US2867173A - Pump - Google Patents

Description

Jan 6, 1959 K. R. LUNG 2,867,173

PUMP Y Filed April 29. 1955 FIG-1 v 25 SIS IN V EN TOR.

KENNETH R. LUNG BY w M, M-

ATTORNEYS United States Patent P Kenneth R. Lung, Dayton, Ohio, assignor to The Tait Manufacturing Company, a' corporation of Ohio Application April 29, 1955, Serial No. 504,783

z Claims. (cl. s- 87) This invention relates to sump or drain pumps, vand more particularly to such pumps of the submersible type wherein the motor is mounted in close relation with the impeller housing for submergence in the liquid in the space to be drained.

It is a primary object of the invention to provide a submersible sump pump of the type embodying a centrifugal impeller driven on a vertical axis by a motor located above the impeller housing wherein the motor casing and the impeller housing are releasably coupled together by a simple and effective mechanism facilitating their disconnection for servicing, and wherein special provision is made for screening solid material from access to this connection between the motor casing and impeller housing as well as from access to the pumping chamber itself.

It is also an object of the invention to provide a submersible sump pump as outlined above wherein a screen member is mounted in engagement with both the motor casing and the impeller housing to screen solid material from access to the connection therebetween as well as to the inlet to the pumping chamber in the impeller housing, and wherein this screen member is constructed and arranged to minimize the development of forces tending to cause solid material from collecting on and/or penetrating through the screen.

Additional objects and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claims.

In the drawingl Fig. 1 is a view generally in vertical section through the motor casing and impeller housing of a submersible sump pump constructed inaccordance with the present invention; and

Fig. 2 is a section on the line 2 2 of Fig. 1.

Referring to the drawing, which illustrates a preferred embodiment of the invention, the pump includes an mpeller housing 10 and a motor casing comprising upper and lower sections 11 aud 12 bolted together in sealed relation at 13. The upper casing section 11 supports the motor stator 15, which is suspended therein by means of bolts 16, and this casing section also supports the control switch for the motor, which is actuated by a lever arm 21 mounted on the outside of the casing and by its associated weight 22 and iloata 23 on a cord 24, reference being made in this connection to my copending application Serial No. 504,782 filed of even date herewith and assigned to the same assignee as this applicacation now Patent No. 2,748,220 issued May 29, 1956. The electrical supply conduit 25 to the motor enters the casing section 11 through a sealed plug 26, and thus the stator 15 and its entire associated electrical parts and connections are independent of the lower casing sec'- tion 12 and may be removed therefrom as a unit for any necessary service.

The drive shaft of the motor supports the rotor 31 and is in turn supported by a pair of bearings 32 and 33 in the housing sections 11 and 12 respectively.

The lower end of shaft 30 projects through a boss 35 depending from housing section 12 and cooperating with the shaft to mount a rotary seal 36 sealing the interior' of the motor housing against access of liquid along the shaft. This seal is supplemented -by the bearing 33, which includes sealing disks 37 and 38 carried by the outer race thereof and overlying the ball-receiving space therethrough to minimize pressure leakage in either direction'through bearing 33.

The impeller housing 10 includes a split boss portion 40 at its upper end which ts over the motor housing boss and is secured thereto by a strap type clamp 41 and clamp bolt 42. The bottom wall Vof the impeller housing is provided by a removable metal plate 44 which also may conveniently include a downwardly extend` ing flange portion 45 forming the base of the unit, the plate 44 being bolted directly to housing 10 at 46. The interior of housing 10 forms a pumping chamber 50 having inlet passages 51 through the vupper portion of the housing between the ribs 52 connecting boss 40 with the lower part of housing 10. A generally tangentially arranged outlet passage 53 leads from chamber 50 for connection with a discharge pipe 54.

Within the pumping chamber 50 is the impeller 55, which is shown as cast or molded from a suitable plastic material such as a phenolic resin and which includes a shroud portion 56 forming the bottom of the impeller and a plurality of upwardly extending curved vanes 57. The impeller is splined on the lower end of shaft 30 by means of a key 5S to provide for limited axial movement' of the impeller with respect to the shaft, reference being made in this connection to my copending application Serial No. 504,781 led of even date herewith and assigned to the same assignee as this application. A curved abutment 59 on the under side 0f the impeller supports it on the bottom plate 44 when the pump is at rest, and in operation, the pressure developed between the shroud 56 and plate 44 causes the impeller to rise out of engagement with plate 44 for free rotation in the pumping chamber.

Screening means are provided in accordance with the invention for screening solid material from access both to the inlet passages 51 and also to the clamped connection between the motor casing and the impeller housing. This screening means comprises a cylindrical perforate screen 60 which encircles the space between the impeller housing and the motor casing. The lower casing section 12 is formed with a depending annular shoulder 61 having a cylindrical outer surface 62 forming a seat for the upper end of screen 60, and a similar cylindrical seat 63 is provided by an upstanding boss portion 64 on the impeller housing 10 outside and below the inlet passages 51. Thus the screen 60 engages both of these seats and is releasably secured in engagement therewith by simple detachable means such as'a pair of sheet metal screws4 65 connecting the overlapping ends of the perforate sheet which forms the screen 60.

It will be seen that this screen construction offers important practical advantages in use. Since the screening area is large in comparison with the flow area through the inlet passages S1, the average suction elective at each point along the face of the screen is correspondingly lower than the suction through the inlet passages, thus having a reduced tendency to draw solid sediment through this screen. In addition, with the screening surface essentially vertical, solid particles in the liquid being pumped are unlikely to stick to the screen surface but will more naturally be drawn by gravity to the bottom of the space being pumped,.namely below the level of the inlet passages to the pumping chamber. At the same time, this screening unit is of simple construction and is also simple tof remove andV replace in connection with any servicing requirements, l

While the form of apparatus herein described, constitutes a preferred embodiment of the invention, it is tol be understood that the invention'is not limited to this precise formof apparatus, and that changes may be made'y therei'without departing from the scope of the invention which is,` dened in the appendedA claims.

What is claimed is:

1. A submersible pump of the character described comprising an impeller housing including a pumping chamber having an inlet in the upper portion of said housing, a substantially Water-tight motor casing having motor parts therein vincluding a drive shaft projecting downwardly therefrom, a tubular boss' depending from said casing'in surrounding relation with said shaft and of substantially smaller diameter than said casing, said impeller housing-r including a tubular boss extending upwardly therefrom above and' radially inwardly of said inlet,rs aid housing boss being split and proportioned to telescope over the lower end ofsaid casing boss, means forreleasably clamping said bosses together in telescoped relation tov form the entire vsupport for said casing on said housing with said drive shaft extending therethrough into saidv pumping chamber, said casing having an annular shoulder on the lower end thereof substantially concentric with and of substantially greater diameter than said -boss thereon, means forming on said housing a peripheral surface ylocated radially outwardly of said inlet and -matching the radially outer peripheral surface of Said shoulder in aligned relation therewith, and a tubular perforate screen encircling and seating on said peripheral surfaces to screen solid particles from access to said bosses andY to said pumping chamber inlet.

`2. A submersible pump of the character described comprising an impeller housing including a pumping chamber having an inlet in the upper portion of said housing, a substantially water-tight motor casing including a cupshaped lower ycasing section, an upper casing section proportioned to seat on the upper end of said lower casing t 4 I section, a motor stator located within said casing, means securing said stator directly to said upper casing4 section independently of said lower section, a control switch for said motor also supported entirely within said upper casing section, a rotor positioned within said stator and including a drive shaft journaled in both said casing sections and projecting downwardly from said lower section, said lower section. including a tubular boss depending therefrom in surrounding relation with said shaft and of substantially smaller diameter than said section, said impeller housing including a tubular boss' andA a tubular perforate screen encircling and seating on said peripheral surfaces to. screen solid particles from accessto said bosses and to said pumping chamber.

References Cited in the file of this patent UNITED STATES PATENTS 2,121,299 Peters lune 21, 1938 2,361,747 Curtis et al. Oct. 3l, 1944 2,394,860 Korte Feb. 12, 1946 2,417,197 Hewitt et al. Mar. 11, 1947 2,662,206 Schaefer Dec. 8, 1953 2,722,892 French Nov. 8, 1955 2,744,466 Difford May 8, 1956 FOREIGN PATENTS 651,619 Great Britain Apr. 4, 1951

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