JPH02188689A - Motor unit for centrifugal pump - Google Patents

Abstract

PURPOSE: To provide a bearing for rotor of a magnetic shaft joint by placing a ceramic ball of a step bearing in a metal shell, and fixing the ball in strut of a unit fixed part. CONSTITUTION: An impeller 6 farms vane 7, convex magnet 8 and an rotor unit, it is driven by a concave magnet 9 in shaft 10 of motor 11 and is attracted to the arrow shown 15 direction by magnetic force. A step bearing is composed of a rotation cap 16 and ceramic a ball 17, the ball 17 is fixed on a strut 18, edge 21 of a metal shell 20 overlaps a little the equator 22, and the ring part 23 of the ball 17 forms in combination with concave area of the cap 24 a slide surface. An annular bearing member 19 made of resilient materials prevents shift of the rotor unit opposite to the arrow 15. While the rotor unit moves to the direction of the arrow 15, it slide-contacts with the outer surface of the shell 20. This constitution is suitable for a spherical rotor of a bearing attached with a ceramic ball.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a motor unit for a centrifugal pump. More particularly, the invention relates to a bearing for a rotor of a motor or a magnetic shaft coupling driven by a motor, having a spherical magnetic air gap between the driven rotor and a driving stator or a driving outer magnetic ring. Regarding.

(Prior Art) Spherical motors or spherical magnetic couplings are becoming increasingly important in modern pump designs. The impeller of the pump forms a unit with a driven rotor that produces a water thrust that opposes the magnetic thrust.

When the electricity is cut off, the magnetic force of the drive stator ceases immediately, whereas the water thrust caused by the pressure difference between the suction side and the rear side of the impeller slowly increases as the rotation of the impeller decreases. reduced. As a result, after the electricity is cut off, the water force tries to push the impeller, including the rotor, away from the step bearing. if,
The same change in the direction of axial thrust occurs in magnetic shaft couplings if the hydraulic force can overcome the magnetic force during operation. Therefore, it is not only necessary to support the rotor in the direction of the magnetic force during steady operation, but also to prevent the rotor from moving in the opposite direction by means of a ring-shaped annular rotating member.

A spherical bearing is known that is composed of a metal cap and balls. A metal ball can be brazed to the tip of the post. Unfortunately, metal bearings are prone to seizing as dry friction creates very small fractions on the surface that fuse the cap and ball together when the melting temperature of the metal is reached.

Cylindrical bearings produce a film of lubricating fluid, which produces high forces that prevent contact between the two parts of the bearing due to the principle of hydrodynamic lubrication; spherical bearings produce such a film. It does not operate in dry or semi-dry conditions. Therefore, the possibility of seizure is much greater in spherical bearings than in cylindrical bearings, which makes it difficult to replace metal balls with balls made of ceramic materials such as aluminum oxide, zirconium oxide or silicon carbide. This is the reason for replacing it. Since the melting points of these oxides are very high, the frictional heat does not reach that high. The same applies to silicon carbide, which also has no melting point at all since it sublimes.

[Problem to be solved by the invention]

A disadvantage of ceramic balls is that the balls cannot be welded or brazed onto the posts. It is therefore known in the art to press a ball into a hollow post by forcing the ball into a hole slightly deeper than the radius of the ball.

However, the available surface becomes smaller than the hemisphere. Also, these bearings with ceramic balls
- It can only support axial forces in the force direction and therefore acts only as a step bearing. This limits the application of bearings with ceramic balls to spherical rotors in applications under conditions where the environmental hydraulic forces do not exceed the magnetic forces under any circumstances.

The main object of the invention is therefore to provide a motor unit for a centrifugal pump that can overcome the limitations in such applications of ceramic balls.

[Means to solve the problem]

The present invention is directed to a spherical bearing having a second annular bearing member.

In a first solution of the invention, the ball is then surrounded by a partially spherical metal shell.

The edge of the shell reaches slightly beyond the equator of the ball, so that the ball is clamped by that edge, the outer surface of the shell follows the spherical contour on that area of the ball, and the water thrust overlaps the magnetic thrust. If so, the second annular bearing member comes into contact with the shell on its spherical surface.

In a second solution of the invention, a circular groove is formed in the ball with a distance from the equator wide enough to leave a sufficient sliding surface for the annular bearing member mentioned above.

In a third solution of the invention, the stem is formed on the ball, which is press-fitted into the hole in the strut, leaving sufficient sliding surface for the annular bearing member mentioned above.

A fourth variant of the invention shows a ball with a groove and a metal part fixed in the slot.

A fifth variant of the invention shows a ball with a hole passing through the ball and a screw fixing the ball on the post, preferably with springs to cushion the harsh shocks.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

〔Example〕

FIG. 1 illustrates a cross section through a centrifugal pump comprising a housing 1 with an outlet opening 2 and an inlet opening 3. FIG. The duct 4 directs the fluid to the eye region 5 of the impeller.

The impeller 6, together with the vanes 7 and the convex magnets 8, forms a rotor unit, which is driven by a concave magnet 9 provided on the shaft 10 of the motor 11, between the convex magnet 8 and the concave magnet 9. is provided with a partition 12 which separates a humid chamber 13 from a dry chamber 14. The rotor impeller magnet unit 6.7.8 is attracted by the magnetic force in the direction of the arrow 15. The step bearing is formed by a rotating cap 16 and a fixed ball 17. The cap is part of the rotor impeller magnet unit. The balls are fixed on posts 18 which form part of the bulkhead. An annular bearing member 19 made of a slightly elastic material replaces the zero-turn magnet 9 which prevents the rotor unit from moving in the direction opposite to the arrow 15, so that the fixed stator with its windings also receives a rotating magnetic field. can occur, in which case the convex magnet 8 would be replaced by a convex armature.

2 shows an enlarged view of the area enclosed by circle H in FIG. 1, ball 17 is surrounded by shell 20. FIG. The edge 21 of the shell slightly overlaps the equator 22. The spherical ring portion 23 of the ball 17 together with the recessed area of the cap 24 forms a sliding surface. shell 2
0 has a spherical surface 25 that forms a narrow clearance 26 with the annular bearing member 19. When the rotor unit 6.7.8 begins to move in the direction of the arrow 15, the annular bearing member 19 comes into sliding contact with the spherical outer surface of the shell 20. The shell 20 has a projection 28 secured to the post by snap action or brazing. Note that the protrusion 28 itself may constitute a support.

FIG. 3 shows a shell 30 forming a generally spherical body, which is secured to the column 1B' by a brazing material 29.

FIG. 4 shows a spherical pump motor unit, which unit has an inlet opening 40 and an outlet opening 43, which together with a space 42 form the wet part of the pump motor unit. A magnetically permeable septum 44 surrounds the wet chamber together with a flange portion 45 and a pump housing 46. An impeller 47 with vanes 48 and an armature 49 form a rotor unit. impeller 4
The hub portion 50 of 7 includes a bearing cap 51 . This cap and fixed ball 52 constitute a step bearing. The ball 52 has a circular groove 53.

The edge 54 of the permanently mounted shell 55 is bent slightly so as to fit into the groove 53. The shell 55 is the pillar 5
7. The cap 51 reaches beyond the equator 56.

FIG. 5 shows the end of a column 58, which is a hollow body made of stainless steel sheet metal.

This post 58 has a collar 59 that defines a seat for the annular shaft surface 60 of a polished ball 61. The interior of the ground portion forms a stem 62. The inner diameter 63 of the strut is different in the area of the annular shoulder 64,
This shoulder 64 , which is slightly larger than the stem 62 , holds the stem 62 by press-fitting.The peripheral edge of the collar 59 has a spherical shape that matches the spherical surface of the ball 61 . surface 60
The larger diameter of the collar 59 matches the diameter of the ball 61, or preferably is slightly smaller, such that the smaller diameter of the collar 59 has a small axial distance 65 from the equator 66. It matches the inner diameter of the annular member 19 shown in FIGS. 1 and 2.

Such a device is manufactured through the following steps: (a) A concave portion is formed on one hemisphere of the ball 61 by a polishing step, a stem 62 is formed by the same step, and the stem 62 (b) A strut 58 in the shape of a rotating body with a hollow cylindrical end is formed by a deep drawing process, such that the inner diameter of said end is smaller than the diameter of the stem 62. (C) the edge of said end is bent outward to form a flange 67a; (d) the inner diameter of the end is slightly increased on each side of the annular shoulder 64; (e) The stem 62 of the ball 61 is driven through the shoulder 64 until the axial surface of the flange 67a rests on the flat annular surface 60 of the ball 61; and (f) the collar 6 is removed by machining to remove the corners.
The outer surface 59 of 7a is spherically shaped so that its spherical surface aligns with the spherical surface of ball 61.

FIG. 6 shows the same ball shape, but a rotating body 68 is disposed between the column 58a and the ball 61a, and this rotating body 68 is held in the hole of the column 58a by press fitting.

The stem 62a of the ball 61a is press-fitted into the rotating body 68.
is held in the hole 64a.

Figure 7 is a blind end bore.
Ball 71 is shown having a base around counterbore 77 resting on top edge 74 of post 72 . screw 73
is used as a fixing means. The outer diameter of this screw 73 is slightly larger than the diameter of the hole. As a result, high frictional force is obtained. The screw 73 is preferably lubricated with a viscous lubricant.
After assembly, the lubricant is evaporated by high temperature processing. A two-component resin such as an epoxy that hardens and provides high shear forces may be used beforehand, with an O-ring 75 inserted into the groove to prevent contact between the epoxy and the lubricating fluid to be conveyed. will be placed in

FIG. 8A shows a ball 91 with an axial annular groove 97; the end 93 of the strut 92 is formed as a hexagon to provide high friction on the surface of the stem 98.

FIG. 8B shows a cross section through the plane CC of FIG. 8A.

FIG. 9 shows a counterbore ball 111 with a slight undercut, the counterbore being wider in region 117 than opening 119. FIG. This hole is filled with hot metal. Hot metal 118 is then brazed to the ends of struts 112.

FIG. 10 shows the ball 132 with a counterbore and widened reset for the screw head; the post 81 has a tangent angle 8
It has a conical end with an opening angle that is less than or equal to the complementary angle to angle 82, which corresponds to 3. The screw 66 enters the screw 685 and the ball 132 is pressed against the edge 84.

FIG. 11A shows a variation on the design of the FIG.
It is pushed into 00.

FIG. 118 is a view of the support column from above.

FIG. 12A shows a post with a slot 87 whose width matches the width of the nut 88 that holds the screw 86a.

FIG. 12B shows a cross section taken along line AA in FIG. 12A.

FIG. 13A shows a similar design in which the nut 88b is placed inside the six 89. The screw head rests on the annular plane ll3.

Figure 13B shows a cross section through line B--B in Figure 13a.

FIG. 14 shows a cross section through strut 115 with tapered end 116, ball 117 resting on edge 118. The ball is pushed to the edge 1 by the force of the prestressed spring washer 119.
18 and this force is transmitted to the ball 17 by a screw 120 and a nut 121. screw 120
The direction of rotation for tightening is the same as the direction of rotation of bearing cap 122, which is held in place by bearing ring 123.

Ball 117, such as occurs when a pump stops, etc.
If too much force is applied to the ball, the ball will move away from the edge 118 and the spring washer l19 will collapse. Immediately thereafter, the ball is snapped back to its operating position and centered by edge 118.

FIG. 15 shows a design similar to the FIG. 14 embodiment, particularly suitable for a cylindrical column 125 with a tapered edge 126. The spring 127 is formed as a coil spring and is supported by three lashes 12 B (lashes) bent inwardly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a pump with a magnetic shaft coupling. FIG. 2 is an enlarged view of a bearing with a shell. FIG. 3 is an illustrative view showing another method of fixing the shell to the support. FIG. 4 is a cross-sectional view of a pump in which the balls have grooves. FIGS. 5 and 6 are illustrative views showing a ball having a stem, respectively. FIG. 7 is an illustrative view showing an embodiment including a ball with a hole. FIGS. 8A and 8B are illustrative views showing a ball having an axial groove. FIG. 9 is an illustration showing a ball with a hole forming a slight undercut. FIG. 10 is an illustrative view showing a ball screwed to a column. 11A and 118 are illustrative views showing a modification of the embodiment of FIG. 10 in which a nut is inserted into the hole. 12A and 12B show a variation of the FIG. 10 embodiment having a nut positioned in the slot. 13A and 13B are illustrative views showing a modification of the FIG. 10 embodiment having a nut inserted into the hole. FIG. 14 is an illustrative view showing another embodiment with a ball biased by a spring washer. FIG. 15 is an illustrative view showing a modification of the embodiment of FIG. 14 having a screw-type spring. In the figure, 17, 52, 61.61a, 7191.1
01,111.117,130,132 is ball, 18
．． 18', 57, 58.58a,? 2,81.92,1
12, 115, 125 are struts, 20, 30.55 are shells, 24.51° 122 are caps, 73.86a, 8. 8B, 88a, 89 are washers, 1262.62a is a stem, 666b, 120, 131 are screws 8b, 121 is a nut, and 117 is a screw type spring. Patent Applicant Kirsten Ah Lang (and 2 others) Agent Patent Attorney Yama 1) Righteous Person Figure 22X Figure 10 Figure 12A Figure 14 Figure 15

Claims (1)

[Scope of Claims] 1. A motor unit of a centrifugal pump, comprising an impeller forming a unit with a rotor, the impeller rotor unit being a driven part of a device having a drive part, the rotor facing a step bearing. the rotor impeller unit is separated from the drive by a spherical magnetically permeable bulkhead, the step bearings surrounding a common annular sliding area; In such a centrifugal pump motor unit consisting of a convex member fixed on a fixed post and a concave cap, the convex member of the step bearing comprises a ball (17) made of ceramic material, said ball having a metal shell. (20, 30), and the central area (28, 29) of said metal shell is a fixed part (1) of the motor unit of the pump.
2) A motor unit for a centrifugal pump, characterized in that it is fixed to the support column (18, 18') which is a part of the motor unit. 2. A motor unit of a centrifugal pump according to claim 1, characterized in that a spherical shell (20) surrounds more than half of the surface of the ball (17). A motor unit of a centrifugal pump, wherein the impeller rotor unit is a driven part of a device having a drive part, and the rotor is driven by the drive part that generates a rotating magnetic field that produces a magnetic force directed in an axial direction toward a step bearing. the rotor impeller unit is separated from the drive part by a spherical magnetically permeable bulkhead, said step bearing consisting of a convex member fixed on a fixed strut surrounding a common annular sliding area and a concave cap, the impeller rotor The unit is subjected to an abnormal axial force acting in the opposite direction to the force during normal operation, said abnormal axial force tending to move the impeller rotor unit away from the balls (17, 52). In the pump motor unit, the balls (17, 52, 61, 6
1a, 71, 91, 111) at the center of the spherical surface exceeds 180°, thereby
) forms an undercut with respect to the equator of the ball, and an annular region extending beyond the auxiliary bearing member (1
9, 123), together with the annular region, the operating clearance (26) and the axial force during continuous operation are the cap (24).
, 122) from the balls (17, 117). 4. A motor unit of a centrifugal pump, comprising an impeller forming a unit with a rotor, said impeller-rotor unit being a driven part of a device having a drive part, the rotor being oriented in an axial direction towards a step bearing. The rotor impeller unit is driven by a drive part generating a rotating magnetic field producing a magnetic force, the rotor impeller unit being separated from the drive part by a spherical magnetically permeable bulkhead, said step bearings being mounted on a fixed strut and a concave cap surrounding a common annular sliding area. In such a motor unit of a centrifugal pump, the ball (61, 61a) is a concave cavity having a stem portion (62, 62a) that is fixed to a hole in the support (58, 58a). The support has a ball (61, 61a) around it.
The color part (59, 5
9a) A motor unit for a centrifugal pump, characterized in that it has: 5. Motor unit of a centrifugal pump according to claim 4, characterized in that the bore of the strut (58) exhibits an annular shoulder (64) providing a press fit onto the surface of the stem (62). 6 A rotating body whose collar lies within the spherical surface of the ball (68)
is fixed to the support column (58a), and the ball (61
The stem (62a) of a) is inserted into the hole (6) of the rotating body (68).
4a) A motor unit for a centrifugal pump, characterized in that the motor unit is held by press-fitting. 7 A motor unit of a centrifugal pump, comprising an impeller forming a unit with a rotor, said impeller-rotor unit being a driven part of a device having a drive part, the rotor being oriented in an axial direction towards a step bearing. The rotor impeller unit is driven by a drive section that generates a rotating magnetic field that generates a magnetic force, and the rotor impeller unit is separated from the drive section by a spherical magnetically permeable partition.
In such a motor unit of a centrifugal pump, the step bearing consists of a convex member fixed on a corresponding recess surrounding a fixed column and an annular sliding area, wherein the balls (71, 91, 111) are counterbored. A motor unit for a centrifugal pump, characterized in that the motor unit has a structure and is fixed to a support column (72, 92, 112) by a rod-shaped member. 8. The centrifugal pump motor unit 9 according to claim 7, wherein the rod-shaped member is a screw (73), the head of which is located inside the column (72).
9. The centrifugal pump motor unit according to claim 8, wherein the motor unit is hollow. 10. characterized in that the screw (73) is glued inside the counterbore, thereby forming a watertight seal (75) between the ball (71) and the post (72),
A motor unit for a centrifugal pump according to claim 8. 11 The counterbore hole of the ball (111) is made of metal (118
), and the metal is brazed onto the strut (112). 12. A motor unit of a centrifugal pump, comprising an impeller forming a unit with a rotor, said impeller-rotor unit being a driven part of a device with a drive part, the rotor being oriented in an axial direction towards a step bearing. The rotor impeller unit is driven by a drive section that generates a rotating magnetic field that generates a magnetic force, and the rotor impeller unit is separated from the drive section by a spherical magnetically permeable partition.
In the motor unit of such a centrifugal pump, the step bearing consists of a convex member fixed on a corresponding recess surrounding a fixed column and an annular sliding area, wherein the ball (91) is arranged in an axial circular groove (97). ), and the hollow end (93) of the support (91) is provided with a stem (9
8) A motor unit of a centrifugal pump, characterized in that it forms a polygon that provides directional friction. 13. A motor unit of a centrifugal pump, comprising an impeller forming a unit with a rotor, said impeller-rotor unit being a driven part of a device having a drive part, the rotor having a magnetic force oriented in the axial direction towards a step bearing. The rotor impeller unit is separated from the drive by a spherical magnetically permeable bulkhead, said step bearings resting on fixed struts and concave caps surrounding a common annular sliding area. In such a centrifugal pump motor unit consisting of a fixed convex member, the balls (130, 117) are arranged so that the balls (130, 117) are attached to the edge (84).
, 118, 126) against the screws (66, 8
6a, 131, 120, 120a). 14. The motor unit of a centrifugal pump according to claim 13, characterized in that the screws (120, 120a) are suspended by springs (119, 127) with prestress. 15 The spring (119) is of a washer type,
and the support column includes a spring (119) and a ball (117).
A tapered portion (116) forming a seat (118) for
) having a cylindrical portion (115),
The centrifugal pump motor unit according to claim 13. 16. Motor unit of a centrifugal pump according to claim 16, comprising a ball (132) pressed against the edge (84) of the conical bore. 17 Nuts (88, 8) with screws (86a, 131) installed in holes (87, 89) extending perpendicularly to the column
17. The motor unit of a centrifugal pump according to claim 16, characterized in that it is held by 8b). 18 The hemisphere of said ball (17, 61, 61a) together with the cap (24) forms a sliding area and is made of ceramic material, while the undercut area partially (59
, 59a) is an auxiliary bearing member (1) made of metal material.
The motor unit of a centrifugal pump according to claim 1 or 4, characterized in that, together with (9), an operating clearance (26) is formed. 19. A method for manufacturing a strut equipped with a ceramic ball according to claim 4, comprising: (a) forming a concave portion on one hemisphere of the ball (61) by a polishing step; forming a stem (62) with a length shorter than the radius; (b) producing by a deep drawing process a strut (58) in the form of a rotating body with a hollow cylindrical end, such that the inner diameter of said end is equal to that of the stem; (62), and (c) bend the edge of said end outwards to form a flange (67).
(d) the inner diameter of said end is slightly increased on each side of the remaining ring portion forming an annular shoulder (64); (e) a stem (62) of the ball (61); flange (6
7a) drive through said shoulder (64) until the axial surface of the ball (61) sits on the flat annular surface of the ball (61), and (f) remove the corners using a tool to remove the outer surface of the collar (67a). (59) has a spherical shape that matches the spherical surface of the ball (61).