Rotary kinetic fluid motors or pumps – Working fluid passage or distributing means associated with... – Specific casing or vane material
Reexamination Certificate
2001-08-31
2004-03-23
Verdier, Christopher (Department: 3745)
Rotary kinetic fluid motors or pumps
Working fluid passage or distributing means associated with...
Specific casing or vane material
C415S216100, C415S217100, C416S24400R, C416S24100B, C417S423300, C417S423600, C417S424100, C464S113000, C464S159000, C403S305000, C403S306000, C403S361000, C403S383000
Reexamination Certificate
active
06709234
ABSTRACT:
TECHNICAL FIELD
The present invention relates to pumping molten metal and more particularly to an impeller shaft connection between a drive and an impeller in a molten metal pump.
BACKGROUND OF THE INVENTION
Pumping molten metal is a difficult task and a challenge to designers of pumping equipment. The high temperature of molten materials (such as aluminum) and the corrosive effect of the molten material and components used in the refining or smelting processes prohibit the use of ordinary pumping equipment.
The pump drive motor, for example, should be situated above the molten metal level to isolate the components of the motor and drive assembly from the molten metal. Thus, an impeller shaft assembly is typically provided between the drive shaft and the impeller to transmit rotational forces from the driver or motor to the impeller.
It has been found that a graphite refractory, “Silon”
™
, silicon carbide, and other heat resistant materials are suitable for impeller shafts due to the ability of these types of material compositions to withstand the heat and corrosive effects of molten metal.
FIGS. 1-3
are illustrative cross-sectional views of a shaft assembly A in which a shaft end B is received within a connector socket C. The socket C is typically connected to the drive shaft of a drive motor. Some prior devices transmit torsional forces from the type of socket C shown in
FIGS. 1-3
and a shaft end B by providing a “modified square” coupling arrangement. The socket C includes a formed socket part D and the shaft end B includes a complimentary configuration E. The two shapes are closely fitted together.
On the other hand, if the two members are loosely interfitted as shown in exaggerated form in
FIGS. 1-3
, transmission of torsion from the socket member to the shaft is concentrated closer to the corners of the “modified square” configuration of the shaft end. This places the corner portions in shear and can cause fracture and premature wear.
It has thus remained desirable to obtain a fitting arrangement whereby an impeller shaft can be removed for replacement from an impeller and drive assembly, but in which transmission of torque, especially at the coupling area between the drive shaft and impeller shaft is transmitted without excessive shear forces being concentrated at corner sections of the formed impeller shaft end.
REFERENCES:
patent: 2634991 (1953-04-01), Stevens
patent: 4954167 (1990-09-01), Cooper
patent: 5078572 (1992-01-01), Amra et al.
patent: 5092821 (1992-03-01), Gilbert et al.
patent: 5165858 (1992-11-01), Gilbert et al.
patent: 5181828 (1993-01-01), Gilbert et al.
patent: 5294245 (1994-03-01), Gilbert et al.
patent: 5470201 (1995-11-01), Gilbert et al.
patent: 5622481 (1997-04-01), Thut
patent: 5685701 (1997-11-01), Chandler et al.
patent: 5993728 (1999-11-01), Vild
patent: 63-120897 (1988-05-01), None
Dion Robert D.
Gilbert Ronald E.
Kauffman Roger
Palmer Mark A.
Ratzlaff Kristopher M.
Pyrotek Inc.
Verdier Christopher
Wells St. John P.S.
LandOfFree
Impeller shaft assembly system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Impeller shaft assembly system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Impeller shaft assembly system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3273750