Shaft loading parameters
P106285
Center of gravity - pump 1
Center of gravity - pump 2
L 1
L 2
Mounting flange
Input shaft torque rating and spline lubrication
A spline running in oil-flooded environment provides superior oxygen restriction in addition to
contaminant flushing. An oil-flooded spline is found in a pump to pump drive (mounted on the auxiliary
pad of another pump). An oil-flooded spline connection can withstand a continuously applied torque up
to the published maximum rating. Maximum torque ratings are based on torsional fatigue strength of
the shaft and assume a maximum of 200,000 load reversals.
Coupling arrangements that are not oil-flooded require a reduced torque rating due to spline tooth wear.
Contact your Danfoss representative for torque ratings if your application involves non oil-flooded
couplings.
Danfoss recommends mating splines adhere to ANSI B92.1-Class 5. Danfoss external splines are modified
class 5 fillet root side fit. The external major diameter and circular tooth thickness dimensions are reduced
to ensure a good clearance fit with the mating spline. See
dimensions and data.
Maintain a spline engagement at least equal to the pitch diameter to maximize spline life. Spline
engagement of less than ¾ pitch diameter is subject to high contact stress and spline fretting.
Alignment between the mating spline's pitch diameters is another critical factor in determining the
operating life of a splined drive connection. Plug-in, or rigid spline drive installations can impose severe
radial loads on the shaft. The radial load is a function of the transmitted torque and shaft eccentricity.
Increased spline clearance will not totally alleviate this condition; but, increased spline clearance will
prevent mechanical interference due to misalignment or radial eccentricity between the pitch diameters
of the mating splines. Maximize spline life by adding an intermediate coupling between the bearing
supported splined shafts.
Torques are additive for multiple pump installations. Ensure total through torque for the main pump and
auxiliary pump does not exceed published maximum shaft torque. See
on page 27 for shaft
torque ratings.
Understanding and minimizing system noise
A table in the
on page 20, gives sound levels for each displacement. Sound level data are
collected at various operating speeds and pressures in a semi-anechoic chamber. Many factors contribute
to the overall noise level of any application. Here is some information to help understand the nature of
noise in fluid power systems, and some suggestions to help minimize it.
Noise is transmitted in fluid power systems in two ways: as fluid borne noise, and structure borne noise.
Fluid-borne noise (pressure ripple or pulsation) is created as pumping elements discharge oil into the
pump outlet. It is affected by the compressibility of the oil, and the pump's ability to transition pumping
Technical Information
LPV Axial Piston Pumps
System design parameters
©
Danfoss | September 2017
520L0954 | BC00000044en-US0102 | 13