Case description - Rexroth hydraulic engine
In our workshop, we carried out the regeneration of hydraulic components - a hydraulic drive motor and a hydraulic pump. Both the engine and the pump came from a Agria TH-160-4X4 forklift. In today's Case Study, we will look at the Rexroth A A10V M hydraulic motor. In this case, it was the hydraulic motor that required thorough verification, and the hydraulic pump service was reduced only to replacing seals and cleaning.
First stage - verification of parts
After disassembly and detailed verification, we discovered a defect that caused problems with the operation of the hydraulic motor during driving. The cause turned out to be a deformation of the working surface inside the hydraulic motor housing. The defect was serious and disqualified the housing for further use. A completely new specimen had to be ordered for the hydraulic motor rebuild to be effective, and other elements such as the control piston and a set of seals were also replaced.
At this point, it is worth recalling the basic difference between an engine and a hydraulic pump, as both components are very similar in terms of construction and external appearance, but differ in role and principle of operation. The hydraulic pump is the core of the entire hydraulic system, as it is the energy generator in this system, converting mechanical energy into hydraulic fluid energy.
The hydraulic motor is the receiver of the aforementioned energy, and its operation is opposite to that of the pump - it converts hydraulic fluid energy into mechanical energy through the movement of pistons in the cylinder and in this way drives, for example, the machine's movement.
Second stage - repair and regeneration
A well-conducted diagnosis and precise determination of the technical condition of individual engine components allowed for the implementation of appropriate actions to restore the hydraulic motor to optimal operating parameters. Finding the real source of the problem is the basis for effective rebuilding and should always be handled by specialized personnel with the appropriate knowledge and tools.
A professional service usually has access to manufacturer's diagrams and catalogs, as well as the necessary experience and knowledge about the construction of hydraulic systems of individual construction machines. Relying on scraps of knowledge obtained from the Internet is a bad idea that can lead to the occurrence of further problems.
Third stage - assembly and engine rebuild
Having knowledge about the causes of the failure and the necessary parts for its repair, we moved on to the next stages of rebuilding the hydraulic motor. It is important that all components are well cleaned of all deposits before being assembled into a whole. Contamination of hydraulic systems is a common ailment of construction machines and leads to faster wear of components such as pumps and hydraulic motors.
Used hydraulic oil loses its lubricating properties, and very long intervals in its replacement pose the risk of sudden and serious failure, which are usually very costly. It is also worth occasionally ordering the filtration of hydraulic oil in a construction machine.
The Rexroth A10V M hydraulic motor was rebuilt on previously prepared parts - the motor received a completely new housing, and the rest was regenerated. One of the basic activities during the renovation is the so-called "running-in", i.e. precise matching of the cooperating surfaces of the hydraulic pump or motor. Running-in is designed to reduce the friction of elements interacting with each other and to ensure their maximum durability during operation.
Summary - grinding and final tests
The working surface of the renovated hydraulic motor was subjected to grinding to remove all irregularities, scratches or other mechanical damage as much as possible. All renovation activities must be performed using professional tools to ensure the necessary precision, so important in the case of hydraulic components.
The effectiveness of the renovation was confirmed by tests at the diagnostic station, where the engine was subjected to the necessary load and performance tests. The final stage was painting the hydraulic motor housing and its assembly in the machine.
