| Claims 1. Method for the precise dosing of a pressurized liquid, with the aid of a device, in which there is a pair of gears (4, 5), which are installed on shafts (2, 3) in a gear housing, in the wall of which there is a channel (15), the shaft (2) being hollow, and in the wall of the shaft (2) there is an opening (17), in order to permit a liquid flow between the external and internal spaces of the shaft, characterized in that the speed of dosing of the liquid brought through the channel (15) to the gear pair (4, 5) is regulated by rotating the hollow shaft (2) with the aid of a drive device (16), or by using a braking device combined with with a spring (21) opposing the rotation of the shaft (2), and that the part of the flow exceeding the desired amount is cut off with the aid of the rotation of the gear (4) relative to the shaft (2), when the opening (17) is throttled by the rotation. 2. Method according to Claim 1 , characterized in that the precisely dosed outflow of the liquid is guided through the hollow interior of the shaft (2) out from the end of the shaft. 3. Method according to Claim 1 , characterized in that the rotation of the gear (4) relative to the shaft (2) is limited by a pin-like element (14) in the shaft (2), which moves against the shaft surface of the gear, inside a recess in the surface. 4. Device for the precise dosing of a pressurized liquid, comprising a pair of gears (4, 5), which is installed on shafts (2, 3) in a gear housing, in the wall of which is a channel (15), the shaft (2) being hollow, and there being an opening (17) in the wall of the shaft (2), in order to permit a flow of liquid between the internal and external spaces of the shaft, characterized in that in the device there is a drive device (16) rotating the shaft (2), or a brake device combined with a spring (21) opposing the rotation of the shaft (2), and that the gear (4) can rotate to a limited extent relative to the hollow shaft (2) to reduce the opening (17) for the purpose of regulating the flow. 5. Device according to Claim 4, characterized in that the device includes a connection (19) located at the end of the hollow shaft (2), for leading the dosed liquid out through the hollow interior of the shaft (2). 6. Device according to Claim 4, characterized in that, in order to limit the rotation of the gear (4) relative to the shaft (2), the shaft (2) has a pin-like element (14), and that in the gear there is a recess (13), in which the pin (14) can move in the recess from one edge to the other. 7. Device according to Claim 4, characterized in that the drive device (16) is an electric motor, which can be connected to the end of the hollow shaft, in order to rotate it. 8. Device according to Claim 6, characterized in that the spring (21) is located in the recess (13) and is supported on the pin-like element (14) and the wall of the recess. |
The present invention relates to a method and device for the precise regulation of a liquid flow.
Finnish patent application 20080086 discloses a device, with the aid of which a liquid flow can be distributed equally to several objects. According to the invention, the liquid flow transported by pairs of gears is equalized by using a self-regulating system, which is based on disequilibrium being corrected in a self-regulating manner, based on the throttling effect caused by the movement of a gear rotating to a limited extent on a hollow shaft.
The present invention is intended to use a solution that is essentially of the type described above, but it has now been surprisingly observed that, by using the rotation of the hollow shaft created by an external drive device, the self-regulating, precise dosing of a liquid dependent on the rotation speed is created.
The aforementioned and other benefits and advantages of the present invention are achieved in the manner described as characteristic in the accompanying Claims.
In the following, the invention is described in greater detail with reference to the accompanying drawings, in which
Figure 1 shows an exploded view of the device according to the invention, and
Figure 2 shows a cross-section of the said device.
Thus, Figure 1 shows an exploded view of one embodiment of the invention.
The device 1 is formed of gears 4 and 5 attached to shafts 2 and 3. In the assembled device, the gears 4 and 5 are very tightly fitted to a spacer piece 7 comprising a gear housing 6. Once the end pieces 8 and 9 have been assembled as a package with the spacer piece 7, the gears 4 and 5 are in the housing 6, in such a way that a fitting without play with both the walls of the housing 6 and the end pieces 8 and θ is ensured. Assembly can take place suitably with screws, the holes for which are marked by way of reference with the number 12. Of course, any other form of attachment whatever is also possible.
The sealing of the shaft 3 is ensured with the aid of end plugs 10 and 11. The fitting of the gear 5 to the shaft 3 is freely rotating. The rotation of the gear 4 on the shaft 2 is, however, limited in such a way that only a relative movement of a specific amount is possible between the shaft and the gear.
Figure 2 shows in greater detail the property permitting the aforesaid relative movement. Thus, in the gear 4 is a recess 13 closest to the shaft 2, which, as can be seen, has a shape equipped with edges parallel to the radius of the shaft. The recess extends mainly from one edge of the gear to the other. For its part, the shaft 2 has a pin-like element 14, the direction of which is preferably parallel to the radius of the shaft. Once the device has been assembled, the pin 14 will be inside the recess and mutual movement of the shaft and gear will be possible to the extent to which the pin moves in the recess from one side of it to the other. One extreme position of the pin 14 is outlined with the reference number 14'.
In both Figure 1 and in Figure 2 a hole or channel 15 can be seen. Through this channel, the liquid to be precisely dosed by the device according to the invention is fed to the device. The motor, which rotates the device in order to dose the liquid, is marked with the reference number 16. The motor is connected to the shaft 2 with the aid of a suitable intermediate piece 18.
The shaft 2 is hollow, as can clearly be seen from Figure 2. The hole/channel penetrating the wall of the shaft is marked with the reference number 20.
In brief, operation is as follows. The pressurized liquid to be dosed is brought between the gears 4 and 5 through the channel 15. The gears forward the liquid through the recess 20 in the end piece 9, feeding it through the channel 17 in the jacket of the hollow shaft 2 and through the outlet nipple 19 to the desired object. With the aid of the device according to the invention, precise regulation of the flow of a liquid is achieved, in such a way that a change in the mutual position described above of the gear 4 and the shaft 2 relative to the pin 14 and the recess 13 of the gear 4 will automatically create a precise adjustment. This is because, if the liquid flowing in from the channel 15 seeks to rotate the gears 4 and 5 faster than the motor 16 rotates the shaft 2, this will cause a change in the position of the gear 4 relative to the shaft 2. This change signifies a relative rotation of the gear 'counterclockwise' to the shaft. This movement begins to close the flow opening 17, which throttling signifies a search for a state of equilibrium and the flow remaining very precisely in the pace set by the motor.
Figure 2 shows a component permitting a second embodiment, i.e. a spring 21. When the motor 16 is used, the spring 21 is not used. But, if a spring 21 turning the pin-like element 14 to a specific position in a normal situation is added to the recess 13, the motor 16 can be replaced with a brake, which is not shown here. The brake device and spring operate together in the same way as the motor 16 operates without the spring 21.
In the basic construction described above, there is only one pair of gears. However, it is obvious that there can be several pairs, if this is needed.