Inventory of several wiring methods for robot harnesses

1、 Internal wiring inventory

At present, there are only two forms of robot body wiring harnesses that we see, one is external wiring and the other is internal wiring.

The external wiring currently has a relatively single form, and we haven't thought of many generalizations yet.

Today, we will first talk about internal wiring.

Internal wiring used to mainly exist in small robots, but now gradually, medium-sized six axes are also adopting internal wiring.

In fact, both internal and external wiring have their own advantages and disadvantages, which are related to application scenarios or company technical characteristics, and are not necessarily good or bad.

Today, we will mainly review the designs of various internal wiring.

2、 Hollow reducer wiring

In SCARA robots, a typical hollow reducer wiring is inverted SCARA.

At present, most inverted SCARAs adopt a layout similar to EPSON, that is, the A1A2 axes use hollow reducers, and then the motors are biased.

The reducers and motors are driven by synchronous belts.

The use of synchronous belts is to eliminate backlash and achieve maximum accuracy close to direct connection.

Among the small six axes, the A1 axis and A4 axis are more common. Especially for the A4 axis, it is common to use a hollow reducer, while the A1 axis has a different approach, which we will discuss later.

Let's take two typical examples and first look at ABB's IRB 1100.

The A1 and A4 axes of IRB 1100, like the inverted SCARA, are both biased by motors and driven by synchronous belts.

We won't go into detail here, just refer to the above diagram.

Then let's take a look at IRB 1300.

Although the A1A4 axis of IRB 1300 also uses a hollow reducer, the transmission mode of A1 axis has changed.

We did not use synchronous transmission, but instead adopted gear transmission.

This is mainly due to the fact that the load and arm length of 1300 are larger, and the torque demand is greater, so a hollow RV reducer is used, which is usually driven by gears.

Of course, this is not absolute. If necessary, the C series RV can also be modified into a synchronous belt drive, depending on the necessity of the design.

In addition, A1A2A3A4 all adopt a six axis cable with hollow reducers, and Staubli is a typical example of this.

Staubli benefits from the globally unique gearbox design, which enables all six axes to adopt a hollow wiring structure supported by a single arm, making it highly recognizable.

3、 C-joint routing

This design mainly stems from the following requirements:

1. To achieve hollow wiring without corrugated pipes or other wiring mechanisms;

2. I don't want to use a hollow reducer because the hollow aperture of a typical hollow reducer is not too large;

3. I don't want to add a first level transmission between the motor and the reducer, which will affect efficiency and accuracy.

So there was a design where the motor was directly connected to the gearbox, but with a C-shaped cable conduit added between the gearbox output end and the arm.

For example, the classic small six axis IRB 120 A4 axis.

For example, Omron's i4 SCARA, although it implements internal wiring, does not use a hollow reducer, but instead adopts the form of a C-shaped conduit.

It is also common on the small six axis, which is a double support structure.

One side is supported by the reducer, and the other side is supported by auxiliary support while wiring.

Originally, it was mainly used on the small six axis, but now there are also a few medium-sized six axes that adopt this design.