Internal and External Earth of Starter Motors

To understand the internal and external earth of the starter, you must understand what the earth is first. The earth is a term of circuit, most commonly seen in the auto repair industry.

The path that current flows through is called circuit. The current starts from the positive pole and pass through the entire circuit, of course, there must be resistance in the circuit or there will be a short circuit. After the current passes through all the electrical appliances and back to the negative pole that’s a formed closed loop.

There are also positive pole and negative pole on the battery of the car. The current flows from the positive pole of the battery and pass all the appliances on the car to the negative pole which formed a closed loop to supply the electricity to all the electrical appliances, so that all the appliances on the car can work properly. And because the body of the car is made of metal which has electrical conductibility so when people design the car they usually use the body of the car as the negative pole to connect with the negative pole of the battery.

The internal earth of the starter means the armature of the starter is directly connected with the housing. Because the housing is installed on the frame of the car, the current directly flows through the frame and back to the negative pole of the battery to form a closed loop. The external earth is the armature of the starter insulates from the housing, it needs a terminal to connect the negative pole of the battery to form a closed loop.

Tips from: Shuocun Zhou

Starter Motor Reference for Nissan TD42; Komatsu 6D102

Nissan Starter Cross Reference for Nissan TD42

Komatsu Starter Cross Reference for Komatsu 6D102

Ford to cut production at five North American vehicle plants

DETROIT (Reuters) - Ford Motor Co (F.N) said on Tuesday it plans to idle five North American vehicle assembly plants for a total of 10 weeks to reduce inventories of slow-selling models.

The plants affected include three assembly plants in the United States and two in Mexico, the company said in a statement. The vehicle models include the Ford Fusion and Lincoln MKZ midsize sedans, the Ford Focus compact car, the Lincoln Continental and Ford Mustang, Ford Fiesta and the Ford Transit van.

The factories involved employ more than 15,000 people, according to Ford’s website. The company did not say how many of those workers would face temporary layoffs.

As of Sept. 1, Ford had 111 days’ worth of unsold Mustangs, 87 days’ supply of Fusions, and a 103 days’ supply of Transit vans, according to Automotive News. Dealers had enough unsold Lincoln Continentals to last 162 days. Automakers aim for 65 to 70 days of inventory of most models.

Ford and rival General Motors Co (GM.N) have wrestled most of this year to rein in high inventories of passenger cars as consumers have shifted to buying pickup trucks and sport utility vehicles. 

Production cuts slice into revenue, but also could help the automakers avoid deeper price cuts on vehicles they can sell.



News from:https://ca.reuters.com

Material Selection of Armature Commutator

Commutator is a component of starter motor which changes the direction of current in order to allow the starter motor keeps turning.

Copper is a key material of commutator, usually the hardness ranges in HB80-HB120 and the best range should remain between HB95 and HB105. Besides adding silver into the copper can ensure that the commutator have sufficient hardness even at extreme temperature.

When the starter motor is running, the commutator is subjected to a high linear velocity. So when it changes the direction, the spark will constantly ablate the surface of the commutator, causing a dramatic increase in the surface temperature of commutator. But after adding a certain amount of silver into the copper, it can increase the high temperature resistance of the silver-copper alloy as well as the hardness of the commutator, so that the surface of the commutator won’t be distorted easily. And there is a misunderstanding that the more silver it contents in the copper the better it is. In fact, it is not the case. With higher content of the silver, the conductivity of the silver-copper alloy will decline, also it brings negative impact to the commutator itself which makes it not easy to form a useful oxide film.

One other factor that needs to be considered is the softening temperature of the copper. The general softening temperature is 150℃ and it can rise to 250℃ when the copper contains 0.06% of silver. Hence here involves another issue, the matching problem of carbon brush. With higher silver content of the copper, the hardness of the carbon brush should adjust accordingly or the life of the carbon brush will be shorter. So the content of silver in the copper can’t be generalized.

At present, the general material using in the commutator of low-end configuration starter motor in domestic is T2 copper ( US grade C11000/ Japan grade C1100) or 0.08% silver-copper for standard ones.

The case of the commutator is made of glass-reinforced thermosetting plastics or bakelite powder which has high requirements on the heat resistance and mechanical strength of plastic, and also requires the thermal expansion to be as close as possible to the copper of the commutator segment, so the material of the bakelite in the commutator is also critical.

Bakelite is a kind of hard and brittle thermosetting plastic which has high mechanical strength, good insulation, tough wear-resistant, dimensional stability, heat and corrosion resistance.

Generally the bakelite powder using on the commutator of high-end configuration starter motor is 6830 and for standard configuration ones is 6630. As for low-end starter motors, some manufacturers will use fiberglass to replace bakelite powder too.



Tips from Shuocun Zhou

Starter Motor Cross Reference For Yanmar 4TNV94L; Daewoo 350

Yanmar Starter Cross Reference for Yanmar 4TNV94L

Daewoo Diesel Engine Starter for Daewoo 350

Starter Motor Cross Reference For CAT 304;VOLVO FM9

Caterpillar Starter Motor Cross Reference for CAT 304

VOLVO Diesel Engine Starter for VOLVO FM9

Why recently Chinese factories can’t deliver the shipments on time?

According to the news of Ministry of Environmental Protection, the seventh round of the yearlong strict inspection on air pollution control started on 7^th July and completed on 20^th July ( details: 

http://english.mep.gov.cn/News_service/news_release/201707/t20170727_418638.shtml ).

​​​​​​​During the period, the inspection teams checked a total of 5,322 businesses (organizations), and found environmental incompliances in 1,389 of them. Of the incompliant enterprises, 347 were unlicensed small polluters, two did not attain emission standards, 252 failed to install pollution control facilities, 160 failed to keep such facilities in normal operations, 536 had VOCs control problems, and four had other problems.

Starting 21st July, the inspection team launched the eighth round strict inspection over the air pollution in the Beijing-Tianjin-Hebei region and surrounding areas. On the sidelines of the eight strict inspections, the Ministry is about to initiate six rounds thematic inspection in Hebei and Henan which will last for 84 days.

Thus many factories have to close for reorganization in order to meet the standards of the Ministry. The production has been suspended and resulting the delay of the lead time.