Continuously variable transmission

Abstract

The invention relates to a continuously variable transmission having an input shaft, an output shaft, an intermediate shaft, a variable transmission, a hydrostatic transmission, a housing and a support plate, the hydrostatic transmission being arranged in a side view in an installation position geometrically parallel to the variable transmission. The output shaft is offset relative to the input shaft in the horizontal direction and in the vertical direction when viewed in the axial direction, and wherein the housing is one-piece and is open on one side, and wherein the output shaft is offset relative to the input shaft in the horizontal direction and in the vertical direction when viewed in the axial direction. The housing and / or the support plate has a plane on the outside, and the plane is designed to fix the module component on the outer side of the continuously variable transmission.

Description

Technical Field

[0001] The present invention relates to a continuously variable transmission having a hydraulic component for use in a vehicle. Background Art

[0002] Continuously variable transmissions with hydraulic components are used in agricultural vehicles. The operation allows the drive force to be distributed over the hydraulic and mechanical branches of the transmission with continuously variable gears or gear ranges. In agriculture, different drive requirements are imposed on the drive devices. Firstly, the drive on the engine route is a prerequisite for transport work with low to medium torques. Secondly, some areas need to be formed with the aid of medium to high torque attachments. Hydraulic continuously variable transmissions have proven to be advantageous in this area. Maintenance and robustness together with a long service life are advantageous in these areas.

[0003] A hydraulic continuously variable transmission generally has a hydrostatic unit, a shift range and a means for switching between forward and reverse operation. In order to increase the efficiency of such a transmission, the number of tooth meshes between the gears used is generally minimized.

[0004] The installation space of the transmission is limited by the area connected to it; this applies in particular to the overall length of such a transmission in the vehicle direction. At the same time, the overall height, i.e. the vertical extension, is also limited by the shaft position specifications in the transmission in relation to the input shaft and the output shaft, so that the installation space cannot be reduced arbitrarily. Summary of the invention

[0005] The invention solves the problem by providing a continuously variable transmission with reduced installation space. Furthermore, the tooth meshing is minimized in the invention.

[0006] According to the present invention, a continuously variable transmission has an input shaft, an output shaft, an intermediate shaft, a speed transmission mechanism, a hydrostatic transmission mechanism, a housing and a support plate, wherein the housing at least partially surrounds all shafts and components and has an input side for power input and an output side for power output, wherein the continuously variable transmission has an installation position provided during operation, wherein the input shaft is connected to the intermediate shaft by means of a gear through one or more tooth meshings, wherein the speed transmission mechanism is arranged on the intermediate shaft, wherein the intermediate shaft is connected to the output shaft through one or more tooth meshings, wherein the hydrostatic transmission mechanism is arranged geometrically parallel to the speed transmission mechanism in the installation position in a side view, and the power flow can be distributed between the hydrostatic transmission mechanism and the speed transmission mechanism, wherein the output shaft is horizontally and vertically offset relative to the input shaft in the installation position when viewed axially, wherein the housing is one-piece and open on one side, and the components in the continuously variable transmission are held in the housing by the support plate in the installation position, wherein the housing and / or the support plate have planes on the input side and / or the output side, and the planes are designed to fix the module components on the outside of the continuously variable transmission.

[0007] The input shaft transfers the driving force from the drive shaft to the continuously variable transmission. The driving force is output to the connected modules via the intermediate shaft and the output shaft. The speed transmission mechanism can provide different speed ranges for the vehicle drive through gear pairing and clutches. The hydrostatic transmission mechanism in the continuously variable transmission represents a power branch via which part of the power is guided parallel to the speed transmission mechanism. The invention thus allows a compact design of the continuously variable transmission together with a shortened overall length. Due to the offset and geometrically parallel arrangement of the shafts, i.e., they are arranged on the same section in the longitudinal direction in the installation position, additional installation space is saved in length and can therefore be used for other modules such as lubricant supply or four-wheel drive.

[0008] In one refinement, the output shaft (30) has a forward-reverse clutch (90).

[0009] By providing a forward-reverse clutch on the output shaft, additional installation space can be saved in the length of the transmission.

[0010] In another embodiment of the present invention, the output shaft has a forward clutch and the intermediate shaft has a reverse clutch.

[0011] This arrangement allows a space-saving accommodation of the reverse clutch and the associated idler gear for reversing the direction of rotation.

[0012] In one refinement, the output shaft has a reverse clutch and the intermediate shaft has a forward clutch.

[0013] This arrangement allows a space-saving accommodation of the reverse clutch and the associated idler gear for reversing the direction of rotation.

[0014] In another embodiment of the present invention, the speed change transmission mechanism is a planetary gear transmission mechanism and / or a superimposed planetary gear transmission mechanism.

[0015] Designing as a planetary gear mechanism allows for a small installation space while having a large distribution of the transmission. The planetary gear mechanism has a high efficiency due to the minimum required tooth meshing. The embodiment as a superposition transmission allows the hydrostatic transmission and its power output to be used as an additional input of the speed change transmission.

[0016] In one embodiment, the continuously variable transmission has an auxiliary shaft. The auxiliary shaft can be used for the arrangement of a hydrostatic transmission mechanism.

[0017] In another embodiment of the present invention, the intermediate shaft is connected to the input end of the hydrostatic transmission mechanism through one or two tooth meshings; and the output end of the hydrostatic transmission mechanism is connected to the input end of the speed change transmission mechanism through tooth meshings.

[0018] Minimizing the required tooth engagement improves the efficiency of the CVT and has an effect on noise and ride comfort.

[0019] In one development, the output shaft is shorter than the input shaft and is arranged axially offset relative to the input shaft in the installed position.

[0020] The shortening of the output shaft reduces the installation space in the longitudinal direction of the continuously variable transmission. The offset of the output shaft results in all gears of the input shaft and the output shaft being in a vertical plane with the center of the tooth flank or tooth width. This arrangement provides uniform dimensions for mounting the gears and shafts in the support plate. The support plate can thus be designed in a flat shape without projections. This in turn leads to material savings, weight reduction and a strong seal between the housing and the support plate, since complex sealing geometries are avoided.

[0021] According to one embodiment, the hydrostatic transmission (60) is arranged in the installed position in a lowest position below all other shafts.

[0022] Arranging the hydrostatic transmission in the lowest position in the installed position allows a spatial arrangement in which the input shaft and the output shaft are arranged at a higher position and are at the same time offset relative to one another in the horizontal and vertical direction. With this arrangement, the length of the required installation space can be significantly reduced because the individual components are arranged in parallel.

[0023] In another embodiment of the invention, the gears are arranged so that on one side in the mounted position they are longitudinally inside the housing with the tooth flanks lying in the same plane or so that the centre of the respective tooth width lies in a plane lying perpendicularly with respect to the axis.

[0024] The alignment of all gears on one side of the transmission as seen in the transverse direction provides the possibility of forming a common support in the housing support plate. This arrangement allows for a flat end of the support plate, as a result of which it is also provided with a continuous flat surface. This is particularly advantageous for further connecting the module to the continuously variable transmission.

[0025] In one embodiment, the input shaft is arranged in a high position above all other shafts in the installed position in a side view.

[0026] The arrangement in the highest position together with the hydrostatic transmission in the lowest position makes it possible to save installation space and allows a compact arrangement of the hydrostatic transmission and the speed change transmission in a parallel configuration variant. The overall length of the continuously variable transmission is shortened and the amount of material used is reduced.

[0027] In another embodiment of the present invention, the support plate has an open configuration or a closed configuration.

[0028] In the open configuration, the support plate can have multiple openings for consumables such as lubricants to pass through. Multiple openings can also be provided for hydraulic lines, electrical wires or even mechanical shafts or connections. This configuration allows direct connection of other functional modules to the housing or support plate of the continuously variable transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Other embodiments of the present invention are described with reference to the accompanying drawings, in which:

[0030] Figure 1 A diagram showing a continuously variable transmission, and

[0031] Figure 2 The view in the transverse direction of the installed position is shown together with the shaft position within the continuously variable transmission. DETAILED DESCRIPTION

[0032] The continuously variable transmission 10 has an input shaft 20, which is connected to an intermediate shaft 40 by at least one tooth meshing. The intermediate shaft 40 is firstly connected to the input of the variable transmission 50 and then to the auxiliary shaft 100 by another tooth meshing, which in turn is connected to the input of the hydrostatic transmission 60. On the output side of the hydrostatic transmission 60, the introduction into the input of the variable transmission 50 is achieved by another tooth meshing. The variable transmission 50 is connected to the forward-reverse unit 90 and its clutch via the output by means of a tooth meshing. Downstream of the forward-reverse unit 90, the power is output to the connected modules and traction drives.

[0033] The input shaft 20 may have a toothing system on one side, which transmits the power to the intermediate shaft 40. The ratio of the intermediate shaft 40 to the auxiliary shaft 100 may be achieved with a reversal of the direction of rotation, such as Figure 1As shown. The hydrostatic transmission mechanism 60 represents one power branch and the speed change transmission mechanism 50 represents another power branch. These power branches converge in the speed change transmission mechanism 50 and the combined force is output to the forward-reverse unit 90 through the meshing system. The forward-reverse unit 90 selects forward or reverse travel through a clutch.

[0034] The transmission 50 can be configured as a planetary gear, wherein the output torque and the output speed are determined by superposition, that is to say by the speed and torque differences of the two power branches that occur.

[0035] Figure 1 A so-called stick diagram is shown, in which the functional relationships between the shafts and components are reproduced. Therefore, the partial arrangement of the shafts is not shown. The hydrostatic transmission 60 is arranged at the lowest point in the invention, as a result of which the output shaft 30 is arranged in the center. Figure 1 There is no objection to this arrangement, but the method of operation of the continuously variable transmission 10 is described in a two-dimensionally reproduced manner.

[0036] Figure 1 The toothing system of the input shaft 20 and the intermediate shaft 40 is shown to be arranged in one plane.

[0037] Figure 2 An embodiment of a continuously variable transmission 10 is described, in which the shaft is arranged axially in a longitudinal view. The housing 70 at least partially surrounds the individual components of the continuously variable transmission 10. The housing is covered or closed by a support plate 80. The support plate 80 can have a plurality of openings through which the consumables are conveyed or through which a mechanical connection is established. The support plate 80 can also be arranged in a completely sealed configuration, with the result that a mechanical connection is achieved only by means of the shaft, wherein the shaft is sealed.

[0038] The input shaft 20 is in the highest position in the installation position. With this arrangement, the gap between the input shaft 20 and the output shaft 30 can be increased so as to arrange all components on their respective shaft sections. The intermediate shaft 40 is arranged below with an offset in the horizontal direction and in the vertical direction. The intermediate shaft 40 includes a speed change transmission mechanism 50 and is connected to the input shaft 20 by tooth engagement.

[0039] The output shaft 30 is arranged below the intermediate shaft 40, offset in the horizontal direction and in the vertical direction relative to the input shaft 20 and the intermediate shaft 40. This arrangement has the advantage that the installation space for the speed change transmission 50 and for the hydrostatic transmission 60 can be optimally arranged in the housing 70. In addition, the two transmissions 50, 60 can thus be arranged parallel to each other.

[0040] In the installed position, the hydrostatic transmission 60 is arranged in the lowest position within the continuously variable transmission 10 . This arrangement allows for optimal utilization of the installation space and easy access for maintenance in the housing 70 .

[0041] The power path of the continuously variable transmission 10 is guided through the input shaft 20 and is divided between the hydrostatic transmission 60 and the speed change transmission 50 on the intermediate shaft 40 by one or more tooth meshings. The power path is merged into the speed change transmission 50 downstream of the hydrostatic transmission 60, wherein the speed change transmission 50 is designed as a superposition transmission. The power path is then guided to the output shaft 30 via the forward-reverse clutch 90.

[0042] The proposed continuously variable transmission 10 allows a compact and (as seen along the axis in the length of the installation space) short design, which allows an advantageous integration into the power train of a vehicle. The invention expands the application possibilities and the modular structure of the power train. Other modules and components of a standardized design can be connected to the flat outer surface of the less complex continuously variable transmission 10. The continuously variable transmission 10 allows scaling across other model series and standardization of connecting modules.

Claims

1. A continuously variable transmission (10), comprising: Input shaft (20), Output shaft (30), Intermediate shaft (40), A speed change transmission mechanism (50), Hydrostatic transmission mechanism (60), a housing (70) and a support plate (80), wherein the housing (70) at least partially surrounds all shafts and components and has an input side for power input and an output side for power output, wherein the continuously variable transmission (10) has a mounting position provided during operation, wherein the input shaft (20) is connected to the intermediate shaft (40) by means of a gear by meshing one or more teeth, The speed change transmission mechanism (50) is arranged on the intermediate shaft (40). wherein the intermediate shaft (40) is connected to the output shaft (30) via one or more tooth meshings, wherein the hydrostatic transmission mechanism (60) is arranged geometrically parallel to the speed-changing transmission mechanism (50) at the installation position in a side view, and the power flow can be distributed between the hydrostatic transmission mechanism (60) and the speed-changing transmission mechanism (50), The output shaft (30) is axially offset relative to the input shaft (20) at the installation position in the horizontal direction and the vertical direction. The housing (70) is integral and open on one side, and the components in the continuously variable transmission (10) are held in the housing (70) by the support plate (80) in the installed state. The housing (70) and / or the support plate (80) have a flat surface on the outside, which is designed to fix a module component on the outside surface of the continuously variable transmission (10).

2. The continuously variable transmission (10) according to claim 1, characterized in that: The output shaft (30) has a forward-reverse clutch (90).

3. The continuously variable transmission (10) according to claim 1, characterized in that: The output shaft (30) has a forward clutch, and the intermediate shaft (40) has a reverse clutch.

4. The continuously variable transmission (10) according to claim 1, characterized in that: The output shaft (30) has a reverse clutch, and the intermediate shaft (40) has a forward clutch.

5. A continuously variable transmission (10) according to any one of the preceding claims, characterized in that The speed change transmission mechanism (50) is a planetary gear transmission mechanism and / or a superposition transmission mechanism.

6. A continuously variable transmission (10) according to any one of the preceding claims, characterized in that The continuously variable transmission (10) has an auxiliary shaft.

7. A continuously variable transmission (10) according to any one of the preceding claims, characterized in that The intermediate shaft (40) is connected to the input end of the hydrostatic transmission mechanism (60) through one or two tooth meshings, and the output end of the hydrostatic transmission mechanism (60) is connected to the input end of the speed change transmission mechanism (60) through tooth meshing.

8. A continuously variable transmission (10) according to any one of the preceding claims, characterised in that The output shaft (30) is shorter than the input shaft (20) and is axially offset relative to the input shaft (20) at the installation position.

9. A continuously variable transmission (10) according to any one of the preceding claims, characterised in that In the installed position, the hydrostatic transmission (60) is arranged in the lowest position below all other shafts.

10. A continuously variable transmission (10) according to any one of the preceding claims, characterised in that The gears are arranged in the mounting position on one side inside the housing (70), wherein the tooth flanks are located in the same plane, or the gears are arranged in such a way that the centers of the respective tooth widths are located in a common plane located perpendicularly relative to the shaft.

11. A continuously variable transmission (10) according to any one of the preceding claims, characterized in that In the installed position, the input shaft (20) is arranged in a highest position above all other shafts in a side view.

12. A continuously variable transmission (10) according to any one of the preceding claims, characterised in that The support plate (80) is designed to be open or closed.

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