which are transmitted from the ground to the housing and could damage the latter, and finally it is extremely abrasion-resistant.
The invention lends itself to numerous possibilities for the formation for the lower housing pot. The invention will be explained in greater detail hereinafter by reference to a form of embodiment of a submersible electric motor-pump assembly in accordance with the invention which is represented as an example, with the parts essential to understanding, in the accompanying drawing.
BRIEF DRSCRIPTION OF THE DRAWING
FIG. 1 shows a side elevational view of the pump assembly, the lower part thereof illustrated in section; and
FIG. 2 shows a sectional view along the line 2--2 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the submersible electric motor-pump assembly as illustrated in the drawing, an electric motor and a pump coupled therewith are accommodated as is conventional in one common housing 11; the pump being formed as a centrifugal pump and the centrifuge wheel 12 is arranged directly by the suction opening 13 of the housing. The suction opening is surrounded, at a certain interval, by a pot or filter appropriately shaped so as to form a yieldable pot or cage 14 which forms the lower part of the housing 11 and the pot comprises preferably an elastic material such as rubber or the like. This pot 14 is provided around its periphery with passage means distributed at intervals, preferably in the form of a plurality of slots 15 for the delivered medium. The wall parts remaining between the slots are of such stout dimensions that they are capable of carrying the entire pump assembly. If, therefore, impacts are exerted upon the pump assembly from the underside, for example, due to firm placing upon the ground, due to a fall or the like, they are taken up by the yieldable pot 14. The pot or filter which is preferably made from rubber, plastic or the like or similar material is also extremely abrasion-resistant and thus it contributes and supports the measures to reduce failure by abrasion carried out on the pump by means of linings 16 and 17. The linings together aid in reducing abrasion failure along with such pot about the suction opening and pump passageway for the medium or fluid to be pumped.
It will also be appreciated that in the prior art when a housing fractures or shatters because of it being damaged during use, there is difficulty in removing the pump assembly because of the possibility that the internal components of the assembly can fall out of the housing when the assembly is lifted out of a trench. While the pot or filter serves to absorb shock, it will also remain intact because of its being more elastically yieldable even if the housing fractures or shatters and thus provides a means of pulling up the entire assembly without the internal components falling out of the assembly.
While I have shown and described preferred embodiments of the invention, there are many changes, modifications, and improvements which may be made therein without departing from the scope of the invention as defined in the appended claims.