US2257349A - Pump - Google Patents

Description

Sept. 30, 1941. D. SHERWOOD PUMP Filed 'Jan. 18, 1959 2 Sheets-Sheet l Patented Sept. 30, 1941 UNITED STATES PATENT OFFICE PUMP David Sherwood, Grosse Pointe Park, Mich., as-

signor to Sherwood Brass Works, Detroit, Mich., a corporation of Michigan Application January 18, 1939, Serial No. 251,479

1 Claim. (01. 103-126) This invention relates generally to pumps and more particularly to the arrangement of seals therefor.

It is an object of the present invention to provide a pump having a new and improved arrangement of the operating and associated parts thereof.

Another object of the invention is to provide a pump including sealing means so arranged as to permit easy and ready assembly and/or disassembly of the pump.

Other objects of the invention will become apparent from the following description taken in connection with the accompanying drawings in which- Figure 1 is a view shown in longitudinal central section of my improved pump;

Fig. 2 is a view shown in cross section of the pump, taken along the line and in the direction of the arrows 2-2 of Fig. 1;

Fig. 3 is a view shown partly in elevation and partly in section of the pump, taken along the line and in the direction of the arrows 3-3 of Fig. 1;

Fig. 4 is a detail view in cross section taken along the line 4-4 showing certain associated parts of the pump;

Fig. 5 is a detail view partly in elevation and partly in section showing certain associated parts of the pump, and s Fig. 6 is a view shown in longitudinal section of a modified form of my pump.

The invention resides in the arrangement of the parts and construction of the pump hereinafter described in detail and particularly pointed out in the appended claim.

Referring to the drawings by characters of reference and first to Figs. 1 to 5 inclusive, the pump includes a casing which is of sectional construction comprising hollow end sections I and II and a removable wall or plate |2 interposed between the end sections l0 and II. The sections II and II have opposed open ends separated by the removable wall or plate l2 which cooperates with section III to provide a pump chamber l3 and cooperates with section II to provide a seal chamber l4, the end sections I0 and II and the plate l2 may be rigidly secured together by screws IE or by other suitable means. The pump chamber I3 is provided with an inlet l and an outlet H for liquid and disposed within the chamber i3 between the inlet |8 and the outlet H, a pair of cooperating impellers or pump gears l8 and 13 are mounted respectively on a pair of parallel shafts 24 and 2|. For efllcient pumping action the widths of the pump gears I8 and I3 are made substantially equal to the. width or depth of their chamber l3 such that the opposite side faces of the gears will be in close proximity to the opposed surfaces of the casing end wall 23 and the plate l2. The drive gear I8 is pressed and keyed onto the drive shaft and these parts as a unit are assembled with the other pump parts to facilitate assembly, as will later be seen.

The shaft '20, which is the drive shaft, extends through the chambers I3 and I4 and the gear I! may be keyed, as at 22, to the shaft 23, the gear I! being an idler gear which is pressed on the shaft 2|. The end wall, as at 23, of the end casing section l0 and the end wall, as at 24, of the outer end casing section are provided with aligned bores 25 and 26 respectively for receiving and rotatably supporting the drive shaft 20 which extends through a bore 21 in the plate I2. The shaft 2| has opposite portions supported in bored recesses 28 and 29 respectively provided in the casing sections Ill and and this shaft is provided longitudinally thereof ,with a lubricant passage 30 which communicates with a vertical passage 3| that connects the bored recesses 25 and 28 to supply lubricant to the opposite ends of the shaft 2| and to the end of shaft 20 which is joumaled in the bored recess 25 of the end casing section III.

In order to prevent leakage of liquid along shaft 20 through the bore 26 of easing end section II, a seal, designated in general by the numeral 32 is provided in the seal chamber l4. This seal includes a cup-shaped member 33 which surrounds the shaft 20, the member 33 being provided with a hub portion 34 which fits snugly onto the shaft which is provided with a transverse pin 35 having its opposite ends projecting from the shaft to engage in slots 36 provided in the hub portion 34 whereby the cup-shaped member 33 rotates with the shaft. Surrounding the shaft 20 within the cup member, compressible packing material 31 and a retainer cup or abutment member 33 are provided, the packing material 31 being compressed between the retainer cup 33 and a plate 40 by means of a helical coil spring 4| which surrounds the shaft20 having one end abutting the retainer 38 and the other end of the spring abutting the end wall of the cup-shaped member 33. The spring 4| crowds the packing material 31 down around the shaft 2|! and urges the plate 43 whichfis preferably impregnated with lubricant against an inwardly directed boss 42 of the end wall 24. In its outer periphery, the plate or disc 40 is flanged, as at 43, to engage in slots 44 provided in the open end of the cup-shaped member to provide a driving connection therebetween.

whereby the entire seal device 82 rotates with the shaft 20.

Preferably, the casing end section II, includes an extended portion 46, projecting from and cast integral with the end wall 2, the outer end of the extension being enlarged, as at 41, and provided with a recess 48 to receive a ball bearing 48. The bearing 49 comprises spaced inner and outer races 50 and respectively and ball bearings 52 therebetween, the outer race 5| abutting theshoulder formed by the recess 48. A drive coupling 53 fits over the outer end of the shaft 20 and is secured thereto by apin 54 which extends transversely through aligning apertures in the shaft and coupling, the coupling abutting the inner race 58, and the outer race 5| abutting the recessed wall will hold the shaft 20 against end thrust in opposite directions whereby to prevent wear on the opposite faces of the gears l8 and I9. In the removable plate l2 oppositely disposed slots 55, Fig. 3, are provided which intercept the bore 21 and constitute clearance apertures for the pin 35 on assembling and/or disassembling the pump.

In operation of the pump, liquid will leak from the pump chamber l3 into the seal chamber l4 in the bore 21 and slots so that chamber l4 will be full of liquid but the seal device 32 will prevent any leakage of liquid along shaft 20 through bore 25. It will be seen that the present pump embodies a pump chamber in which the opposite faces of the pump gears are in close proximity to the opposed walls of the pump chamber and provides a leak proof seal chamber which are so constructed as to permit ready assembly and/or disassembly of the pump. For example to disassemble the pump, the screws l5 are first removed after which the end casing section 23 may he slipped off of the shafts 20 and 2| but gear i8 is not removable for as previously mentioned it is press fitted onto shaft 20. Next, the

chambers 84 and 55 and are rotatably supported in aligned bores in the casing end sections and in the separating plate 82. Surrounding each of the shafts 68 and 59, within the chamber 65 are seal devices 18 and 'II which are the same in c'onstruction and therefore a description of one of the devices is deemed sufficient. The seal devices 10 and 1| include a drive cup 12 which surrounds the shaft 68 or 69 and is connected to rotate therewith by a pin 13 which extends through a transverse bore in the shaft and has its opposite ends engaging in slots I4 in the open end of the drive cup. Surrounding the shafts 68, 69 within the drive cup 12 an abutment member 13a is movable'on the shaft longitudinally thereof and abuts a rotatable disc 15 which in turn abuts or contacts the inner end of a hollow boss 'I'I which is integral with an intermediate internal wall 16 of the end casing section 5|.

These pins 13 also serve as stops to prevent movement of the seal devices to the left. Within the drive cup 12, a helical coil spring 18, under compression urges and holds the plate or disc 15 in engagement with the end of the hollow boss Tl. In the outer periphery of the plate 15 notches provide spaced extended portions 88 which are received in radially spaced notches 8| in the open end of the drive cups whereby the cups will cause the plates 15 to rotate upon rotation of the shafts.

The end casing section 5| is provided with an outer wall 82 which is recessed to receive roller bearing units 83 in which the shafts are lownalled and surrounding the shafts between the bearing units and the internal wall 16, seals 84 which may be of any suitable type are provided pin 54 is removed and then the shaft 20 may be pressed to the right, Fig. 1 through the coupling 53 and through the inner race 50 of the bearing 49 after which the casing section II may be removed. The seal 32 can now be slipped off of the left end of the shafts and then aligning pin 35 with slots 55, the removable wall or plate member l2 may be slipped off of the left ends of the shafts, thus disassembling the pump units without removing the pump gears from their shafts. By press fitting the drive gear l8 onto its shaft 20 and assembling these parts as a unit with the other parts of the pump it will be seen that the gear may be quickly fixed on the shaft accurately with respect to the position it must assume in the pump chamber on assembly which is particularly advantageous in pumps wherein the'side faces of the pump gears must be in close proximity to the opposed chamber walls for efficient pumping action.

Referring now to the modified form of pump shown in Fig. 6, this pump also includes a sectionally constructed casing comprising hollow end sections 60 and GI separated by a removable wall or plate 62 which parts may be rigidly secured together by. screws 63 or by other suitable means. The plate 62 divides the interior of the casing into a pump chamber 64 and a seal chamber 65. In the pump chamber 64, a pair of cooperating pump gears 68 and 61 are press fitted and, keyed respectively to a. pair of parallel shafts 88 and 69 which extend through the to prevent oil leakage from the bearings 83, On the outer ends of the shafts 68, 58 cooperating gears are provided and keyed to'the shafts,

as at 86, the gears being held against axial movement on the shafts by pins 81. j

In the outer wall 81a of the end casing section 60 a recess 88 is provided through which the upper shaft 68 extends and mounted on the shaft 68 within therecess is a sealing device or unit which is the same in structure as the previously described units 1|. The recess is closed by a removable closure member 90 which cooperates with the recess to provide a fluid tight chamber for the sealing device II and this closure member is provided with abore 9| for rotatably receiving the shaft 68. The removable closure member 90 is further provided with a housing 93 wherein a roller bearing unit 94 is received for the shaft 68, thehousing having an open end for access to the bearing which may be held in place by a snap ring 95.

In the pump of Fig. 6 it will be seen that the shaft 68 is provided on opposite sides of the pump chamber with rotatable sealing units II to prevent leakage along the shaft beyond the closure member 90 and beyond the internal wall I6 of easing section 6|. In this pump, the internal casing wall, as at 96, and the plate 62 are provided with clearance apertures 91 for the pins 13 so that the parts may be disassembled which may be done in substantially the same manner as the pump of Figs. 1 to 5 inclusive.

While I have shown and described my invention in detail it is to be understood that the same is to be limited only by the appended claim sections having aligning bores, a drive shaft mounted in said bores, a removable plate disposed between said sections and having a bore to receive said shaft; said plate cooperating with one of said casing sections to provide a pump chamber and cooperating with the other of said casing sections to provide a second chamber, said pump chamber having an inlet and an outlet, said shaft extending through both of said chambers and having one end projecting externally 10 of said second-named chamber, a sealing device surrounding said shaft in said second-named chamber, an abutment pin for said sealing device for detachably and positively connecting said sealing device to said shaft, said abutment pin extending transversely through said shaft, clearance apertures in said plate for said pin, and pump gears in said pump chamber and driven by said shaft.

DAVID SHERWOOD.

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