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Patent Searching and Data


Title:
DRIVE UNIT OF A GANG SAW
Document Type and Number:
WIPO Patent Application WO/2019/022625
Kind Code:
A1
Abstract:
A drive (3) unit of a frame sawing machine, the crankset of which, comprising crankshafts, connecting rods (4), balancing masses (2) and flywheels is arranged inside a massive crankcase (7), wherein both the main bearings of the crankshafts and the bearings of the connecting rods (4) are rolling bearings (5).

Inventors:
KRAWCZUK, Arkadiusz (ul. Sudecka 16/6, 58-500 Jelenia Góra, PL)
Application Number:
PL2018/000073
Publication Date:
January 31, 2019
Filing Date:
July 19, 2018
Export Citation:
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Assignee:
KRAWCZUK, Arkadiusz (ul. Sudecka 16/6, 58-500 Jelenia Góra, PL)
International Classes:
B27B3/12
Foreign References:
US2875795A1959-03-03
GB2349417A2000-11-01
US5873333A1999-02-23
DE1043615B1958-11-13
EP0002265A21979-06-13
DE1628872A11971-04-01
US2875795A1959-03-03
Attorney, Agent or Firm:
ŚLĘΖΚΑ, Joanna (Kancelaria Patentowa REJMAN s.c, ul. Ciepła 15 lok.41, 50-524 Wrocław, PL)
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Claims:
Claims

1. A drive unit of a frame sawing machine provided with a drive motor, a gearbox, drive crankshafts and connecting rods, and flywheels and balancing masses, wherein the crankshafts are arranged perpendicular to the plane of the saw frame and have symmetrically distributed balancing masses, characterised in that the crankset unit comprising the crankshafts (3), the connecting reds (4) as well as balancing masses and flywheels, is arranged inside a massive crankcase, wherein the crankshafts (3) are divided at where the crank bearings (5) are embedded.

2. The unit according to claim 1 , characterised in that the crankshafts (3) are supported at both ends by the main bearings (8) of the crankshaft (3), which are preferably rolling and self-lubricating.

3. The unit according to claim 1 or 2, characterised in that the flywheels are arranged inside the crankcase (7) on the crankshafts (3) and supported on both sides by the main bearings (8) of said shafts.

4. The unit according to claim 1, characterised in that it can be arranged both above and below the saw frame of the frame sawing machine (1), as needed.

5. The unit according to claim 1, characterised in that the individual units of said drive can be coupled in any configuration, thereby forming the frame sawing machine units.

Description:
DRIVE UNIT OF A GANG SAW

The invention relates to a drive unit of a frame sawing machine.

The drive unit of a frame sawing machine belongs to the commonly known and commonly used drive family which involves a change in the rotating movement to reverse-acting movement. Such a drive is used in the construction of work machines of various types, including in saw frame drives of frame sawing machines.

In the solutions that are used at present, the saw frame is driven by a drive shaft via connecting rods, wherein the drive shaft is usually arranged parallel to the transverse edge of the saw frame. The drive unit according to the prior art is schematically shown in the drawing, Fig. 1. in which the drive crankshaft provided with two flywheels with balancing masses drives the saw frame of a frame sawing machine via two connecting rods.

Another example according to the prior art includes the description of the invention US2875795, where the saw frame is driven via two shafts at the ends of which drive wheels are arranged that at the same time are flywheels, and at opposite ends balancing masses are arranged with crank pins and crank bearings. Drive shafts are supported by bearings arranged internally between the drive wheels and the balancing weights, and their housings are fixed to the supporting frame of the frame sawing machine.

The drawback of the solution shown in Fig. 1 is that it is virtually impossible to transversely balance the system. Balancing masses compensate well for the weight of the saw frame in the longitudinal direction, tangent to the frame, whereas it is virtually impossible to balance the system in the transverse direction. Dynamic loads associated with inertia forces of cells cause vibrations and fatigue operation of parts of the machine. These loads, transferred through fixed nodes to the frame and the supporting structure of the frame sawing machine, cause variable loads and vibrations of the supporting structure, adjacent devices as well as foundations and entire buildings. Increasing the work speed of the frame sawing machine using such a drive gives rise to increasing vibrations which hinder the operation thereof, and as the speed increases, which results in the increase of dynamic loads, it produces the risk of damaging and/or destroying the unit When the number of cycles of movement of the frame sawing machine approaches the normal vibration mode of the machine (resonance proximity), the increasing vibration amplitudes give rise to great stresses and the possibility of rapid destruction of the structure. The increase in the speed of devices gives rise to a rapid increase in the effects described above, because the inertia forces increase along with the square of the speed of the device.

The drive of the frame sawing machine according to the patent description of US2875795 appears to be a far more advantageous solution, but in this case too the balancing loads heavily burden the main bearings of the crankshaft, and the drive wheels supported on one side and balancing masses situated at the ends of the crankshafts can give rise to transverse vibrations to the shaft axes that adversely affect the work of the drive, especially as regards attempts to work at higher speed.

In order to eliminate the drawbacks of known solutions, a solution was developed in which crankshafts are arranged inside a massive crankcase, so that both the balancing masses and flywheels as well as crankshafts are located between the main bearings of the crankshaft. This solution clearly eliminates the vibrations in the transverse direction of the crankshaft, and the inertia forces are transferred by properly selected main bearings.

The invention also solves the issue of selecting main and crank bearings. The main bearings of the crankshaft, as arranged at the ends thereof, can be easily mounted as rolling bearings, both at the ends of the shaft and at the bearing slots of the crankcase. The mounting of rolling bearings as crank bearings requires the crankshaft to be divided at where they are to be mounted.

The crankshaft of the invention is divisible at the point of the crankshaft pin journal with the possibility of a stable connection of both of parts thereof after mounting the rolling crank bearing.

The use of rolling bearings alone in the drive that are lubricated with solid grease or self- lubricating removes the need of a central lubrication installation that is necessary for plain bearings. Such installation for the frame sawing machine unit appears highly difficult, if not impossible to implementThe invention is shown in the embodiment in the drawing, in which Fig. 2 is a front view of the frame sawing machine unit, Fig. 3 is an axonometry view of the frame sawing machine unit, and Fig. 4 is an axonometry view of the crankcase of the frame sawing machine drive, with the exploded view of the individual parts of said crankcase.

The drive unit of the frame sawing machine of the invention enables, first and foremost, a significant acceleration of the working speed of the machine, and the use of rolling bearings alone, both the main bearings of the crankshaft and the crank bearings, removes the need of using burdensome central lubrication systems that are necessary when plain bearings are used.

An embodiment of the invention is shown in the drawing, where Fig. 2 illustrates the drive unit mounted on the supporting frame of the frame sawing machine. The crankshafts of the drive 3 driven by the engine through the transmission rotate in opposite directions and are arranged in the crankcase 7. The connecting rods 4 are pivotally connected with the saw frame 1.

Drawing of Fig. 3 is the frame sawing machine unit complete with the drive unit, in axonometry.

Drawing of Fig. 4 is an axonometry view of the crankcase of the frame sawing machine drive, with the exploded view of the individual parts of said crankcase. In this drawing, important details include the connecting rods 4 mounted on rolling bearings 5 and arranged between the balancing masses 2 of the divided crankshaft 3, wherein the division spot of the crankshaft 3 is designated with the reference numeral 6.