JP2004019848A - Variator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variator capable of mutually sealing two pressures by leading two independent pressures into an axial hole at the same shaft end of a primary shaft or a secondary shaft in the variator of a belt type continuously variable transmission. <P>SOLUTION: Independent pressures are allowed to act on a variator pressure chamber 31 and a second pressure chamber 8 through the axial hole of a variator shaft 1. A pressure supply to the variator pressure chamber 31 is performed through the first hole portion 13 of the axial hole 10, a pressure supply to the second pressure chamber 8 is performed through a non-rotating tube 7 and the second hole portion 15 of the axial hole 10, and the tube 7 is disposed in the first hole portion 13. The tube 7 comprises two packing rings 73 for dynamically sealing a pressure supply passage to the variator pressure chamber 31 and the second pressure chamber 8. The variator shaft 1 comprises air vent holes 9, 92 one of which is positioned between two packing rings 73 and the other of which is led to the inner chamber 94 of the transmission. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a variator for adjusting the speed ratio of a belt-type continuously variable transmission based on the general concept of claim 1.
[0002]
[Prior art]
Usually, a belt-type continuously variable transmission has a variator for adjusting a gear ratio. The variator includes a first tapered pulley pair on the input shaft, and a winding means circulating between the second tapered pulley pair and the tapered pulley pair on the output shaft, for example, a link chain with a link or a thrust link belt. Each tapered pulley pair includes a first pulley fixed in the axial direction and a second taper pulley movable in the axial direction. Usually, the input shaft of the variator is called the primary shaft, and correspondingly the first tapered pulley pair is called the primary pulley pair. Similarly, the output shaft of the variator is commonly called a secondary shaft, and the second tapered pulley pair is called a secondary pulley pair. The axial direction adjustment of the primary pulley or the secondary pulley and the adjustment of the speed ratio associated therewith are performed by a pressure medium. For this purpose, an electro-hydraulic control device controls the pressure levels in the control chambers of the primary and secondary pulleys via an electromagnetic operating part and a hydraulic valve. Normally, the pressure medium is sent by an electro-hydraulic transmission control device through a passage arranged in the transmission housing to an axial hole in the primary or secondary shaft and from there to the pressure chamber of the primary or secondary pulley. Can be The required hole diameter or hole cross section is then determined by the required adjustment volume of the variator.
[0003]
The input shaft end of the primary shaft has a first axial hole for supplying pressure to the clutch, and the primary shaft end opposite the input portion has a second axial hole for supplying primary pressure. Such a continuously variable transmission is known from DE-A-195 33 959. The supply of the primary pressure to this second axial bore of the primary shaft takes place from a passage arranged in the transmission housing via a sleeve press-fit into a passage opening in the transmission housing. The sleeve projects into a second axial hole in the primary shaft. A single flat compression ring is provided for sealing between the stationary sleeve and the rotating primary shaft.
[0004]
An axial hole formed as a stepped hole is provided in the primary shaft, and this axial hole sends the primary pressure to the pressure chamber of the primary pulley, and also sends the lubrication pressure independent of the primary pressure to another load device. A continuously variable transmission is known from DE-A-193 32 339. A primary pressure passage extending generally radially toward the center of the primary shaft in the transmission housing, between the primary pulley and the housing cover adjacent to the primary shaft, for the supply of pressure oil needed to adjust the primary pulley. It is provided and communicates with an inner cover which ensures a seal between the cover and the inside of the large bore of the axial step in the primary shaft. A single flat compression ring is provided as a seal between the stationary inner cover and the rotating primary shaft. Further, the housing cover has a cylindrical projection serving as a lubricating pressure passage. The cylindrical projection is recessed into the small hole of the axially stepped hole of the primary shaft and seals it against the large hole of the axially stepped hole of the primary shaft. For this purpose, a flat compression ring is arranged outside the recessed protruding end. The lubricating oil is sent through the inner hole of the cylindrical projection of the cover to the small hole of the axial stepped hole of the primary shaft and from there to another load device. Thus, the primary pressure acts on the annular chamber between the outside of the cylindrical projection of the cover and the inside of the large hole of the axial step hole of the primary shaft, while the small hole of the axial step hole of the primary shaft has lubricating pressure. Works.
[0005]
Failure of the flat compression ring, which isolates these two pressure zones from each other, resulted in transmission failure if excessive (primary pressure) pressure levels were applied to the second load equipment due to large leakage of the flat compression ring. In case, and also when undesired lubricating pressure is introduced into the pressure chamber of the primary pulley and the adjustment of the variator is activated or prevented, and also if the second load device is a shift element and the piston chamber of this clutch A dangerous operating situation results if the primary pressure is pumped in and thereby triggers an undesired shifting operation.
[0006]
Finally, German Offenlegungsschrift DE-A-196 03 598 discloses that the secondary shaft has an axial bore through which the secondary pressure is applied to the secondary pressure chamber and independent of the secondary pressure. A secondary set of variators for a continuously variable transmission is described in which a high lubricating pressure is sent to a pressure regulating chamber of a secondary pulley. The supply of pressure oil to the secondary pressure chamber is performed from a passage in the transmission housing through a pipe oil-tightly inserted into the transmission housing. This tube projects into the axial bore of the secondary shaft. The supply of lubricating oil for the dynamic pressure compensation of the secondary set takes place via an annular chamber between the outside of the tube and the inside of the axial bore of the secondary shaft. For the mutual sealing of the two pressure supply channels, a plain bearing pressed into the axial bore of the secondary shaft is provided between the stationary tube and the axial bore of the secondary shaft.
[0007]
Again, if an undesirably high pressure level acts on the pressure-regulating chamber of the secondary pulley, excessive leakage of the slide bearings separating the discharge sides of the two pressure supply passages of the axial bore of the secondary shaft from each other may cause The variator may be broken.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to provide a variator for adjusting the transmission ratio of a continuously variable transmission in which two independent pressures are introduced into the axial bore of the primary or secondary shaft at the same shaft end of the primary or secondary shaft. The aim is to provide a variator in which the two pressures are reliably sealed from one another.
[0009]
[Means for Solving the Problems]
This task is solved by a variator having the features of the main claim. Advantageous embodiments and implementations are evident in the dependent claims.
[0010]
The variator according to the invention has, starting from the prior art, a variator shaft supported on a transmission housing and a pulley supported on the variator shaft, the pulley being moved axially by exerting pressure on a variator pressure chamber. It is possible. The variator shaft has an axial hole at the shaft end through which independent pressure can be exerted on the variator pressure chamber and the second pressure chamber. In this case, the pressure supply to the variator pressure chamber is performed by the first hole portion of the axial hole of the variator shaft, and the pressure supply to the second pressure chamber is performed by the pipe fixed to the transmission housing and the axial hole of the variator shaft. This is done by the second hole part. The tube is disposed inside the first hole portion.
[0011]
According to the invention, said tubes are arranged in axially parallel, preferably flat compression, for dynamic sealing of the pressure supply to the second pressure chamber and the pressure supply to the variator pressure chamber. It has two packing rings formed as rings. According to the invention, the variator shaft has a vent hole, one end of which communicates between the two flat compression rings and the other end of which communicates with the interior of the transmission.
[0012]
In this way, a mutual positive seal of the two pressures introduced from the same shaft end of the variator shaft into its axial bore is obtained. That is, first of all, the reduction of the compressive alternating load of the individual packing rings of the double dynamic seal results in a higher failsafe compared to the prior art of this rotary seal. In addition, the leakage of the packing ring, particularly the leakage of the packing ring facing the pressure chamber in which high pressure is applied, is exhausted to the transmission inner chamber at least approximately without overpressure by the air vent disposed between the two packing rings, In this way, an undesired leakage flow between the two pressure chambers is reliably avoided.
[0013]
Next, the present invention will be described in detail for an example of a primary set of a variator based on the following figures. The solution of the invention shown here for the primary shaft can of course also be transferred to the secondary set of variators.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Parts performing common or the same functions in FIGS. 1 and 2 have the same reference numerals.
[0015]
FIG. 1 shows a first embodiment of the variator of the present invention. Reference numeral 1 denotes a variator shaft, which is a primary shaft in the present embodiment. The variator pulley 2, in this embodiment, the primary pulley, is supported by the variator shaft 1 and is moved in the axial direction by the linear guide 21. The cylinder 3 fixed to the variator shaft 1, in this embodiment, the primary cylinder, together with the variator pulley 2, forms a variator pressure chamber 31, in this embodiment, a primary pressure chamber. Adjustable pressure oil can be fed into the primary pressure chamber for adjusting the speed ratio of the variator. In another embodiment, it is of course possible to provide a plurality of cylinders to form a multi-stage pressure chamber in the variator.
[0016]
The variator shaft 1 is supported on a transmission housing 5 via a bearing 4. The transmission housing 5 has a housing cover 6 on the shaft end side supported. In another embodiment, the transmission housing in the bearing area of the variator shaft can be formed in one piece and there can be no separate cover in this area.
[0017]
An axial hole 10 is provided in the variator shaft 1 at the shaft end of the variator shaft 1 supported on the transmission housing 5. The axial hole 10 can also be formed as a stepped hole. Independent pressure oil is supplied to two different pressure chambers, namely a variator pressure chamber 31 and a second pressure chamber, via the axial hole 10 of the variator shaft 1.
[0018]
In order to supply the variator pressure chamber 31 with the required pressure oil for the axial adjustment of the variator pulley 2, the variator pulley 2 and the variator shaft 1 (as described in DE-A-196 32 339). A variator pressure passage 61 extending substantially radially toward the center of the variator shaft 1 is provided in the transmission housing 5 between the housing cover 6 and the inner cover 62 which is oil-tightly inserted into the housing cover 6. Leads to. The inner cover 62 ensures a seal between the housing cover 6 and the inside of the axial hole 10 of the variator shaft 1. For this purpose, the inner cover 62 has a cylindrical projection 63 projecting into the axial hole 10 of the variator shaft 1 so that the inner cover 62 and the rotating variator shaft 1 between the housing cover-side part of the variator shaft 1 can be provided. A packing ring 12, preferably formed as a flat compression ring, is arranged outside the cylindrical projection 63 as a dynamic sealing element.
[0019]
The housing cover 6 also has a cylindrical projection 65 protruding into the axial hole 10 of the variator shaft 1 and used as a second pressure passage for refueling the second pressure chamber 8. In the embodiment shown in FIG. 1, the projection 65 of the housing cover 6 is oil-tightly fixed to the housing cover side portion 71 of the pipe 7 disposed inside the axial hole 10 of the variator shaft 1. . An annular gap remains between the projection 65 of the housing cover 6 and the projection 63 of the inner cover 62, and between the outside of the tube 7 and the inside of the axial hole 10 of the variator shaft 1. This first part of the axial bore 10 of the variator shaft 1 is indicated by 13.
[0020]
The tube 7 is provided with two packing rings 73 arranged axially in parallel according to the invention outside the second tube section 72 on the opposite side of the housing cover, preferably formed as flat compression rings. Have. The packing ring 73 seals the stationary tube 7 against the inside of the axial bore 10 of the rotating variator shaft 1 as a dynamic sealing element. This provides a mutual dynamic sealing of the two sections of the pressure supply channels 61 and 66 passing through the interior of the variator shaft 1. In the first part 13 of the axial bore 10 of the variator shaft 1 an adjustable variator pressure acts, while in the second part 15 that follows the first part 13 of the axial bore 10 in the second direction. The pressure assigned to the pressure chamber works. This pressure is likewise adjustable or at least approximately constant depending on the type of the second pressure chamber. A radial hole 14 branches off from the first part 13 of the axial hole 10 of the variator shaft 1, and the pressure oil required for adjusting the variator pulley 2 reaches the variator pressure chamber 31 via the radial hole 14. . A radial hole for oiling the second pressure chamber 8 branches off from the second part 15 of the axial hole 10 of the variator shaft 1.
[0021]
In another embodiment of the pressure supply to the axial hole of the variator shaft, the cylindrical projection 65 of the housing cover 6 can extend in the axial direction beyond the radial hole 14 of the variator shaft 1. In this case, the pipe 7 can be omitted, and the two packing rings 73 can be directly disposed outside the cylindrical projection 65. If the section of the bearing 4 of the variator shaft is integral and a transmission housing without housing cover is provided, a cylindrical projection with a second pressure passage 66 for refueling the second pressure chamber 8 is provided by a transmission. It can be formed as a projection on the housing.
[0022]
According to the invention, the area between the two packing rings 73 arranged on the second pipe section 72 is vented to at least an approximately overpressure-free inner side of the transmission housing 5. . In the first embodiment of the variator according to the invention shown in FIG. 1, the variator shaft 1 has at least an approximately radially ventilated hole 9. The vent hole 9 opens into the axial hole 10 of the variator shaft 1 in the area between the two packing rings 73 of the tube 7 and is closed by a cover 91 outside the variator shaft 1 and at least approximately in the axial direction. Branching out from the air vent hole 92 facing the air outlet. The axial vent hole 92 communicates with the transmission interior 93 near the bearing 4 at the shaft end of the variator shaft 1 facing the housing cover.
[0023]
In another embodiment of the venting from the area between the two packing rings 73 of the pipe 7 to the transmission housing interior section 93 close to the bearing 4, the venting holes are formed as oblique holes in the variator shaft 1, whereby the cover It is also possible to configure so that 91 is omitted.
[0024]
Due to the double dynamic seal between the two pressure zones by the two packing rings, the compressive alternating load applied to the individual packing rings is reduced, so that a higher failsafe of this rotary seal compared to the prior art is achieved. There are benefits to be gained. By means of the air bleeding arranged between the two packing rings, leakage of the packing ring, in particular of the packing ring facing the pressure chamber in which the high pressure is applied, is discharged at least approximately to the pressure-free interior of the transmission, so that It is particularly advantageous to ensure that unwanted leakage flows between the two pressure chambers are avoided.
[0025]
FIG. 2 shows a second embodiment of the variator according to the invention. Compared to the first embodiment described with reference to FIG. 1, the structure of the air vent in the area between the two packing rings 73 that provides a dynamic sealing of the two pressure zones inside the axial bore 10 of the variator shaft 1 It has been simplified. Another difference concerns the structural design of the two pressure passages 61 and 66 of the housing cover 6.
[0026]
The primary variator shown in FIG. 2 has two cylinders 3 and two variator pressure chambers 31 whose discharge sides are connected to each other. Thus, the variator pressure chamber 31 acts as a multi-stage pressure chamber in relation to the variator pulley 2. Of course, in another embodiment, only a single cylinder 3 and a single variator pressure chamber 31 can be provided.
[0027]
As shown in FIG. 2, the variator pressure passage 61 is now formed as a hole in the housing cover 6. Therefore, there is no inner cover 62. The packing ring 12, which is preferably formed as a flat compression ring and assures a dynamic seal between the stationary housing cover 61 and the rotating variator shaft 1 as a rotary sealing member, is here provided on the housing cover-side part 11 of the variator shaft 1. It is arranged outside. A bearing race 64 is inserted into the housing cover 6 as an opposing surface of the flat compression ring 12. The bearing race 64 is preferably manufactured from steel or plain bearing material. Of course, in another embodiment of this contact surface, the packing ring 12 can be configured to rotate directly on the housing cover 6, i.e., to eliminate the bearing race provided as a separate member. This requires a suitably designed housing cover material, for example silicon-doped aluminum die casting.
[0028]
The cylindrical projection 65 of the housing cover 6 still projects into the axial hole 10 of the variator shaft 1, but is shorter in the axial direction than in the first embodiment. The tube 7, which is arranged inside the axial bore 10 and is oil-tightly connected to the projection 65, is correspondingly long, and the inside of the tube 7 allows the pressurized oil to pass through the second pressure passage 66 of the housing cover 6 to the second To the pressure chamber 8. This arrangement has the advantage that the oil supply to the variator pressure chamber 31 is improved since the cross section of the annular gap between the inside of the first part of the axial hole 10 of the variator shaft 10 and the outside of the tube 7 is increased. .
[0029]
As in the first embodiment of the invention, the tube 7 has two packing rings 73 arranged axially parallel to the second tube section 72, preferably formed as flat compression rings. The packing ring 73 ensures a mutual dynamic sealing of the two pressures for the adjustment of the variator pulley 2 and for the second pressure chamber 8. The air vent according to the invention in the region between the two packing rings 73 is in this case formed as a single radial air vent 9 in the variator shaft 1. One end of the air vent hole 9 is located inside the axial hole 10 of the variator shaft in the area between the two packing rings 73, and the other end is located below the variator winding member (not shown) such as a belt (variator winding). The area inside the variator shaft 1 (area covered by the hanging member) communicates with the transmission inner chamber 93. Thus, the air is vented in the area between the primary set or the secondary set of tapered pulley pairs, depending on whether the variator shaft 1 is a primary shaft or a secondary shaft.
[0030]
In another embodiment of the venting of the area between the two packing rings 73, the venting holes 9 are formed as oblique holes, one end of which is inside the axial hole 10 of the variator shaft in the area between the two packing rings 73. Alternatively, the other end may be configured to communicate with the transmission inner chamber 93 outside the variator shaft 1 in an area below the variator winding member.
[0031]
In the second embodiment of the variator according to the invention shown in FIG. 2, the reliability of the dynamic seal of two independent pressures inside the axial bore 10 of the variator shaft is described with reference to FIG. 1. An advantage similar to that of the first embodiment is obtained. In the second embodiment, it is particularly advantageous that the bleeding of the area between the two packing rings 73 is very simple in construction and the production costs are correspondingly low. As another advantage, the elimination of the axial bleed hole 92 improves the possibility of designing an annular gap between the outside of the tube 7 and the inside of the first part of the axial hole 10 of the variator shaft, for example the variator shaft 1. It is possible to enlarge the cross section for supplying pressure to the variator without impairing the strength of the variator.
[0032]
As mentioned above, the solution according to the invention of the above-mentioned problem can be applied to both primary and secondary shafts. If the variator shaft 1 is a primary shaft, the second pressure chamber 8 is preferably assigned to the shift element as a clutch pressure chamber or a pressure regulating chamber. In this case, the second part of the axial bore 10 of the variator shaft receives the clutch pressure adjusted by the electrohydraulic transmission control or the lubricating pressure for correcting the dynamic pressure of the rotating clutch. However, it is also possible to assign the second pressure chamber 8 to, for example, a pressure regulating chamber (not shown) for correcting the dynamic pressure of the rotating primary pressure chamber 31 to apply a lubricating pressure. If the variator shaft 1 is a secondary shaft, the above-mentioned second pressure chamber 8 is a pressure regulating chamber for correcting the dynamic pressure of the secondary pressure chamber particularly rotating, for example, a clutch disposed on the secondary shaft. It can also be a clutch room.
[Brief description of the drawings]
FIG. 1 is a diagram of a first embodiment of a variator according to the present invention.
FIG. 2 is a diagram of a second embodiment of a variator according to the present invention.
[Explanation of symbols]
Reference Signs List 1 variator shaft 10 variator shaft axial hole 11 variator shaft housing cover side portion 12 variator shaft packing ring 13 first variator shaft axial hole first portion 14 variator pressure supply passage radial hole 15 variator shaft shaft The second part of the direction hole 2 The variator pulley 21 The linear guide of the variator pulley 3 The cylinder 31 The variator pressure chamber 4 The bearing 5 The transmission housing 6 The housing cover 61 The variator pressure passage 62 of the housing cover 62 The inner cover 63 The cylindrical projection 64 of the inner cover The variator Ring 65 for flat compression ring of shaft Cylindrical projection 66 of housing cover Second pressure passage 7 of housing cover Tube 71 Tube portion 72 on housing cover side Second tube portion 73 Tube packing ring 8 Second Pressure chamber 9 Air vent hole 91 Air vent hole Bar 92 axially vent hole 93 lower within the transmission chamber area of in the transmission chamber area 94 vol hooking member in contact with the bearing

Claims (10)

A variator shaft (1), and a variator pulley (2) supported on the variator shaft (1) and moved in an axial direction by applying pressure to at least one variator pressure chamber (31); An axial hole (10) is provided at the axial end of the variator shaft (1). The axial hole (10) allows the variator pressure chamber (31) and the second pressure chamber (8) to operate independently of each other. A pressure supply to the variator pressure chamber (31) is made through the first hole portion (13) of the axial hole (10), and the pressure supply to the second pressure chamber (8) does not rotate ( 7) and a second bore portion (15) of the axial bore (10), wherein the tube (7) is arranged inside the first bore portion (13) and the variator pressure chamber Pressure supply path to (31) and pressure to the second pressure chamber (8) Feeding passage is sealed to one another, in the variator for speed ratio adjustment of the belt type continuously variable transmission,
The pipe (7) is arranged axially in parallel for dynamic sealing of the pressure supply to the second pressure chamber (8) and the pressure supply to the variator pressure chamber (31). And two packing rings (73).
The variator shaft (1) has air vent holes (9, 92), one side of the air vent holes (9, 92) communicates between the two packing rings (73), and the other side has a speed change gear. A variator, wherein the variator communicates with the cabin (93, 94). The variator according to claim 1, characterized in that the air vent (9) communicates with the transmission inner chamber (94) radially below the variator winding means. 3. The variator according to claim 2, wherein the air vent holes (9) are formed as radial holes or oblique holes. The variator according to claim 1, wherein the variator shaft (1) is supported on a transmission housing (5).
A variator, characterized in that the air vent holes (9, 92) communicate with the transmission inner chamber (93) in the area of the bearing of the transmission housing (5) relative to the variator shaft (1). The air vent holes (9, 92) communicate with the transmission inner chamber (93) on the end face side of the shaft end having the axial hole (10) of the variator shaft (1). A variator according to claim 4. The variator according to claim 1, wherein the variator shaft is a primary shaft of the variator. The variator according to claim 1, wherein the variator shaft is a secondary shaft of the variator. A variator according to any of the preceding claims, characterized in that the second pressure chamber (8) is a clutch pressure chamber in which an adjustable shift pressure acts. The variator according to claim 1, wherein the second pressure chamber is a pressure regulating chamber in which a lubricating pressure acts. Instead of the pipe (7), a cylindrical projection (65) of a housing cover (6) or a cylindrical projection of a transmission housing (5) that covers a bearing portion of the variator shaft (1) is provided. The variator according to any one of claims 1 to 9, characterized in that the packing rings (73) are arranged in parallel in the axial direction outside the cylindrical projection (65).

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