IL34819A - Gear box - Google Patents

Description

The invention concerns a gear More the invention concerns a power transmission device adapted to transmit a rotary movement from a prime an electric at two alternative speeds of The invention aims at providing a simple mechanism of this kind to be conjunction with machines and appliances of the kind which are programmed to operate at two different An of suc machine a washing which operates at low speed durin the washing cycle and at high speed he drying There are many other in where a similar programming is In washing for the washing cycle is performed at a speed of revolution of approximately 60 rpm while drying is performed at a speed of approximately In other the speed ratio the slow and fast cycle in this case of order of 20 and in other be even To achieve such a ratio by transmission means has so far been considered practical since has been the general belief that a very complicated gear system is required for the purpose as hitherto been common practice to achiev these high speed variations by electrical by using multipole electric motors and selecting the pole combination for each cycle accordin to such electric motors are equally expensive and bulky and it the object of the present invention to provide a simple mechanical power transmission assembly of the kind In accordance with the invention there is rovided a a power input forming part of or coupled to the prime powor means freely rotatable on said a planetary system comprising a planetary wheel permanently to said power means and at least one spur wheel coupling means shiftable extreme in one of the planetary and spur wheels coupled to said shaft while in the other extreme position of the coupling means the are stationary and prevent the spur wheel or as the case may from rotation means linkin said spur wheel or wheels to said coupling means in such a way that when the latter is stationary the former may perform oscillatory eccenter means keyed on said shaft in engagement with said spur wheel wheels so as to cause the oscillatory motion of the when said coupling means are in the disengaging When the coupling means are in the engaging the planetary and spur wheels are coupled to the power shaft and rotate at the speed of revolution the eccenter means which are permanently keyed on said shaft rotate at the speed of revolution of the in the engaging position the coupling means the eccenter the spur wheels and the planetary wheel all rotate in the same direction at the same speed and result of all the above is that in the engaging position of the coupling means the power means are directly coupled to the power input shaft and rotate together with it at the same high the coupli gmeans is shifted into the disengaging position the spur wheel or wheels no longer rotate together with the Said oocenter means which are in engagement with the spur wheel wheels and which are keyed the now bring about an oscillatory motion of the spur wheel or wheels which i turn causes a slow rotation of the planetary wheel and with it of the power this position then the power means revolve at a reduced speed of the ratio being determined by the ratios between the number of dents on the spur and planetary The mechanism said coupling means between the engaging and disengaging positions may be mechanical or In a of the invention the coupling means comprise clutch one disc of which is biased towards the other in the engaging and magnetic means are provided for shifting said disc into the disengaging position against said In accordance with One embodiment of the invention there are provided two spur wheels both linked to said coupling means in the manner in such a way that in the position of the coupling means there is a phase difference between the oscillatory motions performed by the two In this way any vibration of the device in consequence of the oscillatory motion of the spur wheels is The invention is by way of example 1 section through a power mission device according to i J 2 is a section along line of and 3 is ah axial section through another embodiment of a power transmissio device according to the The device illustrated in 1 and 2 comprises a power input directly linked to a prime mover 2 and freel rotatable a pulley 3 which serves as power means which is integral with a cylindrical guard Sandwiched between a disc 5 and pulley is a planetary wheel 6 and the assembly is held together by means of tightening screws Located withi planetary is spur wheel 8 whic comprises circular 9 each loosely engaged by a pin so that the spur wheel 8 cannot rotate about its axis independent o shaft 1 but may perform an oscillatory motion whose ampl tude is limited by the play of pins 10 within the holes The other end of pi received with a tight within a in hub of a disc 11 freel mounted on shaft The hubs of discs 5 and 11 are coupled to each other by a friction collar integral with the hub of disc Keyed on shaft 1 is an eccentrically balanced wheel a circumferential groove 14 engaging the inner rim of heel The coupling means of the device shown in 1 and 2 are the of friction clutch comprising a first disc keyed on shaft 1 and second disc 17 freely mounted on shaft a plurality of bolts 18 to disc 11 and fitted an annular friction lining Disc is biased towards disc 5 into the engaging position shown in Shaft 1 comprises collars 20 and 21 designed to prevent any axial dislocation of the various members mounted on the as described Mounted on prime mover 2 is an electromagnet 23 which when energized capable of attracting clutch disc 17 against the action of the biasing springs The operation of the device according to 1 and 2 is as In the position shown in 1 in which electromagne 23 is not energised clutch disc is in engagement with the clutch disc in consequence of the biasing action of springs This position is the engaging as defined As shaft 1 revolves it causes disc 1 to revolve due to the fact that the latter is on to the and consequence of this and the clutching engagement between discs 15 and the latter is also As disc 17 revolves disc 11 revolves with it due to the fact that the two discs are locked to each other by means of bolts Due to the engagement between discs and 5 provided by collar 12 on hand and engagement between disc 1 1 and spur Wheel 8 provided by pins 10 on the other the revolution of disc causes the simultaneous revolution of spur wheel 8 and planetary wheel at the same angular Also the eccenter wheel revolves at the same speed since it is keyed on shaft as As the planetary wheel 6 is locked to the pulley the revolves at the same speed and the consequence of all the above that in the engaging position of disc 17 there is direct power transmission from the shaft 1 to pulley The latter is connected by means of a When the electromagnet energized may be brought about manually or b disc is attracted to it and thereby shifted from the engaging position of 1 to the disengaging position which it disociated from disc In is arrested and no longer revolves and this in turn causes arrest of disc 11 as well due to the locking engagement between the two discs by means of bolts As a result of the the which connected to disc through pins is also prevented from At same the eccenter wheel continues to revolve as it is keyed on The eccenter wheel now acts on spur wheel 8 as a cam and causes it to perform a determined by the play pins within holes The so Vibratin spur wheel 8 is in mesh with the planetary wheel consequence drives the latter into a rotary The friction engagement between collar and the of wheel 5 which latter is locked to the planetary wheel 6 designed tha it does not prevent the rotation of the brough about by vibratory motion of the spur wheel I in the disengaging position of disc 17 the planetary wheel 6 nnd with the pulley 3 revolve at educed the rate of reduction being determined by the ratio between the of the spur and planetary wheels as is known For where the spur wheel comprises 59 teeth the planetary wheel the ratio between the input revolutionary speed and the output revolutionary speed in the disengaging position of disc 17 is It is thus seen how in accordance with the invention provided a simple mechanical power transmission device The embodiment illustrated in 1 and 2 comprises only one single spur Vibrations of the device due to motion performed by this wheel in the ing position of clutch disc 17 is to a large extent cancelled by the eccentric balance of the eccenter wheel This design is modified in the embodiment of 3 which comprises two juxtaposed spur wheels whose relative angular position on the shaft is such that the oscillatory motions occur at a phase difference so calculated that while both spur wheels drive the planetary wheel in the same the resulting vibrations are in opposite directions and therefore substantially cancel each As this embodiment comprises a input shaft 31 directly c onnected to a prime mover 32 an electric Freely rotatable on shaf 31 is a pulley 33 and sandwiched that a disc 34 is a planetary wheel assembly being held together by a plurality of screws Located within the planetary wheel 35 are two juxtaposed spur wheels 37 each comprising a plurality of holes at and As holes and are staggered relative to each and the form pairs each of which engaged by one in 40 whose opposite end is received in a tight fit by a bore in the hub of a disc 41 freely rotatable on shaft The hubs of discs 34 and 41 are in mutual engagement by means of friction collar 42 integral the hub of disc similar and function as collar 1 of 1 Keyed on shaft 31 is an eccenter wheel 43 which gages wheels 37 and 38 the same way as eccenter wheel of 1 and 2 engages the spur wheel insufficientOCRQuality

Claims (1)

1. insufficientOCRQuality