Machine Assembly & Production

TESLA EMS Production can provide you with enormous productivity advantages with your assembly work. We combine electronics as well as mechanics and deliver your functional assembly. Our highly qualified team procure, assemble and package your unit according to your specifications with the utmost precision. We provide you with more time for your core competency. We are your partner in the field of mechanical and electromechanical components, as well as complex customer-specific assemblies, including taking over procurement and supply chain management. We accompany you along the entire product life cycle.

  • Development of complete assemblies
  • Mechanical assemblies
  • drive units
  • Partial and complete assembly
  • Assembly of individual parts
  • Fast and flexible prototyping
  • Integration of printed circuit boards
  • Cable assembly, cabling
  • Testing and functional tests
  • Creation of documentation and operating instructions
  • Integration with the customer – Just in time
  • Warehouse and distribution logistics
  • Packaging and box moving
  • Delivery to end customers

Motor Assembly & Production

 

Conventional (“Slotted”)BLDC manufacturing processes

The BLDC manufacturing process can be looked at in terms of the following elements: stator manufacturing, rotor manufacturing, final assembly, test and drive electronics manufacturing and final system test.

Stator Manufacturing:

Stamping of laminations (lams) The first step is to stamp the laminations (lams) out in the right geometry with a suitable stamping die and stamping press. This is a critical stage of the manufacturing process. A poorly designed lam or a poorly manufactured lam can cause heating, loss of efficiency and problems in final assembly. Low loss electrical steels such as M19 or M36 with surface coating for rust protection are commonly used in this process. The tooling of the lamination and choice of the die is a very important decision and great care must be taken before choices are made. Stamping dies can cost between Rs. 2,10,000 to Rs. 5,00,000 (for a high speed steel low volume die) to Rs. 10,00,000 (for a high volume carbide die). Poor choice of dies are a source of major disaster down the road when the motor is in production.

Stacking

Once the lams are stamped, they are stacked using a variety of processes such as notching, gluing, welding or pinning, depending upon the experience of the motor manufacturer.

Insulating of stack

The next step is to insulate the stack with electrostatic (characteristically bright lue in color) coating to insulate the copper wire from the sharp edges of the steel lam stack. Plastic insulators are used for high volume applications and in some cases paper insulators are also used.

Winding

The next most crucial process is winding. The choice of the winder must be made with care with due consideration to capacity, flexibility, set up time and above all, reliability. A poor choice of winder can break the project. Winders range in price form a few thousand dollars for low volume labor intensive applications to several hundred thousand dollars for high volume automatic manufacturing of multiple stators at a time.

Prepping

After winding the stator wires need to be properly connected and end turns formed as required by the design, varnished to keep the wires in place and get the stator ready for final assembly.

Stator Manufacturing Process:

Manufacturing

Step Critical parameters

Cost implications

Lam stamping

Lam geometry, no burs or sharp edges, the cut of the lams needs to be smooth and clean

Lam dies can cost from Rs. 80K to Rs. 800K depending upon volume requirements

Lam Stacking

Lams stack has to be welded, interlocked with notches, glued or held fastened together with steel pins. The lams in some cases need to be skewed to achieve certain performance characteristics of the motor. The stack needs to be perfectly lined up to avoid problems in final assembly.

Stacking fixtures and process are critical to the overall manufacturing process.

Stack insulation

This process is to prevent shorting of the magnet wire in the slots to the stack. 1500 volts DC is a typical “high pot” test to ensure the integrity of the insulation. The insulation material must provide the needed electrical isolation but it also needs to be very thin in order not to occupy too much of the valuable slot space.

Low volume stacks are coating with characteristically blue powder which is electrostatically deposited. Plastic insulators are used for high volume applications.

Winding

This is the most critical process and its integrity depends much on the winder and the winding tooling

Winders can cost between more depending upon the volume requirements, flexibility and capacity

Prepping

The ends turns are shaped, connectors attached with a suitably reliable process and the assembly is varnished to keep the windings in place

Automatic trickle varnish systems and fixtures for end turn shaping if required are critical processes

Test

High pot test and resistance test at this stage are used to ensure the integrity of the stator

Automatic in line data logging is done at this stage to offer traceability in case of problems down the road.

Rotor Manufacturing:

Shaft machining:

The rotor manufacturing starts with the machining of the stainless steel shaft. The bearing journals need to be ground to tight tolerances. Shafts are either manufactured in house or procured from subcontractors who specialize in the manufacture of shafts or complete rotor assemblies with magnets. In correct machining of the shafts, especially the grinding process, can lead to trouble down the road.

Hub machining:

This is a round piece of steel with a hole through it for the shaft and it has the right diameter for the magnets to be glued on to it. The hub is sometimes made from powder metal with higher tooling cost but lower piece part cost.

Magnets gluing:

Magnets are typically bonded Neo rings for smaller motors and sintered Neo pole pieces for larger motors. These magnets are glued on to the hub. The gluing process is not trivial at all and has been perfected by each individual manufacturer based on years of experience. Kevlar tape or a steel band is added over the magnets for extra security especially for rotors which are to be used in high speed applications.

Bearing press:

At this stage, the bearings are pressed on and the rotor is ready to mate with the rest of the parts in final assembly. Care needs to be taken with appropriate fixtures to avoid improper or cocked seating of the bearings.

Manufacturing Step

Critical parameters

Cost implications

Shaft machining

Machining tolerances especially around bearing journals and where feedback sensors are to attach

This is a labor intensive part and best sourced as a complete machined part or a a complete rotor assembly with the hub and magnets

Hub machining

The ID and OD of the hub are critical for trouble free assembly to the shaft and to the magnets.

Powder metal parts are sometimes tooled to reduce labor cost. Powder metal tooling may cost as much as $10,000.

Magnet gluing

This is deceptively simple process. If it is not done properly it can cause a great deal of headache down the road.

Gluing fixtures and tools need to be put in place to reduce the manufacturing cycle time.

Bearing press

Fixtures need to be in place to prevent improper and cocked installation of the bearings.

Housing and End Bell Manufacturing:

In most modern small motors, the end bells are made from aluminum or from Zinc. The housings are steel shells or extrusions suitable for good heat transfer. Castings and machining are done at subcontractors. The bearing journals again are critical dimensions, which must be held to tight tolerances. Normal casting hygiene ( no porosity or bubble holes) need to be practiced.

Advances in BLDC technology are driven by two main factors:

– Advances in magnetic materials.

– Advances in DSP’s.

Advances in magnetic materials:

Early permanent magnet motors (primarily brush type DC motors) appeared on the scene in the early seventies. By the early eighties, BLDC motors were establishing themselves in an increasing number of applications. The early permanent magnet motors had ceramic or ferrite permanent magnets in them. The figure of merit of these magnets was quite low (about 3-4 MGOe2 ). Bonded Neo (Neodymium Boron Iron) magnets with 10-12 MgOe came on the scene in the eighties, followed quickly by sintered Neo magnets with 30-45 MgOe. As the materials have advanced in their energy product, BLDC motor designs have kept up with them. The higher the magnet strength, the higher the motor efficiency and the higher the torque which can be put out by the motor. It is interesting to note that while BLDC designs have kept up with advancing materials, vintage brush type DC motors continue to be offered only with low performance ceramic magnets. The gradual progression of the performance envelope of Neo magnets will continue in the near future.

Advances in DSP’s:

The advent of low cost DSP’s in the late nineties, has given the BLDC motors a major boost. The performance of motors using DSP’s is significantly increased with very little incremental cost. New and innovative features which were never possible before are now routinely available. Features such as high speed feedback control loops (servo loops), digital communication, diagnostics, memory, programmable input/output control are now all possible with very little extra cost. It is like having a small PC inside the motor! As the advances in DSP’s continue clever BLDC motor companies will ride on the crest of these waves and harness the power of DSP’s to their advantage. Conversely, those companies who do not use DSP’s in their BLDC products will lose and be left behind. With increasing performance of magnets, DSP’s and declining costs of power electronics, BLDC motors will continue to be the adopted in an increasing array of of new products. They are already in automobiles, appliances, HVAC, Mil-Aero applications. They will continue to make inroads into an increasing number of commercial applications where the incumbent technologies are either brush DC or induction AC. The advantages offered by BLDC technology are much too compelling to ignore.

Drive Assembly & Production

Electronics Manufacturing:

The printed circuit boards (PCB’s ) are normally not done in house at most motor manufacturers. This is a very capital intensive part of the business and there are numerous companies globally whose business it is to make PC boards and place the electronic components on them. These components can be “through hole” which is an older technology or “surface mounted” (SMT), which is a much newer technology and which is suitable for modern PC boards which have small size tiny components.

An issue which has just come up with PC boards is ROHS compliance. ROHS is European directive against the use of hazardous materials. Past 2006, any boards which are not ROHS compliant will not be allowed to be shipped to any EU country. This is a non-trivial but well defined change in the environment. It does have a cost implication on all PC boards, including PC boards used in BLDC motors.

After the PCB’s are fabricated at a PCB house, they are shipped to a contract manufacturer for “stuffing” or placing of the electronics components on to the PC boards. This again is a capital intensive business and most motor manufacturers get this portion of the manufacturing done at the premises of contract manufacturers rather than doing the work in house.

Thermal management (getting rid of the heat generated in the electronics and detecting and protecting against over temperature conditions), is handled by the heat sink and the associated hardware. This is a major part of the electronics and it represents a case where the motor engineer and the electronics engineer need to work very closely together.

DC Controller Ready to use

 

These simple motor controls for brushless motors offer the user a cost-effective solution to switch motors safely and without wear. Since the controllers already have various standard functions, no programming knowledge is required for commissioning these controllers.

Features
– connection power up to 400 W resp. 2100 W
– versions for 1

BLDC Controller Ready to use

 

These simple motor controls for brushless motors offer the user a cost-effective solution to switch motors safely and without wear. Since the controllers already have various standard functions, no programming knowledge is required for commissioning these controllers.

Features
– connection power up to 20 W to 12000W

Electronic Assembly & production

Customized electronics

TEM Motion develops your application-specific electronics for you.
From the creation of the specification to prototype verifications to serial production we offer you all services.

– Consulting and concept development
– Customized electronics and motion control development
– Embedded hardware development
– Embedded software development
– Validation and testing
– Development accompanying EMC – Pre-compliance tests
– Development of mechatronic systems
– Development of HMI implementation From Feldbussen
– Fast and cost-effective prototype production in the house

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