Bushing, system and method for assembling and disassembling a roller bearing, and rotary electric machine

Abstract

The present invention relates to a system for assembling and disassembling a roller bearing of a rotary electric machine, the system comprising a bushing (2) having a hollow body with a circular cross-section defining a cylindrical inner surface portion (2a) and an outer surface having a cylindrical body portion (6), wherein the hollow body is configured to be arranged on a rotary shaft (1); the outer surface comprises a stop (3a) for limiting the axial movement of a roller bearing (10) arranged on the bushing (2); and the inner surface comprises axial locking means (5) for locking the bushing (2) on the rotary shaft (1).

Description

"BUSHING, SYSTEM AND METHOD FOR ASSEMBLING AND DISASSEMBLING A ROLLING BEARING AND A ROTATING ELECTRIC MACHINE" FIELD OF THE INVENTION

[0001] The present invention relates to a system for mounting and dismounting a roller bearing and to a rotating electrical machine incorporating such a system. FUNDAMENTALS OF THE INVENTION

[0002] Rotating electrical machines are widely known in the engineering field and can include both electric motors and electric generators. It is also well known to those skilled in the art that these machines utilize fixed supports on rotating shafts: so-called roller bearings. These bearings are mechanical support devices that make the transition from a rotating element to a fixed support element.

[0003] In simplified terms, a rolling bearing comprises two concentric raceways or rings with rolling elements arranged between the rings. The rolling elements may include balls, cylindrical rollers, tapered rollers, needles, or any other shapes that allow the elements to roll between the raceways.

[0004] Rolling bearings are widely used in rotating electrical machines with different characteristics, including radial flow, transverse flow, and axial flow machines.

[0005] As those skilled in the art know, one of the drawbacks associated with this type of device is the need to disassemble the rotating electrical machine to replace or maintain the roller bearing.

[0006] In fact, since the bearing is mounted on the machine shaft, it is necessary to disassemble the machine, removing its cover and other components that make up the motor bearing, such as sealing rings, fasteners, and others, so that a bearing extractor tool can be used to remove the device.

[0007] This drawback is particularly prevalent in permanent magnet motors, where the attractive force of the rotor magnets on the stator steel is so high that it necessitates the use of specialized, large-scale equipment for disassembling and reassembling the motor.

[0008] Solutions focused on the assembly and disassembly of a bearing are known in the state of the art.

[0009] Document CN222046428U shows a self-disassembling bearing bushing structure for a double suction pump, comprising a shaft, a bearing, a bearing bushing, a tapered sleeve, and a small round locking nut. The tapered surfaces of the bearing bushing and tapered sleeve allow for interlocking, enabling disengagement when necessary.

[0010] Document CN204878380U shows a pedestal seat with a special sealing washer. The solution features a bearing housing composed of a drain pan and an upper housing, and a multi-lip radial seal.

[0011] WO201479431 A1 document discloses a bearing arrangement with an adapter bushing device comprising an adapter bushing, which has a conical zone having a conically configured outer surface that in the installed state rests on a conically designed inner circumferential surface complementary to the inner bearing ring, and a ring nut for applying an effective bolt force between the inner bearing ring and the adapter bushing.

[0012] The known solutions, however, are specific to a bushing-bearing assembly, requiring a bearing of a specific shape to cooperate with the bushing.

[0013] Thus, the need remains in the art for a bearing mounting and dismounting system that allows for maintenance and / or replacement of the bearing without the need to disassemble and reassemble the machine, and that can be... applied to conventional bearing and shaft formats. OBJECTIVES OF THE INVENTION

[0014] Thus, one of the objectives of the present invention is to provide a system for mounting and dismounting a rolling bearing and a rotating electrical machine incorporating such a system.

[0015] Another objective of the present invention is to provide a bearing mounting and dismounting system that can be used with conventionally shaped bearing housings.

[0016] Another objective of the present invention is to provide a bearing mounting and dismounting system that allows for the maintenance and / or replacement of the bearing without the need to disassemble and reassemble the machine.

[0017] Another objective of the present invention is to provide a bushing for a bearing mounting and dismounting system that allows for the maintenance and / or replacement of the bearing without the need to disassemble and reassemble the machine.

[0018] Another objective of the present invention is to provide a bearing mounting and dismounting system comprising an integrated sealing and grounding solution. BRIEF DESCRIPTION OF THE INVENTION

[0019] The present invention achieves the above objectives by means of a bushing for a rolling bearing of a rotating electric machine of the type comprising a rotating shaft, the bushing comprising a hollow body with a circular cross-section defining a cylindrical inner surface portion and an outer surface with a cylindrical body portion, the hollow body being configured to be disposed over the rotating shaft.

[0020] The outer surface of the bushing comprises a stop to limit the axial movement of a rolling bearing disposed on the bushing, wherein the stop is formed by a circular protrusion on the outer surface of the bushing and a circular wall is formed between the protrusion and a end region of the bushing; and the inner surface of the bushing comprises an axial locking means for locking the bushing onto the rotating shaft.

[0021] The inner diameter of the end region is smaller than the diameter of the threaded region in order to form a guide surface on the inner diameter of the end region, wherein the guide surface orients the bushing on the rotating shaft until the threaded region of the bushing meets the corresponding threaded region of the rotating shaft.

[0022] In one embodiment of the present invention, the end region of the bushing is a region with at least two opposing flat chamfered faces and has a hole for receiving a screw.

[0023] In another embodiment of the present invention, the stop rests against an inner race of the roller bearing.

[0024] The present invention also relates to a mounting and dismounting system for a rolling bearing of a rotating electric machine of the type comprising a rotating shaft, the system comprising a bushing configured to be disposed on the rotating shaft, the bushing comprising a hollow body with a circular cross-section defining a cylindrical inner surface portion and an outer surface with a cylindrical body portion, the outer surface comprising a stop, formed by a circular shoulder, to limit the axial movement of a rolling bearing disposed on the bushing, and an end region, and the inner surface comprising an axial locking means for locking the bushing on the rotating shaft;and a bearing cap configured to be positioned and secured to a cap of the rotating electric machine, wherein an inner diameter of the end region is smaller than a diameter of the cylindrical inner surface portion, so as to form a guide surface on the inner diameter of the end region, the guide surface guiding the bushing on the rotating shaft until the bushing locks onto the rotating shaft.

[0025] A method for assembling a is also provided. bearing housing of a rotating electrical machine of the type comprising a rotating shaft, the method comprising:

[0026] positioning a rolling bearing in a bushing comprising a hollow body with a circular cross-section defining a cylindrical inner surface portion and an outer surface with a cylindrical body portion, the outer surface comprising a stop, formed by a circular shoulder, to limit the axial movement of the rolling bearing, and an end region, and the inner surface comprising an axial locking means for locking the bushing onto the rotating shaft, wherein an inner diameter of the end region is smaller than a diameter of the cylindrical inner surface portion to form a guide surface on the inner diameter of the end region;

[0027] Position the bushing on the rotating shaft, with the guide surface guiding the bushing along the rotating shaft until the bushing locks into place.

[0028] lock the bushing onto the rotating shaft in the threaded areas;

[0029] Position the bearing cap on the rotating electric machine; and

[0030] Secure the bearing cap to a cover of the rotating electric machine.

[0031] In one embodiment of the method of the present invention, the end region of the bushing has a region with at least two opposing flat chamfered faces and a hole, and a step of inserting the screw into the hole is performed after the step of locking the bushing onto the rotating shaft.

[0032] The bearing cap can be attached to the cover of the rotating electric machine with screws. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be described in more detail below, with reference to the accompanying drawings, in which:

[0034] Figure 1 - is a perspective view of a bearing mounting and dismounting system according to an embodiment of the present invention, installed in an electric machine. rotating, with only part of the rotating electric machine being shown;

[0035] Figure 2 - is an exploded perspective view of the bearing mounting and dismounting system according to an embodiment of the present invention;

[0036] Figure 3 - is a cross-sectional view of the bearing mounting and dismounting system according to an embodiment of the present invention;

[0037] Figures 4 (a) and 4 (b) - show the mounting of a roller bearing in a bushing of the roller bearing mounting and dismounting system according to an embodiment of the present invention;

[0038] Figure 5 - is a schematic cross-sectional view of a bearing cap of the bearing mounting and dismounting system according to an embodiment of the present invention; and

[0039] Figure 6 - is a schematic cross-sectional view of the bearing mounting and dismounting system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0040] The present invention will be described below based on a preferred embodiment shown in Figures 1 to 6.

[0041] Although the present detailed description is based on an exemplary embodiment of the invention in which the rotating electrical machine is an electric motor, it should be understood that the bearing mounting and dismounting system of the present invention could be applied to any type of rotating electrical machine, such as, for example, an electric generator. Figure 2 shows the bearing mounting and dismounting system in exploded view.

[0042] The system of the present invention comprises a bushing 2 that is configured to be disposed on the motor shaft 1. In the preferred embodiment of the present invention, the bushing 2 comprises a hollow body with a circular cross-section so as to define a surface portion. an inner cylindrical surface 2a and an outer surface with a cylindrical body portion 6.

[0043] The cylindrical body portion 6 allows for interference mounting of the roller bearing onto the bushing. Furthermore, the cylindrical surfaces of the bushing facilitate machining, simplifying the process.

[0044] In the illustrated embodiment, the outer surface of the bushing has at least one stop 3a to limit the axial movement of the bearing 10. As best illustrated in figure 3, the stop 3a is configured to rest against the inner race 10a of the bearing 10.

[0045] In one embodiment of the invention, the inner race 10a of the bearing 10 is positioned on the bushing 2, its axial movement being limited by the stop 3a. The positioning of the bearing 10 on the bushing 2 can be done hot, by cold pressing, or by any other suitable positioning method. In this regard, it should be noted that the bearing 10 can be a conventional bearing, not requiring any type of shape alteration for mounting on the bushing 2.

[0046] In the embodiment of the invention illustrated in the drawings, the stop 3a is formed by a circular protrusion 3 on the outer surface of the bushing 2, with a circular wall 4 being formed between the protrusion 3 and the end region 7 of the bushing 2.

[0047] As best illustrated in Figure 3, in a preferred embodiment of the present invention, the bushing further comprises an axial locking means.

[0048] In the embodiment illustrated in the figures, the locking means comprises a threaded connection, wherein the inner surface of the bushing has a threaded region 5 configured to be threaded into a corresponding threaded region of the shaft.

[0049] However, in alternative embodiments of the present invention, other axial locking means could be used, such as, For example, a keyway connection, splines, by means of the use of a KMT type nut.

[0050] The inner diameter of the end region 7 is smaller than the diameter of the cylindrical inner surface portion 2a, so a guide surface 7a is formed on the inner diameter of the end region 7. The guide surface 7a guides the bushing 2 on the rotating shaft 1 for mounting on the shaft.

[0051] In this sense, the cylindrical shape of the cylindrical inner surface portion 2a allows for its free movement on the shaft, and the limitation of free movement is linked to the bearing mounting, allowing it to be positioned in a controlled manner, and without adding a new interface to the sum of tolerances.

[0052] In the embodiment shown in the figures, the end region of bushing 7 is a region with hexagonal portions, with at least two opposite flat chamfered faces to allow the use of a wrench.

[0053] Naturally, the end region 7 could have other shapes, such as an eight-sided flat octagon, and the means of attachment and removal could be any suitable means, such as a socket wrench type clamping machine.

[0054] The end region 7 may also include a hole 8 for receiving a screw 9. In alternative embodiments, other axial locking elements could be used, such as a retaining ring.

[0055] Figures 4 to 6 show schematically the assembly of the roller bearing.

[0056] Thus, figure 4(a) shows bushing 2 mounted on shaft 1 (the shaft being partially illustrated) and figure 4(b) shows bushing 2 before it is mounted on the shaft.

[0057] Thus, in figure 4(b), bearing 10 is positioned on bushing 2, so that the inner race 10a rests against stop 3a.

[0058] Bushing 2 is then positioned on the shaft, with the surface Guide 7a guides the bushing until it reaches the locking position.

[0059] Bushing 2 is then locked onto the shaft (see figure 3) and a screw 9 is inserted into hole 8, as shown in figure 4(b). As mentioned earlier, axial locking could be achieved by another means, such as by a retaining ring located adjacent to the bushing towards the end of the shaft.

[0060] After threading the bushing 2, a bearing cap 13 is positioned and secured to the machine cover 15 (see figures 5 and 6).

[0061] Figure 5 shows an exemplary embodiment of bearing cap 13. It should be understood, however, that other types of caps and sealing and grounding configurations could be used within the scope of the present invention.

[0062] Figure 5 shows an exemplary embodiment of the bearing cap 13. It should be understood, however, that other types of caps and sealing and grounding configurations could be used within the scope of the present invention. The bearing cap 13 is fastened to the machine cover 15 with screws 16 and a shim 18 may be used (see Figure 6). It should be noted, however, that the cap could be fastened in another way, such as by a snap-fit ​​or using a retaining ring.

[0063] As illustrated in figures 2 and 6, at least one retainer 14, a spring 11 and a shaft ground 12 are mounted on the bearing cap 13. It should be noted that, as mentioned earlier, the cap could have a different configuration.

[0064] Figure 6 shows the bearing assembly with the bearing cap 13 mounted on the machine cover 15, wherein, in the embodiment illustrated, the bearing cap 13 is fastened to the machine cover 15 with screws 16. It should be noted, however, that the cover could be fastened in another way, such as by a press fit or using a retaining ring.

[0065] As can be seen in this figure, in the illustrated embodiment, After assembly, at least one retainer 14 rests between the cover 13 and the circular protrusion 3, and the shaft grounding 12 rests between the cover 13 and a seating area 17 formed between the circular protrusion 3 and region 7. Thus, in the solution of the present invention, the bushing 2 assists in sealing the assembly.

[0066] It should be noted, however, that the retainer and grounding can be positioned in reverse, that is, the retainer resting against seat 17 and the grounding resting between cover 13 and circular protrusion 3. Furthermore, the solution could employ more than one retainer or grounding.

[0067] For disassembly of the machine, the steps are the reverse of assembly: the bearing cap is removed, the axial locking mechanism (in the illustrated figures, screw 9) is removed, the key 5 is removed, and the bearing 10 is removed from the bushing 2.

[0068] The solution of the present invention thus makes it possible to replace the bearing assembly without the need to disassemble the motor, eliminating the need to remove the machine cover 15 and the use of a bearing extractor tool.

[0069] Thus, the system of the present invention, with the provision of the bearing bushing and the bearing cap, provides a solution that allows the bearing to be mounted and dismounted from the machine in a simple manner, simply by removing the bearing cap and without the need to disassemble the machine cover.

[0070] Having described a preferred embodiment of the present invention, it should be understood that the scope of the present invention encompasses other possible variations of the inventive concept described, limited only by the content of the claims, including possible equivalents.

Claims

CLAIMS 1. Bushing (2) for a rolling bearing of a rotating electric machine of the type comprising a rotating shaft (1), the bushing being characterized in that it comprises: a hollow body with a circular cross-section defining a cylindrical inner surface portion (2a) and an outer surface with a cylindrical body portion (6), the hollow body being configured to be disposed on the rotating shaft (1); the outer surface comprising a stop (3a) for limiting the axial movement of a rolling bearing (10) disposed on the bushing (2), wherein the stop (3a) is formed by a circular shoulder (3) on the outer surface of the bushing (2) and a circular wall (4) is formed between the shoulder (3) and an end region (7) of the bushing; the inner surface further comprising an axial locking means (5) for locking the bushing (2) on the rotating shaft (1);and an inner diameter of the end region (7) is smaller than a diameter (2a) so as to form a guide surface (7a) on the inner diameter of the end region (7), wherein the guide surface (7a) guides the bushing (2) on the rotating shaft (1) until a locking position of the bushing (2) on the rotating shaft (1).; 2. Bushing (2), according to claim 1, characterized in that the stop (3a) rests against an inner race (10a) of the bearing housing (10).

3. Bushing (2), according to either of claims 1 or 2, characterized in that the end region (7) of the bushing is a region with at least two opposite flat chamfered faces and comprises a hole (8) for receiving a screw (9).

4. Mounting and dismounting system for a rolling bearing of a rotating electric machine of the type comprising a rotating shaft (1), the system being characterized in that it comprises: a bushing (2) configured to be disposed on the rotating shaft (1), a bushing comprising a hollow body with a circular cross-section defining a cylindrical inner surface portion (2a) and an outer surface with a cylindrical body portion (6), the outer surface comprising a stop (3a), formed by a circular shoulder (3), to limit the axial movement of a rolling bearing (10) disposed on the bushing (2), and an end region (7), and the inner surface comprising an axial locking means (5) for locking the bushing (2) on the rotating shaft (1); and a rolling bearing cover (13) configured to be positioned and fixed to a cover (15) of the rotating electric machine;wherein an inner diameter of the end region (7) is smaller than a diameter of the cylindrical inner surface portion (2a) so as to form a guide surface (7a) on the inner diameter of the end region (7), wherein the guide surface (7a) guides the bushing (2) on the rotating shaft (1) to a locking position of the bushing (2) on the rotating shaft (1).

5. System according to claim 4, characterized in that the stop (3a) rests against an inner race (10a) of the bearing housing (10).

6. System, according to claim 4 or 5, characterized in that one end of the bushing has a region with at least two opposite flat chamfered faces and a hole (8) for receiving a screw (9) and in which the seating area (17) is formed between the circular shoulder (3) and the end region (7).

7. Method for assembling a rolling bearing of a rotating electric machine of the type comprising a rotating shaft (1), the method being characterized in that it comprises: (I) positioning a rolling bearing (10) in a bushing (2) comprising a hollow body with a circular cross-section defining a cylindrical inner surface portion (2a) and an outer surface with a cylindrical body portion (6), the outer surface comprising a stop (3a), formed by a circular shoulder (3), to limit the axial movement of the rolling bearing (10) and an end region (7), and the inner surface comprising an axial locking means (5) for locking the bushing (2) on the rotating shaft (1), wherein an inner diameter of the end region (7) is smaller than a diameter of the cylindrical inner surface portion (2a) so as to form a guide surface (7a) on the inner diameter of the end region (7); (II) position the bushing (2) on the rotating shaft (1), with the guide surface (7a) guiding the bushing (2) on the rotating shaft (1) until the bushing (2) locks onto the rotating shaft (1); (III) lock bushing (2) on rotating shaft (1); and (IV) position the bearing cap (13) on the rotating electric machine; and (V) fix the bearing cap (13) to a cover (15) of the rotating electric machine.

8. Method according to claim 7, characterized in that the end region (7) of the bushing is an end region (7) with at least two opposite flat chamfered faces and has a hole (8) for receiving a screw (9).

9. Method according to claim 7 or 8, characterized in that the step of fixing the bearing cap (13) to a cover (15) of the rotating electric machine comprises fastening the bearing cap (13) to the cover (15) of the rotating electric machine with screws (16).

10. Rotating electric machine of the type comprising a housing that houses an active core with a rotor and a stator, the rotor being mounted on a rotating shaft, characterized in that it comprises a bearing mounting and dismounting system as defined in any one of claims 4 to 6.

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