RU180147U1 - CENTRIFUGAL PUMP WITH TWO-TURN SPIRAL RETAIN AND HOUSING CONNECTOR IN THE HORIZONTAL PLANE - Google Patents

Abstract

The utility model relates to the field of pump engineering and can be used to create centrifugal pumps with a double scroll spiral outlet having a housing connector in the plane parallel to the rotor axis, for example, oil main pumps. The pump housing is formed by two parts fastened together: housing 1 and cover 2, in the inner the cavities of which the impeller 3 is located. Connector 4 between the housing 1 and the cover 2 is located in a plane parallel to the axis of the rotor (the axis of rotation of the impeller 3). a two-turn branch is located on the body, consisting of spiral grooves 8, 9 made in the cover 2, and spiral grooves 7 and 10 made in the body 1. A part of the two-turn branch is located in the cover 2 (see Fig. 1), where a curved partition is installed 11, the concave surface 12 of which forms the bottom of the spiral groove 9, and the curved channel 13 is located on the convex side 14 of the partition. On the convex surface 14 of the partition, a rib 15 is integral with the partition 11, in which a groove 16 is made on the side of the concave surface with a width "b" less than the thickness "t" of the rib. The groove 16 forms the walls 17 and 18 in the rib separating the cavity of the spiral channel 9 from the cavity of the channel 13. The partition is welded with the walls 19 and 20 of the cover — welds 21, 22. The second part of the two-turn branch is located in the pump housing 1, where the second curved partition is installed 23, in which at the same time a rib 24 is made integrally with the partition 23, in which a groove is made, similar to the groove 16 made in the lid 2, which is also welded to the walls - only to the walls of the body, and not the cover (body walls and welds in the body as well as ditches and rib 24) .If the pump in its cavity created by the high pressure which leads to deformation of the walls 19 and 20 cover and stretchable partition. Due to the groove 16, the walls 17 and 18 of the rib are also deformed. Due to the flexibility of the walls 17 and 18, when they are bent, the forces breaking the welds 21 and 22 are reduced, which reduces the stresses in the welds and thereby increase the reliability of the detachable body and the pump as a whole. 1 s.p. f-ly, 3 ill.

Description

The utility model relates to the field of pump engineering and can be used to create centrifugal pumps with a double helical tap, having a housing connector in the plane parallel to the rotor axis, for example, oil main pumps.

Pumps with double-flow (double-coil or double-spiral) bends are made to reduce the radial forces acting on the bearings in order to increase the service life of the pump.

As a prototype, a well-known centrifugal pump with a double-sided impeller has been selected, comprising a casing consisting of upper and lower parts forming a horizontal connector, an inlet and a two-coil spiral outlet with a welded baffle [RF patent for utility model No. 106680, class. F04D 1/00, F04D 29/00].

To ensure minimal hydraulic losses, the baffle of the double-helical spiral outlet is made of sheet metal of minimum thickness.

The use of a welded baffle of a double-helical spiral outlet allows, prior to its welding, to the walls of the spiral outlet to mechanically clean the flow part of the spiral outlet in the casting with subsequent coating (or without coating) in order to obtain the required surface cleanliness to reduce hydraulic losses and, consequently, increase efficiency, as well as protection against the corrosive effects of the pumped medium.

The main purpose of the partition is to ensure high accuracy of the manufacture of the spiral profile, namely, the depth of the spiral channel that forms the concave surface of the partition - otherwise the requirement to ensure the symmetry of two opposite spiral channels - one of which is formed by the casting wall of the case or cover, will not be met the second channel is formed by a thin-walled curved partition welded to the cast wall of the lid or housing (two or one partitions are in the lid and the other - in the case).

Since the partition has a thickness less than the thickness of the cast walls of the channels to which it is welded, the weak point is the weld (s). When pressure tests are performed on the strength, a high pressure is created inside the body, under the influence of which the body walls and covers are deformed ("inflate"), which loads the welds, whose strength is limited due to the small thickness of the partition and the size of the weld section. The reliability of the fastening of the partition is also low for the reason that defects that may appear in the welds are difficult to detect, since the seams are located in hard-to-reach places.

Thus, the welded partition has a drawback - low reliability due to the difficulty of controlling the quality of the connection (welding), the small thickness of the partition and the small cross section of the welds.

At the same time, due to the insufficient rigidity of the partition, it is difficult to maintain its predetermined configuration (bulge of the partition or profile), which also reduces the reliability of the housing due to deformation of the partition.

The purpose of the utility model is to increase the reliability of a centrifugal pump with a two-turn spiral outlet and a housing connector in the plane parallel to the rotor axis by increasing the stiffness and preserving the curvature parameters of the two-turn branch partition, and also reducing the load on the welds connecting the partition to the walls of the pump casing.

The problem is solved in that in a centrifugal pump with a housing connector in a plane parallel to the axis of the rotor, comprising a housing consisting of upper and lower parts, and a two-coil spiral outlet formed by a curved thin-walled partition welded to the inner surface of the housing, according to a utility model, the partition along the entire length is provided with at least one longitudinal stiffener, in which a groove is made on the back of the partition with a width less than the thickness of the rib and a depth greater than the thickness of the partition.

To ensure a greater reduction in the load on the welds, the groove in the stiffener is made with a depth of more than 3 times the thickness of the partition.

The utility model is illustrated by drawings, in which a general view of a centrifugal pump with a double-scroll spiral outlet and a housing connector in a plane parallel to the rotor axis is shown (a guiding apparatus is not shown): 1 is a fragment of a cross section of a two-turn pump outlet; FIG. 2 is a section AA in FIG. one; FIG. 3 is a section BB in FIG. one.

The list of positions and designations in the drawings:

1 - housing;

2 - cover;

3 - impeller;

4 - flat connector;

5 - hairpin;

6 - a nut;

7, 8, 9, 10 - spiral grooves;

11, 23 - a partition;

12 - concave surface of the partition;

13 - curved channel;

14 - convex surface;

15, 24 - rib;

16 - groove in the rib;

17, 18 - walls in the rib;

19, 20 - the walls of the split housing;

21, 22 - welds;

b is the width of the groove;

h is the depth of the groove;

S is the thickness of the partition;

t is the thickness of the ribs.

The pump housing is formed by two parts fastened together: the housing 1 and the cover 2 (see Fig. 2), in which the impeller 3 is located. The connector 4 between the housing 1 and the cover 2 is located in a plane parallel to the rotor axis (axis of rotation of the impeller 3 ) The housing 1 and the cover 2 are fastened with studs 5 and nuts 6.

Behind the impeller 3, inside the detachable housing, there is a two-turn branch, consisting of spiral grooves 8, 9, made in the cover 2, and spiral grooves 7 and 10, made in the housing 1.

In the assembled pump, the spiral grooves 7 and 8, and 9 and 10 form a two-turn bend, which allows to minimize the radial force acting on the impeller 3, the shaft and bearings (shaft and bearings not shown) of the pump, which increases the service life of the bearings and the pump as a whole .

A part of the double winding tap is located in the cover 2 (see Fig. 1), where a curved partition 11 is installed, the concave surface 12 of which forms the bottom of the spiral groove 9, and the curved channel 13 is located on the convex side 14 of the partition. On the convex surface 14 of the partition, a rib 15 is integral with the partition 11, in which a groove 16 is made on the side of the concave surface with a width "b" less than the thickness "t" of the rib. The groove 16 forms the walls 17 and 18 in the rib separating the cavity of the spiral channel 9 from the cavity of the channel 13. The partition is welded to the walls 19 and 20 of the lid - welds 21, 22.

The second part of the two-turn tap is located in the pump housing 1, where the second curved partition 23 is installed, in which a rib 24 is made integrally with the partition 23, in which a groove is made, similar to the groove 16 made in the cover 2, which is also welded to the walls - only to the walls of the housing, and not the cover (the walls of the housing and welds in the housing, as well as the groove in the rib 24) are not shown.

When the pump is operating (or when testing its strength and tightness), high pressure is created in the pump cavity, which leads to deformation ("inflation") of the lid walls 19 and 20 and stretching of the partition, as shown in FIG. 1 dashed line. Due to the groove 16, the walls 17 and 18 of the rib are also deformed (shown by the dotted line in Fig. 1). Due to the flexibility of the walls 17 and 18, when they are bent, the forces breaking the welds 21 and 22 are reduced, which reduces the stresses in the welds and thereby increase the reliability of the detachable body and the pump as a whole.

The walls 17 and 18 of the rib 15 give rigidity to the partition in terms of maintaining curvature (convexity) in the manufacture of the partition and when welding it to the lid or body.

The ratio of the sizes "b" and "t", "h" and "S" are determined individually for each pump, taking into account the provision of the estimated safety factor, the dimensions of the incoming parts and manufacturing technology.

Thus, by increasing the stiffness and preserving the curvature of the two-winding tap of the welded thin-walled baffle, as well as by reducing the load on the welds connecting the baffle to the walls of the pump housing, the inventive utility model provides a significant increase in the reliability of a centrifugal pump with a two-scroll spiral bend and a connector housing in the plane parallel to the axis of the rotor.

Claims (2)

1. A centrifugal pump with a two-turn outlet and a housing connector in a plane parallel to the rotor axis, comprising a case consisting of upper and lower parts, and a two-turn spiral outlet formed by a curved thin-walled partition welded to the inner surface of the housing, characterized in that the partition is across the length is provided with at least one longitudinal stiffener, in which a groove is made on the back of the partition with a width less than the thickness of the rib and a depth exceeding the thickness of the odki. 2. A centrifugal pump according to claim 1, characterized in that the groove is made with a depth of more than 3 times the thickness of the partition.

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