HOW TO CHOOSE A CARDAN SHAFT

How to choose a cardan shaft

How to choose a cardan shaft? This is the question often asked by people who own a tractor but don’t know which category of driveshaft they need to choose in order for their tractor-coupled implement to work properly

What a cardan shaft is for

A cardan shaft is an articulated mechanical organ that serves to enable the transmission of motion and power between two rotating axes or moving organs.

Dynamically connects the tractor’s PTO with that of the operating machine, whether towed or carried on the three-point hitch. In both cases, during work the two power take-offs (drive on the tractor and driven on the implement) assume varying relative positions that the cardan shaft must have the ability to follow.

How many types of cardan shafts are there?

There are several types of cardan shafts that differ from each other in the following characteristics:

• Standard, barbed with triangular tube, for all agricultural machinery requiring power transmission

• With constant velocity joint for medium-heavy duty applications (on tractor side, implement side, both sides)

• Cardan shafts with welded lemon profile, for lighter applications

• Slotted profile for special applications, for categories 4 and 6

• Cardan shafts with welded triangular tube, from category 1 to 5

The production of complete gimbals is complemented by the range of components, which includes:

• Simple joints, double joints, flanged double joints (can be decoupled for easier mounting on fixed shafts)

• External forks, safety devices, 2- or 4-disc friction torque limiters, pawl torque limiters, bolt torque limiters, free wheels

• constant velocity joints that, thanks to the use of special steels and the use of specific heat treatments, are extremely reliable and of high strength. The protection, made and patented for this type of coupling, integrates with that of the drive shaft and allows complete coverage of all moving parts.

How to use a cardan shaft

In the family of tractor-side (L.T.) couplings, there are all those forks that connect the gimbal shaft to the motion input p.o.p.

These forks differ from each other, mainly, in the type of attachment system and the type of drag profile(p.d.p. profile).

Therefore, the choice of attachment type, is mainly determined by the application in which the fork or shaft will be used.

Safety devices are not included in this family, as according to CE standards the latter can only be mounted on the implement side, and thus with reference to the inner telescopic tube.
The correct installation of the cardan shaft is easily visualized by the decal on the outer protective tube ( g.a).

 

How to choose the right cardan shaft

When choosing the power transmitted by the PTO shaft, the absorption of the implement to be engaged to the tractor must be taken into account.

Example: if the implement draws max 35hp-hp I have to choose a 4th category gimbal that, at 540rpm/minute can transmit a max power of 35hp-hp.

As per table:

SIZE CARDAN SHAFT CATEGORY	540 RPM		1000 RPM
	POWER		POWER
	KW	HP/HP	KW	HP/HP
1	12	16	18	25
2	15	21	23	31
4	26	35	40	55
5	35	47	54	74
6	47	64	74	100
8	70	95	110	150
NOMINAL VALUES DEFINED FOR 5° ANGLES AND DURATION OF 1000h.

Tube and cruise dimensions:

DIMENSIONS CARDAN SHAFT CATEGORY
	A	B	C	D	E	F	Ms
1	22	54	32,4	2,5	26,6	3,5	750Nm
2	23,8	61,3	36,1	3,1	29	4	1050Nm
4	27	74,6	43,4	3,3	36,1	4,5	2000Nm
5	30,2	80	51,3	2,9	44,7	4	2500Nm
6	30,2	92	53,6	3,8	44,7	4	2900Nm
8	34,93	106,4	62,7	4,1	53,6	3,8	3660Nm