Cause and Solutions Regrading Oil Leakage from Excavator Rotating Grapple Motor

The excavator rotating grapple is widely used in forestry, steel mills, mines, and agricultural industries. It is often used to realize the two functions of grabbing, loading and unloading. The rotating grapples can achieve 360°rotation, which is more sensitive, practical, and convenient to operate.

Currently, the excavator rotating grapples are electronically controlled, and the power is changed through the solenoid valve to realize the two rotation directions of forward and reverse. Regarding this point, we would like to focus on the problem of electronic control. Its advantage of electronic control is fasting response speed and it can greatly improve the work efficiency for users. The disadvantage is that the rapid change of direction will produce a large instantaneous impact force, which is a severe test of the quality of the motor and valve core. The performance of high-quality motor and valve cores will be more stable in the face of instantaneous impact. This is also a significant reason why JIANGTU has always adopted high-standard and high-quality motor and valve cores.

Customers often ask us why other companies’ motors make it easy to lose pressure even if working for a few days only . Also, the motor output shaft frequently injects oil outward, and it is still leaking oil after replacing the sealing ring. Why are the motor fixing bolts always loose which causes the oil pipe to be loose and leaking? Why are there so few problems with the motor of JIANGTU?

JIANGTU technical department summarizes the following common reasons and solutions in below

The reasons for oil leakage are as follows:

1. Oil leakage point judgement

1-1: Checking the binding surface of the tread sealing ring and whether the sealing ring is damaged.

1-2: Checking whether there is oil leakage at the head of the oil pipe.

1-3: Checking whether the O-ring at the seam of the motor brake block is damaged or displaced.

2. Analysis of whether the rotating engaging parts are damaged and the concentricity of the rotating motor parts.

First of all, removing the motor, check whether the bearings, gears and swing support ring gear are damaged.
Specific method: After removing the motor, push the upper half of the rotation with your hand, and slowly test it in two directions clockwise and counterclockwise respectively. And then, checking whether the gear is damaged in the area that can be observed. If it can be pushed by hand, it means that the engaging of small gear and the rotary support is normal and the concentricity is good. If there is a friction, it means that the rotation support or rotation base is damaged and deformed.

3. Damage Judgment of the internal sealing ring of the motor.

Within the warranty period, under approval by the manufacturer, the internal structure of the motor can be split to check whether the sealing ring is damaged and the inner is worn. Two reasons cause the damage to the internal sealing rings.

2-1 The internal working pressure of the gerotor motor exceeds the bearing capacity, causing the failure of the seal and oil leakage.

2-2 Unreasonable system pressure setting or excessive load.

4. Identification of looseness for motor fastening bolts

During the motor operation, it will have a vibration. Vibration may cause the fastening bolt to gradually loosen, and make gaps on the joint surface, resulting in oil leakage.

5. Damage Judgment of the motor shaft seal
The shaft seal at the output shaft of the motor is worn, aging, or improperly installed, resulting in oil leakage.

The solutions for the above situation are as follow:

1. If there are oil leaking points, the corresponding seal kits and pipe need to be replaced. If the O-ring has displaced.

2. If the rotating engaging parts are damaged, the corresponding spare parts need to be replaced.

3. If the rotating motors work failure, the corresponding spare parts need to be replaced.

4. If the motor sealing rings are damaged, the corresponding spare parts need to be replaced, and corresponding pressure adjustments should be made according to the reason for internal sealing ring damage.

Above is the reason analysis and corresponding solutions to the motor linkage of excavator rotating grapple attachments. We hope to help users who use our rotating attachments. If you have any questions regarding to installation and use of the JIANGTU attachments, please feel free to contact （whats+86-15653818637）.

JIANGTU rotating grapple mainly adopts two rotating motors: Imported M+S motor and Parker gerotor motor, which have the advantages of high performance, strong safety, high power with high torque output, and good internal sealing effect. The imported motors have been reasonably designed and finely processed by ours, making it fit closely with our motor base, which is more suitable for JIANGTU wood grapples.

The stable quality and extremely low failure rate of the JIANGTU motor have effectively improved the reliability of the grapple and obtained trust and praise from users. Parts of our customers have been using our attachments for over 6-9 years, which rely on our warranty policy of 1-year free fixing and 6-month free replacement.