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Leonard J Lavasser

Dennis J Mancl

Dennis J Manel

A universal motor includes a commutator brush with a cavity for sheltering a constant force spring from a wire shunt. In some examples, the cavity can be formed by milling a blind hole into the brush such that an axial centerline of the hole is perpendicular to the brush's length. The cavity is near the back end of the brush, at the end farthest away from the commutator, but is also slightly forward to leave a rear portion of the brush to serve as a barrier between the wire shunt and the spring. The diameter of the cavity is slightly larger than the width of the brush, so the cavity creates a slot in the side of the brush. The slot allows part of the spring to reach out beyond the cavity to where the spring can hook onto a front edge of a stationary sleeve that supports the brush.

Commutator brush and rolled-up spring assembly

A motor-driven blower, particularly suited for carpet cleaners and other wet vacuuming appliances, includes a rotating separator cup to impede water droplets and foam from being drawn into the blower. The separator cup is removably connected to a spider bracket that is mounted more permanently to one end of the motor shaft. Since the separator cup is not directly connected to the motor shaft, the cup can be removed without disturbing the rest of the blower. Thus, the blower can be run either with or without the separator cup. Moreover, by not attaching the separator cup directly to the motor shaft, the shaft can be made shorter to minimize vibration and noise at high rpm's.

Removable gas/liquid separator for a motor

A universal motor comprises a stator interposed between a housing and a novel plastic bracket. The plastic bracket is a unitary piece that not only defines a plurality of terminal receptacles but also supports the motor's outboard bearing. In some embodiments, the plastic bracket also includes an integral post for supporting a spring that urges a carbon brush against the motor's commutator.

Motor bracket with integral terminals

A high-speed universal motor running at over 10,000 or even over 20,000 rpm includes a non-rubbing water repellent sleeve that protects the bearings from moisture damage. Rather than having a sliding contact seal that can quickly wear out under such high speeds, the sleeve is made of material having a low solid surface energy so that the seal material itself repels waters on its own. TEFLON is the preferred material, which is relatively soft, so to prevent the compressibility of the seal from affecting the axial positioning of parts on the motor shaft, the seal is installed such that the seal does not contribute to the critically precise positioning of the shaft and the parts mounted to it. In some embodiments, for example, the relatively soft seal simply overlies a much stiffer, accurately machined metal spacer.

Water repellent motor sleeve

For a motor having a plastic bracket, a single-piece ground strap grounds both the motor's stator and rotor. The ground strap has one end fastened to a bearing retainer of the motor, an opposite end connected to a ground wire, and an intermediate section that is compressed between the stator and the housing. The end connected to the bearing retainer grounds the rotor, and the intermediate section grounds the stator. The ground strap is fastened to the motor using fasteners that already exist in an otherwise identical but ungrounded motor. In some cases, a combination bearing retainer and ground strap is blanked and formed as a unitary piece.

Ground strap for a motor having a plastic housing

A motor, particularly suited for carpet cleaners and other wet vacuuming appliances, includes a motor housing with a stepped bore. The stepped bore is part of a bearing/seal assembly that simultaneously clamps a bearing and compresses a seal member. The assembly maintains the motor's commutator at a substantially fixed axial location relative to the commutator's brushes, regardless of the extent to which the seal is compressed and regardless of any subsequent creep of the seal.

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Bristol, TN, United States of America

Leonard J Lavasser