slip ring

Split Ring Manufacturing

ICC manufactures not only commutators but slip rings as well. Below you'll see some of the steps involved to create a new set of bronze slip rings with G-10 insulation. 

Before work can begin on the mill a program is designed by our engineers. After the program is working properly the slip ring is clamped center of the machine and the mill can locate the exact points of machining. 

Split Rings after excess has been machined.

Split Rings after excess has been machined.

Bronze Split Rings

The next step is to drill the holes.

Bronze Slip Ring, Split

G-10 Insulation

G-10 is also machined in house. 

G-10 is also machined in house. 

Bronze Slip Ring, Split
G10, G-10, Slip Rings

Final Step is assembly. In this case the steel hub was reusable, so it was sandblasted and painted back to like-new condition. 

Bronze Slip Ring, Split
Bronze Slip Ring, Split
Bronze Slip Ring, Split

When should you buy a complete new commutator?

Most of the time, don't.
A "new" commutator refers to a commutator designed and built from scratch, including all copper, mica and steel components.

The key is steel:
The only time you need a new commutator is when you do not have an existing steel part in good condition to fit the style and size of commutator you need.
• Conversion
• Replacement of damaged parts
• Spare
• Design improvement
Conversion: When an existing unit is molded (i.e. nonrefillable), the commutator needs to be replaced. Either a new molded unit, if available, can be purchased, or a new v-ring or glassband refillable commutator can be manufactured. None of the steel components of molded commutator should be re-used (see Motor Fax Issue 11) due to design limitations and space requirements for maximum stability. Conversions between refillable types also require new steel parts.

Replacement of Damaged Parts: Whether damaged from arcing in operation, galded or warped from removal from the shaft, or cracked due to porous castings, damaged steel parts must be replaced to ensure stability of the commutator in operation.

Spare: With the aim of reducing down time for the future, manufacturing a spare new unit is another circumstance in which new steel is a requirement. Either purchased from the OEM or designed by an aftermarket manufacturer, key dimensions can be obtained from prints or from the existing unit, ideally upon refill. Alternatively, if shaft profile information is available, along with any flange mount details if required, a new unit can usually be designed. As long as accurate and detailed information about the external dimensions of the commutator and its application environment is available, a new commutator can typically be designed to fit.

Design Improvement: In some cases, an existing steel design may cause problems in a specific application. For example, a v-ring commutator with a floating front cap and no spool may prove unstable or particularly susceptible to contamination in the wrong environment.
New steel can be designed to incorporate a front bore fit and spool to address the operational issues. In short, buying a new commutator when a refill is an option is rarely the most cost effective or timely choice. With no sacrifice in quality by re-using good quality steel parts, refilling a commutator typically represents the best option available in motor repair.

Should you or your customer have any questions regarding this issue, contact an ICC representative and we will be happy to assist you in making a decision on your specific
situation.

Why is oven baking time such a hot issue?

Time is money
     ...is the short answer.

And it's why the desire to shorten deliveries to customers, even on straight time work, is so strong. Since bake cycle duration can easily be one of the biggest chunks of time in scheduling a project, it seems to be the perfect candidate for cutting.

But there are technical reasons to keep temperatures relatively low and cycle times in place.

Baking is used both to cure materials, and to create an environment which replicates that
that found in operation. Controlling both the temperature and duration of the bake cycle is important to avoid overheating. During bake-off, for example, overheating can result in a reduction in motor efficiency.

Although today's insulation products can withstand higher temperatures, the resin compound requirements for curing must still be met. Further, the modulus of any given material will only allow it to accept a specific amount of thermal soaking. Raising the temperature unfor-tunately cannot speed this process. Fortunately, with the manufacturing software, process improvements and expedited shipping options available today, deliveries can still be improved, putting more of your time (and money) to the bottom line.

“Bake cycle duration is calculated to obtain the greatest differential expansion of the copper segment pack to the steel assembly. This results in the highest molding pressure on the mica, forcing it to its most stable operating situation. Shortening thermal cycles adversely affects commutator stability under rotational stress.”
— From the professional notes of R.F. Sharrow, PE GE Commutator Design Engineer, 36 years