当前申请(专利权)人地址：
Incorporated in the United Kingdom, Apex Way, HAILSHAM, East Sussex, BN27 3WA, United Kingdom
摘要：
A flow modifier 150 for use with a pump (100, fig. 1) is located adjacent to a pumping chamber (106, fig. 1) outer surface (107, fig. 1) at a shaft opening (116, fig. 1). The flow modifier comprises an annular portion 152 comprising a further shaft opening 156. A spacing member 154 spaces the annular portion from the outer surface, defining a liquid overflow outlet 164 to direct liquid flow from the shaft opening in a direction transverse to the shafts axis. The liquid overflow outlet may be sized to prevent air ingress into the pump cavity (110, fig. 1) through the shaft opening when the surrounding liquid level drops below the shaft opening. The annular portion may comprise a first portion 158 having a further shaft opening and a second portion 160 extending towards the outer surface and defining the liquid overflow outlet, the annular portion defining a stabiliser cavity 166 extending between the shaft opening and the further shaft opening which remains filled with liquid when the surrounding liquid level drops below the shaft opening. Also claimed are a centrifugal pump comprising the flow modifier and a tank pump comprising a liquid tank and the centrifugal pump.
权利要求：
CLAIMS
1. A centrifugal pump comprising:
a pumping chamber having:
an inner surface defining a pump cavity
a pump inlet defined in a first side of the pumping chamber;
a shaft opening defined substantially centrally in a second side of the
pumping chamber, the second side substantially opposing the first side and
arranged to be above the first side, in use; and
a pump outlet;
an impeller retained within the pump cavity; and
a shaft member mechanically connected to the impeller through the shaft opening, whereby rotation of the shaft member causes rotation of the impeller about a shaft axis passing through the shaft opening and movement of a pumping liquid from the pump inlet towards the pump outlet,
wherein the centrifugal pump further comprises a flow modifier provided adjacent to an outer surface of the pumping chamber at the shaft opening to substantially prevent ingress of air into the pump cavity through the shaft opening during operation of the pump even when a water level in a liquid tank surrounding the pumping chamber drops below a level of the shaft opening, wherein the flow modifier comprises:
an annular portion having defined therein a further shaft opening spaced from the shaft opening and having the shaft member passing therethrough,
wherein the centrifugal pump comprises a spacing member spacing the annular portion from the outer surface, and the flow modifier defines a liquid overflow outlet for liquid flow from the shaft opening in a direction substantially transverse to the shaft axis, wherein:
(a) the liquid overflow outlet is sized to substantially prevent the ingress of air into
the pump cavity through the shaft opening during operation of the pump, even
when the water level in the liquid tank surrounding the pumping chamber drops
below the level of the shaft opening; and/or wherein
(b) the annular portion comprises a first portion having defined therein the further
shaft opening and a second portion extending towards the outer surface from
the first portion and defining the liquid overflow outlet, wherein the annular
portion defines a stabiliser cavity extending between the shaft opening and the
further shaft opening and configured to remain filled with liquid during operation
of the pump, even when the water level in the liquid tank surrounding the
pumping chamber drops below the level of the shaft opening.
2. A centrifugal pump as claimed in claim 1, wherein the spacing member extends from the annular portion to the outer surface of the pumping chamber at the second side of the pumping chamber.
3. A centrifugal pump as claimed in claim 2, wherein the spacing member is a plurality of spacing members.
4. A centrifugal pump as claimed in claim 3, wherein the centrifugal pump defines a plurality of liquid overflow outlets defined between adjacent spacing members. 8. A centrifugal pump as claimed in claim 4, wherein the centrifugal pump defines at least 5 liquid overflow outlets.
6. A centrifugal pump as claimed in any preceding claim, wherein the centrifugal pump comprises a plurality of vanes on the outer surface of the pumping chamber, each extending radially outwards at the shaft opening in a direction transverse to the shaft axis. 7. A centrifugal pump as claimed in claim 6, wherein the vanes extend radially inwards of a boundary of the shaft opening.
8. A centrifugal pump as claimed in claim 6 or claim 7, when dependent directly or indirectly on claim 3, wherein the vanes are the spacing members.
9. A centrifugal pump as claimed in any preceding claim, wherein the annular portion comprises a brim portion spaced from the outer surface of the pumping chamber and extending radially outwards relative to the shaft axis and extending substantially parallel to the outer surface of the pumping chamber at the second side of the pumping chamber. 10. A centrifugal pump as claimed in any preceding claim, wherein the liquid overflow outlet is defined partially by the outer surface of the pumping chamber at the second side of the pumping chamber.
11. A centrifugal pump as claimed in any preceding claim, wherein a narrowest extent of the liquid overflow outlet is less than 5 millimetres.
12. A centrifugal pump as claimed in claim 11, wherein the narrowest extent of the liquid overflow outlet is in a direction substantially parallel to the shaft axis. 13. A centrifugal pump as claimed in claim 11, wherein the narrowest extent of the liquid overflow outlet is in a direction substantially circumferential to the shaft axis.
14. A centrifugal pump as claimed in any preceding claim, wherein the flow modifier is a separate component to the pumping chamber.
15. A centrifugal pump as claimed in any preceding claim, wherein the flow modifier is fixedly mounted relative to the pumping chamber.
16. A centrifugal pump as claimed in any preceding claim, wherein a clearance between the further shaft opening and the shaft member is less than a clearance between the shaft opening and the shaft member.
17. A centrifugal pump as claimed in any preceding claim, wherein a spacing between the shaft opening and the further shaft opening is greater than 5 millimetres. 18. A centrifugal pump as claimed in any preceding claim, wherein a total cross- sectional area of the or all of the liquid overflow outlet(s) is at least 3 times a cross- sectional area of the space between the shaft opening and the shaft member. 19. A centrifugal pump as claimed in any preceding claim, wherein the shaft axis is arranged to be substantially vertical, in use.
20. A centrifugal pump as claimed in any preceding claim, for use in a tank pump for air conditioning equipment.
21. A tank pump comprising a liquid tank for receiving a volume of liquid to be pumped, the liquid tank surrounding the pumping chamber of the centrifugal pump as claimed in any preceding claim.
22. A flow modifier for use in a tank pump, the flow modifier comprising:
an annular portion defining a first shaft opening at a first end of the flow modifier, the first shaft opening defining a shaft axis through the flow modifier; and
a spacing member extending from the annular portion towards a second end of the flow modifier and arranged to space the annular portion from an outer surface of a pumping chamber of a centrifugal pump, in use,
wherein the flow modifier is configured to be locatable, in use, over a shaft opening provided on an upper side of the outer surface of the pumping chamber, such that the shaft axis passes through the shaft opening of the centrifugal pump,
wherein, the flow modifier at least partially defines a liquid overflow outlet for liquid flow entering the flow modifier at the second end of the flow modifier, the liquid overflow outlet being arranged to direct liquid flow in a direction substantially transverse to the shaft axis, wherein:
(a) the liquid overflow outlet is sized to substantially prevent the ingress of air through the shaft opening of the centrifugal pump when liquid flow enters the flow modifier at the second end of the flow modifier, even when air surrounds an outer region of the flow modifier outside the liquid overflow outlet; and/or wherein
(b) the annular portion comprises a first portion having defined therein the first shaft opening and a second portion extending towards the second end from the first portion and defining the liquid overflow outlet, wherein the annular portion defines a stabiliser cavity extending from the first shaft opening towards the shaft opening of the centrifugal pump, in use, and configured to remain filled with liquid when liquid flow enters the flow modifier at the second end of the flow modifier, even when air surrounds an outer region of the flow modifier outside the liquid overflow outlet.