Monday, 8 October 2018

Pride's Quantum Motor Brushes

Pride's Quantum Motor Brushes and Repairs

Those who have followed the last few posts know that I spent the summer of 2018 a prisoner of my own home as my Quantum 6000 power wheelchair lost power in one motor.  As a result, the chair was unable to climb the ramp into my home.

The right motor being weaker than the left could not even climb the three-quarter inch raised transition leading to my washroom.  Both wheels would hit that lip but while the right wheel continued to climb over, the left wheel lacked power and subsequently the chair would swivel into, and crash into the right wall.  I needed someone to push the chair over the rise in order to enter.

When first diagnosed, I was told the joystick 'gimbal' was out of alignment so that power was not distributed evenly to the motors.  That didn't sound right to me but the technician told me he measured the motors and they were "bang-on" factory specifications.  So I laid out $900+ dollars for a new joystick.

After waiting a month for the parts and service the new joystick was installed yet the power issue remained.

It was a second technician who installed the joystick and as the problem remained the new assessment was that one motor was not operating properly.

Bingo!  That was my initial thought, yet the first technician said motors were within factory specifications.

The second technician then brought my attention to a damaged 'cap', for lack of a better term, which held one of four motor brushes against the motor armature.  If the first technician did not report this damage, I figure it was he who damaged it.  Regardless, only the slot was broken which is used to unscrew the 'cap' from the motor housing.  The brush still made contact and could not account for the power loss.

So, after initially being told the motors were working fine (though I doubted that), I was told I needed a new motor.  I was advised that if I replaced one, I might as well replace both to be safe---which I chose to do.

Another month passed: up to a week to place the order, two weeks to ship and receive the order and then a week to ten days to wait in queue until a technician is free to install the items.

I spent two months---the 21st of June until the 30th of August unable to leave my house with my powerchair.  Repairs, both unnecessary and necessary amounted to over $3000.00 Cnd.

 Broken brush 'plug' can be see at the end of the top red arrow.  The brush assembly is seen below.  The 4 per motor carbon/metal composite (?) brushes conduct electrical current to the motor.  The brush is sandwiched between a spring which presses it against the armature, and the cap which secures it to the motor.

While it turned out the brushes were not the source of my motor power issue, they are not stocked by the company and as far as I was able to determine from my technician, Pride does not offer replacement brushes.  If they fail, you buy a new motor.

My technician confirmed that motors are not interchangeable so you can't change the housing and swap a left motor for a right if you had a spare.  Damaged motors are not rebuilt or repaired but are trashed.  Some 'Green' world we live in!

A closer view of the cap and spring-brush assembly which fits into the port/hole in the motor above.

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