Technical field

The invention is about a gearbox, in particular a gearbox consisting of a drive axle and a driven axle mounted in the gearbox housing.

Current state of the art

Currently there are a number of gearbox designs used in many areas to couple a drive unit, typically a combustion engine, with a driven machine.

The current gear mechanisms with a mechanical change of torque between the input and the output mainly use 4 to 5 axially mounted gear wheels on the drive axle with gear ratios of 20/80, 40/60, 60/40, 80/20, 00/00. Helical gear wheels are usually used. The reverse shift usually has only one speed.

Czech patent application CZ PV 2007-180 describes a multiple-speed gearbox with transmitted load split. The gearbox consists of four and more speeds in two transmission branches where each speed comprises permanent meshed gear wheels with a single helical gearing of layshafts that are axially locked, or with pinions with double helical gearing for layshafts of a low-speed central gear wheel; the highspeed central wheel has double helical gearing and it is simultaneously stepped mesh with a single helical gearing of layshafts in both transmission branches; the low-speed central wheel has a double helical gearing and is axially locked; the highspeed central wheel is mounted to move axially, both layshafts of the low-speed central wheel with double helical gearing and the single layshaft overhung gear wheel are fitted with an axial alignment device functioning as a ballast mechanism to compensate for power distribution in the two transmission branches of the gearbox. As this solution is mainly for low-speed machines, its design is relatively robust and cannot be used generally.

Another Czech patent application CZ PV 2006-636 describes a reduction eccentric planetary gearbox with a chain. It has a hollow input shaft with an eccentric section accommodating a pivotal gear wheel or gear wheels with external gearing; these gears are prevented from rotating by positioning journals that are anchored in the rotationally shaped supporting frame of the gearbox. The gears mesh with a roller chain, which is part of the rotational housing. It has one, two or more gear wheels on an eccentric section of the hollow shaft and these gear wheels mesh with single, dual or multiple rolling chains enclosed in a loop. The disadvantage of this gearbox is that it cannot be used in high-speed systems, such as vehicle drive trains because it uses a chain.

Czech patent application CZ PV 1996-3245 describes a continuous variable gearbox consisting of a system for changing speed and transmitting it to the output shaft, a system for adjusting the speed according to the output shaft load and a reverse rotation system. It consists of two planetary gears each with a central wheel and a planetary carrier accommodating a planetary gear, a clutch actuated by motive fluid and a power clutch which can be optionally coupled with the output shaft, a low- speed brake situated on the power transmission path between the turbine and the power clutch and a reverse rotation system. Each basic element selected from the two planetary gears is coupled with the impeller, the turbine, the power clutch and the motive fluid actuated clutch and changes the input power to the requested type of operation and transmits it to the output shaft. The disadvantage of this is that it is complicated and has a technologically demanding design resulting in costly manufacture.

Another Czech patent application CZ PV 1996-3235 describes a dynamic planetary gearbox combined with a continuous gearbox that uses the principle of splitting the transmitted power into more branches of which one is mechanical and the others have a magneto electric link. This gearbox includes a connection between the planetary gearbox and at least one rotating electric machine where the planetary gear is mechanically driven by an external drive unit. Here the external drive unit mechanically drives the planetary gear, the planet carrier drives the external load, the planetary gear and, at the same time, the planetary gear or planetary carrier is coupled with rotational parts of electric machines. It can be permanently mechanically coupled with an external rotation power unit or situated between such a power unit and output load without having to use additional clutches, particularly slip clutches, in addition to using it as a flywheel for external rotation of the power unit. It follows from the above that this gearbox has a complicated design making it costly.

Furthermore, Czech patent application CZ PV 1996-2149 describes a hydrostatic gearbox with continuously variable gear ratios consisting of a drive axle coupled with the drive of a hydraulic pump unit, a static motive power unit and a driven shaft. A swinging wedge-shaped disc is pivotally connected to the driven shaft in controlled coupling to achieve the output torque corresponding to the pressure change in the hydraulic fluid between the pump unit and the motive power unit using shaped channels in the swinging disc. The hydraulic gear ratio controller changes the axial positions of spherical bearings that take the weight of the cylinder block of the pump in the hydraulic pump unit to adjust the angles of the swinging disc in relation to the axis of the driven shaft and thus changing the gear ratio. The main disadvantage of this gearbox is that it needs hydraulic fluid to operate. Therefore this gearbox is particularly suitable for static equipment where it is reasonably possible to provide environmentally safe operation.

Patent documentation CZ 273722 describes a transmission that uses a basic gearbox and planetary reduction. The basic gearbox consists of an input shaft with gear wheels and a shifting sleeve for halving individual speed gears, a layshaft with gear wheels and a driven shaft with gear wheels and shifting sleeves for shifting individual speeds of the basic gearbox. The planetary reduction consists of a crown gear wheel and the housing with bevel pinions wheels where the central gear wheel is permanently coupled to the driven shaft of the basic gearbox. The principle of this is that two gear wheels of the input shaft and two gear wheels of the layshaft make up two groups of three gear wheels arranged next to one another, and two gear wheels of the layshaft and two gear wheels of the driven shaft make up two couples arranged next to one another, situated between one group of three gear wheels and the planetary reduction. The disadvantage of this solution is that it has a restricted gear ratio.

Patent documentation CZ 279767 describes a split planetary three-speed gearbox where the first speed consists of a double central gear wheel and two bevel pinion gears and the second speed consists of two double central gear wheels and four bevel pinion gears. The third speed comprises a central gear wheel and four pinion gears. The first speed carrying shafts of the bevel pinion gears are pivotally mounted in the central plane of the gearbox housing and are coupled with the double central gear wheels of the second speed via an expansion clutch. The coupling is sliding, rotating, fixed and torsion flexible. One of the bevel pinion gears of the first speed is tangential-adjustable close-coupled with the adjacent supporting shaft via the first locking clutch and at least two of bevel pinion gears of the second speed are tangential-adjustable close-coupled with the adjacent planetary shafts via second locking clutches. This gearbox has a relatively simple design but it can be used only for plain applications.

The above illustrates a number of disadvantages of the current state of technology.

The purpose of the invention is to design a gearbox with a simple design, low- production cost that will eliminate most of these disadvantages of the current state of the art.

The principle of the invention

A gearbox, specifically a gearbox consisting of a drive shaft and a driven shaft mounted in the gearbox housing according to the invention, the principle of which is that at least two flanged gear wheels are mounted on the drive shaft where the individual flanged gear wheels are coupled with at least one actuation device that engages them.

Individual flanged gear wheels mounted on the drive shaft and individual flanged gear wheels mounted on the driven shaft has the advantage that they are inserted inside each other so that the external gearing of the smaller flanged gear wheel can be accommodated in the internal gearing of the larger flanged gear wheel when not in mesh. This reduces the size of the entire gearbox.

Another advantage is that individual flanged gear wheels are accommodated in a guide disc attached to the driven shaft or the drive shaft.

It is also beneficial that the actuation device is driven by an electromagnetic coil and contains at least one spring to carry out countermovement against the movement of the electromagnetic coils.

The actuation device, a telescopic piston fitted with a point permanent magnet and flanged gear wheels has at least one permanent magnet. This permanent magnet is a ring located against the point permanent magnet.

In its most advantageous version the gearbox contains a reverse housing accommodating the input reverse gear wheel and output reverse gear wheel which are coupled with at least one idle double gear wheel mounted on a journal inside the reverse housing; at least one of the double gear wheels has at least one sliding adjustable pin inserted which is simultaneously inserted in the hole of the reverse housing at the moment of forward motion, and at the moment of reverse motion it is inserted in the double gear wheel by the telescopic piston of the reverse control while the telescopic piston is inserted in a hole of the reverse housing at that moment.

It is advantageous when the input reverse gear wheel and the output reverse gear wheel are mounted on the driven shaft and are firmly attached to this shaft by at least one fixing latch; the driven shaft or the drive shaft are split.

It is also advantageous if the gearbox includes a device for gear shifting consisting of a shift prism and shift lever that has two vertically arranged expansion springs with contacts at their ends connected to a power supply; the shift prism includes three vertically arranged horizontal slots, two of them containing control contacts connected to the actuation device for individual flanged gear wheels; these contacts are always inserted in a pair of slots; when inserted into the slots the contacts are connected to the control contacts and individual shifts for forward and reverse motion are actuated.

It is obvious from this that with the gearbox according to the invention the same number of gears for forward and reverse motion can be selected on the device that is coupled to it. This increases the efficiency of using the power transmitted by the gearbox and results in major energy and cost savings in addition to a significant reduction in air pollution.

Overview of figures in the drawing

The invention can be explained more easily using the drawing in which figure 1 shows the cross section of the overall layout of the gearbox with first forward speed engaged; figure 2 shows the cross section of the overall layout of the gearbox with seventh reverse speed engaged; figure 3 shows the cross section of the dimensional layout of individual flanged gear wheels; figure 4 shows the cross section of the layout of individual reverse gear wheels; figure 5 shows the vertical section of the shifting device for forward motion; figure 6 shows the vertical section of the shifting device for reverse motion; figure 7 shows the horizontal section of the layout of individual contacts in the slot of the shifting device. Sample design of the invention

The gearbox (fig. 1 , fig. 2) of a conveyance consists of the drive shaft 1 and the driven shaft 3 which are mounted in the transmission housing 12.

The drive shaft 1 accommodates seven flanged gear wheels 2. The driven shaft 3 also accommodates seven flanged gear wheels 4. Each of flanged gear wheels 2, 4 is coupled to three actuating devices 5, 6, that engage them.

Figure 3 shows the flanged gear wheels that are not engaged, particularly flanged gear wheel 2 mounted on drive shaft 1, individual flanged gear wheels 4 mounted on the driven shaft 3 which are inserted one in another so that the external gearing 4, 1 of the smaller flanged gear wheel 2, 4 is in the internal gearing 8 of the larger flanged gear wheel 2, 4.

Flanged gear wheels 2 (fig. 1 , fig. 2) are mounted on the drive shaft 1 using the guide disc IQ. The flanged gear wheels 4 are mounted on the driven shaft 3 using the guide disc IJ..

Individual actuation devices 5, 6 contain electromagnetic coils .13 which are mounted in the transmission box 12. Each of the actuation devices 5, 6 contains an expansion spring 14. The actuating devices 5, 6 also contain a telescopic piston 36 mounted on an electromagnetic coil 13 and it has a point permanent magnet 43 at its end. Each of flanged gear wheels 2, 4 also contain a permanent magnet 44 designed as a ring 45. The point permanent magnet 43 and the permanent magnet 44 have reverse polarity which means that flanged gear wheel 2, 4 is pushed into the disengaged position without any physical contact. At the moment when the actuation device 5, 6 is initiated, the telescopic piston 36 retracts and thus, via spring 14, the flanged gear wheel 2, 4 is pushed into mesh.

The gearbox contains reverse housing 15 (fig. 1 , fig. 2) that accommodates input gear wheel 16 for reverse motion and output gear wheel 17 for reverse motion; these wheels are coupled (fig. 4) to three idle double gear wheels 18 which are mounted on journals 19 of the inner parts 20 of the reverse motion housing 15. One of the double gear wheels 18 has two slide-adjustable pins 21 inserted which are simultaneously retracted in holes 22 of the reverse motion housing 15 for forward motion and, for reverse motion, they are inserted into the double gear wheel 18 by the telescopic pistons 23 of the actuator 24 for reverse motion. At this moment the telescopic pistons 23 are inserted into the holes 22 of the reverse motion housing 15.

Input gear wheel 16 for reverse motion and output gear wheel 17 for reverse motion are mounted on the driven shaft 3 and are firmly attached to this shaft 1, 3 by fixing latches 25, 26. The driven shaft 3 is split.

Alternatively, reverse motion housing 15 can be situated on drive shaft 1.

The gearbox also contains a shifting device 7 (fig. 5, fig. 6, fig. 7) which consists of a shift prism 28 and shift lever 9 mounted on sliding cap 42. Shift lever 9 has two vertically assembled expansion springs 30, 3J_ at the ends of which there are mounted contacts 29 connected to the power supply 32. Shift prism 28 contains three horizontal slots 33, 34, 35_arranged vertically one above another; slot 33 has no control contacts 27, slot 34 has control contacts 27 connected to actuation device 5J. to 5J, GΛ_ to 67 of individual flanged gear wheels 2, 4, and slot 35 contains two control contacts 27 designed as a band. Contacts 29 are always inserted in a pair from slots 33, 34. 35- ^B Y inserting expansion springs 30, 3_1 with contacts 29 into slots 33, 34, 35 contacts 29 connects to the control contacts 27 and initiates the actuation of shifting individual speeds for forward and reverse motion.

A forward speed is selected by moving shift lever 9 (fig.5) horizontally with a disengaged (and not illustrated) clutch from the neutral position 37 (fig.7) into a position which, on the second floor of the shift prism 28 (fig.5), couples via spring 3J. to firmly connected sliding contacts 9 (fig.5) resulting in connecting contact 29 with control contact 27 that subsequently initiates the electromagnetic coil 13 (fig.1 ,2), while the telescopic piston of the electromagnetic coil 36 retracts into its body. This releases flanged wheel 2 and pushes it out via springs 14 to mesh with similarly released flanged gear wheel 4 and the respective speed is engaged.

When shifting to a different speed the clutch is disengaged first, then the driver moves shift lever 9 into the position for a new speed, which disconnects contact 29 from control contact 27 of the original speed and connects contact 29 with control contact 27 of the new speed (fig. 7). At the same time actuation devices 5, 6 are deactivated and the original flanged gear wheel 2, 4 is retracted followed by a sequence of functional operations via electromagnetic coils 13 pushing out gear wheels 2, 4 that correspond to the new speed.

Next shift lever 9 is moved horizontally in shift prism 28 into a position for a different speed, which connects contact 29 with control contact 27 of the respective speed (fig. 7) and this speed is meshed as flanged gear wheels 2, 4 for the respective speed (fig. 1 , fig. 2) are engaged by the aforementioned procedure.

For shifting reverse, the clutch needs to be disengaged first. Than shift lever 9 (fig. 6) is moved in shift prism 28 into position 37 for neutral (fig. 7) and after pushing it the slightly conic profile 38 of shift lever 9 touches the bottom 39 and expansion spring 30 pushes contacts 29 into slot 35 and expansion spring 3_1 pushes contacts 29 into slot 34. By pulling it slightly from the bottom of prism 28 the shift lever 9 moves into the position for the respective reverse speed. As soon as the reverse speed is engaged, shift lever 9 is locked in position by fixing journals 4Z ₁ which are pushed into slots 46 in the conical profile 38 by springs 48.

Control contacts 27 are inactive when the position is changed. When a respective reverse speed is engaged expansion springs 30 connects contacts 29 with band-shaped control contacts 27 located in slot 35 and expansion springs 3_1 connects contacts 29 with control contacts 27 located in slot 34. By connecting contacts in slot 35 electromagnetic coils 40.1. 40.2 of the actuator 24 for reverse motion are activated and the telescopic pistons 23 project into holes 22 and adjustable sliding pins 21 inserts into the double gear wheel 18. The gear ratio in the reverse gear set is approximately 1 : 4 slowdown.

Industrial application

The gearbox according to the invention can be used for the drive train of any equipment, particularly means of transport.

List of indices

1 drive shaft

2 flanged gear wheel I

3 driven shaft

4 flanged gear wheel Il

5 actuation device I

6 actuation device Il

7 device for shifting speed

8 internal gearing

9 shift lever

10 guide disc I

11 guide disc Il

12 transmission housing

13 electromagnetic coil

14 spring

15 housing for reverse motion

16 input gear wheel

17 output gear wheel

18 double gear wheel

19 journal

20 inner part

21 adjustable sliding pin

22 hole

23 telescopic piston

24 actuator for reverse motion

25 fixing latch I

26 fixing latch Il

27 control contact

28 shift prism

29 contact

30 expansion spring I

31 expansion spring Il

32 power energy supply

33 slot l

34 slot Il

35 slot III

36 telescopic piston

37 neutral position

38 conic profile

39 bottom

40 electromagnetic coil

41 external gearing

42 sliding cap

43 point permanent magnet

44 permanent magnet

45 ring

46 slot

47 fixing journal

48 spring