CN110062661B

CN110062661B - Centrifugal separator

Info

Publication number: CN110062661B
Application number: CN201780078726.9A
Authority: CN
Inventors: P.卡尔松
Original assignee: Alfa Laval Corporate AB
Current assignee: Alfa Laval Corporate AB
Priority date: 2016-12-20
Filing date: 2017-12-18
Publication date: 2021-04-20
Anticipated expiration: 2037-12-18
Also published as: EP3338897B1; CN110062661A; EP3338897A1; WO2018114833A1

Abstract

A centrifugal separator, comprising: a centrifugal rotor (4); a rotatable spindle (1), to which rotatable spindle (1) the centrifugal rotor (4) is fixedly attached; a fixed frame member (7); at least one bearing (3) journaling the main shaft (1) in the fixed frame part (7); a support arrangement (6) comprising a bearing holder (9) directly supporting the bearing (3). The bearing holder (9) is connected to the fixed frame part (7) by an annular elastic support part (8), which annular elastic support part (8) has an inner annular portion (8a) connected to the bearing holder (9) and an outer annular portion (8b) connected to the fixed frame part (7), thereby forming an elastic connection between the bearing holder (9) and the frame part (7).

Description

Centrifugal separator

Technical Field

The invention relates to a centrifugal separator comprising: a centrifugal rotor; a rotatable spindle rotatable about an axis, the centrifugal rotor being fixedly attached to the rotatable spindle; a fixed frame member; at least one bearing journaling the spindle in the fixed frame member; a support device including a bearing holder directly supporting the bearing.

Background

Conventional spindle support devices for centrifugal separators are mainly of two different kinds, namely, a support device in which a coil spring applies a force to an oscillation damping friction damper and a support device constructed of an elastic rubber element which produces a damping effect by internal friction.

Such known support devices comprise many components which make them complex and expensive. The damping characteristics of the friction damper and the rubber element are difficult to calculate. A coating (coke) is formed on the frictional damping surfaces, which changes the damping characteristics and causes a great risk with regard to clogging. Wear particles are formed in the friction buffer, which shorten the life of the support device. In these known supporting means, the heat conduction is insufficient, because the rubber has a low heat conductivity and the friction surface of the friction buffer deteriorates the heat conduction.

WO89/10794 discloses an example of such a known support device for a centrifugal separator having a centrifuge rotor which is rotatable in a frame part by means of a bearing member. The support arrangement includes a plurality of support members extending radially outwardly from the bearing member and each surrounding a helical spring element. Thus, the support members are arranged to allow relative radial movement between the centrifuge rotor and the frame member by compression in the respective spaces of the frame member. The helical spring element thus acts on a piston which is movable in the space and which abuts against the outer wall of the bearing housing. A certain stiffness of the known support device is obtained by means of the spring constant of the helical spring elements, which stiffness together with, for example, the elasticity of the rotor spindle determines a critical value for the revolution of the centrifuge rotor. In centrifugal separators, helical springs of this type have to be dimensioned for the often very high stress and fatigue risk to which they are subjected.

WO99/46052 discloses a known support device similar to the support device described in WO 89/10794. In several different embodiments, the helical spring elements are embedded in an elastic rubber.

Damping of the radial movement is obtained by means of the friction occurring between the piston and its contact surface, in particular the outer wall of the bearing housing. In addition to damping of the relative movement, the friction that occurs also leads to heating. Such heating is undesirable and forces the bearing to operate at relatively high temperatures, which shortens the life of the bearing. Another problem is that the arrangement for moving the piston is rather space-demanding. Such space may be difficult to provide for a support device in the centrifugal separator, especially outside a so-called middle bearing. In addition, these known support devices have a rather complex construction, which of course makes the manufacturing and installation labour demanding and expensive. In addition, it is difficult to conduct heat away from the bearing components.

Disclosure of Invention

The object of the present invention is to provide a support device which is less complex from a constructional point of view than the support devices known so far and by means of which the above-mentioned problems can be remedied. Further aspects of the invention are apparent from the dependent claims and the description.

This object is achieved by the initially defined support device, which is characterized in that the bearing holder is connected to the fixed frame part by an annular (ring-formed) resilient support member having an inner annular portion connected to the bearing holder and an outer annular portion connected to the fixed frame part, thereby forming a resilient connection between the bearing holder and the frame part.

A support device designed in this way saves space compared to similar support devices known previously. Furthermore, the resilient features are evenly distributed around the circumference of the main shaft.

The resilient support member may have an annular central portion with an annular surface free from contact with the bearing retainer and the fixed frame member.

The inner annular portion of the resilient support member may be fitted (fitted) in an annular radially inner space in the bearing holder, and the outer annular portion of the resilient support member is fitted in an annular outer space in the fixed frame member.

The inner annular portion of the resilient support member may engage with annular inner plates on axially upper and lower annular surfaces, respectively, of the inner annular portion, and the outer annular portion of the resilient support member engages with annular plates on axially upper and lower annular surfaces, respectively, of the outer portion of the resilient support member.

The annular inner plate and the annular outer plate may be made of a metal material.

The annular inner plate and the annular outer plate may be heat-patched to the elastic support member.

The annular inner plate and the annular outer plate may be bonded to the elastic support member.

The elastic support member may be made of rubber.

The fixed frame component may include an annular outer cover attached to the frame component by screws, the annular outer cover defining the annular outer space together with the frame component.

The bearing retainer may include an annular inner cover attached to the bearing retainer by screws, the annular inner cover partially defining the annular interior space.

Drawings

The invention will now be explained by means of different embodiments described as examples and with reference to the accompanying drawings, in which:

fig 1 discloses schematically a side view of a part of a centrifugal separator with a support device according to the invention.

Fig. 2 discloses a radial section through a support device according to the invention.

Detailed Description

Fig. 1 discloses schematically part of a centrifugal separator with a vertical spindle 1, which vertical spindle 1 is journalled in a lower bearing 2 and an upper bearing 3. The lower bearing 2 is most often arranged to absorb substantially radial forces acting on the main shaft 1 and the upper bearing 3 is most often arranged to absorb substantially radial and axial forces acting on the main shaft 1. The main shaft 1 carries a centrifuge rotor 4 at its upper end above an upper bearing 3. The spindle 1 and the centrifuge rotor 4 are rotatable about an axis of rotation x and in the disclosed example are driven by a motor (not shown) via a helical gear 5, but may of course instead be driven directly or by a belt by a motor acting directly on the spindle.

In the example disclosed in fig. 2, the upper bearing 3 is supported by means of a support arrangement 6, which support arrangement 6 comprises a bearing holder 9 directly supporting the outer bearing ring 3a and a substantially fixed frame part 7. The bearing holder 9 is connected to the fixed frame part 7 by an annular elastic support part 8. An annular resilient support member 8 has an inner annular portion 8a connected to the bearing holder 9 and an outer annular portion 8b connected to the fixed frame member 7, thereby forming a resilient connection between the bearing holder 9 and the frame member. The resilient support member 8 may be made of rubber or any resilient material with suitable characteristics.

The fixed frame part 7 comprises an annular outer cover 7a, which annular outer cover 7a may be a separate component attached to the frame part 7 by screws or may be part of said frame part 7. Together they define an annular radially outer space 7b which is open radially inwards. The bearing retainer 9 comprises an annular inner cover 9a, which annular inner cover 9a may be a separate member attached to the bearing retainer 9 by screws, or may be part of said bearing retainer 9. Together they define an annular radially inner space 9b which is open radially outwards.

The inner annular portion 8a of the elastic support member 8 is fitted in the annular inner space 9b in the bearing holder 9, and the outer annular portion 8b of the elastic support member 8 is fitted in the outer space 7b in the frame member 7.

The annular central portion 8c of the elastic support member 8 is positioned radially between the inner space 9b and the outer space 7b, forming a region of the elastic support member 8 whose annular surface is free from contact with the bearing holder 9 and the fixed frame member 7. The bearing holder 9 and the frame part 7 thus do not have any metallic contact with each other. The support means 6 is thereby arranged to allow limited pivotal movement of the main shaft 1 and parts (tails) connected thereto, such as the centrifuge rotor 4 and the upper bearing 3, relative to the frame member 7.

To further enhance the function of the support means 6, as shown in fig. 2, the elastic support member 8 can cooperate with annular inner plates 10 on axially upper and lower annular surfaces, respectively, of said inner annular portion 8a of the elastic support member 8, and with annular outer plates 11 on axially upper and lower annular surfaces, respectively, of the outer annular portion 8b of said elastic support member 8. The inner and

outer plates

10, 11 are preferably metal and are hot-patched or glued to the elastic support members 8 to form a complete elastic bumper.

Without the inner plate 10 and the outer plate 11, the resilient support member 8 will wear much because of much relative movement between the resilient support member 8 and the frame member 7 when the centrifuge rotor 4 generates a dynamic force on the resilient support member 8.

Claims

1. A centrifugal separator, comprising: a centrifugal rotor (4); a rotatable spindle (1) rotatable about an axis, the centrifugal rotor (4) being fixedly attached to the spindle (1); a fixed frame member (7); at least one bearing (3) journaling the main shaft (1) in the fixed frame part (7); -a support device (6) comprising a bearing holder (9) directly supporting the bearing (3), the bearing holder (9) being connected to the stationary frame part (7) by an annular elastic support part (8), the annular elastic support part (8) having an inner annular portion (8a) connected to the bearing holder (9) and an outer annular portion (8b) connected to the stationary frame part (7), thereby forming an elastic connection between the bearing holder (9) and the stationary frame part (7), characterized in that the inner annular portion (8a) of the elastic support part (8) cooperates with an annular inner plate (10) on an axially upper and lower annular surface, respectively, of the inner annular portion (8a) and the outer annular portion (8b) of the elastic support part (8) cooperates with an annular inner plate (10) on the axially upper and lower annular surface, respectively, of the elastic support part (8), and the outer annular portion (8b) of the elastic support part (8) respectively (8b) And annular outer plates (11) on the axially upper and lower annular surfaces of the housing.

2. A centrifugal separator according to claim 1, wherein the resilient support member (8) has an annular central portion (8c) the annular surface of which is free from contact with the bearing holder (9) and the stationary frame member (7).

3. A centrifugal separator according to claim 1 or 2, wherein the inner annular portion (8a) of the resilient support member (8) fits in an annular radially inner space (9b) in the bearing holder (9), and the outer annular portion (8b) of the resilient support member (8) fits in an annular radially outer space (7b) in the stationary frame member (7).

4. A centrifugal separator according to claim 1, wherein the annular inner plate (10) and the annular outer plate (11) are made of a metallic material.

5. A centrifugal separator according to claim 1, wherein the annular inner plate (10) and the annular outer plate (11) are heat-repaired to the resilient support member (8).

6. A centrifugal separator according to claim 1, wherein the annular inner plate (10) and the annular outer plate (11) are glued to the resilient support member (8).

7. A centrifugal separator according to claim 1 or 2, wherein the resilient support member (8) is made of rubber.

8. A centrifugal separator according to claim 1, wherein the stationary frame part (7) comprises an annular outer cover (7a) attached to the stationary frame part (7) by screws, the annular outer cover (7a) defining the annular radially outer space (7b) together with the frame part.

9. A centrifugal separator according to claim 1, wherein the bearing holder (9) comprises an annular inner cover (9a) attached to the bearing holder (9) by screws, the annular inner cover (9a) defining the annular radially inner space (9b) together with the bearing holder (9).