How To Repair Any Bosch Rotary Hammer With Your Own Hands, Knowing The Design Features

2023 Author: Philip Bishop | [email protected]. Last modified: 2023-08-25 07:54

• The main differences in the design of Bosch rotary hammers
• Diagram and design of the Bosch 2-20 perforator
• The design of the intermediate shaft of the Bosch rotary hammer 2-20
• Features of the design of the Bosch rotary hammer 2-24
• The design of the intermediate shaft rotary hammer Bosch 2-24
• Barrel shaft percussion design
• Malfunction of the shaft of the barrel of the percussion mechanism
• Features of the design of the Bosch rotary hammer 2-26
• Barrel shaft percussion design
• Conclusions:
• Video about disassembling the Bosch rotary hammer

The most widespread among professional builders in Russia are Bosch perforators, and among amateurs, household models Bosch 2–20, 2–24, 2–26.

Rock drills not only work well, but are also easy to repair. You can easily find any broken part on them.

The design of the perforators described is based on the same principle, to transmit the rotational moment from the rotor to the shaft of the barrel of the impact unit with the simultaneous transmission of the translational impulse to the working tool.

Structurally, perforators are made according to the same scheme, but individual units or parts have their own characteristics.

If you know the specific differences between the models of the described Bosch rotary hammers, then disassembling and repairing yourself will not be difficult.

Along with the originals, there are a large number of counterfeit tools on the Russian market, including Bosch hammer drills.

The design features of the models and how to disassemble and repair them with your own hands are described below.

The principle of operation of perforators is the same, but the design features are different.

The main parts used in the listed models of Bosch rotary hammers are interchangeable. This applies to the mechanical and electrical assembly.

But there are knots and made that differ in the details used.

To repair a Bosch rotary hammer 2–20, 2–24, 2–26, you need to know these differences. Knowing the design features of each rock drill facilitates the repair process, finding breakdowns and eliminating them.

The designs of Bosch rotary hammers are so simple that they allow you to perform simple repairs, almost with your own hands, and replace any part without contacting service services. You need to have the skills of an assembler, have basic knowledge of electrical engineering and understand the principle of the hammer drill.

The main differences in the design of Bosch rotary hammers

When repairing a Bosch hammer drill, you will not do without an electrical and disassembly diagram for the tool of the model you are going to repair.

The wiring diagrams of Bosch rotary hammers 2–20, 2–24, 2–26 are practically the same. There are some minor differences, though.

But the mechanical blocks are equipped with parts that differ structurally from each other. The main differences are collected in two nodes: in the intermediate shaft and the shaft of the barrel of the impact block.

The biggest differences are in the design of the intermediate shaft, the assembly of the "drunken bearing", in the mode switch. Non-fundamental features are present in the designs of the barrel of the percussion block, striker, striker.

Let's start with the Bosch 2–20 rotary hammer.

Diagram and design of the Bosch 2-20 perforator

Repair of a Bosch 2–20 perforator is not possible without knowledge of the design of the tool being repaired.

The principle of operation of the Bosch 2-20 perforator is based on the transfer of torque from the rotor shaft pos. 3 to the shaft of the impact unit pos. 22 through the intermediate shaft pos. 824, while simultaneously transmitting a longitudinal impulse to the working tool.

The rotor pos. 3 transmits the torque to the helical gear of the intermediate shaft pos. 824.

The helical gear is fixed on the intermediate shaft and transmits the torque to the shaft. A drunk bearing is fixed on the shaft, which receives the torque through the clutch. Due to its design, the drunk bearing transmits the translational motion to the barrel cylinder of the percussion mechanism.

The design of the intermediate shaft of the Bosch rotary hammer 2-20

The intermediate shaft of the Bosch 2–20 perforator consists of a rolling bearing assembly (drunk bearing), a clutch, a large helical gear, and a small spur gear.

Most often, breakdowns manifest themselves in the wear of the clutch splines, which leads to the loss of rotation of the hammer drill chuck in the presence of a shock pulse.

Corrected by replacing the clutch or restoring the teeth of the clutch parts.

Features of the design of the Bosch rotary hammer 2-24

It is best to start repairing a Bosch 2–24 hammer with an acquaintance with the diagram and design features of the tool being adjusted. The operating principle of the Bosch 2–24 rotary hammer is similar to that of the Bosch 2–20 rotary hammer.

The torque is transmitted to the tool holder shaft, simultaneously with the transmission of the shock impulse. The hammer drill has three operating modes: drilling with impact, drilling without impact, impact.

The helical gear of the rotor, poz.803, transmits the torque to the helical gear of the intermediate shaft, pos. 826.

The design of the intermediate shaft rotary hammer Bosch 2-24

The intermediate shaft of the Bosch 2-24 perforator consists of a rolling bearing unit pos. 830, a clutch pos. 823, and shift parts pos. 44. Most often, the clutch fails. Teeth wear out in it. Clutch repair consists in correcting the tooth profile of the engagement in the clutch and on the intermediate shaft.

Barrel shaft percussion design

The barrel shaft of the percussion unit is designed to transmit a rotational impulse with the simultaneous movement of the striker.

Rotation is transmitted from the spur gear of the intermediate shaft to the large spur gear pos. 22 of the barrel shaft pos. 821.

The reciprocating motion is transmitted through a drunk bearing, pos. 830, an impact piston, pos. 26, a firing pin, pos. 27, an impact bolt, pos. 28, to a drill fixed in a chuck, pos. 756.

The design is a hollow shaft on one side. Parts are installed on the shaft from both sides.

From the side of the chuck mounting, a spur gear, pos. 22, is installed on the shaft and fixed on the shaft with a roller, pos. 88, pressed against the shaft shoulder by a spring, pos. 80. The spring itself is fixed with a retaining ring, pos. 85.

In the cavity of the shaft of the barrel of the impact block is inserted: the assembled impact bolt pos. 28 and the impact piston. In the impact piston pos. 26, the firing pin pos. 27 is inserted with a new rubber ring, pos. 73, placed on it. All rubber products are lubricated with the recommended lubricant.

Malfunction of the shaft of the barrel of the percussion mechanism

Due to the weakening of the spring force, falling out of the fixing roller, the gear can turn on the shaft. This is manifested in the disappearance of the torque with the presence of a shock impulse.

The hammer hammer hammers but does not drill

When rubber products (O-rings) wear out, the perforator stops working in the "Chiseling" mode. This happens gradually. The impact force weakens as the rubber rings wear. The thing is that the movement is transmitted from the drunk bearing to the impact piston, pos. 26, in which the firing pin, pos. 27, creates air pressure and acts on the impact bolt, pos. 28.

The hammer drill drills but does not hammer

If you apply a lot of force when operating the hammer drill, this can lead to the destruction of the impact bolt, jamming of the striker in the impact piston. Such malfunctions are eliminated only by complete replacement of the failed part. Learn more about troubleshooting a Bosch rotary hammer.

Features of the design of the Bosch rotary hammer 2-26

Repair of the Bosch 2-26 rotary hammer should begin with familiarizing yourself with the design features of the tool being adjusted. The operating principle of the Bosch rotary hammer 2–24 is similar to that of the Bosch rotary hammer 2–26.

Rotation is transmitted from the rotor shaft, through the intermediate shaft, to the shock barrel shaft. At the same time, a drunk bearing attached to the intermediate shaft transmits a reciprocating motion to the impact piston.

The hammer drill has three operating modes: drilling with impact, drilling without impact, impact.

The helical gear wheel of the rotor, pos. 803, transmits the torque to the helical gear of the intermediate shaft, pos. 823.

The intermediate shaft is similar to the shaft in the design of the Bosch 2-24 rock drill and is interchangeable with itself and the parts that make up the intermediate shaft of the Bosch 2–24, 2–26 rock drills. Instructions for disassembling the Bosch punch.

Barrel shaft percussion design

The barrel shaft of the percussion block is similar in design to the barrel shaft of the Bosch 2-24 rock drill. Failures are caused by faults in the same parts as in the Bosch 2-24 rotary hammer.

Features of the shaft of the Bosch 2-26 perforator is that the driven large spur gear, pos. 22, is fixed on the shaft by three pins, pos. 37, in contrast to the fixing roller in the Bosch 2-26 puncher.

When disassembling the barrel shaft of the percussion block of the Bosch 2-26 hammer drill, pay attention to the method of fixing the gear. Before removing the gear, you must remove the three pins. The order of the correct assembly of the Bosch rotary hammer.

Conclusions:

1. Knowing the differences between the given models of Bosch rotary hammers will allow you to quickly disassemble the tool, replace defective parts. For this you do not need to contact the service department.
2. Structurally, Bosch rotary hammers are so simple that they allow you to carry out repairs of almost any complexity.
3. All that is required of you is desire and basic knowledge in mechanics.

It happens that fake models of Bosch rotary hammer come across in more detail about this.

Video about disassembling the Bosch rotary hammer