FR3011895A1 - CUSHION ASSEMBLY, BUSHING SUPPORT FOR A CIRCULATION PUMP - Google Patents

Abstract

The invention relates to a method of manufacturing a bearing assembly (22), bushing support for a motor shaft of a flooded rotor fluid circulation pump comprising the steps of providing the one of a pad (30) and a pad holder (32), and making the other one of a pad holder (32) and a pad (30) by overmolding said one of the pad (30) and the pad holder (30). pad (32). The invention also relates to a bearing assembly, bearing support obtained by this method, a rotor assembly comprising such a bearing assembly, bushing support and a circulating pump of a flooded rotor fluid comprising such a rotor assembly.

Description

The present invention relates to a bearing assembly, a bearing support, a method for manufacturing such an assembly, a rotor assembly for a motorized rotor pump with a drowned rotor, and a rotor assembly. a motor pump with flooded rotor. Fluid impeller pumps are used in climatic engineering, particularly in hot water heating systems, in the looping of domestic hot water distribution circuits, as well as in renewable energy installations (solar, pumps heat, air conditioning, ...). In the rotor motor technology used for circulation pumps, the rotor of the motor is in a so-called rotor cavity filled with the fluid conveyed by the pump. The rotor cavity is filled with the fluid for reasons of lubrication of the bearings (or bearings) supporting the rotor shaft, engine cooling, and operating silence, while avoiding the presence of air in the fluid, which would cause an increase in operating noise. However, because of their use in a heating installation, the circulation pumps are subjected to significant thermal stresses. As a result, the components of these pumps can expand and undergo creep type deformations. As a result, the fixing of the components of these circulation pumps, conventionally made by shrinking, does not ensure the maintenance of these components in place and, therefore, the integrity of these circulation pumps. This problem is particularly sensitive for the attachment of the pads on the bearing supports. The bushings receive the shaft which makes it possible to drive the turbine in rotation by means of the motor while the bearing supports are intended to hold the said bearings in position. As a result, when the attachment of the pad relative to the bearing support can no longer ensure the maintenance in position of these elements, the bearing support is inoperative and the position of the pad is likely to be modified. The pad no longer performs its function and there is a risk of premature damage to the circulation pump. There is therefore a need for a means of ensuring the positioning of the pads relative to the bearing supports, which is less sensitive to thermal stresses than the hooping. The object of the present invention is to provide a method of manufacturing a bushing assembly, bearing support, having increased thermal stress resistance. For this purpose, the invention proposes a method of manufacturing a pad assembly, bearing support. for a motor shaft of a flooded rotor fluid circulation pump comprising the steps of: - providing one of a bearing and a bearing support, and - producing the other from a support of pad and a cushion overmolding said one of the pad and the pad support. According to preferred embodiments, the method according to the invention has one or more of the following characteristics, taken alone or in combination: the method comprises the steps of: providing a pad support, and producing the pad by overmolding cushion support; the method comprises the steps of: providing a pad, and making the pad support by overmolding the pad; said one of the pad and the pad holder which is overmoulded to make the other one of the pad support and the pad, has a relief, preferably axial splines, to prevent the rotation of the other one of the pad carrier. pad and pad, relative to said one of the pad and the pad pad; overmolding is performed so as to leave axial openings in the bearing support; - The bearing support comprises at least one radial projection, made during overmoulding if necessary; - The bearing support has at least one recess on its radially outer surface; the at least one radial projection extends in said at least one recess; - said bearing support comprises a housing, made during overmoulding if necessary, adapted to cooperate with a lug of a filter element for fixing the filter element relative to said bearing support; and - the bearing support comprises, on a radially outer face, a fluid passage section, made during overmoulding if necessary. The invention also relates to a pad assembly, pad support obtained by a method as described above, in all its combinations.

The invention also relates to a rotor assembly for a flooded motor motor circulating pump comprising: - a cavity-forming cartridge, R: \ 34500 \ 34519 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 11 2/12 519 PSL 3 - two sets of bearings, bearing support as described above, received in the cavity in the cartridge, and - a shaft associated with a rotor in the cavity in the cartridge, the shaft being received in the bushings of the bushing assemblies, bearing support and extending partly outside the cavity in the cartridge. The rotor assembly may further include a filter element closing the cavity in the cartridge. The filter element may be attached to a bearing support of a bearing assembly, bearing support.

Finally, the invention relates to a circulating pump motor with an impeller, comprising: - a pump body comprising a stator, - a rotor assembly as described above, in all its combinations, fixed in the pump body such that the rotor associated with the shaft is substantially disposed in the middle of the stator, and - a turbine on the portion of the shaft extending outside the cavity of the cartridge. Other features and advantages of the invention will appear on reading the following description of preferred embodiments of the invention, given by way of example and with reference to the appended drawings, which show: FIG. a partial representation in axial section of an exemplary rotor assembly for a circulating pump motor with canned rotor; - Figure 2, a perspective representation of a broken view of the rotor assembly of Figure 1, devoid of its rotor; FIG. 3, a first bushing assembly, bushing support implemented in the rotor assembly of FIGS. 1 and 2, FIG. 4, a second bushing assembly, bushing support used in the rotor assembly of FIGS. 1 and 2, - Figure 5, the steps of fixing a floating ring on the bearing assembly, bearing support of Figure 4, - Figure 6, a partial representation in axial section of a second example of rotor assembly, and - Figure 7, a representation in axial section of a third example of a rotor assembly.

In the remainder of the description, the elements that are identical or of identical function bear the same reference sign. For the sake of brevity of the present description, the elements identical to the various examples are not described with regard to each one of the following: PSL \ 34519--131011-dde tq filed.docx 13/10/11 3/12 519 PSL 4 of these examples. In other words, only the differences between the different examples are described in detail, the common elements being described with regard to a single example. FIG. 1 shows a rotor assembly 10 for a flooded motor motor circulation pump. This rotor assembly 10 essentially comprises: a cartridge 12, for example made of composite material (such as PES - for Polyethersulfone - or PPS - for phenylene Polysulfide), stainless steel or PES loaded with carbon fiber, having a face before 14 substantially flat, the cartridge defining a cylindrical cavity 16 opening at the front face 14 of the cartridge 12, the cavity being closed at its rear end, opposite its outlet in the front face 14 of the cartridge 12, - a shaft 18 received in the cavity 16 so that an end 20 of the shaft 18 extends outside the cavity 16, the shaft 18 being hollow to allow the flow of fluid from the bottom of the cavity 16 to the 20 end of the shaft 18 which extends outside the cavity 16, - a rear assembly 22 and a front assembly 24 bearing bushing support which are intended to guide the shaft 18 in rotation and to maintain it in posit ion in the cavity 16, - a rotor 26, made by a coil or a permanent magnet, cylindrical, integral in rotation with the shaft 18, and - a filter element 28 closing the cavity. Here, the filter element 28 is a floating ring. Alternatively, the filter element 28 may be a shutter, a lip seal or a filter closing the cavity 16. The rotor assembly 10 may in particular be manufactured as will be explained below. We begin by making the two sets 22, 24 pad, bearing support as shown in Figures 3 and 4.

To do this, a pad 30 is provided and the pad support 32 is molded onto the pad 30. In other words, the pad is overmoulded to form the pad support 32. This is particularly advantageous. Indeed, the realization of the bearing support 32 by overmolding the bearing 30 provides a reliable and homogeneous fixation of these two parts, even in the case of high thermal stresses. The bearing support 32 may for example be made of graphite or ceramic. PSL To prevent rotation of the bearing support 32 relative to the bushing 30, the bushing 30 may be provided with grooves 34. As shown in FIG. , in particular axial grooves, visible on the partial section shown in FIG. 1. Of course, other reliefs can be imagined which also make it possible to prevent rotation of the bearing support 32 with respect to the pad 30 and which can be overmolded . In addition, the embodiment of the bearing support 32 by overmolding the bearing 30 makes it possible to provide a bearing assembly 22, 24, bearing support having many features and advantageous functions for such an assembly. Thus, for example, the over-molding of the pad 30 to form the pad support 32 can be performed so that the latter has recesses 36 on its radially outer surface 37. In this case, the bearing pad 32 of the assembly rear 22 comprises four such recesses 36, while the bearing support 32 of the front assembly 24 has only two. The recesses 36 are intended to receive bosses 38 (see FIG. 2) formed on the inside wall of the cavity 16 in the cartridge 12, to prevent or at least limit the rotation of the pad assembly, pad support relative to the cartridge 12. The angular position of the assemblies 22, 24 in the cavity 16 of the cartridge 12 is thus ensured. It should be noted that it is possible to leave a clearance between the bosses of the inner wall of the cavity of the cartridge and the recesses of the outer surface of the bearing support, in order to allow the circulation of fluid in the cavity. The overmolding of the pad 30 may also be made in such a way that the pad support 32 has orifices 39 intended to allow the circulation of fluid in the cavity 16 of the cartridge 12. The overmolding of the pad 30 may be made in such a way that the support pad 32 is adapted to receive deflectors for guiding the flow of fluid in the cavity 16 of the cartridge 12 and / or filter elements for filtering the fluid flowing in the cavity 16. In addition, the overmolding of the pad 30 may be made so that the bearing support 32 has a complex shape, for example two crowns - at least partial - connected by a core, so that the bearing assembly, bearing support can absorb high axial and radial clamping stresses . There is thus generally a first radially inner ring delimiting the receiving housing of the pad and a second radially outer ring having the elements necessary for fixing the pad assembly, pad support in the cavity in the cartridge. Thus, the overmolding of the pad 30 may be made to form one or more radial pins 40. These radial pins 40 preferably extend in one of the following directions: The radial lugs 40 are intended to penetrate into a corresponding housing 42 formed in the wall of the cavity 16 of the cartridge 12. , to clip the bearing assembly, bearing support into the cavity 16. Thus, the axial position of the bearing assembly, bearing support is ensured. In the case where the radial lugs 40 extend into the recesses 36 formed in the radially outer surface of the bearing support, then the housings 42 are formed in the bosses 38 formed on the inner wall of the cavity 16 in the cartridge 12. The front pad assembly 24, bearing support is further provided to form a means for fixing the filter element 28. To do this, the pad support 32 is made by overmolding the pad 30 so as to form two opposed housings 44 formed in radially inwardly projecting surfaces. The filter element 28 has appendices 46 of corresponding shape. The filtration element 28 is thus fixed on the bearing support 32 by implementing a bayonet-type fastening system: the appendices 46 are passed into the empty ring-shaped surface in which the two projection surfaces extend radially inward. Then the floating ring 28 is rotated relative to the bearing support, until the appendices 46 are clipped into the housings 44. To facilitate the clipping of the appendages 46 in the housings 44, the adjacent surface of these housings can be beveled to promote the Another difference to the front assembly 24 is that a passage section 48 may be formed on the radially outer surface 38 of the pad support to allow for the flow of non-fluid. filtered by the filter element 28 in the cavity. The cross section of the passage section is less than 1 mm 2. In addition, the passage section is here made in the form of a longitudinal groove on the radially outer surface of the bearing support. However, this passage section may take other forms, such as a circumferential groove, on the radially outer surface of the bearing support.

Figure 6 illustrates a second example 100 of rotor assembly. The rotor assembly 100 according to this second embodiment differs from the first by the manner of proceeding to manufacture the assemblies before 22 and back 24 pad, bearing support. Here, in fact, to produce these assemblies, there is provided a bearing support 32 (having all the features described above with respect to the first example) and the pad 30 is produced by overmolding the bearing support 32. The bearing support may in particular be made by molding, in particular if it is a composite material PSL 7 composite 34.519 PSL 7 34519 PSL 7 34519-131011-dde tq filed. The pad is made by overmolding the pad support, preferably using a material having good tribological characteristics such as PEEK - for Polyetheretherketone - or POM - Polyoxymethylene. Again, in doing so, it provides a reliable and durable attachment of the pad relative to the bearing support. In addition, this solution makes it possible to reduce the quantity of material having good tribological characteristics necessary to form the assembly since it only covers the bearing support. FIG. 7 illustrates finally a third example 200 of rotor assembly, set up in a circulation pump. In this third example 200, the bearing supports 32 are made of a material that is resistant to compression, is not very sensitive to creep and accepts overmolding, such as, for example, metal - typically brass - sintered material or even ceramic. The bearing supports 32 can then be made by machining, shrinking, stamping or molding, in particular, depending on the case. As for the second example, the bearing supports 32 here have a T-section, the horizontal bar of the T being entirely received in a groove of complementary section formed by the bearing 30. This can be easily achieved when the bearing 30 is made of Overmolding the bearing support 32. This shape cooperation of the pad and the bearing support ensures the relative position of these parts. Furthermore, according to the third example shown, the rear pad 30 does not have a lug 40 adapted to cooperate with a housing formed in the cartridge 12. Of course, alternatively, the pad 30 front or rear can have such a lug, the cartridge then having a complementary housing. Finally, the cartridge 12 is, in the third example, made in the form of a plug 202 (or flange) which blocks a rear end of a liner 204, a part 206 forming the front face 14 of the cartridge 12 being welded to the jacket, at its end opposite the plug 202. The plug 202 is welded to the jacket 204. The welds are made so as to make the cartridge 12 tight. It should be noted that the cartridge could also be made in one piece in this third example, as in the first and second examples presented. Similarly, the cartridge according to the first and second examples presented could also be formed as indicated above by three parts welded in pairs, as shown in FIG. 7. The rotor assemblies 10, 100, 200 can in particular be implemented in a flooded motor motor pump. To manufacture such a pump from this rotor assembly, it is sufficient to fix the rotor assembly. in a pump body comprising a stator such that the rotor associated with the shaft is substantially disposed in the middle of the stator, and to fix a turbine on the portion of the shaft which extends out of the cavity of the cartridge . The rotor assembly may in particular be mounted in a sealed air gap tube, itself mounted in a manner fitted radially inside the stator. Of course, the present invention is not limited to the examples described above but is capable of numerous variants accessible to those skilled in the art. Thus, the shaft 18 is not necessarily hollow but may, on the contrary, be full.

A: \ 34500 \ 34519 PSL \ 34519-131011-d of tq filed.docx 13/10/11 8/12

Claims (15)

REVENDICATIONS1. A method of manufacturing an assembly (22; 24) pad, bearing support for a shaft (18) of a motor of a flooded rotor fluid pump comprising the steps of: - providing the one of a pad (30) and a pad holder (32), and the other of a pad holder (32) and a pad (30) by overmolding said one of the pad (30) and the pad holder (30). pad (32). 10 The method of claim 1, comprising the steps of: - providing a bearing support (32), and - producing the bearing (30) by overmolding the bearing support (32). 15 The method of claim 1, comprising the steps of: - providing a pad (30), and - providing the pad support (32) by overmolding the pad (30). The method of one of claims 1 to 3, wherein said one of the pad (30) and the pad pad (32) is overmoulded to provide the other one of the pad pad (32) and the pad (30) has a relief (34), preferably axial splines, to prevent rotation of the other one of the pad support (32) and the pad (30) relative to said one of the pad (30). ) and the bearing support (32). 25 5. A method according to any one of claims 1 to 4, wherein the overmolding is performed to leave axial openings (39) in the bearing support (32). 30 6. Method according to any one of claims 1 to 5, wherein the bearing support (32) comprises at least one radial projection (40), made during overmoulding if necessary. The method of any one of claims 1 to 6, wherein the bearing support (32) has at least one recess (36) on its radially outer surface (37). A: \ 34500 \ 34519 PSL \ 34519-131011-dde tq filed.docx 13/10/11 9/12519 PSL 10 The method of claims 6 and 7, wherein the at least one radial projection (40) extends into said at least one recess (36). 9. A method according to any one of the preceding claims, wherein said bearing support (32) comprises a housing (44), made during overmolding where appropriate, adapted to cooperate with a lug (46) of a filter element. (28) for fixing the filter element (28) with respect to said bearing support (32). 10. A method according to any one of the preceding claims, wherein the bearing support (32) comprises, on a radially outer face (37), a fluid passage section (48), made during overmolding where appropriate. 11. Assembly (22; 24) pad, pad holder obtained by a method according to any one of claims 1 to 10. 12. Rotor assembly (10; 100; 200) for an impeller motor driven circulating pump comprising: - a cartridge (12) forming a cavity (16), - two sets (22; 24) bearing bush, bearing support Claim 11, received in the cavity (16) in the cartridge (12), and - a shaft (18) associated with a rotor (26) in the cavity (16) in the cartridge (12), the shaft (12), 18) being received in the bushings (30) of the bushing assemblies (22; 24), bearing support and extending partly outside the cavity (16) in the cartridge (12). 25 The rotor assembly of claim 12, further comprising a filter element (28) closing the cavity (16) in the cartridge (12). A rotor assembly according to claim 13, wherein the filter element (28) is attached to a bearing support (32) of a bearing assembly (24) bearing support. 15. Motor pump with an impeller rotor, comprising: - a pump body comprising a stator, - a rotor assembly (10; 100; 200) according to one of claims 12 to 14, fixed in the pump body such that the rotor associated with the shaft is substantially disposed in the middle of the stator, and R: \ 34500 \ 34519_101011-dde tq filed.docx 13/10/11 10/12 19 PSL 11 a turbine on the portion of the shaft extending outside the cavity of the cartridge. RA34500 \ 34519 PSL \ 34519--131011-d of tq filed.docx 13/10/11 11/12