Discovery MR750w and SIGNA™ Architect T 3.0T System Service Methods
5690002-2EN Revision 4
Object ID: 00000018WIA305D1130GYZ
Topic ID: id_15271101 Version: 3.3
Date: Oct 11, 2021 8:57:02 PM

Bridge and Longitudinal Drive Belt Replacement

Prerequisites

Table 1. Personnel requirements
Required persons	Preliminary requirements	Procedure	Finalization
2	Not Applicable	30 to 75 minutes	10 minutes

Table 2. Tools and test equipment
Item	Quantity	Effectivity	Part number	Manufacturer
Nonmagnetic Titanium Service Tool Kit, Small Set or Nonmagnetic Titanium Service Tool Kit, Large Set	1	-	5113258 or 5112581	-

Table 3. Replacement parts
Item	Quantity	Effectivity	Part number	Manufacturer
Front Split Bridge Assembly	1	-	See FRU Manual.	-
Long Belt Drive	1	-	See FRU Manual.	-
Front Sprocket Pulley	1	-	See FRU Manual.	-

Table 4. Safety

Warning

Ferrous material hazard

The pulley assembly contains parts made with ferrous components. Holding this assembly too close to the magnet bore will forcibly attract it to the magnet.

To prevent possible bodily injury or damage to components, remove the assembly directly. Do not move it into the magnetic field more than is necessary.

Warning

Ferrous material hazard

The front bridge support assembly contains parts made with ferrous components. Holding this assembly too close to the magnet bore will forcibly attract it to the magnet.

To prevent possible bodily injury or damage to components, remove the assembly directly. Do not move it into the magnetic field more than is necessary.

CAUTION

Heavy equipment

The bridge weighs 85 pounds.

Two people are required to lift the bridge.

About this task

Overview

This procedure explains how to replace the patient transport front split bridge, the front sprocket pulley, and the long drive belt. Plan on about 30 minutes to remove the bridge. Plan on 60 minutes if you are reinstalling the same bridge components. Plan on at least 75 minutes if you are installing a new bridge with subcomponents assembled.

Topic ID: id_SL539740-1058154

Front Bridge Removal

Procedure

Drive the LPCA and cradle into bore to within 1 ft (30 cm) of the end of the bridge.
At the foot of the table, twist or squeeze the cradle release handle to detach the cradle from the LPCA, and then pull the cradle by hand to the home position so that it is fully retracted back onto the table top.
Undock the table and relocate it away from the magnet.
Follow all LOTO procedures by turning off the applicable breaker in the PDU. See the MR Service Safety Manual, PN 5452735.
Remove the two rear pedestal covers.
Loosen the drive belt tensioner and the two securing screws.

Figure 1. Drive Belt Tensioner
Remove the LPCA cover by removing the four screws.

Figure 2. Location of Screws on LPCA Cover
Unscrew the two nuts on each of the two belt clamps that hold the belt clamp plate in place.

Figure 3. Belt Clamps
Remove the four screws holding the belt guide cover (located on the top rear of the rear pedestal) then remove the cover.

Figure 4. Location of Screws on Belt Guide Cover
Pull the drive belt free from the rear pedestal, and carefully unthread the drive belt from the rear pulley.

If the same bridge is to be reinstalled, leave the drive belt on the front bridge for easier to reinstallation.

Figure 5. Drive Belt Threading Through Rear Pulley

Note:
To continue with bridge removal, proceed to Step 11. To remove and replace the longitudinal drive belt, proceed to Longitudinal Drive Belt (Cradle Belt) Replacement and Tension Adjustment.
At the rear of the split bridge, remove the four M10 nuts and washers that attach the rear pedestal to the split bridge using a 17 mm wrench.

Figure 6. Location of Nuts at Rear of Split Bridge
Using a 5 mm Allen wrench, remove the four M6 screws holding the front bridge cover in place, and remove the cover.

Figure 7. Lower Cosmetic Cover
Using a 17 mm wrench, remove the two M10 bridge bracket bolts. When these bolts are removed, the height adjuster and spacer are no longer secured.

Figure 8. Bridge Bracket Height Adjuster and Spacer

CAUTION

Heavy equipment

The bridge weighs 85 pounds.

Two people are required to lift the bridge.

Slide the bridge out from the magnet, ensuring that the drive belt comes along with the bridge. (There are wheels on the rear of the bridge for easy transport.)

Topic ID: id_SL543007-1058154

Replacing Bridge Part within Bridge Assembly

Procedure

Lay the bridge on its top, and use a 5 mm Allen wrench to remove the four M10 screws that attach the bridge mounting bracket.

Figure 9. Bridge Bracket Screw Locations
Remove the belt from the bridge.

Figure 10. Pulley with Belt Removed

Warning

Ferrous material hazard

The pulley assembly contains parts made with ferrous components. Holding this assembly too close to the magnet bore will forcibly attract it to the magnet.

To prevent possible bodily injury or damage to components, remove the assembly directly. Do not move it into the magnetic field more than is necessary.

Turn the bridge over so the top is facing up. Using a straight-blade screwdriver, remove the two screws under the bridge top.

Figure 11. Screw Location Under Bridge Top

Remove the pulley.

Topic ID: id_SL1555020-1058154

Bridge Installation

Procedure

CAUTION

Heavy equipment

The bridge weighs 85 pounds.

Two people are required to lift the bridge.

If necessary, reinstall (or newly install) the pulley ASM and drive belt onto the new bridge by reversing the steps in Replacing Bridge Part within Bridge Assembly.

To install the bridge, reverse the steps in Front Bridge Removal.

Note:
When replacing the belt, move the LPCA back on the rear bridge until the rollers extend past the notch in the guide. This allows the LPCA to be lifted for easier threading of the belt.

Figure 12. LPCA Roller

Topic ID: id_SL2209571-1058154

Longitudinal Drive Belt (Cradle Belt) Replacement and Tension Adjustment

Procedure

Route the longitudinal drive belt.

Figure 13. Drive Belt Threading Through Rear Pulley
Reattach belt clamps at the LPCA before reattaching the belt guide cover at the table. With the belt tensioner fully down (no tension), set the front belt clamp to show 3 exposed belt teeth and set the back belt clamp to show 15 exposed belt teeth.

Figure 14. Screw Setting Tension on Cradle Belt

Item Description
1 Tension released
2 Tension set
Raise the belt tensioner fully to set the cradle belt tension.
Tighten the two securing screws.

Item	Description
1	Tension released
2	Tension set

Topic ID: id_15358516

Finalization

If the bridge was replaced, check for proper bridge alignment (see Bridge Alignment).
Reattach the two rear pedestal covers.
Reattach the LPCA cover, front bridge cover, and front trim rings, and ensure a proper fit.
Confirm that the table top height is properly adjusted and level.
Perform a Check Scan to ensure that the system is functioning properly.