GN 808.2

Universal joint shafts with friction bearing GN 808.2 not only join the offset between two shafts, but also enable the alignment of lengths, which depending on the overall length l₁ enables the corresponding extraction length l₂. The power transmission is achieved by two universal joints  DIN 808 (type EG) a splined shaft and a sliding sleeve. 

It is important to check the accuracy when connec-ting the splined shaft to the sliding sleeve: The markings -> <- have to be opposite to each other. Any kind of misconnection leads to an inhomogeneous output and to a quick abrasion.

• different length l₁ - l₂

• Bores without keyway

• Bores with square

• Bores with hexagon

• with other or unequal bores

• Version in Stainless Steel

• Permissible r.p.m. and torque 

• Keyway DIN 6885

• Cross holes GN 110.1

• ISO-Fundamental Tolerances

 

The single universal joints transfer the initial smooth rotation as an irregular rotation. One revolution of the drive shaft via single universal joint will cause the driven shaft to accelerate and decelerate twice. The extent of the irregularity depends on the operating angle ß.

In order to obtain a smooth rotation of the driven shaft two single or one double universal joint is required. In such cases where minor irregularities in the movement are acceptable or where minor operating angles are the norm a single universal joint will do.

 

 

 

Furthermore the bearings must be as close as possible to the universal joints.

For continuous operation of universal joints with friction bearings adequate lubrication is essential. If drip lubrication is not possible they should be lubricated at least once a day. It is also possible to fit the universal joint with a gaiter GN 808.1 which can be filled with oil or grease.

Universal joints with friction bearing, Type EG

 

The table shows the transferable output N and/or torques M of universal joints DIN 808, type EG (single friction bearing) in relation to the RPM n.

The values are only applicable to a constant speed of rotation, constant load and an operating inclination angle of max. 10°. They are not applicable to universal joints in Stainless Steel.

For larger inclination angles ß a nominal output N increased by the correction coefficient k and/or a nominal torque M has to be selected (see example below).

Conversion formulae:

Torque M [Nm] = 9550 N[kW]/n[min-¹]

Output N [kW] = M [Nm] x n [min-¹]/9550

1 kW = 1.36 PS / 1 PS = 0.736 kW

Example 1

Output to be transferred N = 0.65 kW

R.p.m. n = 230 min-¹

Angle of inclination ß = 10°

Correction coefficient k = 1

Indicative output N‘= Nominal output N

Intersection point P is arrived at from 0,65 kW and 230 min-¹ (which corresponds to a torque of 27 Nm).

The next size up universal joint corresponding to point P is the model with a diameter d₁ = 25.

Example 2

Torque to be transferred M = 27 Nm

R.p.m. n = 230 min-¹

Angle of inclination ß = 30°

Correction coefficient k = 2.25

Indicative torque = 2.25 x 27 Nm = 60 Nm

Intersection point P1 is arrived at from 61 Nm and 230 min-¹ (which is equivalent to an indicative output N = 1.47 kW).

The next size up universal joint corresponding to P₁ is the model with a diameter d₁ = 36.