Close
Close
6 comments

Engineering360: "How the world’s first large-scale electric excavator works"

07/29/2019 3:05 PM

Read Engineering360 article: How the world’s first large-scale electric excavator works.

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru

Join Date: Aug 2012
Posts: 1064
Good Answers: 92
#1

Re: How the world’s first large-scale electric excavator works

07/29/2019 10:53 PM

Here's a picture of an even larger electric excavator- that could easily pick up one of these Cats in its' bucket!

(Photo courtesy wikipedia -Big Muskie, the world's largest ever single bucket shovel, weighed about 12,000 tons!)

I guess a dragline isn't quite the same as a hydraulic excavator, so how about these?

(Photo courtesy Vancouver Sun. Also a little bit smaller than Big Muskie.)

Yes, I guess these are still wire rope shovels, not hydraulic excavators, but...

(Photo courtesy hitachiconstruction.com)

...this 1,800,000 plus pound midget still far outdoes the Cat! Although the model shown appears to be a diesel unit, Hitachi's website notes that it, as well as a number of its smaller siblings, are also available with an electric drive instead.

In all reality, the big keynote here is that someone's finally producing a battery powered unit that can give the versatility contractors look for in these units, as opposed to the dedicated requirements of a mining shovel.

Register to Reply
Guru

Join Date: May 2018
Location: Under the spreading Bunya Trees, South Burnett, Queensland, Australia
Posts: 646
Good Answers: 59
#2

Re: How the world’s first large-scale electric excavator works

07/30/2019 7:01 AM

When I read this article I had to check the calendar to make sure it wasn't April the first. Pay three times the price for an excavator to run for quarter of a day of continuous work and then have it down for a similar time to charge.

Might be good in town but they are more often used in remote areas where there is no power source for recharging. So what do you do, buy three of them and a low loader to cycle them through the charging station so one is working, one is travelling/parked and one is on charge.

Then there is the statement that they can be connected to a supply for continuous work except that means trailing cables to a supply or have a "nasty smelly diesel" generator set to power them. I have worked with machines needing trailing cables and the logistics of shifting substations and cables limits the mobility.

I think one of these may excite a Tesla driver or a green regulator but for get them for general use and what about the ROI on one of these?

__________________
Hare today, goon tomorrow!
Register to Reply
Guru

Join Date: Aug 2012
Posts: 1064
Good Answers: 92
#3
In reply to #2

Re: How the world’s first large-scale electric excavator works

07/30/2019 8:34 AM

Pretty simple- just the same way that our former Ontario government managed to vastly increase our cost of electricity!

  1. Mandate these MUST be used on government jobs.
  2. All contractors bidding on these jobs will then pad their prices accordingly (this of course includes the extra profit to maintain margins, as they know everyone else is doing the same),
  3. and you, the taxpayer, will then pay the difference.
  4. The machine will then be used on some other jobs in industrial areas where they actually have access to power with the wattage needed to recharge one of these units (somehow I doubt the average subdivision development will),
  5. with the major point being photo shoots that are carefully cropped to cut out the diesel genset in the background!

There's no question that these will have some advantages over a diesel unit- mainly in terms of maintenance and long term operating costs. But to pay off that price jump?!?!

Register to Reply
Member

Join Date: Jul 2019
Posts: 6
#4

Re: How the world’s first large-scale electric excavator works

07/30/2019 10:29 AM

This Z-line machine points toward the power future. Battery-electric machines currently serve in especially emissions- and heat-sensitive environments such as in underground mining and urban earthworks, but remain cost-prohibitive for general adoption. Diesel-electric machines which are now rapidly proliferating will fill the gap for many years. Though still powered by diesel engine, they employ a generator, motors and power electronics to greatly reduce wear-prone drivetrain parts, enhance operator control and increase both fuel and operational efficiency. Battery-electric heavy machines will remain both a cost-control and feasibility challenge for years to come, but the nearer-future of diesel-electric will lay an ongoing groundwork for their eventual practicality.

Register to Reply
Participant

Join Date: Apr 2019
Posts: 2
#5

Re: How the world’s first large-scale electric excavator works

08/15/2019 10:10 AM

A good start... But shouldn't the advantages of servo motors be used to better advantage, by installing them in strategic points or combining further linkages to make the most of mechanical and electrical efficiency. "Just" "electrifying" machines is not the solution (assuming the reason for its conversion to an electrical digger is for efficiency purposes" "The excavator is nearly identical to the diesel-powered Cat 323F excavator, except its diesel engine has been replaced with an electric powertrain".

Obviously these machines need to be robust but to me some parts seem a little "over engineered" (therefore there is/would be a waste of material and energy in their original production and consumption of energy in their daily use), something for the design engineers to look at...

Register to Reply
Guru

Join Date: Aug 2012
Posts: 1064
Good Answers: 92
#6
In reply to #5

Re: How the world’s first large-scale electric excavator works

08/15/2019 10:37 AM

The simple fact is, servo motors would have limited facility in most excavation equipment except for propulsion and possibly excavator swing.

Additional linkages and gear train that would be required to provide the torque needed for arm movements and bucket breakout using servo motors will add lost efficiency due to friction etc., increase cost and wear points (which also means more grease points, not something an operator wants to hear), and some will be located on the arm and dipper stick- both place subject to dirt, abrasion and impact. Not a good place for this.

As far as being over-engineered, I'd beg to differ. The point of these machines is that the manufacturers want to sell them, and the only reason the purchasers want to buy them is so they can complete the work that justifies purchasing them. Comparing an excavator design to something like a car isn't even an apples and oranges comparison, it's more like apples and carrots. These machines have to be designed to work at near capacity for one or two shifts a day. What may seem over-engineering is the level required to let a typical machine reach a 10,000- 15,000 hour lifetime of this.

Register to Reply
Register to Reply 6 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Copy to Clipboard

Users who posted comments:

Bernie Barton (1); JNB (3); michealocong (1); Stef (1)

Advertisement