TECHNICAL FIELD
[0001] The present invention relates to a vertical pump having a single or a plurality of
helical or spiral blades and, more particularly, to a pump suitable for sewage treatment
or the like.
BACKGROUND ART
[0002] Conventionally, in a vertical pump, a rotor having a plurality of blades extending
radially in a plane perpendicular to a main spindle of the pump is arranged at a lower
position within a casing of the pump and is rotated to execute drawing or suction
of water from a lower end of the casing.
[0003] However, this vertical pump has the following disadvantages. That is, since the pump
comprises the plurality of blades which are so spread as to extend radially in the
plane perpendicular to the main spindle of the pump, toward the casing, a passing
area of water stream or flow is limited or narrowed. Particularly, in a case where
sewage is sucked or drawn, cloths and solid matters which may be contained in the
sewage lodge within the pump.
[0004] Further, a centrifugal pump is known which is disclosed in Japanese Patent Laid-Open
No. SHO 57-181997, as a pump having a single helical blade.
[0005] However, such a centrifugal pump has the following disadvantage. That is, since water
drawn in a direction of the main spindle of the pump flows in a direction perpendicular
to the main spindle, solid matters and the like lodge within the pump.
[0006] Furthermore, depending upon water pumping environment, there may be a case where
a vertical type non-blocked pump is required.
[0007] It is an object of the invention to provide a vertical pump which is non-blocked
and which is large in lift and in discharge quantity or delivery.
DISCLOSURE OF THE INVENTION
[0008] In order to achieve the above-described purpose, in a vertical pump according to
the invention, a single helical blade is fixedly mounted on a tip of a rotary drive
shaft of the pump, an outer peripheral edge portion of the single helical blade is
in proximity with an inner surface of a casing of the pump, the casing extends in
the direction of the rotary drive shaft, the helical blade is arranged with superior
balance with respect to the rotary drive shaft, an interval between upper and lower
blade portions of the blade is widened, and a plurality of long twisted guide vanes
are arranged at a flow passage above the blade.
[0009] By this arrangement, even if water is water including cloths and solid matters such
as sewage or the like, there is no case where the water drawn from a lower portion
of the casing into between the blade portions of the helical blade having the wide
flow passage causes the pump to be clogged. Moreover, since the blade is contiguous
to each other in a helical form so as to be formed into a single blade extending upwardly,
it is possible to raise the lift. Further, since the blade is arranged with superior
balance with respect to the drive shaft, there is less in case where harmful oscillation
or vibration occurs in the pump. Furthermore, water flow pumped up helically is adequately
and gradually straightened or uniformed by the plurality of twisted long guide vanes
so that there is less that harmful vibration occurs in the pump.
[0010] In an aspect, the pump is brought to a vertical oblique-flow pump in which a configuration
of the casing at a portion in which the helical blade and the guide vanes exist is
brought to a bowl or pot type configuration.
[0011] In an alternate aspect, in order to further improve the pump performance, a plurality
of helical blades each having the above-described aspect are arranged with them in
shift in phase with equal intervals each other about the rotary drive shaft of the
pump.
[0012] With the above arrangement, volumetric efficiency is raised, and it is possible to
raise the lift. Furthermore, it is possible also to enlarge the caliber or aperture
of the pump so that the discharge quantity or delivery can increase. Generally, since
enlargement of the aperture of the pump increases the dimension of the blade so that
its weight considerably increases, balance with respect to the drive shaft of the
blade is apt to be deteriorated by the single helical blade so that harmful vibration
is generated in the pump and the efficiently of the pump is reduced. In the pump according
to an embodiment of the invention, however, since the plurality of helical blades
are arranged, the balance is extremely improved so that vibration imparted to the
pump is extremely reduced. In a case where there are two helical blades, suction ports
and discharge ports within the casing are located shaft-symmetrically with respect
to the main spindle of the pump. Accordingly, balance becomes superior. Moreover,
also in a case where there are three helical blades, since the suction ports and the
discharge ports are similarly distributed symmetrically, there can be produced similar
advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013]
Fig. 1 is a schematic cross-sectional view showing a vertical pump having a single
or two or more helical blades, according to the invention;
Fig. 2 is a partially cross-sectional view of a forward end portion of the pump illustrated
in Fig. 1, showing a case having a single helical blade;
Fig. 3 is a partially cross-sectional view of a forward end portion of the pump illustrated
in Fig. 1, showing a case having two helical blades;
Fig. 4 is a bottom view of Fig.3; and Fig. 5 is a bottom view showing a pump having
three helical blades, according to the invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0014] A pump having a single or a plurality of helical blades, according to the invention,
will be described below in further detail with reference to the drawings.
[0015] Fig. 1 is a schematic view showing a pump 1 according to the invention. A hub 8 is
fixedly mounted on a forward end of a rotary drive shaft 2 which is rotated by drive
means, for example, a motor (not shown). At least one helical blade 10 is mounted
on the hub 8.
[0016] When the drive shaft 2 is rotated, water is drawn from a suction port 4 of a bell
mouth 24 which is arranged below a casing 20 of the pump 1. The drawn water is straightened
or uniformed by a plurality of twisted guide vanes 14 which are arranged above the
helical blade 10 at a location within the casing 20, and is pumped up to a tube 18
at an upper portion of the casing 20. It is required that the guide vanes 14 gradually
uniform the water flow pumped up helically along the helical blade, so as to flow
straight within the tube 18, to eliminate evils such as vibration or the like to the
pump. For this purpose, the guide vanes 14 are twisted about 270° . Moreover, the
twisted guide vanes 14 are lengthened in order to obtain or produce adequate uniforming
of the flow.
[0017] As a result that the guide vanes 14 are lengthened, the casing 20 is lengthened.
Accordingly, the casing 20 is divided into multi-stage portions 21, 22 and 23 at a
location between the helical blade 10 and the guide vanes 14 and at a location at
an intermediate portion of each of the guide vanes 14, for the purpose of assembling
and maintenance of the pump.
[0018] Fig. 2 is a partially cross-sectional side elevational view showing a principal portion
of a lower end section of the pump illustrated in Fig. 1, showing the pump 1 having
a single helical blade 10.
[0019] Description will be made to the helical blade 10. The blade 10 has a configuration
thereof wound helically about the rotary drive shaft 2 through an adequate angle.
The blade 10 is mounted on the hub 8 at a proximal end portion 30 of the blade 10.
An outer peripheral edge portion 32 opposite to the proximal end portion 30 is in
proximity with an inner surface of the casing 20. The hub 8 and the helical blade
10 may be formed integrally as a casting. A forward end potion 33 of the helical blade
10 extends downwardly less than a forward end portion 9 of the hub 8, whereby the
wide suction port 4 is formed. An interval between the upper and lower blade portions
serving as a flow passage is adequately widened so as to allow cloths and solid matters
included in sewage and the like pumped up, to pass.
[0020] When the drive shaft 2 is rotated, the pumped-up water is drawn from the suction
port 4, flows toward a discharge port 5 through gaps between the blade portions, and
is uniformed by the plurality of twisted guide vanes 14 each of which is long in length,
as described previously.
[0021] The helical blade 10 is so formed that weight balance is superior with respect to
the drive shaft 2. Further, the blade exists continuously over the predetermined length
in the direction along the drive shaft, different from the conventional pump which
has the plurality of blades only in a single plane perpendicular to the drive shaft
2. Thus, it is possible to increase the lift.
[0022] In the figure, the vertical oblique-flow pump 1 is shown whose configuration is such
that a portion of the vertical oblique-flow pump 1 including the helical blade 10
and the guide vanes 14 of which casing 20 is swelled or bulged into the form of a
bowl- or pot-like configuration. However, the vertical pump 1 may be a vertical axial-flow
pump having no bowl portion and having a configuration in which the casing 20 is straight
as a whole.
[0023] Fig. 3 is a partially cross-sectional side elevational view showing a principal portion
of a lower end section of the pump 1 illustrated in Fig. 1. Fig. 4 is a bottom view
of Fig. 3, showing the pump 1 having a pair or helical blades 10 and 11.
[0024] Each of the helical blades 10 and 11 is manufactured such that a sheet material is
processed into a helical configuration. As will be understood from Fig. 4, the blades
10 and 11 are wound helically through 360° about the rotary drive shaft 2 of the pump
1 such that their phases shift 180° from each other so as to be symmetrical with respect
to the shaft. The blades 10 and 11 are mounted on the hub 8 at their respective proximal
end portions 30 and 30. Outer peripheral edge portions 32 and 32 opposite respectively
to the proximal end portions 30 and 30 are in proximity with the inner surface of
the casing 20. The forward end portions 33 and 33 of the respective helical blades
10 and 11 extend downwardly from the forward end portion 9 of the hub 8, to thereby
form wide suction ports 4 and 4. An interval of the alternate blade portions of the
two blades 10 and 11 serving as a flow passage is adequately widened so that cloths
and solid matters included in the sewage and the like pumped up can pass.
[0025] When the drive shaft 2 is rotated, the pumped water is drawn simultaneously from
the two suction ports 4 and 4 which are located in symmetrical relation to each other
with respect to the shaft, passes through gaps between the blade portions, generates
a flow in a single helical direction, flows into the two discharge ports 5 and 5 which
are located in symmetrical relation to each other with reference to the shaft, and
is uniformed by the plurality of twisted guide vanes 14 which are long in length,
as described previously.
[0026] As described above, in a case where two helical blades 10 and 11 are provided in
this manner, the blades are arranged symmetrically with respect to the shaft, and
the suction ports and the discharge ports are also arranged in symmetrical relation
to each other. Thus, the pump is brought to a pump extremely superior in balance.
Further, in a case of a single helical blade, assuming that a single plane extending
perpendicularly to the drive shaft 2 is considered, energy is given to the water at
a single eccentric location, and energy cannot be applied equally, so that volumetric
efficiency is bad. Generally, the delivery or discharge quantity of the pump is in
proportion to the caliber or aperture of the pump. In a case of a single helical blade,
however, it is impossible to cover the whole volume of the water for the reason discussed
above. Accordingly, if the aperture of the pump increases, the discharge quantity
does not increase in proportion thereto. On the other hand, in a case of a pump having
two helical blades, energy is given to water at two locations symmetrical to each
other with respect to the shaft, simultaneously in every or all planes extending perpendicularly
to the drive shaft 2 so that the volumetric efficiency becomes superior. As a result,
it is possible to raise the lift and enlarge the aperture of the pump in oder to increase
the discharge quantity. Tests have been conducted with respect to a vertical oblique-flow
pump illustrated in Fig. 3. As a result, it has been known that efficiency is superior
4 - 5% as compared with the conventional oblique-flow pump.
[0027] Fig. 5 shows a case where three identical helical blades 10, 11 and 12 are mounted
on the hub 8 in place of the two helical blades of the pump illustrated in Fig. 3,
with phases shifted 120° from each other. Also in this case, the blades as well as
the suction ports and the discharge ports are dispersed equally similarly to the pump
illustrated in Fig. 3, so that the pump is brought to a pump superior in balance and
superior in volumetric efficiency.
[0028] It is preferable that the number of provided helical blades is decided depending
upon a condition in which the dimension of the casing 20 of the pump 1 and the flow
of the fluid within the pump are brought into uniformity, and other design conditions.
In this connection, Fig. 3 shows the vertical oblique-flow pump 1 in which a portion
including the helical blades 10 and 11 and the guide vanes 14 of the casing 20 are
bulged in the form of a bowl or pot. However, the pump may be brought to a vertical
axial-flow pump in which there is no bowl portion and which has a configuration in
which the entire casing 20 is straight.
INDUSTRIAL APPLICABILITY
[0029] As described above, since the pump having a single or a plurality of helical blades,
according to the invention, can be made large in lift and large in discharge quantity,
there are produced advantages that a conventional relay station for pumping up arranged
in a case where the lift is small can be omitted, and the like. Thus, it is possible
to utilize the pump widely in various industries.
[0030] Moreover, since the flow passage within the pump is relatively wide and is a single
direction in the direction of the drive shaft, things or objects do not lodge. Thus,
the pump can also be utilized for pumping up of sewage or the like containing articles
such as a block of cloth or papar which tends to block conventional pumps.
1. A vertical pump in which a single helical blade (10) is fixedly mounted on a forward
end of a rotary drive shaft (2), and an outer peripheral edge portion (32) of the
single helical blade (10) is in proximity with an inner surface of a casing (20),
characterized in
that said casing (20) extends in the direction of said rotary drive shaft (2),
that a plurality of twisted guide vanes (14) long in length are arranged in a flow
passage above an upper portion of said blade (10), and
that said blade (10) is arranged in superior balance with respect to said rotary
drive shaft (2), and an interval between upper and lower blade portions of said blade
(10) is large.
2. The pump of Claim 1, wherein
a portion of said casing (20), by which said helical blade (10) and said guide
vanes (14) are surrounded, is formed into a bulged bowl-shaped configuration, and
said bowl-shaped configuration portion of said casing is divided at a location
between said blade (10) and said guide vanes (14) and at an intermediate portion of
said guide vanes (14) and is formed by a multi-stage portions (21, 22, 23), thereby
the pump is configured as a vertical oblique-flow pump.
3. A vertical pump wherein a plurality of blades (10, 11, 12) are fixedly mounted on
a forward end of a rotary drive shaft (2) and wherein an outer peripheral portion
(32) of each of said plurality of blades (10, 11, 12) is in proximity with an inner
surface of a casing (20), characterized in that said casing (20) extends in the direction
of rotary drive shaft (2), and
that said plurality of blades (10, 11, 12) are helical in configuration, and are
arranged with their phases equidistantly shifted respectively about said rotary drive
shaft (2).
4. The vertical pump of Claim 3, wherein two helical blades (10, 11) are mounted on said
rotary drive shaft (2), said blades being arranged symmetrically with respect to said
shaft with their phases shifted 180° from each other about said rotary drive shaft
(2).
5. The vertical pump of Claim 3, wherein three helical blades (10, 11, 12) are mounted
on said rotary drive shaft (2), said blades being arranged with their phases sifted
120° from each other about said rotary drive shaft (2).
6. The vertical pump of Claim 3, wherein a portion of said casing (20), surrounding said
plurality of elical blades (10, 11, 12) have a configuration bulged in the form of
a bowl, thereby the pump is configured as a vertical oblique-flow pump.
7. The vertical oblique-flow pump of Claim 6, wherein a plurality of twisted guide vanes
(14) long in length are arranged at a flow passage in an upper portion above said
helical blades (10, 11, 12) in said bowl-shaped configuration portion of said casing
(20), and
said bowl-shaped configuration portion of said casing (20), by which said helical
blade (10, 11, 12) and said guide vanes (14) are surrounded, is divided at a location
between said blades (10, 11, 12) and said guide vanes (14) and at an intermediate
portion of said guide vanes (14) and is formed by a multi-stage portions (21, 22,
23).