Multi-stage submersible pump

This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 60/999,960 filed on Oct. 23, 2007, the entire contents of which is incorporated herein by reference.

Booster pumps are commonly used to drive pressure cleaners for swimming pool and spa applications. For such pressure-side pool cleaners to operate, the booster pump must increase the water pressure of the system to about 50 pounds per square inch (PSI) in order to have sufficient pressure at the cleaner to clean the pool. Typically, this pressure increase is achieved by using a single-stage centrifugal pump with a large diameter impeller.

A drawback of such systems is that to provide a pump capable of such increased pressures, the diameter of the impeller must be increased. Larger diameter impellers require additional power to drive them, leading to greater power consumption and reduced efficiency. Another drawback of such systems is that the motor for driving the pump as well as the pump itself are typically larger than desired. In general, smaller motor and pump assemblies are preferred because less power is required to operate them.

In some embodiments, a booster pump to pressurize fluid for use by a pool cleaner in a pool or spa is provided. The booster pump includes a front housing and a motor housing. The front housing includes an inlet to receive fluid from the pool or spa. A plurality of diffuser units are positioned in the front housing. The motor housing detachably couples to the front housing and has an outlet to provide fluid to the pool cleaner. A submersible motor is positioned in the motor housing and is operatively coupled to the diffuser units. A space is defined between an outer surface of the motor and an interior surface of the motor housing. A self-contained fluid flow path is formed from the inlet, through the diffuser units, and through the space to the outlet.

Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings.

Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.