阅读说明：本技术 用于控制包括分流器区段的有级变速器中的润滑的装置 (Device for controlling lubrication in a stepped transmission comprising a splitter section ) 是由 安德斯·海德曼 于 2018-01-22 设计创作，主要内容包括：本发明涉及一种用于控制有级变速器中的润滑的润滑装置,所述有级变速器包括具有输入轴(I)的分流器区段(10、20)以及具有输出轴(O)和副轴(C)的主齿轮区段(30、40、50、60)；其中,所述分流器区段(10、20)包括：第一分流器齿轮组(10),所述第一分流器齿轮组能够由第一换档机构(23)连接到所述输入轴(I)；以及第二分流器齿轮组(20),所述第二分流器齿轮组能够由所述第一换档机构(23)连接到所述输入轴(I),并且能够由第二换档机构(33)连接到所述输出轴(O)。用于所述第二分流器齿轮组(20)的润滑布置结构被布置成由所述第一换档机构(23)和第二换档机构(33)的当前位置控制；其中,当所述第一换档机构(23)和第二换档机构(33)同时连接到所述第二分流器齿轮组(20)或与所述第二分流器齿轮组断开连接时,所述润滑布置结构被控制成至少减少润滑。(The present invention relates to a lubrication arrangement for controlling lubrication in a step-variable transmission comprising a splitter section (10, 20) with an input shaft (I) and a main gear section (30, 40, 50, 60) with an output shaft (O) and a countershaft (C); wherein the flow divider segment (10, 20) comprises: a first splitter gear set (10) connectable to the input shaft (I) by a first gear shift (23); and a second splitter gear set (20) connectable to the input shaft (I) by the first gear shift (23) and to the output shaft (O) by a second gear shift (33). A lubrication arrangement for the second splitter gear set (20) is arranged to be controlled by the current positions of the first and second gearshifts (23, 33); wherein the lubrication arrangement is controlled to at least reduce lubrication when the first and second gear shift (23, 33) are simultaneously connected or disconnected to the second splitter gear set (20).)

1. A lubrication arrangement for controlling lubrication in a step-variable transmission comprising a splitter section (10, 20) with an input shaft (I) and a main gear section (30, 40, 50, 60) with an output shaft (O) and a countershaft (C); wherein the flow divider segment (10, 20) comprises:

-a first splitter gear set (10), the first splitter gear set (10) being connectable to the input shaft (I) by a first gear shift (23);

-a second splitter gear set (20), the second splitter gear set (20) being connectable to the input shaft (I) by the first gear shift (23); and connectable to said output shaft (O) by a second gear shift mechanism (33);

it is characterized in that

-a lubrication arrangement for the second splitter gear set (20) is arranged to be controlled by the current positions of the first gear shift (23) and the second gear shift (33); and is

-the lubrication arrangement is controlled to at least reduce lubrication when the first gear shift (23) and the second gear shift (33) are simultaneously connected to or disconnected from the second splitter gear set (20).

2. The lubrication arrangement as recited in claim 1, characterized in that the lubrication arrangement is controlled to be deactivated when the first gear shift (23) and the second gear shift (33) are simultaneously connected to the second splitter gear set (20) or disconnected from the second splitter gear set (20).

3. The lubrication device according to claim 1 or 2, characterized in that the lubrication arrangement comprises a first and a second supply means for lubricant, wherein the first and the second supply means comprise a first and a second sliding closure device (24, 34, 24'), which are controllable by the first or the second gear shift mechanism (33).

4. The lubrication device of claim 3, wherein the first and second supply means comprise:

-a first and a second opening in a lubricant oil groove (26; 53; 63), said lubricant oil groove (26; 53; 63) being connected to a lubricant supply (36, 37; 46, 47; 56, 57; 66, 67); and

-first and second sliding closure devices (24, 24 '), arranged to close the first and/or second openings in response to the position of the first and second gear shift mechanisms (23, 33), 25'.

5. The lubrication device of claim 3, wherein the first and second supply means comprise:

-a first injection nozzle (36) and a second injection nozzle (37), said first injection nozzle (36) and said second injection nozzle (37) being adjacent to said second splitter gear set (20) and connected to a lubricant supply (38); and

-a first sliding closure device (34) and a second sliding closure device (35), said first sliding closure device (34) and said second sliding closure device (35) being arranged to at least partially close said first injection nozzle (36) and/or said second injection nozzle (37) in response to the position of said first gearshift mechanism (23) and second gearshift mechanism (33).

6. The lubrication device according to any one of claims 3 to 5, characterized in that said first gear shift mechanism (23) is mechanically connected to said first closing means (24; 34; 24 '; 24 ") by said first sealing means (S1) and said second gear shift mechanism (33) is mechanically connected to said second closing means (25; 35; 25'; 25") by second sealing means (S2).

7. The lubrication arrangement as recited in any one of claims 3-6, characterized in that the lubrication arrangement is controlled to at least reduce lubrication when the second splitter gear set (20) is disconnected from the input shaft (I) by the first gear shift (23) and at the same time from the output shaft (O) by the second gear shift (33).

8. Lubricating apparatus according to any one of claims 3-7, characterised in that the first gear shift mechanism (23) is arranged to act on the first sliding closure device (24; 34; 24 '; 24 ") to at least partly close the first supply means and the second gear shift mechanism (33) is arranged to act on the second sliding closure device (25; 35; 25'; 25") to close the second supply means when the second splitter gear set (20) is disconnected from both the input shaft (I) and the output shaft (O).

9. The lubrication arrangement as recited in any one of claims 3-6, characterized in that the lubrication arrangement is controlled to at least reduce lubrication when the second splitter gear set (20) is connected to the input shaft (I) by the first gear shift (23) and at the same time to the output shaft (O) by the second gear shift (33).

10. Lubricating apparatus according to any one of claims 3-6 or 9, characterised in that the first gear shift mechanism is arranged to act on the first sliding closure device (24; 34; 24 '; 24 ") to at least partially close the second supply means, and the second gear shift mechanism (33) is arranged to act on the second sliding closure device (25; 35; 25'; 25") to at least partially close the first supply means, when the second splitter gear set (20) is connected to both the input shaft (I) and the output shaft (O).

11. The lubrication device according to any of the claims 3 to 10, characterized in that the first sliding closure device (24; 34; 24'; 24 ") comprises a sliding portion arranged to at least partially close the first supply means when the second splitter gear set (20) is disconnected from the input shaft (I) and arranged to open the first supply means and at least partially close the second supply means when the second splitter gear set (20) is connected to the input shaft (I).

12. The lubrication device according to any of the claims 3 to 11, characterized in that the second sliding closure device (25; 35; 25'; 25 ") comprises a sliding portion arranged to at least partially close the second supply means when the second splitter gear set (20) is disconnected from the output shaft (O) and arranged to at least partially close the first supply means and open the second supply means when the second splitter gear set (20) is connected to the output shaft (O).

13. Lubricating apparatus according to claim 11 or 12, characterised in that the sliding portions of the first and second closure devices (24, 24 ', 24 ", 25', 25") each comprise a sealing surface having a through hole (44, 45) alignable with the first and second supply means, respectively.

14. The lubrication device according to claim 11 or 12, characterized in that the sliding portions of the first closing device (24, 24 ', 24 ") and of the second closing device (25, 25', 25") each comprise a cam (24a ', 25 a'), the cams (24a ', 25 a') being arranged to act on a first pivot valve (54) or a second pivot valve (55) to close the first supply means or the second supply means; wherein the valve is spring loaded (58, 59) towards an open position.

15. Lubricating apparatus according to claim 11 or 12, characterised in that the sliding portions of the first and second closing means each comprise a cam (24a ", 25 a"), the cams (24a ", 25 a") being arranged to act on a first (64) or a second (65) pivot valve to close the first or second supply means,

wherein each valve is spring loaded towards a closed position by a first spring (68a, 69a) and displaced towards an open position by a second spring (68b, 69b) under the action of either of the first and second gear change mechanisms (23, 33).

16. A vehicle transmission comprising a lubrication device according to any one of the preceding claims 1 to 15.

17. A vehicle provided with a step-variable transmission including a lubricating apparatus according to any one of claims 1 to 15.

Technical Field

The present invention relates to a device for controlling lubrication in a step-variable transmission comprising a splitter section.

The invention can be applied to heavy vehicles, such as trucks, articulated trucks, buses and construction equipment, which may be manned or unmanned. Although the invention will be described for a heavy vehicle, the invention is not limited to this particular vehicle, but may also be used for other vehicles, such as buses, articulated haulers, wheel loaders and other work machines comprising a stepped transmission with a splitter section.

Background

Gear transmissions in heavy vehicles typically include a manually controllable gearbox with a stepped transmission, also referred to as an automated manual transmission or Automated Mechanical Transmission (AMT), controlled by a control system. Typically, AMT gearboxes are lighter and less expensive to manufacture than dual clutch gearboxes. They also have higher efficiency than conventional automatic transmissions. AMT gearboxes are particularly suitable for heavy goods vehicles (which are mainly used for long-haul transport). AMT gearboxes of this type are generally countershaft inline transmissions (countershaft transmissions) and comprise three parts managed by a common control system: a splitter section, a main gearbox and a range gear.

A countershaft inline transmission includes an input shaft connected to a source of propulsion power (e.g., an internal combustion engine) and an output shaft connected to at least one pair of drive wheels via a driveline. The input shaft and the output shaft are coaxially arranged. The transmission also includes at least one countershaft disposed parallel to the input and output shafts. Typically, power is transferred from the input shaft to the layshaft via a primary gearset and to the output shaft via one of a plurality of selectable secondary gearsets (commonly referred to as a main gearbox). A range gear can be disposed between the output shaft and the drive line.

Some vehicles (e.g., heavy trucks and buses) typically require a relatively large number of gears in the transmission. One well-known way to achieve this is a splitter design in which there are at least two main gear sets. These gear sets are capable of selectively transferring power from the input shaft to the countershafts, and are commonly referred to as flow splitters or flow splitter gear sets. In one operating state, one of the primary gear sets is connected to the layshaft for transmitting power to the primary gearbox. The other main gear set will still rotate but not transmit power. This will result in load-independent power losses due to oil pumping, oil splashing and windage caused by supplying oil to the inactive main gear set.

In another mode of operation, the input shaft is directly rotatably connected to the output shaft, a condition referred to as "direct gear". In long haul heavy vehicles, this direct gear is also typically the highest gear, and is the most frequently used gear. For best fuel economy, the highest gear in such vehicles is typically the direct gear. In the direct gear, none of the gear sets in the main gearbox are active. This reduces load-related power losses in the transmission, thereby increasing efficiency and improving fuel consumption. However, although no propulsive power is transmitted in the direct gear, the gears in the main gearbox are still rotating. This will result in load-independent power losses due to oil pumping, oil splashing and windage caused by supplying oil to the gears. Thus, when the vehicle is operating in a direct gear, there is a waste of energy that constantly lubricates and cools the gear teeth of the gear set.

In this type of transmission, it is necessary to provide lubrication and cooling to the gear teeth. The lubrication and cooling of the gear teeth can be implemented as wet lubrication, wherein the lowermost gear of the gear set is partially below the oil level. Alternatively, injection lubrication can be provided for one of the gears, so that the oil flow is directed onto the gear teeth via at least one nozzle. However, only the gear set that is operating and transmitting power needs to be so. When the gear set is not in operation, the need for lubrication and cooling may be negligible, or at least relatively low.

Accordingly, it is desirable to provide an improved method and arrangement (arrangement) for controlling lubrication in an automated manual transmission or a countershaft inline transmission in order to overcome the above-mentioned problems.

Disclosure of Invention

It is an object of the present invention to provide a method and an arrangement for controlling the lubrication of gears, in particular of a splitter gear set, in a layshaft inline transmission with a splitter section, which arrangement is described in the dependent claims.

Hereinafter, the splitter section is described as including a first splitter gear and a second splitter gear. The first and second splitter gears are also referred to as "low split" (LS) and "high split" (HS) and are used with the range gears to provide a wider range of gear ratios to the gearbox. The present invention relates to a lubrication device for controlled lubrication in a step-variable transmission comprising a splitter section with a main gear set and a main gear section with a secondary gear set. The splitter section includes an input shaft and the main gear section includes an output shaft. The secondary shaft is parallel to the input and output shafts. The diverter section includes a first diverter gear set having a first diverter idler gear (loose gear) and a second diverter gear set having a second diverter idler gear. In this context, the idler gear does not transmit power until it is connected to the shaft by the shift mechanism. The first diverter idler gear can be connected to the input shaft by a first shift mechanism and the second diverter idler gear can alternatively be connected to the input shaft by the first shift mechanism and can be connected to the output shaft by a second shift mechanism. The first and second shift mechanisms are located on opposite sides of the second diverter idler gear. The first and second splitter idler gears are arranged to rotate freely relative to the input and output shafts, respectively, when not connected to transmit power.

A lubrication arrangement for the second splitter gear set is arranged to be controlled by the positions of the first and second gearshifts. These positions are the currently selected positions that represent the gears selected by the driver or an electronic control unit connected to the transmission. The lubrication arrangement is further controlled to reduce lubrication at least when the first and second gearshifts are simultaneously connected to or disconnected from the second splitter idler gear.

Lubrication of the second splitter gear set occurs when the position of the first and second gearshifts causes power transfer in the form of drive torque between gears in the second splitter gear set (i.e., between the input shaft and the countershaft, or between the countershaft and the output shaft) via the second splitter gear set. This occurs when one of the first and second gearshifts is positively connected to the second diverter idler gear.

However, when no drive torque is being transferred from the second splitter gear set to the countershaft (or vice versa), lubrication of the second splitter gear set is reduced or interrupted. This occurs when both the first and second gearshifts are connected to the second diverter idler gear, which then drives the output shaft. In this case, torque is transmitted from the input shaft to the output shaft in the direct gear. Alternatively, this occurs when both the first and second gearshifts are disconnected from the second diverter idler gear, which then idles around the output shaft. In this case, torque is transferred from the input shaft to the output shaft via the first splitter gear set and the countershaft. In this case, the path for transferring torque bypasses the second splitter gear set. Each shift mechanism can have a neutral position in which it is not connected to any gear set and at least one operating position in which it is connected to a gear set. In this example, the first shift mechanism has a first operating position in which the first shift mechanism connects the first splitter idler gear to the input shaft and a second operating position in which the first shift mechanism connects the second splitter idler gear to the input shaft. The neutral or rest position of the first shift mechanism is located between the first and second operating positions. Similarly, the second shift mechanism has a first operating position in which the second shift mechanism connects the second diverter idler gear to the output shaft and an optional second operating position in which the second shift mechanism connects the gear in the main gearbox to the output shaft. The neutral or rest position of the second shift mechanism is located between the first and second operating positions.

The lubrication arrangement can be controlled to: reducing or stopping lubrication when the first and second shift mechanisms are simultaneously positioned to connect to or disconnect from the second diverter idler gear.

The lubrication arrangement can comprise first and second supply means for lubricant, wherein the first and second supply means comprise first and second sliding closure devices that can be controlled by the first and second gear shift mechanisms. In this context, the term "sliding" is used to describe the displacement of the closure device relative to the opening for supplying lubricant. Since the displacement of the closing means is controlled by a respective gear shift mechanism, a sliding movement of the gear shift mechanism parallel to the input and output shafts is transmitted to the closing means. Thus, the displacement of the closure device will be substantially parallel to the input and output shafts of the transmission.

According to one example, the first and second supply means comprise a first and second supply opening, respectively, which are located in a lubricant oil groove connected to a lubricant supply device. The lubricant sump is disposed adjacent a lowermost gear of the gear set constituting the second splitter gear set. The first and second sliding closure devices are arranged to at least partially close the first and/or second openings in response to the position of the first and second gear shift mechanisms.

According to another example, the first and second supply means comprise first and second spray nozzles adjacent to or below a lowermost gear of the second splitter gear set, the spray nozzles being connected to a lubricant supply. The first and second sliding closure devices are arranged to at least partially close the first and/or second spray nozzle in response to a position of the first and second gear shift mechanisms.

The first shift mechanism can be mechanically coupled to the first closure device by a first seal device. Similarly, the second shift mechanism is mechanically coupled to the second closure device by a second seal. Such sealing means are arranged to connect the gear shift mechanism to the respective closing means. The sealing arrangement is arranged to at least partially enclose the second splitter gear set to reduce injection and windage between gear sets on either side of the second splitter gear set.

According to one example, the lubrication arrangement is controlled to: at least reducing lubrication when the second diverter idler gear is simultaneously disconnected from the input shaft by the first shift mechanism and from the output shaft by the second shift mechanism. In this case, the second splitter idler gear is idle with respect to the output shaft and no lubrication is required since the second splitter gear set does not transmit power. When this condition occurs, the first gear shift mechanism is arranged to act on the first sliding closure device to at least partially close the first supply means and the second gear shift mechanism is arranged to act on the second sliding closure device to at least partially close the second supply means as long as the second diverter idler gear is disconnected from both the input shaft and the output shaft.

According to another example, the lubrication arrangement is controlled to: lubrication is at least reduced when the second diverter idler gear is simultaneously connected to the input shaft by the first shift mechanism and to the output shaft by the second shift mechanism. In this case, the second splitter idler gear is connected to the input and output shafts and no lubrication is required because the second splitter gear set does not transmit power. This gear selection corresponds to the direct gear in which none of the gear sets in the main gearbox transmit power.

When this condition occurs, the first gear shift is arranged to act on the first sliding closure device to at least partially close the second supply means, and the second gear shift is arranged to act on the second sliding closure device to at least partially close the first supply means, as long as the second diverter idler gear is connected to both the input shaft and the output shaft.

The first sliding closure device comprises a sliding part arranged to at least partly close the first supply means when the second diverter idler gear is disconnected from the input shaft, and arranged to open the first supply means and at least partly close the second supply means when the second diverter idler gear is connected to the input shaft. Furthermore, the second sliding closure device comprises a sliding portion arranged to at least partially close the second supply means when the second diverter idler gear is disconnected from the output shaft and arranged to at least partially close the first supply means and open the second supply means when the second diverter idler gear is connected to the output shaft.

According to one example, the sliding portions of the first and second closing devices each comprise a sealing surface having a through hole (indexable) capable of being aligned with the first and second supply means, respectively.

According to another example, the sliding portions of the first and second closing devices each comprise a cam arranged to act on the first or second pivot valve to at least partially close the first or second supply means; wherein the valves are spring loaded towards an open position.

According to another example, the sliding portions of the first and second closing means each comprise a cam arranged to act on the first or second pivot valve to at least partially close the first or second supply means, wherein each valve is spring-loaded towards a closed position by a first spring and displaced towards an open position by a second spring under the action of either of the first and second gear shift mechanisms.

Each of the above examples allows the closing means to at least partially close the supply means, wherein the supply means comprises an immersion lubrication arrangement, such as a lubricant sump or a lubricant spray nozzle.

In the above examples, it is stated that the closing means can be arranged to at least partially close the supply means. In some transmissions, the second splitter gear set may not require lubrication when power is not being transferred, wherein the supply of lubricant can be shut off. In this case, the closure device will close, causing the oil level in the wet lubrication arrangement to drop below the periphery of the lower gear in the second diverter gear set. In a spray lubrication arrangement, the closure device will simply close off or cover the lubricant spray nozzle to prevent lubricant from flowing to the second splitter gear set.

However, other transmissions may require that at least a minimum level of lubricant supply be maintained when the second splitter gear set is not transmitting power. In this case, the closure device will be partially closed, causing the oil level in the wet lubrication arrangement to reach the desired level, but not below the periphery of the lower gear in the second splitter gear set. This can be achieved in many different ways, for example by offsetting the position of at least one closing means with respect to the supply opening, or by providing the closing means with through holes or the like, in order to ensure a minimum supply level. The offset of the position of at least one closure device relative to the supply opening can be effected in the direction of displacement of the closure device or transversely thereto. The provision of through holes in the closure means can be achieved by allowing the through holes to align with the supply opening when the closure means are moved to their closed position, or by providing a groove or the like in the lower surface of the closure means facing the supply opening.

The invention also relates to a vehicle transmission comprising a lubricating apparatus as described above, and to a vehicle comprising such a transmission.

By providing a lubrication device as described above, which is controlled by a gear shifting process in a layshaft inline transmission, such as a manual transmission, it is advantageous that the lubrication device is controlled by mechanical operation. This type of lubrication device is not affected by the loss of electric or hydraulic power. It is also an advantage that the lubrication device comprises relatively few moving parts, making the device durable and simple to maintain.

Further advantages and advantageous features of the invention are disclosed in the following description and in the dependent claims.

Drawings

With reference to the accompanying drawings, the following is a more detailed description of embodiments of the invention cited as examples. In these figures:

FIG. 1 shows a schematic vehicle provided with a transmission including a lubrication device according to the present invention;

2A-2B show schematic views of a transmission suitable for use with a lubrication device according to the present invention;

3A-3B show schematic views of a transmission including a lubrication device according to a first embodiment of the present invention;

FIGS. 4A-4I illustrate schematic diagrams of the control of the closure device of FIG. 3A;

5A-5D show schematic views of a transmission including a lubrication device according to a second embodiment of the present invention; and is

Fig. 6A to 6D show schematic views of a transmission including a lubricating apparatus according to a third embodiment of the invention.

Detailed Description

The schematically shown vehicle 1 comprises a transmission arrangement 3 with a lubrication device according to the invention. The vehicle 1 is provided with an Internal Combustion Engine (ICE)2, which ICE 2 is connected to a transmission 3, such as an Automated Manual Transmission (AMT), for transmitting torque to a rear driven axle (not shown). The ICE 2 is connected to a radiator arrangement 4 for cooling engine coolant and oil from the ICE 2. The transmission 3 is controlled by the driver or automatically via an Electronic Control Unit (ECU) 5. The ECU 5 is provided with a control algorithm for controlling the transmission independently or in response to a driver requested gear shift. The automatically or manually requested gear change is effected by the ECU 5, which ECU 5 is arranged to control the gear change mechanism in the gearbox 3. The transmission is controlled to select a speed change ratio between the engine 2 and the pair of drive wheels 6.

Fig. 2A to 2B show schematic views of a transmission suitable for use with the lubricating apparatus according to the present invention. The transmission described in this example is an AMT gearbox known as a layshaft inline transmission. The transmission comprises three parts, namely: the diverter segments 10, 20, the main gearboxes 30, 40, 50, 60, and the range gears (not shown) are managed by a common control system (see fig. 1). This gear is not included in this example as it is not relevant to the present invention.

The transmission in fig. 2A includes an input shaft I connected to a source of propulsion power (e.g., an internal combustion engine) and an output shaft O connected to at least one pair of drive wheels via a driveline, as shown in fig. 1. The input shaft I is arranged coaxially with the output shaft O. The transmission also includes a countershaft C arranged in parallel with the input and output shafts I and O. Power can be transmitted from the input shaft I to the countershaft C via a primary gearset 10, 20 with gears 11, 12 and 21, 22 and to the output shaft O via one of a plurality of optional secondary gearsets 30, 40, 50 with gears 31, 32, 41, 42 and 51, 52, 60. In the present example, the splitter section includes a first splitter gear set 10 and a second splitter gear set 20. Additionally, the second splitter gear set 20 and the first and second secondary gear sets 30 and 40 are associated with three forward gears, while the third secondary gear set 50 is associated with reverse gear R. The range gear is provided between the output shaft and the transmission line, and is not included in the drawing.

The splitter sections 10, 20 include two main gear sets 10, 20 having gears 11, 12 and 21, 22. These gear sets are capable of selectively transferring power from the input shaft I to the countershaft C, and will be referred to hereinafter as splitter gear sets. In one operating state, the first splitter idler gear 11 of the first splitter gear set 10 can be connected to the countershaft C in order to transmit power to the countershaft. This connection is made by means of a first gear shift 23, which first gear shift 23 can be actuated to lock the normally idle first splitter idler gear 11 of the first splitter gear set 10 to the input shaft I. On the other hand, the corresponding second splitter idler gear 21 of the second splitter gear set 20 is idle with respect to the output shaft O. In this operating condition, the gears 21, 22 of the second splitter gear set 20 will rotate but not transmit power, and no lubrication will be required.

In another operating condition, the input shaft I is rotatably connected to the output shaft O, which condition is referred to as "direct gear". This connection is achieved by means of a first gear shift 23, which first gear shift 23 can be actuated to lock the normally idle second diverter idler gear 21 of the second diverter gear set 20 to the input shaft I, and a second gear shift 33, which second gear shift 33 can be actuated to lock said gear 21 to the output shaft O. This state is shown in fig. 2A. In long haul heavy vehicles, the direct gear is typically the highest gear, and is the most frequently used gear. In the direct gear, none of the sets of pinions 30, 40, 50 are active. This reduces load-related power losses in the transmission, thereby increasing efficiency and improving fuel consumption. However, although no propulsive power is transferred in the direct gear, gears 21, 22 of the second splitter gear set 20 are still rotating. If the gear set is lubricated and cooled at all times when the vehicle is operating in a direct gear, this will result in load-independent power losses due to oil splash, oil pump blow and windage caused by supplying oil to the gears.

A similar situation occurs when both the first gear shift 23 and the second gear shift 33 are disconnected from the second diverter idler gear 21. This may occur when both the first and second shift mechanisms 23 and 33 are in their neutral or non-operating positions (as shown in fig. 2B). Alternatively, this occurs when at least the first gear shift mechanism 23 is actuated to connect with gear 11 in the first splitter gear set 10, wherein torque is transferred from the input shaft I to the output shaft O via the first splitter gear set 10 and the countershaft C. In this condition, the transmission torque path bypasses the second splitter gear set 20.

Each of the shift mechanisms 23, 33, 43 in the transmission has a neutral position in which each of the shift mechanisms 23, 33, 43 is not connected to any of the gear sets, and at least one operating position in which each of the shift mechanisms 23, 33, 43 is connected to a gear set. In the present example, the first gear shift mechanism 23 has a first operating position LS (low-gear) in which the first gear shift mechanism 23 connects the first splitter idler gear 11 to the input shaft I (not shown) and a second operating position HS (high-gear) in which the first gear shift mechanism 23 connects the second splitter idler gear 21 to the input shaft I (fig. 2A). The neutral or rest position of the first shift mechanism 23 is intermediate the first and second operating positions (fig. 2B).

Similarly, the second gear shift mechanism 33 has a first operating position in which the second gear shift mechanism 33 connects the second splitter idler gear 21 to the output shaft O (fig. 2A) and a second operating position in which the second gear shift mechanism 33 connects the other gear 31 to the output shaft O (not shown). The neutral or rest position of the first shift mechanism 33 is intermediate the first and second operating positions (fig. 2B).

Fig. 3A to 3B show schematic views of a transmission including a lubricating apparatus according to a first embodiment of the invention. In this type of transmission, it is necessary to provide lubrication and cooling to the gear teeth. Fig. 3A shows an example of gear tooth lubrication and cooling implemented as wet lubrication, wherein the lowermost gear 22 of the second splitter gear set 20 is partially below the oil level of an oil supply of the oil sump 26 type.

This lubrication arrangement comprises first and second supply means (not shown) in the form of first and second openings 46, 47 for lubricant supplied under pressure from a lubricant source. The first and second supply means further comprise a first and second sliding closure device 24, 25 which may be controlled by the first or second gear shift mechanism 23, 33, respectively. The first gearshift mechanism 23 or the second gearshift mechanism 33 is mechanically connected to the first sliding closure device 24 and the second sliding closure device 25. According to one example, these interconnecting sliding portions can form sealing devices S1, S2, which sealing devices S1, S2 extend between the first and second splitter gear sets 10, 20 and between the second splitter gear set 20 and the adjacent gear set 30, respectively. In this way, lubricant splashing and wind resistance between the rotating parts can be reduced. In this context, the term "sliding" is used to describe the displacement of the closure device 24, 25 relative to the first and second supply openings 46, 47. Since the displacement of the closing devices 24, 25 is controlled by the respective gear shift mechanism 23, 33, the sliding movement of these gear shift mechanisms parallel to the input and output shafts is transmitted to these closing devices. Thus, the displacement of the closure devices 24, 25 in the oil sump 26 will be substantially parallel to the input and output shafts of the transmission. It should be noted that the mechanism described herein is only one example of a suitable solution. As will be appreciated by those skilled in the art, other types of mechanisms and movements may be equally suitable.

Fig. 3A shows an operating state in which the second diverter idler gear 21 is disconnected from both shifting mechanisms 23, 33. In this state, the gear sets 21, 22 are not transmitting power and the need for lubrication and cooling is negligible, or at least relatively small. Thus, the openings 46, 47 for supplying lubricant to the oil groove 26 are closed by the closing means 24, 25.

Alternatively, spray lubrication can be provided for the gears, as shown in fig. 3B, whereby lubricant supplied under pressure from a conduit 38 connected to a lubricant source is directed onto the gear teeth via nozzles 36, 37 (not shown).

Fig. 3A and 3B show the same gear operating state as in fig. 2B. The first and second supply means further comprise a first sliding closure device 34 and a second sliding closure device 35, which first and second sliding closure devices 34, 35 can be controlled by the first or second gear shift mechanism 23, 33, respectively. The first gear shift mechanism 23 or the second gear shift mechanism 33 is mechanically connected to the first sliding closure device 34 and the second sliding closure device 35. According to one example, these interconnecting sliding portions can form sealing devices S1, S2, which sealing devices S1, S2 extend between the first and second splitter gear sets 10, 20 and between the second splitter gear set 20 and the adjacent gear set 30, respectively. In this way, splashing and pumping of lubricant between the rotating parts and wind resistance can be reduced. In this context, the term "sliding" is used to describe the displacement of the closure devices 34, 35 relative to the first and second supply openings 36, 37. Since the displacement of the closing devices 34, 35 is controlled by the respective gear shift mechanism 23, 33, the sliding movement of these gear shift mechanisms parallel to the input and output shafts is transmitted to these closing devices. Thus, the displacement of the closure devices 34, 35 relative to the nozzles 36, 37 will be substantially parallel to the input and output shafts of the transmission.

Fig. 3B shows an operating state in which the second diverter idler gear 21 is disconnected from both shifting mechanisms 23, 33. In this state, the gears 21, 22 rotate but do not transmit torque, and the need for lubrication and cooling is negligible, or at least relatively small. Thus, the nozzles 36, 37 for supplying lubricant to the second splitter gear set 20 are closed by the closing devices 34, 35.

Fig. 4A to 4I show schematic diagrams of the control of the closure device in fig. 3A. These figures show the lower gear 22 of the second diverter gear set 20 positioned for wet lubrication at the oil sump 26. A first gear shift mechanism, schematically indicated by arrow 23, is connected to the first closing device 24, while a second gear shift mechanism, schematically indicated by arrow 33, is connected to the second closing device 25. The oil sump 26 is provided with fixed first and second openings 46, 47, said first and second openings 46, 47 being selectively opened or closed by the closing means 24, 25. The first closure device 24 has a first opening 44 for opening or closing the lubricant supply, which first opening 44 can be aligned with a first opening 46 in the oil groove 26. Similarly, the second closing means 25 has a second opening 45 for opening or closing the lubricant supply, which second opening 45 can be aligned with a second opening 47 in the oil groove 26. These closing means can be arranged to close off or at least reduce the lubricant supply.

Fig. 4A shows an operating state in which the first gear shift mechanism 23 is in its first operating position LS, so that a first splitter idler gear (not shown) is connected to the input shaft, and the second gear shift mechanism 33 is in its first operating position, so that a second splitter idler gear is connected to the output shaft, so that the second splitter gear set is used as a third transmission gear (indicated by "3"). In this state, the second splitter gear set transfers power from the countershaft to the output shaft, thus requiring lubrication. In the present example, the second closing means 25 is arranged to cover and close the first opening 46 in the oil sump 26. At the same time, the second opening 45 in the second closing means 25 is aligned with the second opening 47 in the oil groove 26, allowing a lubricant to be supplied as indicated by arrow L.

Fig. 4B shows an operating state in which the first gear shift 23 is in its first operating position LS, so that the first splitter idler gear (not shown) is connected to the input shaft, and the second gear shift 33 is in its neutral position, so that the second splitter idler gear is disconnected from the output shaft. In this state, the second splitter gear set does not transfer power from the countershaft to the output shaft, and therefore no lubrication is required. In the present example, the second closing means 25 is arranged to cover and close the first opening 46 in the oil sump 26. At the same time, the second closing means 25 is arranged to cover and close the second opening 47 in the oil groove 26, thereby preventing lubricant supply.

Fig. 4C shows an operating state in which the first gear shift mechanism 23 is in its first operating position LS, so that a first splitter idler gear (not shown) is connected to the input shaft, and the second gear shift mechanism 33 is in its second operating position, so that an adjacent gear set ("30", see fig. 3A) is connected to the output shaft, so that a second transmission gear (indicated by "2") is selected. In this state, the second splitter gear set does not transmit power from the countershaft to the output shaft, so no lubrication is required. In the present example, the first closure device 24 is arranged to cover and close the first opening 46 in the oil sump 26. At the same time, the second closing means 25 is arranged to cover and close the second opening 47 in the oil groove 26, thereby preventing lubricant supply.

Fig. 4D shows an operating state in which the first gear shift 23 is in its neutral position, so that it is disconnected from both the first splitter idler gear (not shown) and the second splitter idler gear, and the second gear shift 33 is in its operating position, so that the second splitter idler gear is connected to the output shaft, so that the second splitter gear set is used as the third transmission gear. In this state, the second splitter gear set is able to transfer power from the layshaft to the output shaft, and therefore lubrication is required. In the present example, the second closing means 25 is arranged to cover and close the first opening 46. At the same time, the second opening 45 in the second closing means 25 is aligned with the second opening 47 in the oil groove 26, allowing the lubricant to be supplied as indicated by arrow L.

Fig. 4E shows an operating state in which both the first gear shift 23 and the second gear shift 33 are in their neutral positions, so that the second splitter idler gear is disconnected from the input and output shafts. In this state, the second splitter gear set does not transmit power and therefore does not require lubrication. In the present example, the first closure device 24 is arranged to cover and close the first opening 46 in the oil sump 26. At the same time, the second closing means 25 is arranged to cover and close the second opening 47 in the oil groove 26, thereby preventing lubricant supply.

Fig. 4F shows an operating condition in which the first gear shift mechanism 23 is in its neutral position, thereby disconnecting both the first splitter idler gear (not shown) and the second splitter idler gear, and the second gear shift mechanism 33 is in its first operating position, thereby connecting an adjacent gear set ("30", see fig. 3A) to the output shaft for selecting the second transmission gear (indicated by "2"). In this state, the second splitter gear set does not transmit power and therefore does not require lubrication. In the present example, the first closure device 24 is arranged to cover and close the first opening 46 in the oil sump 26. At the same time, the second closing means 25 is arranged to cover and close the second opening 47 in the oil groove 26, thereby preventing lubricant supply.

Fig. 4G shows an operating condition in which the first gear shift mechanism 23 is in its second operating position HS, thereby connecting the second shunt idler gear to the input shaft, and the second gear shift mechanism 33 is in its first operating position, thereby connecting the second shunt idler gear to the output shaft, so as to place the transmission in the direct gear. In this state, the second splitter gear set does not transmit drive power to or from the counter shaft, and therefore lubrication is not required. In the present example, the second closing means 25 is arranged to cover and close the first opening 46 in the oil sump 26. At the same time, the second closing means 25 is arranged to cover and close the second opening 47 in the oil groove 26, thereby preventing lubricant supply.

Fig. 4H shows an operating state in which the first gear shift 23 is in its second operating position HS, so that the second splitter idler gear is connected to the input shaft, and the second gear shift 33 is in its neutral position, so that it is disconnected from the second splitter gear set and the adjacent gear set. In this state, the second splitter gear transmits power from the input shaft to the counter shaft, and therefore lubrication is required. In the present example, the second closing means 25 is arranged to cover and close the second opening 47 in the oil sump 26. At the same time, the first opening 44 in the first closure device 24 is aligned with the first opening 46 in the oil groove 26, allowing lubricant to be supplied as indicated by arrow L.

Fig. 4I shows an operating state in which the first gear change mechanism 23 is in its second operating position HS, so that the second splitter idler gear is connected to the input shaft, and the second gear change mechanism 33 is in its second operating position, so that an adjacent gear set ("30", see fig. 3A) is connected to the output shaft, so that a second transmission gear (indicated by "2") is selected. In this state, the second splitter gear set transfers power from the input shaft to the countershaft, thus requiring lubrication. In the present example, the second closing means 25 is arranged to cover and close the second opening 47. At the same time, the first opening 44 in the first closure device 24 is aligned with the first opening in the oil groove 26, allowing lubricant to be supplied as indicated by arrow L.

By way of example, it can be seen that the first and second closure devices 24 and 25 are displaced by the first and second shifters 23 and 33, respectively, to reduce the supply of lubricant to the second splitter gear set at least when the first and second shifters are simultaneously connected or disconnected from the second splitter gear set. This occurs at the following times: when both gearshifts are simultaneously connected to the second diverter idler gear, so that the transmission operates in a direct gear, or when both gearshifts are simultaneously disconnected from the second diverter idler gear (the second diverter idler gear then idles with respect to the output shaft).

Fig. 5A to 5D show schematic views of a transmission comprising a lubricating apparatus according to a second embodiment of the present invention. These figures show the lower gear 22 of the second diverter gear set positioned for wet lubrication in the oil sump 53. A first gear shift mechanism, schematically indicated by arrow 23, is connected to the first closing means 24 'and a second gear shift mechanism, schematically indicated by arrow 33, is connected to the second closing means 25'. The oil groove 53 is provided with fixed first and second openings 56 and 57, the first and second openings 56 and 57 being selectively opened or closed by the closing means 24 ', 25'. The sliding portions of the first closing means 24 'and the second closing means 25' comprise a first cam 24a 'and a second cam 25 a', respectively, said first cam 24a 'and second cam 25 a' being arranged to act on the first pivot valve 54 or the second pivot valve 55 to close the first opening 56 or the second opening 57 of said supply means. The pivot valves 54, 55 are spring loaded towards the open position by first and second suitable resilient members 58, 59, such as coil springs.

Fig. 5A shows an operating state in which the first gear shift 23 is in its neutral position, so as to be disconnected from both the first splitter idler gear (not shown) and the second splitter idler gear, and the second gear shift 33 is in its first operating position, so as to connect the second splitter idler gear to the output shaft, so as to use the second splitter gear set as the third transmission gear. In this state, the second splitter gear set is able to transfer power from the layshaft to the output shaft, and therefore lubrication is required. In this example, the cam 24a 'on the first closing means 24' and the cam 25a 'on the second closing means 25' are arranged to act on and close the first pivot valve 54 and the first opening 56 in the oil groove 53. At the same time, second pivot valve 55 is biased by resilient element 59 towards the open position of second pivot valve 55 to uncover second opening 57 in oil groove 53, allowing lubricant to be supplied as indicated by arrow L.

Fig. 5B shows an operating state in which the first gear shift mechanism 23 is in its first operating position LS, so that a first splitter idler gear (not shown) is connected to the input shaft, and the second gear shift mechanism 33 is in its second operating position, so that an adjacent gear set ("30", see fig. 3A) is connected to the output shaft, so that a second transmission gear (indicated by "2") is selected. In this state, the second splitter gear set does not transfer power from the countershaft to the output shaft, and therefore no lubrication is required. In this example, the cam 24a 'on the first closure device 24' is arranged to act on and close the first pivot valve 54 and the first opening 56 in the oil groove 53. At the same time, the cam 25a 'on the second closing means 25' is arranged to act on and close the second pivot valve 55 and the second opening 57 in the oil groove 53, thereby preventing lubricant supply.

Fig. 5C shows an operating condition in which the first gear shift mechanism 23 is in its second operating position HS, thereby connecting the second shunt idler gear to the input shaft, and the second gear shift mechanism 33 is in its first operating position, thereby connecting the second shunt idler gear to the output shaft, so as to place the transmission in direct gear. In this state, the second splitter gear set does not transmit power and therefore does not require lubrication. In this example, the cam 24a 'on the first closing means 24' is arranged to act on and close the second pivot valve 55 and the second opening 57 in the oil groove 53. At the same time, the cam 25a 'on the second closing means 25' is arranged to act on and close the first pivot valve 54 and the first opening 56 in the oil groove 53, thereby preventing lubricant supply.

Fig. 5D shows an operating state in which the first gear shift 23 is in its second operating position HS, so that the second diverter idler gear is connected to the input shaft, and the second gear shift 33 is in its neutral position, so that it is disconnected from the second diverter idler gear and the adjacent gear set. In this state, the second splitter gearset is able to transmit power from the input shaft to the layshaft, and therefore lubrication is required. In this example, cam 24a 'on first closing means 24' and cam 25a 'on second closing means 25' are arranged to act on and close second pivot valve 55 and second opening 57 in oil groove 53. At the same time, first pivot valve 54 is biased by resilient member 58 toward the open position of first pivot valve 54 to uncover first opening 56 in oil groove 53, allowing lubricant to be supplied as indicated by arrow L. It should be noted that the mechanism described herein is only one example of a suitable solution. Other types of mechanisms and movements may be equally suitable, as will be appreciated by those skilled in the art.

Fig. 6A to 6D show schematic views of a transmission including a lubricating apparatus according to a third embodiment of the invention. These figures show the lower gear 22 of the second splitter gear set positioned for wet lubrication in the oil sump 63. A first gear shift mechanism, schematically indicated by arrow 23, is connected to the first closing means 24 "and a second gear shift mechanism, schematically indicated by arrow 33, is connected to the second closing means 25". The oil sump 63 is provided with fixed first and second openings 66, 67, which first and second openings 66, 67 are selectively opened or closed by the closure devices 24 ", 25". The sliding portions of the first closing means 24 "and of the second closing means 25" comprise respectively a first cam 24a "and a second cam 25 a", said first cam 24a "and second cam 25 a" being arranged to act on the first pivot valve 64 or on the second pivot valve 65 to close the first opening 66 or the second opening 67 of said supply means. The pivot valves 64, 65 are spring loaded towards the closed position by first and second suitable resilient members 68a, 69a (e.g. coil springs) acting between the oil sump 64 and the respective pivot valves 64, 65. The first closing means 24 "and the second closing means 25" each comprise a first elastic element 68b and a second elastic element 69b, for example a helical spring, the spring constant of which elastic elements 68b, 69b is higher than the spring constant of the elastic elements 68a, 69a connected to the pivot valves 64, 65. When the first closing device 24 "and/or the second closing device 25" are actuated towards the second splitter gear set, their first elastic element 68b and second elastic element 69b are arranged to act on the pivot valves 64, 65 to overcome the closing force of the respective elastic elements 68a, 69a connected to the pivot valves 64, 65, thereby opening the first pivot valve 64 and/or the second pivot valve 65.

Fig. 6A shows an operating state in which the first gear shift 23 is in its neutral position, so as to be disconnected from both the first splitter idler gear (not shown) and the second splitter idler gear, and the second gear shift 33 is in its first operating position, so as to connect the second splitter idler gear to the output shaft, so as to use the second splitter gear set as the third transmission gear. In this state, the second transmission gear set is able to transmit power from the counter shaft to the output shaft, and therefore lubrication is required. In this example, the cam 24a "on the first closing device 24" and the cam 25a "on the second closing device 25" are arranged to act on the first pivot valve 64 and the first opening 66 in the oil groove 63 to maintain the first pivot valve closed. In this position, the first resilient element 68b on the first closure device 24 "is positioned adjacent the first pivot valve 64, but does not exert a force in the opening direction of the valve. At the same time, the second resilient element 69b on the second closing means 25 ″ exerts a force in the opening direction of the second pivot valve 65 which is sufficient to overcome the closing force of the resilient element 69a connected to the second pivot valve 65. The second pivot valve 65 is displaced by the resilient element 69b on the second closing means 25 "towards the open position of the second pivot valve 65 to uncover the second opening 67 in the oil groove 63, allowing lubricant to be supplied.

Fig. 6B shows an operating state in which the first gear shift mechanism 23 is in its first operating position LS, so that a first splitter idler gear (not shown) is connected to the input shaft, and the second gear shift mechanism 33 is in its second operating position, connecting an adjacent gear set ("30", see fig. 3A) to the output shaft, in order to select a second transmission gear (indicated by "2"). In this state, the second splitter gear set does not transmit power and therefore does not require lubrication. In this example, the cam 24a "on the first closure device 24" is arranged to act on and close the first pivot valve 64 and the first opening 66 in the oil groove 63. At the same time, the cam 25a "on the second closing means 25" is arranged to act on and close the second pivot valve 65 and the first opening 67 in the oil groove 63, thereby preventing lubricant supply.

Fig. 6C shows an operating condition in which the first gear shift mechanism 23 is in its second operating position HS, thereby connecting the second shunt idler gear to the input shaft, and the second gear shift mechanism 33 is in its first operating position, thereby connecting the second shunt idler gear to the output shaft, so as to place the transmission in direct gear. In this state, the second splitter gear set does not transmit power and therefore does not require lubrication. In this example, the cam 24a "on the first closing means 24" is arranged to act on and maintain closed the second pivot valve 65, thereby closing the second opening 67 in the oil groove 63. At the same time, the cam 25a "on the second closing means 25" is arranged to act on the first pivot valve 64 and maintain it closed, thereby closing the first opening 66 in the oil groove 63, thereby preventing lubricant supply. Although both the first and second elastic elements 68b, 69b on the first and second closing means 24 ", 25" act on the respective first and second pivot valves 64, 65, the cams 24a ", 25 a" prevent these valves from opening.

Fig. 6D shows an operating state in which the first gear shift 23 is in its second operating position HS, so that the second diverter idler gear is connected to the input shaft, and the second gear shift 33 is in its neutral position, so that it is disconnected from both the second diverter idler gear and the adjacent gear set. In this state, the second splitter gearset is able to transmit power from the input shaft to the layshaft, and therefore lubrication is required. In this example, the cam 24a "on the first closing means 24" and the cam 25a "on the second closing means 25" are arranged to act on and close the second pivot valve 65 and the second opening 67 in the oil groove 63. At the same time, the first resilient element 68b on the first closure device 24 ″ exerts a force in the opening direction of the first pivot valve 64 which is sufficient to overcome the closing force of the resilient element 68a connected to the first pivot valve 64. The first pivot valve 64 is displaced by the resilient element 68b on the first closure device 24 "towards the open position of the first pivot valve 64 to uncover the first opening 66 in the oil groove 63, allowing lubricant to be supplied. It should be noted that the mechanism described herein is only one example of a suitable solution. As will be appreciated by those skilled in the art, other types of mechanisms and movements may be equally suitable.

The above examples relating to fig. 4A to 4I, 5A to 5D, and 6A to 6D describe a lubrication device using wet lubrication. However, it is within the scope of the present application to replace these oil grooves and their openings with the lubrication ducts and injection nozzles shown in FIG. 3B. The embodiments in fig. 4A-4I, 5A-5D, and 6A-6D have openings 46, 47, 56, 57, 66, and 67 that are fully closed when the second splitter gear set is not transmitting power. As will be appreciated by those skilled in the art, by adjusting the size and/or location of these openings, a partially closed (for reducing), but still non-zero, supply of lubricant will likewise be possible.

In the above examples, it is stated that the closing means can be arranged to close the supply device. This option is used when no power is transmitted and transmission lubrication of the second splitter gear set is not required, wherein the supply of lubricant can be completely closed. In this case, the closure device will close, causing the oil level in the wet lubrication arrangement to drop below the periphery of the lower gear in the second diverter gear set. In a spray lubrication arrangement, the closure device will simply close or cover the lubricant spray nozzle to prevent lubricant from flowing to the second splitter gear set.

The closure device partially closes in the event that the transmission requires at least a minimum level of lubricant supply to be maintained when the second splitter gear set is not transmitting power. This causes the oil level in the wet lubrication arrangement to reach the desired level, but below the periphery of the lower gear in the second splitter gear set. This can be achieved in a number of different ways, e.g. by offsetting the position of the closing means relative to the supply openings by placing a predetermined part of the flow area of at least one supply opening outside the area covered by the closing means or by providing a predetermined gap (e.g. fig. 4A to 4I) in front of the cooperating surfaces of the supply opening and the closing means. Alternatively, the closure device can be provided with through holes in order to ensure a minimum supply level (e.g. fig. 5A to 5D; fig. 6A to 6D).

It is to be understood that the invention is not limited to the embodiments described above and shown in the drawings; rather, one of ordinary skill in the art appreciates that various modifications and changes can be made within the scope of the claims set forth below.