US3033120A - Turbo pump - Google Patents

Description

y 8, 1962 J. G. WILLIAMS 3,033,120

TURBO PUMP Filed July 18, 1961 a Sheets-Sheet 1 JOHN G. WILLIAMS y 8, 1962 J. G. WILLIAMS v 3,033,120

TURBO PUMP v Filed July 18, 1961 3 Sheets-Sheet 2 0" TURBINE '37 CONTROL.

COOLER 35' TO SERVO 33 Mo'roR FILTER 40 (3|) \.L/ I n9 I f I l f 1 EDuc-roR To TO (3 PUMP PUMP I 'NLET. OUTLET I/ DRAIN JOHN G. WILLIAMS IN VEN TOR.

3,033,12ti TURBO PUMP John G. Williams, Springfield, NJL, assignor to Worthington Corporation, Harrison, NJ., a corporation of Delawere Filed July 18, 1961, Ser. No. 124,982 7 Claims. (Cl. 103-87) This invention relates generally to an improved turbo pump having a unitary casing and used aboard ships or in other places subjecting the unit to exacting size requirements.

More particularly the improvement consists of a novel shaft supporting bearing having cooling fluid supplied thereto and disposed relative the shaft to nullify the effects of high temperatures on the bearing member.

Turbo pump units for the specific function and installations as indicated above are in widespread industrial use and have for some time been considered as needing improvement. One such improvement is shown in applicants US. Patent No. 2,933,044. It has been found in operating the units shown in the above prior patent that the construction proposed therein does not meet the requirements of a high temperature installation.

As was the case in the above US. patent the present invention contemplates an improvement of considerable practical value wherein it is an object to provide as a support for the shaft of a turbo pump unit a bearing which receives cooling fluid from an external source which not only improves bearing performance but in addition has the effect of greatly reducing the size of the turbo pump unit.

In addition to obtaining the advantages listed in above patent, the present invention provides an arrangement including a sleeve disposed relative the shaft to effectivly nullify the effects that heat flow, from the turbance to the pump along the shaft, has on the bearing member mounted therebetween.

To accomplish these and other objects, in addition to a novel bearing constructed to be etfectively cooled and lubricated as will be subsequently more fully described herein, the turbo pump of the present invention has a fluid passage system interconnecting the bearing, turbine control and educator unit. Cooling fluid which is allowed to flow into the bearing and is continuously circulated about the bearing and the shaft associated therewith by an auxiliary impeller to cool same also functions to power the turbine control and induce a vacuum in the eductor unit.

Other objects and advantages of the invention including the basic design and the nature of the improvements thereon will appear from the following description taken in conjunction with the following drawings, in which:

FIGURE 1 is a longitudinal view in cross-section of a turbo pump unit, in which the location of the novel bearing is shown.

unitary casing designated 1 and is provided with a single rotatable shaft 2 on which the turbine generally designated 3 and the pumping means 4 are suitably mounted. The

shaft 2 is journaled in a bearing 5 to the right of the turbine 3 and between the turbine and pump 4 in a fluid cooled and lubricated bearing assembly generally designated 5.

The F luz'd Cooled and Lubricated Bearing Referring to FIGURE 3 it will be evident to those skilled 3,633,120 Patented May 8, 1962 in this art that due to the higher temperatures in the turbine section of the unit a heavier shaft is required for association with this turbine section, whereas a shaft of lesser dimension can be provided in the pumping portion of the unit.

The portion 7 of the shaft 1 between the turbine and pump unit gradually tapers in dimension from that of the turbine unit 3 to that of the pumping means 4. A gradual reduction in size of the shaft as is contemplated hereinabove eliminates any stress concentrations that would be caused by sharp reductions in shaft dimension.

A sleeve 8 is force fit at the center section 9 of shaft portion 7 between the turbine and pump. The sleeve 8 and shaft are shown as having at one end a relatively narrow clearance therebetween as at 1-0 and at the other end a relatively larger annular clearance 11 therebetween.

While the drawings show a narrow clearance at one end and a larger clearance at the other end, it is not intended to limit the invention to this construction.

The site of clearance is dependent upon the type fluid utilized for providing an insulation or heat flow barrier. For example, clearance 16 is narrow because the large vanes 23a of impeller 23 communicating therewith tend to flow all liquid therefrom. Accordingly, all that remains is gas and/ or steam which has a high insulating quality.

Because liquid leaking from pump 4 collects in clearance 11 and since fluid is not as effective a heat insulator as steam, a larger clearance has to be fashioned at the opposite end of the sleeve.

As will be evident insulating qualities are obtained in clearance 11 because the shaft and sleeve are rotating at the same speed whereby the relative velocity of the fiuid will approach zero.

The bearing 6, including a self-aligning housing 12 of any well known construction, is provided for and maintained in operating position by a bearing pin 13 disposed partially in the bearing bracket 14 and partially in the top portion of the housing 12, and is properly centered about a bearing member 15 disposed about the sleeve 8 to provide a fixed narrow annular clearance chamber 16 with the sleeve. Means 19 are provided for discharging fluid leaking to the bearing from the pump 4 and passing same to way in turn communicates with a port 22 formed in the hearing which communicates at one end with the narrow annular chamber 16 formed between the bearing member 15 and sleeve 8.

Accordingly, it will be evident that fluid passing to the bearing from the pump can be flowed to the cooler and from the cooler can be passed through the above passageways and ports to the narrow annular passageway 20 to cool and lubricate the shaft and bearing. An auxiliary impeller 23 is mounted on the sleeve member at the end thereof and adjacent the turbine portion of the unit. This auxiliary impeller functions to impel cooling fluid through the above mentioned passageways and out the discharge means 19 which is connected to the'cooier to return the fluid to be cooled thereby.

Although for purposes of illustration in FIGURE 3 the narrow annular clearance chamber 16 has been greatly exaggerated, in practice it cannot have a sizeable radial dimension since the fluid delivered through the radial passageway to be used to lubricate the outer surface of the sleeve member has a low viscosity and cannot be passed through an excessive running clearance space without adversely affecting the effectiveness of the hearing as a load carrying member. However, with the provision of the insulation spaces at the opposite ends of the sleeve and by the return of cooling fluid to the portion of the sleeve connected to the shaft, it has been found that the high temperatures in the portion of the shaft adjacent the turbine are precluded from being transmitted to the sleeve portion by the steam insulation in space and the high temperatures adjacent space 11 are precluded rom being transmitted to the sleeve by liquid insulation provided for in space 11. By providing for a central connection of the sleeve and shaft it is now possible to keep this portion cool by concentrating the cooling fluid in this area. This is accomplished as will be clear by fashioning the passageways 18, 20, 21 and 22 so that initial entry of cooling fluid is directed at the point of connection between the sleeve and shaft. Constant recirculation provided for by auxiliary impeller 23 to the cooler maintains the cooling fluid at a desired temperature so that it can function in its cooling purpose. The thermal gradient of an application is shown in FIGURE 3. Note that lowest temperature is at point of contact between shaft and sleeve.

It will also be noted, particularly with reference to FIGURE 3, that the bearing 6 comprises a housing portion 12 disposed in stationary member 14 to compensate for misalignment during assembly of the turbo pump unit as will be understood by one skilled in the art. Furthermore, housing portion 12 is fashioned of a heat and corrosion resistant material that is well known in the art to thereby coact with the above described cooling arrangement to provide for more effective performance.

Added Feature In addition to providing circulating cooling fluid flow to the bearing the auxiliary impeller 23 and particularly vanes 24 and vanes 23a thereof act as the circulating implement for passing this fluid to the turbine control 29 and eductor unit 30. The fluid pumped into the discharge chamber 28 is carried away from the turbo pump unit through an outlet 19 connected to the casing section as is clearly shown in FIGURE 2, and while flowing through this pipe is strained through a filter element 31 and emptied into a cooling unit 32. Most of the fluid on leaving the cooler unit returns to the turbo pump unit through a return pipe 33 connected to the casing section adjacent the outlet pipe 19 but some portion is also diverted through a tap-off pipe 34 for use in powering turbine control 29 and through a second tap-off pipe 35 for use in operating eductor unit 30.

The turbine control 29 will be understood to be a conventionally designed unit readily purchasable on the open market which functions generally to maintain desired pressure conditions in the steam entering the turbine and limits the turbine to safe operating speeds with the further pro vision that it will cause shutdown in response to pressure conditions within the pump in the event of possible pump failure. An explanation of the mode of operation of the turbine control as a safety shutdown device however is sufiicient for purposes of the present invention since it illustrates the importance of supplying this control with a powering fluid through the tap-off pipe. In this connection whenever the pump suction pressure passing through the line 36 varies from a predetermined value the fluid available in the tap-off pipe 34 is allowed to pass through the control to effect shutdown of the turbine. This fluid, more particularly, after passing through the control enters into a pipe 37, which pipe as clearly shown in FIGURE 1 delivers the fluid to a servo motor. As a powering fluid in the servo motor the fluid causes a valve 38 to move onto a valve seat 39 which thereby prevents the continued introduction of steam into the turbine causing it to shut down.

To operate the eductor unit 30 fluid is continuously made available to this unit through the tap-off pipe 35, being passed through its shaped central passageway 49 thereby inducing a vacuum in the unit which is applied to a remote point through a pipe 41 suitably connected to the unit. As shown in FIGURE 1, the end of pipe 41 is connected to apply the vacuum of the eductor unit 30 to a seal chamber 42 formed in the turbine between the sealing rings 43 and bearing 5 disposed about the shaft. Accordingly, steam which has managed to leak along the shaft past the innerseal rings 43 is prevented from also leaking past the outer sealing ring 44 and thereby exhausting to atmosphere, first by being withdrawn by the vacuum and entering the seal chamber 42, and second, by being blocked by an opposing stream of air being drawn by the vacuum past the sealing rings 44.

Although this invention has been described with reference to specific apparatus, it will be appreciated that a wide variety of changes may be made within the ability of one skilled in the art without departing from the scope of this invention. For example, some of the components of the apparatus may be reversed, certain features of the invention may be used independently of others, and equi" alents may be substituted for the apparatus all within the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In a bearing for a pumping unit including a shaft, a turbine mounted on a portion of said shaft, a pumping means mounted on another portion of said shaft, the portion of said shaft having the turbine mounted thereon being of greater dimension than the portion of said shaft having the pumping means mounted thereon, means on the portion of said shaft between the pumping means and the turbine providing a gradual reduction of shaft dimension from the dimension of the turbine portion to the di mension of the pumping means portion, said bearing comprising a sleeve member force fit at its central portion onto the portion of said shaft between said turbine and pumping means, said sleeve and shaft having a relatively small annular passageway formed therebetween at one end, and a relatively larger annular passageway at the other end, means connected to said bearing whereby fluid leaking into said bearing from said pump is passed to a cooling source, and means connected to said bearing for returning cooled fluid to said bearing.

2. In a bearing for a pumping unit including a shaft, a turbine mounted on a portion of said shaft, a pumping means mounted on another portion of said shaft, the portion of said shaft having the turbine mounted thereon being of greater dimension than the portion of said shaft having the pumping means mounted thereon, means on the portion of said shaft between the pumping means and turbine providing a gradual reduction of shaft dimension from a dimension of the turbine portion to the dimension of the pumping means portion, said bearing comprising a sleeve member force fit at its center point onto the portion of said shaft between said turbine and pumping means, said sleeve and shaft having a relatively narrow annular passageway formed therebetween at one end and a relatively larger annular passageway at the other end, a bearing member mounted about the sleeve to form a narrow annular chamber therebetween, said bearing including a port connected to said narrow annular chamher, a bearing housing suitably mounted by bracket means to the casing about the bearing member, said bracket means having a hollow dome-like extension formed thereon and having a passageway connected to the port in said bearing member, outlet means for discharging fluid passed to said narrow annular passageways from said pump, an annular auxiliary impeller mounted on said sleeve member whereby fluid passed to said narrow annular passageways is passed out said last mentioned means to a cooling source and means connected to said passageways for re turning cooling fluid to said narrow annular chamber between the bearing member and the sleeve whereby the cooling fluid functions to form a heat insulator between the shaft and sleeve at the opposite end portions thereof.

3. The hearing as claimed in claim 2 including a cooler connected between the cooling fluid inlet and outlet for cooling the recirculated fluid prior to delivery to said narrow annular chamber.

4. The combination with the hearing as claimed in claim 2 of a fluid operated turbine control and a tap-off connection from said means passing cooling fluid to the bearing to said turbine control whereby the recirculated water is utilized for the additional purpose of operating said turbine control.

5. The combination with the hearing as claimed in claim 4 of a fluid operated eductor unit connected to apply a vacuum to a turbine seal and tap-01f connections from the means passing cooling fluid to said bearing to the said eductor unit whereby the circulated water is utilized for the additional purpose of operating the eductor unit.

6. The combination with the bearing as claimed in claim 2 of a fluid operated turbine control and an eductor unit connected to apply a vacuum to a turbine seal and tap-0E connections from the means supplying cooling fluid to the bearing to each of these units whereby the circulated water is utilized for the additional purpose of operating these units.

7. In a bearing for a pumping unit including a shaft, a turbine mounted on a portion of said shaft, a pumping means mounted on another portion of said shaft, the portion of said shaft having the turbine mounted thereon being of greater dimension than the portion of said shaft having the pumping means mounted thereon, said bearing comprising a sleeve member force fit at its central portion onto the portion of said shaft between said turbine and pumping means, said sleeve being spaced from said shaft at the opposite ends thereof to form annular passageways with the shaft operating to reduce heat flow from said shaft to said sleeve, means connected to said bearing whereby fluid leaking into said bearing from said pump is passed to a cooling source and means connected to the bearing to return cooled fluid to said bearing.

References Cited in the file of this patent UNITED STATES PATENTS

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