HV Inverted Tooth Chain0 pages

‘HV’ Inverted Tooth Chain Drives
For High Velocity, High Horsepower and High Efficiency Drives with smooth transmission
of load in a compact space.
Morse HV Drives provide the Drive Designer with a new concept in the transmission of power for high speed, high load applications.
Proven in a wide range of applications from high production automobiles to custom-designed flood control pumps, HV Drives offer
opportunity for flexibility, compactness, weight saving and economy.
In the late 1940’s Morse Chain Engineers developed the original design of ‘HV’ to meet the high speed, high load requirements of Oil
Well Drilling equipment. The first chain 2” Pitch x 12” Wide transmitted 1300kW at 650 r.p.m. on the slush pump of a drill rig. Success on
this and similar applications led to the further development of a family of chains from 3/8”to 2” pitch which have been successfully applied
to a wider variety of industrial applications including Roll Grinders, Dynamometers, Pump Drives, Gas Turbine Starters, four Square Test
Rig, and many Automotive Transmissions. Further development of HV chain enables drives over 2,500kW being accommodated with
standard chain widths.

‘HV’ Chain Design
The Chain assembly consists of inverted tooth link plates, laced alternately and connected by two steel pins of the same cross sectional
geometry, which form an articulating joint between the link sections.

‘HV’ Link Plate Design
The link design in the original HV pitches - 3/4”, 1”, 11/2” and 2” (Fig 1) had been tested
and proven for many years. The link crotch is located slightly above the line of pull
and all corners are rounded to minimise the possibility of stress risers and to ensure
maximum performance on high load industrial applications.
The 3/8” and 1/2” pitch chains (Fig. 2) have a new link contour for increased speed
requirements, with the link crotch below the line of pull, and this design is now
extended to include 3/4” and 1” pitches. Photo-elastic studies of various link shapes
and aperture positions produced the design with the lowest level of stress
concentration. Improved metallurgy, and development in design and pressure angle,
achieve maximum load capacity with high speed performance. Carefully controlled
shot-peening of the links gives them a uniform, matt grey finish and results in an
improved level of link fatigue resistance.

Concentric Pin and Rocker Joint
The joint consists of a pin and rocker of identical cross section and contact radii.
When chain engages the sprocket teeth the curved surfaces roll on each other
eliminating sliding friction, and joint galling. The radii of the pins is selected to give
almost perfect pitch compensation to minimise chordal* action. Before engagement
with the sprocket the contact point of pin and rocker is below pitch line (Fig. 3).
When chain engages with the sprocket teeth, the contact point moves upwards (Fig.
4) with slight elongation of the pitch to wrap the sprocket along the pitch line.

Chordal Action

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The compatible design of HV links, joints and sprockets reduces the detrimental
effects of chordal action to a minimum. The chordal action of conventional chain
drives is the vibratory motion caused by the rise and fall of the chain as it engages
sprocket teeth. This motion causes vibration and limits high speed load carrying
capability. Of all types of chains, HV operates most efficiently at all speeds because
chordal action is reduced to a minimum.
Fig 5. shows how HV chain enters approximately tangent to the pitch circle of the
sprocket and maintains this position as it travels around the sprocket. This smooth
engagement permits high speed capabilities with efficiency and quietness.

Involute Tooth Sprocket

Te l

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Email

sales@crossmorse.com

CROSS+MORSE

High Power in Narrow Widths

The third criteria for the success of HV is the mating sprockets. An involute tooth
form, differing from the straight sided teeth of conventional silent chain sprockets is
designed for smooth engagement of the chain with the sprocket teeth. All HV
sprockets are top-hobbed and the teeth heat treated for tough wear resistant surface.
Unlike the single tooth engagement of spur gears, many teeth share the load on a HV
drive, resulting in low stresses, less wear, and long sprocket life.

You get more with ‘HV’
The features of ‘HV’ link design, compensating pin and rocker joint, with the involute hobbed sprockets means HV chain can transmit
more power, at higher speeds, in less space than other transmission media, with smooth action and minimum of noise.

High Speed Performance
applications.

capacities up to 6000 kW.

Operating chain speeds range from 10 to 35 metres per sec. with higher speeds (to 55m/sec) on special
HV chain transmits more power per inch of width than any other chain or belt drive, with

Smooth Quiet Operation

The rolling action of the chain joints combined with smooth sprocket engagement minimise induced
vibrations. This enables HV chain to provide quiet drives on high speed applications.

High Efficiency

Smooth operation, with minimal frictional losses, provide transmission efficiencies up to 99.7%.

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