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Design & structure

Start from the application to define electromagnetic, thermal and structural limits.

Simulations
6
Structural
3
Sealing steps
6
Test report
Pending

Start from the application to define electromagnetic, thermal and structural limits.

Development starts from the application. Electromagnetic, mechanical and thermal simulation establish design limits, while integrated construction, interfaces and sealing define the assembly and protection path.

This page presents six structural protection measures recorded in the available material. Ratings such as IP55 are test conclusions and require a report identifying the models covered.

The one-piece casing and front cover
The one-piece casing and front cover
G-02Simulation

Development starts from the application and multi-dimensional design validation

Two groups, six analyses. The electromagnetic set fixes the limits of torque and loss; the mechanical and thermal set fixes those of structure and heat. Both happen before any tooling is cut.

01Electromagnetic simulation

  • Back-EMF distribution
  • Magnetic density distribution
  • Magnetic line of force distribution

Sets torque ripple, iron loss and demagnetisation margin — whether torque holds at low speed is settled here.

02Mechanical & thermal simulation

  • Stress analysis of the frame
  • Thermal analysis of the control cover
  • Stress analysis of the rear cover

Under negative-pressure duty the cooling airflow is falling away, so the control cover’s heat path has to be settled in simulation first.

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Six simulation plots: back-EMF, flux density, field lines, frame stress, control-cover temperature, rear-cover stress

The original simulation outputs are needed from the factory, each labelled with its analysis condition — speed, load, ambient — and the software version. A plot without its condition is decoration, not evidence.

G-03Structural design

Integrated construction, interfaces and sealing

An integrated motor and controller reduce external connections and separate components. Structural design focuses on the housing, interfaces and sealing paths.

01Front cover merged with the frame

  • Reduces assembly steps
  • Improves tolerance stack-up
  • Eliminates the waterproofing failure risk of a mechanical joint

One joint fewer is one path for water fewer. It is also the first of the six steps to IP55 below.

02Sandwich structure of the rear cover

  • Eliminates redundant connecting parts
  • Simplifies assembly
  • Reduces the overall length of the motor

Overall length decides the mounting envelope. On roof units and in-duct direct drives, where space is tight, this is a selection threshold.

03Potting of the motor control

  • Improves control heat dissipation
  • Improves the waterproofing of the control
  • Eliminates the risk of loose electronic components

An integrated machine puts the controller on the motor, where it takes the motor’s vibration and temperature rise. Potting addresses both at once.

BSource: the product and development overview page of the standalone English site. That site has been unreachable since 2026-09-15; this is compiled from cache and the wording needs factory confirmation before publication.

G-04How the sealing is built

Six steps, from one-piece forming to the shaft seal

The order runs outside in: first remove joints, then seal the joints that remain, and finally deal with the rotating parts. Each step closes the leak path the one before it cannot.

  1. 01Motor casing and front cover formed as one piece
  2. 02O-ring end-face seal between casing and end cover
  3. 03Contact surfaces machined to ensure end-face flatness
  4. 04Additional sealant between casing and end cover
  5. 05A domestic branded shaft seal
  6. 06The front bearing sealed with a rubber cover

Six steps are not a report

These six are construction measures. They explain how protection is achieved; they are not an IP55 test report. Stating "IP55" as a product rating still requires an ingress-protection test report naming the versions covered.

Bhttps://rasta-motor.com/ec-motor-80-series/ (FAQ 6.8)

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Sealing-path section: one-piece face, O-ring, sealant, shaft seal, front bearing cover

One section drawing explains all six steps far better than six lines of text. Either request a structural section from the factory, or draw a schematic from the engineering drawings once they arrive, labelled as schematic rather than as a drawing.

G-05Boundary

Validation boundaries for design and protection ratings

Documented construction details

  • BCasing and front cover are formed as one piece
  • BThe end face is O-ring sealed on machined surfaces
  • BThe controller is potted
  • BSimulation covers electromagnetic, mechanical and thermal

Conclusions requiring test reports

  • D"Rated IP55"Needs an ingress-protection test report naming the versions covered
  • D"700-hour salt spray"The coating brand can be stated; the duration has no report and is withdrawn
  • DSimulation results as measurementsSimulation is a design basis, not validation evidence — see the duty validation page
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