Multi-Speed Industrial Electric Motor for Pumping Units

Multi-Speed Industrial Electric Motor for Pumping Units



Multi-Speed Industrial Electric Motor for Pumping Units

Direct-drive, high torque, low speed PM motor with multiple pole configurations — eliminates the gearbox and its maintenance burden in beam pumps, screw pumps, and conveyors.

Why Multipole Multispeed Motor?

The gearbox is the most failure-prone, highest-maintenance component in any rod-pump or screw-pump drive train. It leaks oil, wears bearings, strips gears, and requires regular oil changes — all while consuming 3 – 8% of input power in frictional losses. The Jingtao Energy Multipole Multispeed Motor eliminates the gearbox entirely by generating rated torque at the load’s native speed. Instead of a 1,500 rpm 4-pole motor + 10:1 gearbox, a 40-pole multipole motor delivers full torque at 150 rpm — directly coupled to the polished rod or pump shaft. Multiple pole configurations (8, 12, 16, 24, 32, 40, 48 poles) allow precise speed matching to the application without mechanical reduction. The motor uses permanent-magnet rotor technology for high efficiency and power factor, and integrates with a VFD for soft starting, speed trimming, and regenerative braking. Field data from Changqing and Daqing show that eliminating the gearbox reduces total drive-train maintenance cost by 60 – 75% while improving system efficiency by 8 – 12 percentage points — savings that accumulate over the motor’s 15 – 20 year service life.

Specification Highlights

  • Pole configurations: 8, 12, 16, 24, 32, 40, 48 poles — synchronous speed at 50 Hz from 750 rpm (8-pole) down to 125 rpm (48-pole)
  • Multispeed operation: Pole-changing winding (Dahlander / PAM) for 2 or 3 discrete speeds without VFD; or continuous speed regulation with VFD
  • Torque density: Up to 40,000 N·m continuous at <100 rpm in largest frame — eliminates gearbox entirely
  • Power range: 7.5 kW – 250 kW; rated torque from 500 N·m to 40,000 N·m
  • Rated speed: 60 – 750 rpm (pole-configuration dependent)
  • Voltage: 380 V / 660 V three-phase; medium-voltage on request
  • Efficiency: IE4 minimum at rated load; IE5 achievable in selected configurations
  • Power factor: 0.94 – 0.97 (PM excited)
  • Direct-drive coupling: Hollow-shaft or flange-mount options — bolts directly to load shaft, no belts, no gears, no coupling alignment
  • Enclosure: IP55 TEFC standard; IP65 / IP66 for outdoor and washdown environments
  • Cooling: IC416 (force-ventilated) for low speed continuous-torque operation; IC411 for higher-speed applications
  • Bearing: Oversized spherical roller bearings (SKF / Timken) rated for L10 life >100,000 hours at full radial and axial load
  • Feedback: Resolver or absolute encoder for closed-loop VFD control at <1 rpm
  • Maintenance savings: 60 – 75% reduction in drive-train maintenance cost vs. induction motor + gearbox

How Multipole Direct-Drive Technology Works

Conventional drive trains pair a 4-pole (or occasionally 6-pole) motor running at 1,500 / 1,800 rpm with a gearbox to convert high speed and low torque into the low speed and high torque the load requires. The Multipole Multispeed Motor inverts this logic:

1. Pole-count torque multiplication: Motor torque is proportional to the product of magnetic flux and the number of poles. A 40-pole motor produces — for the same flux density and current — 10 times the torque of a 4-pole motor at 1/10th the speed. This is intrinsic electromagnetic torque multiplication, achieved without mechanical components. NdFeB permanent magnets on the rotor provide the high flux density needed to make high pole counts practical in a compact frame.

2. Direct shaft coupling: The motor shaft directly drives the load at its native speed — no gearbox, no belts, no chains. For beam pumps, the multipole motor’s hollow shaft accepts the polished rod directly. For screw pumps, a flange-mount connects to the drive head. The only rotating components are the motor bearings and the load shaft — eliminating gear-mesh friction, oil-churning losses, and seal leakage.

3. Multispeed flexibility: For applications requiring occasional speed changes (e.g., different pump speeds for different well conditions), pole-changing windings provide 2 – 3 discrete synchronous speeds from a single motor winding — no VFD required. For continuous speed regulation, the motor pairs with a VFD operating in sensorless or closed-loop vector control. At very low speeds (<10 rpm), a resolver or absolute encoder provides precise rotor position feedback for smooth torque delivery without cogging.

4. Regenerative capability: On beam pumps, the downstroke is an overhauling load — gravity pulls the rod string down. The multipole motor, driven by a 4-quadrant VFD, operates as a generator during the downstroke, returning energy to the DC bus or grid. This regenerative braking recovers 10 – 15% of cycle energy that would otherwise be dissipated as heat in a mechanical brake.

Multipole Multispeed Motor vs. Conventional Solutions

Feature Geared Induction Motor Single-Speed PM Motor Jingtao Multipole Multispeed Motor
Speed Flexibility Fixed — gear ratio determines speed Fixed — single pole configuration Multiple pole configs — multi-speed operation
Gearbox Required Yes — adds cost, maintenance, efficiency loss Sometimes — depends on speed match No — direct drive, high torque at low speed
Starting Torque 1.5× rated (with gear reduction) 2× rated 2.5× rated — handles cyclic beam pump loads
Maintenance Points Motor + gearbox oil changes, bearing greasing Motor only Motor only — IP55, sealed bearings
Efficiency at Low Speed Poor — gear losses compound Good — but fixed speed limits optimization Excellent — IE4+ across speed range
Application Fit Fixed-speed beam pumps Single-speed applications Beam pumps, screw pumps, conveyors — variable duty

Field-Proven Applications

  • Beam pumping units (rod pumps) — Changqing Oilfield: 32-pole, 22 kW multipole motor direct-driving a 10-type beam pump at 125 rpm. Eliminated 10:1 double-reduction gearbox. Gearbox oil-change crew reassigned; zero gearbox-related downtime in 30 months.
  • Progressive cavity pumps (PCP) — Xinjiang heavy oil: 40-pole motor driving PCP at 150 rpm via hollow-shaft coupling. Previously required 4-pole motor + belt drive + right-angle gearbox — three components reduced to one.
  • Belt conveyors — Coal mine surface conveyor: 16-pole, 75 kW motor direct-driving head pulley at 375 rpm. Eliminated fluid coupling and helical-bevel gearbox; total drive-train length reduced by 1.8 m.
  • Screw pump surface drive — Daqing polymer-flood wells: 24-pole motor at 250 rpm, VFD speed trimming ±20% for production optimization. Gearbox-free drive reduced wellhead footprint by 40%.
  • Mine hoist auxiliary drive — low speed, high torque positioning duty: 48-pole motor at 125 rpm with encoder feedback, providing smooth creep-speed control without the mechanical backlash of a geared drive.

Get Your Multipole Motor Technical Proposal

Every application has a unique torque-speed requirement. Our engineers will review your load profile — speed, torque, duty cycle, and mounting constraints — and deliver a custom technical proposal with pole-count selection, frame sizing, VFD pairing recommendation, system efficiency comparison (against your current geared drive), and a total-cost-of-ownership analysis — within 48 hours.

Request Your Technical Proposal

Or contact us directly: +86 18661390903 | [email protected]

Explore Related Solutions

Ready to Deploy the Multipole Multispeed Motor?

Get a free technical assessment with deployment proposal, datasheets, and pricing for your specific application.

Response within 24 hours · Technical datasheets included · Virtual factory tour available

Related Products