Products and Services -> Shaft Repair

RPM has used laser cladding technology to repair a wide variety of shafts since 2004. From out-of-tolerance ash crusher shafts to galled drag line swing shafts, laser cladding has proven itself to be the most timely and reliable solution to shaft wear problems. Unlike spray repair, laser cladding provides a metallurgical bond that won’t lift or spall under tough operating conditions. Our engineers will choose the best alloy for your specific wear environment.

Some shaft repairs that have been completed by RPM & Associates include Trunion Shafts, Coal Pulverizer Journal Shafts, PA Fan Shafts, Atomizer Shafts used in Flue Gas Desulfurization Systems, and Pump Shafts. Following are a number of specific case studies of shaft repairs RPM & Associates has completed.

Case Study: 4340 Atomizer Shaft Used in Electric Power Generation

A high-speed 4340 drive shaft was repaired using a conventional spray process. Note the severe spalling in the repaired tapered area of the shaft. The user tolerated this recurring problem due to lack of other options for repair. The LCT process was introduced to the customer and now several of these shafts have been successfully repaired using 420 stainless.

This atomizer shaft is a high speed (8800rpm) precision shaft used to drive a rotary spray head typically used in “Flue Gas Desulfurization” (FGD) scrubber systems in Coal Fired Power Plants and Incinerators.
Developed Repair Process for tapered fit section and seal surface of 4340 Atomizer Shaft utilizing 420 SS.
Shafts were previously repaired by a Spray Process featuring a “Mechanical Bond.” The LCT Process utilizes a “Metallurgical Bond” that generates a high quality permanent repair, which saves thousands of dollars over purchase of a new shaft.

Bearing and seal diameters, tapers and treads may all be repaired!!!

Atomizer Shaft as Received Failed Spray Repair

Atomizer Shaft with Laser Deposit

Atomizer Shaft with Final Machining

Case Study: HP 1103 Coal Pulverizer Journal Shaft

An HP 1103 Journal Shaft from a coal pulverizer system was brought into our shop for repair. The shaft was worn on three surfaces and one face. RPM & Associates has since repaired a number of these shafts.

Shaft During Deposit

Journal Shaft was part of the complete repair of an HP1103 journal.
Shaft was worn on three surfaces and one face
Developed a process using LCT to deposit 420 SS on three surfaces and one face.
420 SS was used to increase wear resistance of the repaired areas.
A number of these shafts have been repaired using this process

Shaft Post Deposit

Shaft After Final Machining

Case Study: Spindle Sleeve for Horizontal Boring Mill

RPM & Associates performed a repair of a spindle sleeve for a horizontal boring mill using Laser Cladding Technology (LCT). The cladding for this part, due to its size, was performed in open atomosphere. Distortion was kept to a minimum by running the laser at 465 watts and using a 1 mm spot size. 420 LC SS powder was used to give the part better wear resistance.

Spindle Sleeve As Received

The Precitec head was used for the cladding and the part was repaired in a open atmosphere.
Distortion was kept to a minimum by running at approximately 465 watts and using the 1mm spot size.
420 LC SS powder was used to give the part better wear resistance.

Wear Surface Pre-deposit

Wear Surface Post-deposit

Spindle Sleeve Post-machine

Case Study: Trunion Shaft

This example Trunion Shaft had two sections that had worn out. The shaft was machined to minimum cleanup. A process was developed to deposit 420 SS (stainless steel) to build up both surfaces of the Trunion Shaft. The 420 SS material improved the wear resistance of the part to future wear. After material was built up, the Trunion Shaft was then machined to its final dimensions.

Trunion Shaft Wear Surface Before Repair

Trunion Shaft had two sections that had worn out.
Laser Cladding Technology (LCT) used to build up two sections using 420 SS.
420 SS increased wear resistance of the surfaces.
After material deposited, Trunion Shaft machined to its final dimensions.

Trunion Shaft Before Repair

Trunion Shaft Final Machined

Trunion Shaft Wear Surface Final Machined

Case Study: 4340 Swing Shaft for a Drag Line

The following repair was done on a 4340 Swing Shaft used on a drag line in a coal mine. The 4340 Swing Shaft is 16 1/2 ft. long and weighs 25,000 pounds. Conventional repairs on this type of shaft were not possible due to high heat input.

RPM & Associates developed a repair process for the bearing surfaces of the 4340 Swing Shaft using 420 SS (stainless steel) and the Laser Cladding Technology process.

The repair cost is approximatley 65% less than new and extends the operational life of the shaft compared to new due to the materials used. A number of these shafts ranging in various sizes have been repaired.

Worn Bearing Surface

4340 Swing Shaft - 16 1/2 feet long weighing 25,000 pounds.
Used on a drag line in a coal mine.
Repaired using Laser Cladding Technology (LCT) and 420 SS (stainless steel)
Repair cost 65% less than purchasing a new shaft.
Operational life extended beyond that of a new shaft.
A number of these shafts ranging in various sizes have been repaired.

Shaft During Deposition

Shaft Final Machined

Case Study: 1035 PA Fan Shaft Repair

A 1035 PA Fan Shaft was knocked out of tolerance due to a crash that occurred while in service. The shaft is a precision shaft that runs at 1,725 RPM and 3,500 horsepower in an ambient condition. Diametrical tolerances are within 0.0005" and run out tolerances are also within 0.0005".

RPM & Associates developed a repair process using Laser Cladding Technology (LCT) that added material to the shaft and allowed the shaft to be machined back into specified tolerances.

1035 PA Fan Shaft is a precision shaft that runs at 1725 RPM, and 3500 horsepower in an ambient condition.
The shaft was knocked out of tolerance due to a crash while in service.
Diametrical tolerances are within 0.0005”, and run out tolerances are also within 0.0005”.
The shaft was ground to meet final dimensions.

During Laser Deposition

After Laser Deposition

After Final Machining

Case Study: CE1003 Pulverizer Journal Shaft

While overhauling a CE11003 journal, we found the shaft had a prior spray on bronze repair at bearing fit location that was failing. Bronze debris was contaminating the oil. RPM pre-machined to remove failed repair, Laser Clad with 420 SS, and post machined to correct tolerances.