Method of improving the overall operating efficiency of an electric motor-powered assembly

• US 7,143,502 B2
• Filed: 02/09/2004
• Issued: 12/05/2006
• Est. Priority Date: 08/12/2002
• Status: Expired due to Fees

• Current Assignee: Aquatron Incorporated (Fluidra, S.A.)
• Original Assignee: Aquatron Incorporated (Fluidra, S.A.)
• Inventors: Fridman, Igor, Porat, Joseph
• Primary Examiner(s): Tugbang, A. Dexter
• Assistant Examiner(s): PHAN, THIEM D
• Application Number:
  US10/775,730
• Publication Number:
  US 20040168299A1
• Time in Patent Office: 1,030 Days
• Field of Search: 295/86, 294/47, 294/58, 294/59, 295/98, 134/6, 285/381.1, 403/273
• US Class Current: 29/596
• CPC Class Codes: E04H 4/1654 Self-propelled cleaners
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine
• CPC Class Codes: Y10T 29/49012 Rotor
• CPC Class Codes: Y10T 29/49865 by temperature differential [e.g., shrink fit]
• CPC Class Codes: Y10T 29/49885 with coating before or during assembling
• CPC Class Codes: Y10T 29/49886 to roughen surface
• CPC Class Codes: Y10T 403/48 Shrunk fit

Abstract

A submersible robotic pool cleaner is provided with an integral sealed rechargeable battery and an inductive charging assembly, a first portion of which is mounted in the pool cleaner housing and during the charging, receives a second separate portion that is connected by a cable to a conventional power source. The pump motor drive shaft is treated with a specialized anti-friction lubricant composition to minimize frictional energy losses where the shaft contacts the seal(s) and any shaft bearing(s), to maximize efficiency and minimize the power consumption of the pump motor assembly and permit the pool cleaner to completely traverse the surfaces to be cleaned within the fully-charged power capacity of the battery.

Claims

1. A method for improving the efficiency of an electric motor contained in a waterproof motor housing having at least one drive shaft extending through a waterproof seal in said motor housing, the method comprising the steps of heating the drive shaft to a temperature of about 40°

C.;

applying a liquid automotive crankcase anti-friction lubricant additive to the shaft;

heating the coated shaft to a temperature of about 80°

C.;

cooling the shaft to ambient temperature;

assembling the drive shaft to the motor; and

placing the seal on the drive shaft and operably installing the motor and seal in the housing.

2. The method of claim 1, wherein the lubricant composition is a polymeric material.

3. The method of claim 1, wherein the liquid lubricant composition is applied to the portion of the shaft in contact with the seal.

4. The method of claim 1, wherein the drive shaft is stainless steel.

5. A method of improving the overall operating efficiency of an electric motor-powered assembly, the assembly comprising an electric motor, a drive shaft connected to the motor, a driven unit connected to the drive shaft and one or more contact units through which the drive shaft passes axially, the contact units selected from the group consisting of seals, bearings and journals, the method comprising the steps of:

heating the drive shaft to a temperature of about 40°

C.;

applying a liquid automotive crankcase anti-friction lubricant additive to the shaft;

heating the coated shaft to a temperature of about 80°

C.;

cooling the shaft to ambient temperature;

assembling the drive shaft to the motor; and

placing the seal on the drive shaft.

6. The method of claim 5, wherein the lubricant composition is a polymeric material.

8. The method of claim 5, wherein the liquid lubricant composition is applied to the portion of the shaft in contact with the contact unit.

9. The method of claim 5, wherein the drive shaft is stainless steel.

10. The method of claim 5 in which the driven unit is a water pump and the electric motor is contained in a waterproof housing.

7. The method 6, wherein the polymeric lubricant additive includes tetrafluoroethylene, fluorocarbon polymers, fluorinated ethylene propylene resins and combinations thereof.