An important milestone in the history of mobility of water was the invention of the vertical HOLLOSHAFT® motor in 1922. This year, as U.S. MOTORS® celebrates 100 years since the invention of this game changing motor technology, we are not only commemorating an important innovation that has brought water pumping to new levels – but also an event that is a marker of how far the science of pumping has progressed through time. Below is a brief insight into the history of the vertical Holloshaft motor and how the technology evolved over time. (Click images to enlarge)
Introduction of the revolutionary Vertical HOLLOSHAFT motor with ball bearings for the pumping industry
Introduction of the U.S. Uniclosed motor aided by the partnership with Johnston Pumps. The motor featured a HOLLOSHAFT design for ease of pump impeller adjustment, thrust handling ball bearings, a non-reversing clutch, alternate mounting base sizes and shaft whipping protection.
Introduction of a streamline, weatherproof design called type CFU
Introduction of the Lubriflush® lubrication, a transverse lubrication that forced new grease though the bearing, flushing out the old
- Introduction of Reg-U-Lube® oil flow of 20HP and up
- Introduction of an improved Verticlosed type CFU motor with Vis-O-Lube® flush type oil gauges, optional Ball-O-Matic backstops, choice of single or tandem thrust bearings for high or extra high thrust capacity proportioned to fit smaller pump heads
Introduction of the new U.S. MOTORS® Streamway Verticlosed
- Launch of the Holloshaft Right Angle Gear drives for deep well pumping
- Introduction of the type HU HOLLOSHAFT motor
- Introduction of the single phase Hollo® shafts
- Introduction of the BALL-O-MATIC® for vertical HOLLOSHAFT motors. This non-reverse ratchet prevents reverse rotation
within 4.5 degrees of rotation, has unlimited depth setting and can be used in explosion proof applications.
- Introduction of Lubriport®, a visible oil indicator with a retractable fill opening
New design for the HOLLOSHAFT is created and released. An additional rotating seal is added to protect the lower guide-bearing against the entrance of sand during handling and transportation
Introduction of the RU HOLLOSHAFT featuring double-downdraft ventilation and a square shape that cools the entire motor while maintaining full weather protection
Launch of the VPI epoxy insulation system on 440 frame and larger. Introducing Class F and Class H insulation materials, 8000 and 7000 frames type HU and HV and Weather Protected II enclosure and also increasing voltage capability up to 6900V and thrust capacity up to 30,000 pounds
Introduction of ALLGUARD® Motor Quality System combining the industry’s best motor winding protection with the latest advancements in motor bearing lubrication
Introduction of the Energy Efficient HOLLOSHAFT motor
Introduction of the Premium Efficient VHS to meet expanded DOE efficiency regulations
Introduction of Inverter Grade® Insulation to protect motors against PWM waveforms produced by the ever-increasing use of VFDs for energy savings
Addition of WPI VHS 600HP 1800 RPM 460V stock rating
- Updated inverter duty VHS stock models to include shaft grounding and insulated upper thrust bearing, if 400 frame & larger
- Launch of new WPI & WPII VHS 5813 cast iron frames with max HP of 1750
- Introduction of stock WPI VHS Inverter Duty models with 175% extra high thrust on 100HP through 350HP
- Increased UL Listed Fire Pump certification on VHS motors from 449 frame to 5012 frame and includes inverter duty
- Introduction of new TEFC VHS 5812 frame increasing max HP from 700 to 1100.
Sinewave Optimized® Stock offering specifically designed motors to operate at single speeds.
- Launch of new TEFC VHS 6812 frame increasing max HP from 1100 to 2000
- Launch of new WPI & WPII VHS 6813 cast iron frame with max HP of 4000.
Redesign of Weather Protected I VHS 449 frame increasing max HP from 450 to 500. Also, included new Weather Protected II enclosure and 30.5” base diameter option
- Launch of redesigned Weather Protected I VHS 5008 & 5012 frames with increased reed critical frequency
- Launch of redesigned Weather Protected I VHS 320 through 445 frame, which included new LUBRIPORT® oil sight window, larger volume steel main conduit
boxes, stronger screen material and tiedown provisions