Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
  • H02K7/10—Structural association with clutches, brakes, gears, pulleys or mechanical starters
  • H02K7/1004—Structural association with clutches, brakes, gears, pulleys or mechanical starters with pulleys
  • H02K7/1012—Machine arranged inside the pulley

Definitions

• the invention relates to a press roll unit for a reel-up of a paper cutter, the press roll unit comprising two adjacent rolls around which there runs a belt arrangement operatively interconnecting the rolls, an electric motor driving the roll unit being arranged inside at least one roll.
• Electric motors are usually cooled by blowing air through conduits inside or on the surface of the motor by means of a blower that is mounted on the shaft of the electric motor or is driven by a separate motor. It is essential that the rate of the air current passing the surface to be cooled is rendered sufficiently high.
• the electric motor driving the unit is an external rotor motor which is mounted inside a press roll and which cannot be cooled normally.
• the belt arrangement covering the rolls is usually made of rubber, and so heat does not transfer sufficiently, since the rubber belt has poor heat conductivity as compared with steel, which the rolls are made from.
• the object of the present invention is to eliminate the above drawback, i.e. to effect sufficient cooling of the motor itself and the surface of the roll located at the motor.
• the object is achieved with a press roll unit which is characterized in that at least one aperture is formed in the belt arrangement so as to cool the electric motor and the roll surrounding it.
• the invention is based on the idea that the surface of a rotating roll is brought into direct contact with the surrounding air, which ensures efficient transfer of heat from the roll to the air.
• the most preferable solution is probably one in which the belt arrangement comprises at least two belts spaced at a predefined distance from each other to form the above-mentioned at least one cooling aperture.
• FIG. 1 shows a common press roll unit
• fig. 2 shows a preferred press roll unit according to the invention
• figs. 3 and 4 show alternative embodiments according to the invention.
• a common press roll unit for a reel-up of a paper cutter shown in fig. 1 comprises two adjacent rolls 1 and 2 around which there runs a continuous rubber belt 3 that interconnects the rolls operatively, extends over the entire width of the rolls, and covers them entirely.
• an electric motor 4 is arranged inside both rolls 1 and 2.
• the press roll unit can also be used by an electric motor arranged in a single roll.
• the press roll unit of the invention shown in fig. 2 differs from the common solution of fig. 1 in that the belt arrangement running around the rolls 1 and 2 is divided into two belts 30A and 30B that are spaced from each other such that there is an open space 5 between them at the electric motor 4 located inside the roll 1 ,2.
• the heat conducted from the motor 4 to the roll 1 ,2 can therefore be transferred effectively to the air thanks to the difference of rate between the surrounding air and the roll 1 ,2, and so the temperature of the motor 4 and the roll 1 ,2 can be maintained considerably lower than in the solution described above in fig. 1.
• the belt arrangement is divided into an even larger number of separate belts 30N, and so there is also a larger number of spaces 5 between the belts 30N that cool the roll 1 ,2 and the motor 4. Any heat conducted towards the ends of the rolls 1 ,2 can then be discharged more effectively, as a result of which the heat stress in the roll unit decreases further.
• Fig. 4 in turn shows another alternative structure according to the invention, which comprises a belt 30 running around the rolls 1 ,2 and extending over the entire width of the rolls, like in the common solution shown in fig. 1.
• This structure is perforated (perforations 5') in the circumferential direction at least at the electric motor 4 so as to effect the above-described direct contact between the roll surface and the surrounding air, and the cooling resulting from the direct contact.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Press Drives And Press Lines (AREA)
• Paper (AREA)
• Handling Of Sheets (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8547046

Family Applications (1)

Country Status (4)

Citations (2)

Family Cites Families (6)

• 1996
  • 1996-11-11 FI FI964523A patent/FI102663B1/fi not_active IP Right Cessation
• 1997
  • 1997-11-07 FR FR9714020A patent/FR2755635B1/fr not_active Expired - Fee Related
  • 1997-11-10 DE DE19782110T patent/DE19782110T1/de not_active Withdrawn
  • 1997-11-10 WO PCT/FI1997/000681 patent/WO1998021016A1/en active Application Filing

Patent Citations (2)

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