HRP20020359A2 - Bearing protection assembly for motors - Google Patents

Description

Field of invention

The invention is from the field of mechanical engineering.

This invention belongs to the field of bypassed vacuum motors. In particular, the invention relates to motor bearing protection systems used with water based vacuum cleaners such as those used to collect spills or those used to clean carpets with a water system. In particular, the invention relates to a system for protecting bearings that prevent water or water-rich air from contacting the bearing, whereby the protective system does not contaminate the working air used for the operation of the vacuum system.

State of the art

Currently, some types of cleaning devices are exposed to water or moisture. In particular, wet/dry vacuum cleaners, such as handheld or carpet cleaners, operate under conditions where the impurities picked up from the surface being cleaned enter a mixture of water and air. To prevent moisture-rich air from entering the vacuum-generating motor, bypass motors are used. As is known, the bridged engine/fan assembly is such an assembly in which the working air, created by the working air fan, is driven by the engine, but is completely separated from it. The engine itself has a separate air cooling fan that takes cooling air above the engine armature and surroundings. In any case, the working air and the engine cooling air have completely separate paths and do not mix - except possibly in the exit area.

Bypass motors typically have a working air fan at the end of the motor/fan shaft, with the fan rotating inside the fan shroud. One end of the fan cover has an air inlet opening, while on the outside of the cover there are several mutually spaced discharge outlets or tangential discharge tubes. The inlet is connected to the vacuum chamber of the cleaning device, while the outlet is connected to the surrounding air. The fan cover forms the chamber in which the fan rotates. Once the chamber becomes compressed, air finds its way to the exit ports. Therefore, the working air fan extracts moisture-rich air from the vacuum chamber and disperses it into the surrounding air.

It has been found, especially in applications where moisture prevails in the working air, that moisture goes into the engine housing and causes malfunctions. In particular, these failures typically occur in places where the shaft is blocked inside the bearing. Moisture is in contact with the bearing and eventually causes the breakdown of the lubricant, rusting, which in turn causes the bearing to deteriorate, leading to shaft jamming and engine burnout.

An attempt was made to prevent moisture from entering the reservoir area by means of numerous modifications in the design. One modification uses a grease and/or oil lubricated synthetic rubber seal that is mounted on the shaft between the air path and the bearing. Lubricant is required since the motor shaft typically rotates at high speed. But, moisture-rich air can have a certain amount of strong detergent that emulsifies the lubricant, dries the lubricating material, and attacks the seal so that the moisture eventually travels along the shaft to the bearing. Moreover, the detergent mixes with the lubricating oil and then exits through the outlet surrounding openings, which leads to the appearance of dirt stains or oil stains on the surface on which the vacuum cleaner is used. This is very unfavorable for the user and is the main reason for vacuum cleaner damage. Therefore, the use of synthetic rubber seals as a bearing protection system has been found to be quite ineffective.

An alternative modification is the use of a disk seal with graphite on ceramic. They are typically used for special applications at lower speeds when there is no release of material due to seal wear. When graphite seals on ceramics are worn, they become dusty, where the fine, dark powder can contaminate the surface being cleaned.

One of the best alternatives for sealing the working air fan in relation to the motor is to use a hermetic system to protect the bearings. This system uses positive pressure in the reservoir area, so that contaminants in the working air remain outside the reservoir. The system has been proven to increase the overall lifetime of the reservoir. In such a system, air enters through an opening made on the support and is introduced by a special fan. This creates velocity pressure around the lower (fan end) motor bearing and keeps moisture away from the bearing during operation. Air enters behind the disk and, as it exits, the velocity and pressure in that area keep moisture away from the bearing. Rubber valves prevent moisture from returning to the engine under static or non-operating conditions, although a hermetic bearing protection system has been shown to be more effective, it requires enlarging and lengthening the engine housing and, therefore, increases manufacturing costs.

Based on the above, it is obvious that there is a need in technology for a dry seal: one that does not have an oily lubricant, which is durable, effective, so that if the seal fails, there is no formation of rust or particles that damage the surface.

Description of the invention

Therefore, the aim of this invention is to create a bearing protection assembly for engines.

A further object of this invention is to make an assembly for use with engines having a rotating shaft enclosed in a bearing, the shaft rotating a working air fan which creates a flow of working air which is separate from the bearing and the engine. This separation can be achieved with a fan mount which may or may not be connected to the diffuser.

A further object of this invention is to provide an assembly, such as the above, in which a dry, unlubricated seal is placed between the tensioning element and the support element to significantly increase the service life of the bearing, and therefore the engine. The inner diameter of the seal will at least frictionally fit the outer diameter of the rotating shaft or associated rotating element.

A further object of this invention is to provide an assembly, such as the above, in which a dry, unlubricated seal can be made of a material such as expanded polytetrafluoroethylene, which is impervious to water and cleaning materials and will not fail after heavy use.

It is a further object of the present invention to provide an assembly, such as the above, in which the outer edge of the seal is compressed to increase the inner edge of the seal, thereby increasing contact with the rotating shaft.

The aim of this invention is also the production of an assembly, as mentioned above, in which the seal is placed between the bearing and the path of the working air. The seal can be positioned so that the inner diameter is in parallel or perpendicular contact with the rotating shaft, depending on which gives the best characteristics of the motor assembly.

The aforementioned second aims of the invention will be clearer after the exhaustive description that follows, and they are realized by an assembly for protecting the bearings of a motor with a rotary shaft, and it consists of a bearing that is mounted on the shaft, which has one side that is closer to the motor (proximal side) and one side that is further from the motor (distal side), a support element that is next to the far side of the bearing and is placed around the shaft, a retaining element that is placed around the shaft, wherein the support element and the retaining element form an annular cavity around the shaft, and is a non-lubricating seal located in the annular cavity, and prevents the penetration of moisture towards the bearing along the shaft.

Other aspects of this invention can be achieved by an engine assembly that includes a bearing protection system, which consists of a motor with a rotating shaft, a bracket that holds the bearing against the shaft, a bracket that is attached to the bracket, and a seal that is located between the bracket and the bracket, at why the seal prevents penetration of the government to the bearing.

These and other objects of the present invention, as well as its advantages over the forms of the prior art, will be more understandable after the description that follows, and are achieved by improvements that are later described and protected by patent claims.

Brief description of the drawing

In order to fully understand the objects, techniques and structure of the invention, reference is made to the following detailed description which is accompanied by the drawings, which show the following:

Fig. 1 is a schematic diagram of a bearing protection system, partially in section, used with an engine assembly and made in accordance with the concept of the present invention;

Figure 2 shows details of a bearing protection system, partially in section, used with an engine assembly and made in accordance with the concept of the present invention;

Figure 2A is a schematic diagram of a gasket used in accordance with the present invention;

Figure 3 shows a fragmentary drawing, partially in section, of the following alternative bearing protection system of the present invention;

Figure 3A shows a fragmentary drawing, partially in section, of the following alternative embodiment of the present invention;

Figure 3B is a fragmentary drawing, partially in section, of another alternative embodiment of the present invention;

Figure 4 is a fragmentary drawing, partially in section, of the following alternative embodiment of this invention; and

Figure 5 shows details of the seal in an alternative position.

Preferred embodiment of the invention

A bypass motor assembly made in accordance with the concept of the present invention is generally designated 10 in Figure 1. The motor assembly 10 consists of a motor 12 having a field 14 in operative relationship with an armature 16. The motor 12 rotates a shaft 18 when it electricity is supplied. The shaft 18 has an outer diameter of 20 which is made with a small manufacturing tolerance.

The primary purpose of the bypass motor assembly 10 is to drive a working air fan generally designated 22. The working air fan assembly 22 consists of a working air fan 26 that is connected to a shaft 18. The assembly 22 may have a diffuser 28 that is connected to a bracket. fan 30 and surrounds the working air fan 26. The shell 32 has an opening 36 which is located centrally at one end of the shell. A plurality of outlet openings 38 are located around the outer part of the casing 32. When the working air fan rotates, the working air, which is generally designated by the number 40, is drawn into the opening 36. The working air, depending on the end use of the device, may contain moisture-rich air containing cleaning agent or similar. The working air 40 enters axially in the working air fan 26 and is ejected radially through the outlet openings 38. It should be noted that the motor assembly with a bridge 10 can be oriented horizontally or vertically, depending on the purpose of the device. It was found that the motor assembly 10, if it is in a horizontal position, increases the probability of moisture progressing along the shaft 18, while in a vertical position, the moisture naturally goes towards the opening 36 and exits the motor 12.

At the opposite end of the fan assembly 22 is a commutator support 50 that surrounds the shaft 18. A commutator spring 52 is placed between the commutator support 50 and a commutator bearing 54 carried by the shaft 18. The motor assembly 10 may also have a cooling fan 56 that conveys air across the field 14 and armature 16 so that the motor 12 is cooled during operation. Those familiar with the area know that the cooling air generated by the cooling fan 56 is separate and distant from the working air driven by the working air fan 26.

As seen generally in Figure 1 and partially in Figure 2, the bearing protection system is generally designated 60, is carried by shaft 18, and is positioned between the work air fan assembly 22 and the motor 12. A nut 62 connects the work air fan 26 for one end of the shaft 18. The sealing ring of the fan 64 is inserted between the nut 62 and the lower blade of the fan disk 26. Therefore, when the shaft 18 rotates, the working air fan 26 rotates in the same direction. Bearing 63 is mounted on shaft 18 in a manner well known in the art. Bearing 63 functions to ensure smooth and free rotation of shaft 18 during operation. Between the bearing 63 and the working air fan 26 along the shaft 18, various elements of the bearing protection system 60 are inserted, which enable the moisture-rich air driven by the working air not to travel along the shaft or any other connected part and cause disturbances during the operation of the bearing 63. In this way , a fan sealing ring 64 is inserted between the working air fan 26 and the nut 62. A shaft sealing ring 66 is placed on the underside of the working air fan 26 to provide structural support for the working air fan. The spacer 68 is positioned between the shaft sealing ring 66 and the inner edge of the bearing 63. It should be noted that the spacer 68 is a pressure fit on the shaft 18 and, as such, is located between the shaft sealing ring 66 and the bearing 63 and rotates with the shaft 18 when the motor 12 is started. .If the moisture-rich air is not expelled by the fan 26, it is likely to accumulate between the underside of the fan and the diffuser 28. Therefore, in this embodiment, any moisture movement is along the outer diameter of the spacer 68, rather than the outer diameter of the shaft 18.

The bearing 63 is placed on the opposite inner edge or inner channel by means of the shaft seat 72. Thus, when the nut 62 is tightened, the bearing protection system 60 is located between the nut 62 and the shaft seat 72. The diffuser 28, which can be used in the radial distribution of the work air, as previously described, has a diffuser coupling ring 74 which can be placed around the outer diameter of the spacer 68. The diffuser coupling ring 74 may also be referred to as a coupling or retention element. The diffuser 28 contains an inner diameter of the diffuser 76 whose diameter is greater than the outer diameter of the spacer 78. Thus, the diffuser space 80 exists between the inner diameter 76 and the outer diameter of the spacer 78.

End support 30 includes an end support ring 84 which may also be referred to as a support element. The end support ring 84 has an inner diameter 86 having a cavity 88 between the inner diameter 86 and the outer diameter spacer 78. The end support ring 84 and the diffuser coupling ring 74 form a cavity 90 between them.

A seal, which is generally designated 100, is positioned in the cavity 90 and is located between the diffuser coupling ring 74 and the end support ring 84.

The seal 100 is preferably made of a material such as expanded polytetrafluoroethylene (E-PTFE) manufactured by W.L. Gore and Associates and sold under the trade name Gore-Tex®. Seal 100 is dry unless supplied with lubricating oil, which is standard for seals surrounding rotating parts. As can best be seen in Figure 2A, the seal 100 is a relatively flat piece 102 having an opening 104 therein. The seal 100 has an outer diameter 106 and an inner diameter 108 that is typically slightly smaller than the outer diameter of the spacer 78. The inner diameter as such allows snug or friction fit around the spacer 78. The inner diameter is made either by a punch cut, laser cut or high pressure water cut. Those familiar with the field know that the inner diameter 108 must be concentric with the outer diameter of the spacer so that there is no space between the inner diameter 108 and the outer diameter of the spacer, shaft or other surrounding part. The seal 100 may have a thickness 110 that is greater than the distance between the ring 74 and the ring 78 .

Those familiar with the field know that an E-PFTE seal can absorb wax temperature without deforming so that shaft rotation alone will not adversely affect seal properties. Moreover, the material is very elastic and can withstand various shocks and loads. If the thickness 110 is slightly greater than the spacer between the rings 74, 84, the outer part of the seal will be pressed when placed between them. This causes the inner edge of the gasket to expand into the space of the diffuser 80 and the space of the support 88 and align with the spacer. This further improves the fit between the inner diameter of the seal and the outer diameter of the spacer. Between the lower side of the ring 84 is a supporting sealing ring 114 which, again, rests on the supporting ring of the sealing ring 116 which is placed on the outer part of the outer channel of the bearing 63.

Initial testing of the Bearing Protection System 60 shows that bearing life is extended. It is believed that the gasket material can prevent moisture from entering without any movement along the outer diameter of the spacer. Moreover, the seal is made of a material that does not require a lubricant, and therefore does not fail when exposed to cleaning agents that may enter with moisture-enriched air through the working air fan. Thus, the possibility of damage to the surface being cleaned by disintegrated seal lubricant or the lubrication material itself is significantly reduced.

According to Figure 3, an alternative bearing protection system is made which is designated by the number 120. As in the previous embodiment, the bearing protection system is attached to the motor shaft 18 by means of a locking nut (not shown). In this embodiment, the spacer 128 contains a coupling 130 which is located against the underside of the fan. Opposite the coupling 130 is the end of the spacer 134, which rests on the inner edge of the bearing 138. The opposite side of the inner edge of the bearing 138 rests on the rim of the shaft 140, which is part of the shaft 18.

The base support 144 holds the outer diameter of the bearing channel 138. The inner bearing channel 138 abuts the shaft 18. Specifically, the base support 144 has a hub 146 with an inner surface of the hub 148 surrounding a significant portion of the outer diameter of the bearing 138. The hub 146 forms a cavity 150 between the shaft 18 The hub 146 also has an outer hub surface 15 and an inwardly directed hub lip 154. Between the underside of the hub lip 154 and the outer edge of the bearing 138 are multiple support rings 155. A seal 100 is mounted on the hub lip 154 which functions as a support member. A steel sealing ring is concentrically placed on the seal 100. To hold the seal 100 and the sealing ring 158, a coupling cap 160 is placed above them. The coupling cap 160 has a side 162 with an inside diameter slightly smaller than the outer surface of the hub 152. The coupling cap has a flat member 164 extending vertically from the side 162 with a hole 166 that is larger than the outside diameter of the shaft 18. The coupling cap 160 holds a sealing ring. 158 and the seal 100 so that its inside diameter matches the outside diameter of the spacer 132. In other words, the cap 160 abuts the hub 146 to hold the seal 100 and the sealing ring 158. The sealing ring 158 has a flat uniform surface that helps to connect and press against the outer part of the gasket. It should be noted that the use of steel sealing ring 158 is not necessary. This implementation functions practically in an identical way as the previous implementation, although the supporting configuration is somewhat different.

According to Figure 3A, an alternative embodiment can be made in which there is no supporting sealing ring and cover. In this embodiment, only the base support 144 is used to tighten the seal 100 and the metal ring 158 which, in this embodiment, functions as a support element. The seal 100 may be compressed slightly to increase the interference fit between its inner diameter and the outer diameter of the spacer 132.

The concept of the present invention can also be applied to motor assemblies that use bearings with an elongated inner raceway 139. As can best be seen in Figure 3B, the bearing 138 is mounted on the shaft 18 so that the end of the inner raceway 139 is in contact with the end of the spacer 134. The hub 146 holds the bearing 146 as in the previous embodiment. In this embodiment, the hub ring 154 holds the seal 100 and the sealing ring against the bearing 138. Then, the inner diameter of the seal 108 is in contact with the outer diameter of the elongated inner channel 139. Therefore, the moisture-rich air in contact with the spacer and the elongated inner channel 139 is held apart by gasket 100.

According to Figure 4, another bearing protection system is made, which is marked with the number 170. This realization is most often used on the opposite end of the motor shaft near the motor commutator. Thus, the shaft 18 passes through the motor housing 172. The bearing 174 presses against the joint of the outer diameter of the shaft 18. The base support 178 is mounted and secured to the housing 172 while also holding the bearing 174. The base support 178 has a bearing surface 180 that holds the bearing 174 against the shaft 18. The base support 178 also has a seat 182 which has a support opening 184 on it. Between the seat 182 and the outer diameter of the support 174 is a support ring 186. The seal 100 is located on the outer surface of the seat 182 and its inner diameter is positioned directly to the outside diameter of the shaft. 18.

The coupling cap 160 is mounted on the base support 178 and, in particular, on the seat 182. The coupling cap 160 can slightly reduce the thickness of the seal 100 by pressure and the inner diameter of the seal corresponds to the outer diameter of the shaft 18, as previously explained.

Although embodiments are described as having the inner diameter of the seal 100 substantially parallel to the outer diameter of the shaft 18 or other rotating element, it should be noted that the inner diameter 108 may be positioned to be essentially perpendicular to the rotating element, as seen in Figure 5. Accordingly, the seal 100 aligns the shaft 18 with a portion on the flat surface of the seal 100. Of course, the inner part of the seal can be deflected in any direction. This configuration is believed to provide a greater contact area with the shaft and, therefore, provide additional protection against moisture penetration along the surface of the shaft 18.

Based on the above, the advantages of the bearing protection system are obvious. Primarily, the system effectively prevents the entry of moisture into the engine assembly, and especially the bearing. This has been found to significantly increase engine life. The system also uses a material (E-PTFE) that is impervious to cleaning fluids and has excellent thermal and dimensional stability. As such, the seal 100 does not deteriorate over time and will not directly damage the surface being cleaned by the device used by the engine with the bearing protection system.

Therefore, it can be seen that the objects of the present invention are satisfied by the structure and methods of use, as shown above. Although in accordance with the Patent Statute, the best method and preferred implementation are shown and described in detail here, it is understood that this invention is not limited to it. Therefore, to see the true reach and breadth of the invention, reference should be made to the patent claims.

Claims (10)

1. Bearing protection assembly for an engine having a rotating shaft, characterized in that it consists of the following: - the bearing located on the shaft, and said bearing has one side closer to the engine and one side that is further away from the engine; - the supporting element that is next to the specified far side of the bearing and surrounds the shaft; - a retention element that surrounds the shaft, so that said retention element and said support element form an annular space around the shaft; and - the non-lubricating seal is located in the specified annular space, and the specified seal prevents the progress of moisture towards the bearing along the shaft, - wherein the said support element and the said retention element form a cavity in relation to the rotating shaft, while the compression of the said non-lubricating seal between the said support element and the said retention element causes the expansion of the said seal into the said cavity. 2. The assembly according to claim 1, characterized in that said non-lubricating seal has a thickness greater than the distance between said support element and said retention element, and said seal is at least slightly compressed between said support element and said retention element and friction surrounds the said shaft. 3. Assembly according to claim 1, characterized in that said non-lubricating seal contains: - a flat part that has an opening on it that forms the inner edge, and said inner edge is placed practically parallel to the shaft. 4. Assembly according to claim 1, characterized in that said non-lubricating seal contains the following: - a flat part that has an opening on it that forms the inner edge, and said inner edge is placed practically parallel to the shaft. 5. Assembly according to claim 1, characterized in that it also contains: - the nut attached to the shaft; - the spacer inserted between the specified nut and the specified bearing, the specified spacer rotates with the specified shaft, and the specified spacer has an outer diameter; - the said non-lubricating seal has an opening with an inner diameter that is placed by friction against the said outer diameter of the said spacer, whereby the said supporting element and the said retention element form a cavity in relation to the said spacer, and the compression of the said seal which does not lubricates causes said seal to expand into said cavities; and - the supporting sealing ring is placed between the specified support element and the specified bearing, and the specified support element is the hub that holds the specified bearing to the shaft, the specified retaining element being the cover that is attached to the specified hub to retain the specified seal that is not lubricated between them. 6. An assembly according to claim 2, characterized in that said support element is a base support having a socket with an outer diameter, wherein said retaining element is connected to said socket with a cover to place a non-lubricating seal between them, and said seal which is not lubricated, it has an opening with an inner diameter that is frictionally connected to the outer diameter of the shaft. 7. Engine assembly that has a bearing protection system, characterized by the fact that it consists of: - motor that has a rotating shaft; - the support that holds the specified bearing next to the specified shaft; - the tie with which the mentioned carrier is attached; and - a seal that is placed between the specified support and the specified link, and the specified seal prevents moisture from penetrating into the specified bearing, wherein the specified seal has a flat part that has an opening with an inner diameter, the said flat part has an inner edge, and the said link and said support presses said flat portion so as to increase the thickness of said flat portion at said inner edge and decrease said inner diameter. 8. Assembly according to claim 7, characterized in that said seal is expanded polytetrafluoroethylene which is not lubricated and is resistant to moisture. 9. Assembly according to claim 7, characterized in that it also contains: - a spacer which is carried by the shaft and which rotates with it, and the said spacer has an outer diameter, so the stated inner diameter of the seal is at least slightly smaller than the stated outer diameter of the seal in order to create friction between them. 10. Assembly according to claim 7, characterized in that said shaft has an outer diameter, and said inner diameter of the seal is at least slightly smaller than said outer diameter of the shaft in order to create friction between them.