JPH01400A - Assembly consisting of water pump, bearings and seals - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application) The present invention relates generally to vehicle water pumps, and more particularly to water pumps in which a relatively rotatable sealing ring is in frictional engagement with a seal wear surface to pump coolant to a pump bearing. Regarding water pumps that do not allow water to enter.

BACKGROUND OF THE INVENTION Vehicle cooling systems typically include a belt-driven water pump with a heald-driven shaft and shaft-mounted impeller to deliver coolant to the system. Characteristically, the pump housing is removably connected to the engine block, and the bearing assembly for supporting the shaft is press fit within the sleeve of the housing. It is also known that it is possible to reduce costs and simplify construction by making the outer race of the bearing assembly integral with the pump housing and, at least in theory, partially eliminating it. An example of this is U.S. Patent No. 3.981,61.
It is disclosed in No. 0. However, it is rare that such an integrated pump/housing/bearing assembly is actually used, or
Not at all. This is because the steel suitable for bearing races and passages must be very hard. Conversely, typical pump housings are relatively large, have complex passageway curvatures, and must be constructed of mild steel that can be easily stamped into the desired shape.

However, it is widely recognized that the greatest challenge in vehicle water pump design is sealing, and that sealing problems have not yet been resolved to the complete satisfaction of the vehicle water pump industry. Although magnetic impeller drive means that do not require seals can be used, magnetic drive means are currently relatively expensive.

When using conventional drive impellers, some type of friction seal must be used because the shaft that drives the impeller must physically extend within the pump housing. The location where this seal must be installed is the space between the shaft support bearing and the shaft impeller. In this position, the seal necessarily comes into contact with the hot corrosive coolant. Such coolants are very harmful to common seal materials. A standard industrial water pump seal has two basic parts: a sealing ring and a sealing element having a wear surface on which the sealing ring engages and rotates. One part of the seal is attached to the pump housing and bearing structure and the other part is attached to the impeller and shaft structure. Therefore, in addition to the hot corrosive coolant, the common sealing ring/wear surface interface is exposed to significant frictional heat generated by the relatively high speed of relative rotation between the shaft and bearing. It has also been found that due to the unavoidable wear on this common contact surface and the high pressure of the hot coolant, it is necessary to spring bias the ring and wear surface against each other to maintain firm contact; This will increase frictional heat.

Standard industry practice to address this sealing problem has been to make the wear surface of a non-corrosive ceramic material and the sealing ring of a different non-corrosive material (eg, carbon). However, ceramic materials themselves have many practical problems, and the majority of patents filed in this field seem to involve proposals to solve the inherent difficulties of using ceramic materials. It seems to me. Ceramic materials are brittle, susceptible to thermal shock, difficult to stack on flat surfaces, and difficult to structurally engage the steel components of other parts of the pump.

extremely difficult. For example, U.S. Patent No. 3,782°7.
No. 35 attempts to place a metal hand tightly around a ceramic sealing element to maintain its structural integrity. By using an elastomeric insulator to engage the ceramic sealing element to the metal impeller shaft, the ceramic sealing element is intentionally wobbled to address the alignment and integrity of the sealing interface. It has become.

The elastomer also acts as an insulator, preventing the ceramic sealing element from dissipating frictional heat. Ceramic sealing elements have been well designed in the pump disclosed in U.S. Pat. No. 3,895,811, in which the ceramic element is securely fixed within a deformable metal washer surrounding it; The metal washer holds the ceramic element firmly against the other sealing parts out of plane and provides better heat dissipation.

However, cost has prevented production of this design, and conventional seals of the type previously described are fairly widely used.

SUMMARY OF THE INVENTION The present invention provides a water pump, bearing, and seal combination assembly that overcomes all of the above problems. The present invention is more economically and precisely assembled;
It also aims to improve durability and seal life during operation.

In the preferred embodiment disclosed below, the normally used ceramic sealing element is replaced by an annular ring made of a suitably wear-resistant and corrosion-resistant metal, specifically a stainless steel annular ring. I am using it. This eliminates all defects inherent in ceramic materials. pump·
The housing is formed of a suitably soft metal that is easily stamped, specifically very mild steel. The generally cylindrical bearing housing is made of metal, specifically bearing steel, which rotatably supports the impeller shaft - an integrally formed bearing housing for matched rolling bearing elements. It has sufficient hardness to form a passageway. The pump housing, bearing housing and sealing elements are made of different steels suited to their specific requirements, all of which are weldable and have similar thermal expansion properties, and which are incompatible with other steels. and different from ceramic materials.

Moreover, each of these three components has a special design that makes it especially advantageous to manufacture.

The cylindrical bearing housing has circular edges and
The housing has a central opening having a circular inner edge of approximately the same diameter as the bearing housing. The annular sealing element has a circular outer edge with a diameter comparable to the diameter of the circular edges of the bearing housing and the pump housing. These three edges may be brought together at a common accessible joint and welded together simultaneously to form a one-piece assembly of three components. This is not possible with ceramic materials, and this one-piece assembly is convenient to transport, handle, and install like any other one-piece assembly since the wear surface is also part of the unit. Each component is made from the materials best suited to its unique requirements without any compromises. Since the steels of all three components have similar thermal expansion properties, the structural integrity of the common joint is maintained during pump operation.

The structure of the specific embodiments disclosed below has additional advantages in B-mode of cooperation and interaction without adding any cost in either materials or manufacturing process. Welding at this joint also provides a fluid-tight seal at this common joint. The wear surface of the stainless steel sealing element is radially close to the welded common joint of the three components. Since it is made of metal, frictional heat on the wear surface passes through the common joint to the bearing housing,
It is effectively transmitted to the pump housing and from there to the surrounding atmosphere. The edge of the bearing housing includes a shoulder that fits within the opening of the pump housing, and the sealing element includes a peripheral flange that abuts the edge of the bearing housing. . Thus, prior to welding the three components together, the components are held in a very precise relationship to each other, and the aligned seal interface is much more precisely controlled than with conventional ceramic seals.

Therefore, it is an object of the present invention to
It is an object of the present invention to provide a water pump for a vehicle in which the housing and seal can be made of the most suitable materials and still effectively form an integral assembly.

Another object of the present invention is that the metal sealing element having a wear surface prevents the r! It is an object of the present invention to provide an integrated pump assembly that is incorporated in a manner that effectively removes frictional heat in cooperation with other components of the assembly.

Yet another object of the invention is to enable easier manufacturing by allowing the components to cooperate and align with each other during assembly and to provide seals for improved operation of the integral pump. The object of the present invention is to provide an integrated pump assembly that can be installed precisely and accurately.

(Example) The above and other objects and features of the present invention are illustrated in the following description and drawings.

Referring first to FIG. 1, a preferred embodiment of a vehicle water pump according to the invention is designated by the reference IO.

The pump 10 is shown separated from an engine block, not shown, so that it can be transported as an integral pump assembly for later installation. In fact, two of the basic components of water pump 10 are conventional and do not form part of the invention in the broadest sense, but they are included as part of the overall assembly in accordance with the present invention. It seems most practical to assemble and transport the components. These two conventional components are an impeller, indicated at 12, and a cartridge seal, indicated at 14. Impeller 12 is a standard stamped metal design well known to those skilled in the art. Cartridge seal 14 is a conventional commercially available unit and includes a carbon sealing ring 16, a bellows 18, and a biasing spring 20. This offset spring 20 is compressed between the sealing ring 16 and the impeller 12. The present invention consists of a more basic unitary assembly, shown at 22, comprising a shaft, shown at 24, a bearing housing, shown at 26, and two sides supporting the shaft 24 concentrically within the bearing housing 26. bearing ball 28, a pump housing indicated at 30, and a sealing element indicated at 32. Each of these components and how they are specifically designed to cooperate with each other is described in detail below.

In FIGS. 1 and 3, the bearing housing 26 is generally cylindrical and made of bearing grade steel, such as Al5I52100 or 1040 high carbon steel. in this case,
Bearing housing 26 is sufficiently hard to integrally define bearing passageway 34 on its interior surface. Being cylindrical, the bearing housing 26 has generally circular edges, one of the edges 36 having a notched shoulder 38 formed therein. The bearing housing 26 also has standard vent holes 40 for venting coolant that has leaked past the seal 14. The shaft 24 is made of the same material as the bearing housing 26, and has a bearing passage 42 integrally formed on its outer surface.

The shaft 24 is tapered at one end 44 to which a conventional drive pulley (not shown) can be attached, and the other end 46 is adapted to allow the impeller 12 to be attached.

After fabricating the shaft 24 and housing 26 and subjecting them to appropriate heat treatments, the two side bearing balls 28 are assembled between their respective passages 42, 34 in a conventional manner. There is sufficient radial clearance between the bearing housing 26 and the shaft 24 to allow unobstructed access to add the bearing balls 28 and to supply them with the desired lubricant. be.

A suitable lip seal 48,50 is then provided surrounding the ball 28. At this point, bearing housing 26, shaft 24, and balls 28 constitute a bearing subassembly that can be handled individually.

1 and 3, the sealing element 32 is generally annular in shape and is formed of a suitable corrosion-resistant metal, in this example Al5I303 stainless steel, such as impregnated oil cast iron. Other materials may also be used.

Both materials are highly abrasive, easier to manufacture and handle, and can withstand thermal and mechanical shock much better than ceramic materials.

Since the sealing element 32 is steel or other ferrous metal, it has similar thermal expansion characteristics to the metal of the bearing housing 26 and is weldable. In addition to the generally annular shape, the sealing element 3
2 has structural features that cooperate with other components, which are best seen in FIG. The body of the sealing element 32 is sized only slightly smaller than the inner diameter of the bearing housing edge 36, thus allowing the sealing element 32 to be a sliding fit on the end of the bearing housing 26. The dimensions are such that the pair of O-rings 52 engage with the inner surface of the bearing housing 26 so as to wipe the inner surface of the bearing housing 26. Peripheral flange 54 has an outer diameter slightly larger than the outer diameter of bearing housing shoulder 38 and is adapted to abut edge 36 . A raised wear surface 56 is provided outwardly, which is located proximate the flange 54 both radially and axially. The pump housing 30 is stamped and formed from Al5IIOIO extremely mild steel. Accordingly, the pump housing 30 is formed into a complex convoluted shape with integrally formed coolant inlet and outlet passages and mounting circumferential flanges 58 as required in the pump housing. It's getting easier.

Because the pump housing 30 is steel, it is weldable and has thermal expansion characteristics similar to the metals of both the bearing housing 26 and sealing element 32. The pump housing 30 is also stamped with a central aperture defined by a circular inner edge 60 having a diameter and thickness approximately equal to the bearing housing shoulder 38. As described above, the bearing housing 26, the pump housing 30 and the sealing element 32 are
All are made of a variety of materials to best suit their unique requirements. Nevertheless, the similarity of these materials and the carefully selected structural relationships of the components may result in precise assembly and improved operation for pump 10. . This will be explained below.

Next, in FIGS. 2 and 3, the bearing housing 2
6. Due to the relative dimensions described above for the pump housing 3o and the sealing element 32, 1. these components can be assembled and connected as follows. The inner edge 60 of the pump housing 30 is attached to the bearing housing shoulder 3
8 and very precisely coaxially aligned in a cooperative position. The sealing element 32 is then slidably fitted onto the end of the bearing housing 26 and the flange 54 abuts the edge 36. This slip fit and abutment provides precise coaxial alignment of the sealing element 32 with the bearing housing 26 and wear surface 56.
can be located at right angles to the axis of shaft 24. This is a valuable feature compared to the conventional ceramic sealing elements mentioned above, since they are embedded within the elastomer and therefore cannot be precisely aligned or positioned. This is because it is almost impossible to do so. By bringing the bearing housing 26, pump housing 30 and sealing element 32 together as described above, the respective end edges 36, inner edges 60
and flange 54, which is circled in FIG. 1 and indicated at 62 in FIG. These parts can easily be held in this relationship in a temporary pre-assembled condition with suitable jigs or automated assembly equipment. As best seen in FIG. 3, the common joint 62 is more easily accessible by opening the pump housing 30 and the three edges can be simultaneously welded together by a suitable tool, indicated at 64. . The welding step results in the above-mentioned monolithic assembly 22, and then 3
The two components can be easily handled and transported as if they were integral with each other. Moreover, there is no need to make any compromises regarding the material at the joint 62.
The welding also simultaneously creates a continuous fluid-tight seal without requiring any extra work steps or seal construction. In fact, the weld seal at joint 62 is so good that O-ring 52 can be omitted. Although assembly 22 may be shipped as is, it is most convenient to add cartridge seal 14 and impeller 12, which frictionally engage sealing ring 16 with wear surface 56.

The entire pump unit 10 can then be transported and bolted as one unit to the engine block at the pump housing flange 58.

Finally, with reference to FIG. 1, with the materials and assembly detailed above, significant improvements in pump operation and life can be obtained, primarily due to improved sealing action and life. As shaft 24 rotates and impeller 12 drives coolant, the frictional engagement of sealing ring 16 and wear surface 56 together with the weld at joint 62 prevents coolant from contacting bearing balls 28 . Furthermore, any coolant that passes through the sealing ring 16 is prevented from reaching the bearing pole 28 by the lip seal 50 and can be vented to the ambient atmosphere through the vent hole 40. Although the joint 62 is exposed to high temperature coolant, the similar thermal expansion properties of the three different steels maintain the structural integrity of the weld. The precise alignment of sealing ring 16 and wear surface 56 with each other minimizes eccentricity and frictional wear.

The steel wear surface 56 is easily overlapped with sufficient flatness to allow the carbon sealing ring 16 to actually adhere to the wear surface. Due to the improved alignment of the seal 16/wear surface 56 at the common surface, some corrosion of the wear surface 56 is permitted. This is because the spring 20 remains in constant frictional contact as it wears continuously without disrupting the alignment of the parts. Furthermore, because the steel of the sealing element 32 is a good heat transfer material, and because the wear surface 56 is close to the common joint 62, the frictional heat generated at the contact surface can be transferred through the sealing element 32 and the joint 62. Bearing housing 26 and pump housing 30 exposed to outside air
easily transmitted. Coolant flow also extends seal life. Thus, by fabricating the sealing element 32 with tears and assembling it with other steel components, numerous advantages can be obtained with respect to cost, productivity, and seal life, all of which interact together.

The welding at common joint 62 does more than simply provide an integral unit. By adding the sealing element 32, abutting all three components, and welding these components together at 62, there is excellent heat transfer to the outside air and good cooling of the sealing element 32. can be done.

The common joint 62 allows all three components to be easily aligned with each other, yet provides a rigid unit.

Changes may be made in the disclosed preferred embodiment without departing from the inventive concept; for example, in different sized pumps or cooling environments, the wear surface 56 need not be close to the common joint 62. Sealing element 32
The fact that it is made of steel and welded to the bearing housing 26 and pump housing 30 improves productivity and integrity at the Y7 rub seal interface. However, by locating the wear surface 56 in close proximity to the common joint 62, the frictional heat generated during use can be effectively and conveniently dissipated. Similarly, bearing housing shoulder 38 and sealing element flange 54 may be omitted so long as bearing housing 26, pump housing 30 and sealing element 32 all have circular edges of approximately the same diameter that can be mated together at a common joint. It is also possible to simplify the components somewhat. However, the various flanges and shoulders described above are an advantage as they align the components themselves at the common joint 62.

Therefore, the present invention may be embodied in structures other than the preferred embodiments described above, and the present invention is not limited to the embodiments.

[Brief explanation of the drawing]

FIG. 1 is a side view of a preferred embodiment of the invention, with some parts shown in cross section and other parts shown in side view. FIG. 2 is a view taken along line 2-2 in FIG. FIG. 3 is an enlarged view of the circled area in FIG. 1. (Explanation of symbols of main parts)

Claims (1)

[Claims] 1. An assembly consisting of a combination of a vehicle water pump, a bearing, and a seal, of a type in which a relatively rotatable sealing ring is frictionally supported on a seal wear surface, and the sealing ring is installed. a pump having a rotatable shaft, a generally cylindrical bearing housing, a bearing element supporting the shaft concentrically within the bearing housing, and a generally central opening.
comprising a housing and a generally annular sealing element with said wear surface, said bearing housing (26) being of sufficient hardness to provide an integrally formed bearing passageway (34) on its inner surface; The pump housing (30) is constructed of a weldable metal, and the bearing housing (26) has a generally circular edge (36) and the pump housing (30) is constructed of a weldable metal. The pump housing (30) is formed of a weldable metal having thermal expansion properties and soft enough to be easily stamped into a suitable shape, with an opening approximately in the center of the pump housing (30) extending from the bearing housing edge (36). ), the generally annular sealing element (32) having thermal expansion properties similar to the metal of said bearing housing and pump housing and having said seal wear. the sealing element (32) having an outer edge having a diameter approximately equal to the diameter of the bearing housing edge (36); and said bearing housing edge (36), pump housing inner edge (60) and sealing element outer edge are met and simultaneously welded together at a common joint (62) to create an integral assembly and said common A continuous fluid-tight hermetic seal is created at the joint (62) and the welded common joint (62) is assembled when the vehicle water pump/bearing and seal combination assembly (10) is assembled into a vehicle engine. A vehicle water pump, a bearing, characterized in that the bearing remains structurally rigid during pump operation due to the similar thermal expansion properties of the three metals forming the bearing;
An assembly consisting of a combination of seals. 2. When the assembly (10) consisting of a combination of a vehicle water pump, a bearing, and a seal is assembled into a vehicle engine, the bearing housing (26) and the pump housing (3)
0) is exposed to ambient air and the frictional heat generated at the sealing ring/wear surface common contact surface during pump operation is transferred from said wear surface (56) to said common joint (62).
2. The combination vehicle water pump, bearing, and seal assembly of claim 1, wherein said combination vehicle water pump, bearing, and seal assembly is in communication with said bearing housing and said pump housing through said bearing housing and said pump housing. 3. The sealing element wear surface (56) is attached to the sealing element (32).
3. A vehicle water pump/bearing as claimed in claim 2, characterized in that the seal is close to the outer edge of the bearing of the vehicle water pump/bearing of claim 2, further increasing the efficiency of frictional heat transfer from the common contact surface of the sealing ring/wearing surface during pump operation. An assembly consisting of a combination. 4. The bearing housing (26) has a generally circular shoulder (38) at the edge (36), and a generally central opening in the pump housing (30) defines the bearing housing shoulder (38). ), said sealing element (32) having a diameter approximately equal to the diameter of said bearing housing edge (3
6), whereby said bearing housing (26), pump housing (30) and sealing element (32) are simultaneously brought together at said common joint (62). The pump housing inner edge (60) is slid over the bearing housing shoulder (38) and the intersealing element flange (54) is attached to the bearing housing edge (54) before being welded to form an integral assembly. said common joint (6) by abutting said common joint (6).
A vehicle water pump/bearing/seal combination assembly as claimed in any one of claims 1 to 3, characterized in that it is adapted to be aligned with one another at point 2).