DE2706166A1 - DIFFERENTIAL GEARS FOR ROAD VEHICLES - Google Patents

Description

P AT E N T A M WA L ^ F

TER MEER - MÜLLER - S ^t E! \ 'ME: STER

D-COOO Munich 22 D- ^ COO f?! O! Efe! D

Triftstraße 4 r Siekerwall 7 2706166

WG 77-001

st / Hb 1 * · Fet ». £ 77

Nissan Diesel Motor Co., Ltd. 1, Oaza 1-chome, Ageo-shi, Saitama-ken, Japan

Differential gears for road vehicles

The invention relates to a differential gear for road vehicles according to the preamble of the main claim. In particular, it relates to a differential gear with a Differential lock to temporarily block the function of the differential gear.

It is known that a differential gear of a vehicle causes the wheels on both sides of the vehicle to rotate at the same speed when the vehicle is drives straight ahead, while the number of revolutions of the outer wheel compared to that of the inner wheel is increased, so that the tires are prevented from sliding and the vehicle can run smoothly Curves is made possible. In most conventional differential gears, however, one wheel spins freely and loses traction if it gets caught in mud or the like on one side. As a result, the vehicle cannot

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be moved more. The reason is that in the event that one wheel is on one side of the vehicle, the traction loses, the other wheel on the other hand cannot develop any torque to drive the vehicle. Around To prevent this, some types of vehicles are provided with a differential gear that has a locking device for the differential movement. As one of the conventional differential locks, there is a differential lock known with frictional effect. In this known device there is a mechanism in the differential gear provided, which automatically and inevitably generates frictional resistance if one of the wheels spins, so that the drive torque can be transmitted to the wheels from the drive shaft of the vehicle. One However, such a differential lock with frictional effect has the disadvantage that the transmitted drive torque is often insufficient, especially in the case of heavy vehicles. As a differential lock that eliminates this disadvantage, a differential lock with a mechanical clutch mechanism has been used. At this Device, a differential housing and axle shafts are temporarily fixed to one another with the aid of clutch wheels locked, which slide on the axle shafts of the wheels in the axial direction, and the locking takes place accordingly a signal given by the driver who has noticed a wheel spinning. However, if such a Clutch mechanism is used, however, is not only the space for the working area of the clutch wheels, but also the space for the working area of the entire clutch mechanism required, so that the range of application is severely limited. Also results the unpleasant disadvantage that a use in connection with a planetary differential gear with double reduction, in which the speeds always differ between the differential housing and the axle shafts and locking is not possible, is out of the question.

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_ ^ _ 27Q6J66

The invention is directed to a differential gear for a vehicle that overcomes the disadvantages discussed above.

According to the invention, a differential lock is proposed that will be effective for a planetary differential gear can be used with double reduction and only a very small one in the differential gear Takes up space so that it can also be used for other differential gears can be used.

The invention results in detail from the characterizing part of the main claim.

The differential gear according to the invention for motor vehicles includes a drive pinion in communication with a drive source of the vehicle, a drive wheel that is connected to the Drive pinion meshes and connected to a differential housing which is supported so that it rotates with the drive wheel, at least one differential pinion that is fixedly mounted on a shaft which is rotatably supported by the differential housing, two differential side gears, meshing with the differential pinion in the differential case, two separate and axially aligned killed axle shafts or half-shafts, each carrying a vehicle wheel and one of which is rigid with one of the side wheels is connected and rotates with this, a locking shaft to form a mechanical connection between the other Axle shaft and the other differential side wheel, due to which these can be locked and are together rotate together, the locking shaft in the axial direction from the other axle shaft in the direction of the first axle shaft is displaceable and in this position the two differential side gears locked together, devices for biasing the locking shaft in the direction of the other axle shaft and means for moving the locking shaft from the other axle shaft in the direction of one axle shaft. against

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the pretensioning device when actuated by a driver of the vehicle.

In the following, preferred exemplary embodiments of the invention are explained in more detail with reference to the accompanying drawings.

Fig. 1 is a cross section through the main portion of an embodiment of the differential gear according to the invention;
10

Fig. 2 is a schematic operational diagram of a lock shaft actuator and a Signal or display device for the differential gear of Figure 1; 15th

Fig.3 shows a cross section of the main area of a another embodiment of the differential gear according to the invention;

Fig. 4 is a cross section of another embodiment of the differential gear according to the invention.

First, reference should be made to FIG. 1, which shows an embodiment of a planetary differential gear according to the invention shows. A drive pinion 12 is rotatably supported in a holder 16 via bearings 14a to 14c. One end of the drive pinion 12 is connected to a drive shaft, not shown, on the machine drive side via a connected by spline entrained flange 18, so that the drive torque of the machine to the Drive pinion 12 is transmitted. Drive teeth 12a at the other end of the drive pinion 12 mesh with teeth a ring gear 22 so that the ring gear 22 is rotated about an axis perpendicular to the axis of the drive pinion 12. The ring gear 22 is connected in a differential housing 26 with the aid of a screw 24. The differential case

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26 is rotatably held at both ends in the holder 16 via conical bearings 28a and 28b. Adjusting nuts 30a and 30b are screwed into the bracket 16 from the outside at both ends of the differential case 26, and the position of the differential case 26 in the axial direction is precisely adjusted by rotating the adjusting nuts 30a and 30b by an appropriate one Set angle so that the distance between the ring gear 22 and the drive pinion 12 at an optimal Value is held. In the differential housing 26 there are two opposing side gears 32 and 34 and differential pinions 38 and 40 which mesh with the side gears 32 and 34 and are pivotable on both Ends of a shaft 36 are attached so that the axes of rotation of the side gears and the differential pinion cut at right angles. The two ends of the shaft 36 are fixed to the differential case 26, and the central area the shaft 36 is provided with an internal spline 42 into which a locking shaft described later 50 can be inserted. The peripheral surface of the differential side gears 32 and 34 are rotatably supported by the inner wall of the differential case 26. Outer Splines 50a on one end of lock shaft 50 mesh with internal splines 32a in one of the side gears 32 so that the outer spline 50a can slide in the axial direction. An external spline 44a on an axle shaft 44, which is connected to a wheel (not shown) on one side, engages in an internal spline 34a in the other side gear 34. An internal spline 50b is on the other end of the Locking shaft 50 and is in sliding engagement with an outer spline 4 6a of an axle shaft 46 of another, not shown wheel on the other side of the vehicle.

The locking shaft 50 is slidably displaced in the axial direction by operating a button below with reference to FIG Fig. 1 and 2 described device.

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ΓΕΠ MrHER-MÜLLER-STEINMEISTEn Nissan

An annular groove 62 is located in the circumferential surface of the locking shaft 50. A sliding fork 64 engages in the circumferential direction rotatable, in this groove 62, so that the movement of the sliding fork 64 in the axial direction according to the Arrow A in Figure 1 moves the locking shaft 50 in the axial direction.

The sliding fork 64 is moved by a piston 70 of a cylinder 68 via a rod 66, which is at the top End of the sliding fork 64 is attached. The cylinder 68 is attached to the outer wall of the bracket 16. Compressed air passes from a compressed air tank 71 into a chamber 68a on the head side of the cylinder 68 via a Air line 74 and an electromagnetic valve 72. A return spring 67 is located in a chamber 68b on the Rod side of the cylinder 68. The electromagnetic valve 72 is opened or closed by the driver with Using a switch 75 on the dashboard b near the driver's seat. When the electromagnetic valve 72 is turned on, compressed air passes through the air line 74, and when the electromagnetic valve 72 is turned off is, the air line 74 is blocked and the compressed air in the chamber 68a on the head side of the cylinder 68 is released. The switch sensor of a limit switch 76 is located on the inner wall of the chamber 68b on the rod side of the Cylinder 68. When piston 70 arrives at the differential lock position at the end of its stroke, it comes into contact with the limit switch 76, and by a signal from the limit switch 76, which senses this contact with the piston 70, a control lamp 78 on the dashboard b is switched on and indicates that the differential lock is switched on. In Fig. 2 are drawn with 82 and 84 fuses.

The operation of the differential gear explained above will then be described.

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ΛΑ

In the position of FIG. 1, the axle shafts 44 and 46 the differential movement corresponding to normal driving exercised. The drive torque of the prime mover is transmitted to the drive pinion 12 and rotates the ring gear 22 which meshes with it, so that the Differential housing 26 is rotated about the axis of the axle shafts 42 and 44. The shaft 36 is together with the differential housing 26 rotated and takes the differential pinion 38 and 40 with their orbital movement. If there is no difference of the moment of resistance occurs between the two differential side gears 32 and 34, the differential pinions 38 and 40 only pivoted in a circle and the two side gears 32 and 34 are at the same speed rotated so that the vehicle travels straight ahead. If, on the other hand, the section modulus on one of the side gears, for example the left side gear 32, is higher, the differential pinions 38 and 40 begin to rotate about their axis, and the speed of the side gear 32 with higher resistance torque is reduced, while the speed of the right Side wheel 34 is increased with a lower section modulus. In this case, at a constant speed of the drive pinion 12 the sum of the speeds (rpm) of both side gears 32 and 34 is kept constant. When on this Way a difference in the speeds between the two 5 side gears 32 and 34 is generated, get different Speeds to the left axle shaft 46, which is splined with the locking shaft 50, and the right axle shaft 44 so that the vehicle can be turned smoothly.

However, if at least one wheel on one side hits mud, snow or black ice, the section modulus of the corresponding side wheel, for example the right side wheel 34, reduced substantially to zero, and the corresponding axle shaft 44 and the wheel spin. As a result, no torque reaches the other, left side wheel 32, which is connected to the axle shaft 4 6, and that

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Vehicle can no longer be moved. According to the invention this effect can be switched off.

A driver who notices the described condition, operates the switch 75 so that the electromagnetic valve 72 is switched on and the air line 74 opens and compressed air from the compressed air tank 71 into the chamber 68a is initiated on the head side of the cylinder 68. Consequently, the piston 70 is to the right in Figure 2 contrary to the elastic force of the return spring 67 displaced so that the sliding fork 64 issued a stroke on the rod 66 and the locking shaft 50 is moved to the right in Fig.1. Since the locking shaft 50 is splined with the axle shaft 46 and the side wheel 32 and is axially displaceable against this, it is about the axle shaft 46 in the axial direction pushed out, and the outer splines 50a of the lock shaft 50 mesh with the inner splines 42 of the shaft 36. This position is shown in phantom in FIG. Hence the difference the relative speed between the shaft 36 and the left side gear 32 is reduced to zero, and the left side gear, the differential pinions 38 and 40, the right side gear 34, the axle shafts 44 and 46 and the lock shaft 50 become one with the other locked so that all parts are rotated together about the axis of the axle shafts 44 and 46. That means, that the differential effect is switched off and the differential is blocked. Therefore, the driving torque becomes of the vehicle engine to the axle shaft 46 and the corresponding wheel, so that the vehicle from the fixed Position can be extended.

In this position of the blocked differential, the Limit switch 76 actuated by piston 70 of cylinder 68, so that the contact of limit switch 76 is closed will. As a result, the control lamp 78 on the driver's seat lights up, so that the driver is informed that in this position normal driving must be avoided.

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The locking of the differential is done in the following way solved.

The switch 75 is switched to the off position so that the electromagnetic valve 72 is turned off and the air line 74 interrupts. At the same time, the compressed air is in the chamber 68a on the head side of the cylinder 68 to the Environment. At this point in time, the piston is closed by the elastic restoring force of the return spring 67 shifted to the left. As a result, the sliding fork is pushed back to the left in Fig. 1 into the starting position, whereby it takes the locking shaft 50 with it. Therefore, the contact between the piston 70 and the limit switch 76 is broken and the control lamp 78 is switched off.

Another embodiment of the differential gear according to the invention will now be explained with reference to FIG.

The mechanism of this embodiment is essentially the same as that of the first embodiment shown in FIG and 2, with the difference that in the first embodiment, the spline 50a of the locking shaft 50 with the inner Spline 42 of shaft 36 engages when locking the differential, while when the second Embodiment, the spline 44a of the axle shaft 44 is shorter and the stroke of the locking shaft 50 is longer, so that the splines 50a on the locking shaft 50 in the inner splines 34a in the inner side gear 34 (Figure 3) the locking of the differential occurs. In this embodiment, a bore 150a in the central region of the Shaft 36 is provided, the inner diameter of which is greater than the outer diameter of the splines 50a of the locking shaft 50 is. Other design features are the same as in the embodiment of FIG. They are therefore with the same Reference numerals denoted.

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Τί £ Π ΜΕΕΠ-MÜLLER-STEINMEISTER Nissan

In this embodiment, when the differential is locked, the spline 50a engages the locking shaft 50 at the same time into the inner splines 32a and 34a of the two side gears 32 and 34. This will make a difference the respective speed between the side gears 32 and 34 is suppressed and they are rotated together, so that the differential effect works in the same way as at the embodiment of Figures 1 and 2 is turned off.

In the embodiment of FIG. 3, it is possible to additionally have a spline in the central region of the shaft 36, such as to be provided in the embodiment of Figure 1 and the locking shaft 50 with the shaft 36 and the other side wheel 34 to be brought into engagement so that all parts are rotated together.

From the above description it should be apparent that the differential motion even with a planetary differential gear can be blocked with double reduction, while the one used by the blocking device Space in the differential gear is greatly reduced. There is also the advantage that the differential lock can be controlled from the driver's seat without difficulty. In addition, the driver is given a very a-5 fold constructed control device informs that the differential is locked, so that damage can be avoided can.

Another embodiment of the differential gear according to the invention will be described below with reference to FIG. It should be noted, however, that the same parts or elements that have already been explained above are provided with the same reference numerals and not to be rewritten. In the embodiment of FIG. 4, the displacement of the locking shaft 50 caused by a fluid-controlled cylinder mechanism 52 which is adjacent one end of the locking shaft

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is provided. The cylinder mechanism 52 has a cylinder wall 52a, which is provided with a fluid channel 54. The cylinder wall 52a of the cylinder mechanism 52 is provided on its cylindrical surface with the spline 50b of the locking shaft 50, which is provided with the outer spline 4 6a of the axle shaft 4 6 cooperates. An axial groove 56 is located at the end of the axle shaft 46 and connects the fluid channel 54 in the cylinder wall 52a with a cylinder chamber 52b. The cylinder mechanism 52 continues to hold a return spring 53 in the form of a known compression spring, one end of which is the inner face of the Lock shaft 50 and the other end of which contacts a snap ring 55, which is in an annular groove 4 2a at one end of the inner splines 34a of the right side gear 34 is used. In this way, the lock shaft 50 is always pressed by the return spring 53 in the direction of the left axle shaft 4 6.

The hydraulic operating circuit for the cylinder mechanism 52 is constructed as follows.

A channel ring 92 is connected to an axle housing 58 and on the periphery of the cylinder wall 52a of the cylinder mechanism 52 attached, which it surrounds. An annular channel 94 is located in the inner cylindrical surface of the channel ring 92 so that the annular channel 94 always with the fluid channel 54 during the operation of the cylinder mechanism 52 is in communication. The annular channel 94 is further connected to a tube 96 which is shown in FIG the channel ring 92 is screwed in and is connected to a compressed air tank 71 via a fluid line 88. That Valve 72 is turned on or off when the driver turns switch 75 on or off. While the electromagnetic Valve 72 is actuated, the fluid line 88 is opened, and when the valve 72 is turned off is, the fluid line 88 is cut and pressurized air in the cylinder chamber 52b of the cylinder mechanism 52 ″ becomes

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/ I (ρ

drained to the environment. A seal is designated by 86, which prevents the fluid from escaping.

The mode of operation of the embodiment of FIG. 4 is then intended to be discribed.

When at least one vehicle wheel hits mud, snow or the like on one side, the section modulus becomes the corresponding side gear of the differential gear, for example the right side gear 34, considerably reduced to zero and the corresponding axle shaft 44 and the wheel rotate due to the sliding process by. As a result, no torque is transmitted from the vehicle engine to the left side gear 32, the is connected to the axle shaft 46. As a result, the vehicle can no longer be moved. When the driver has this condition noticed, he turns on the switch 75 on the driver's seat so that the electromagnetic valve 72 is turned on and the fluid line 88 is opened and compressed air from the compressed air tank 71 into the cylinder chamber 52b of the Cylinder mechanism 52 arrives. Therefore, the locking shaft 50 to the right in Figure 4 against the elastic force of the Return spring 53 shifted so that it is extended over the axle shaft 4 6 in the axial direction and the outer spline 50a of the locking shaft 50 enters the inner splines 42 of the shaft 36. This position is dashed and dotted indicated in Figure 4. Therefore, the relative speed difference between the shaft 36 and the side gear becomes 32 reduced to zero and the side gear 32 and the differential pinions 38 and 40, the side gear 34, the axle shafts 4 4 and 4 6 and the locking shaft 50 are shared around the common axis of the two axle shafts 44 and 46 as one Unit rotated. As a result, the differential action is interrupted and the drive torque is transmitted to the axle shaft 4 6 and the corresponding wheel, so that the Vehicle is released.

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The differential lock is released in the following way.

The switch 75 is operated again and switched to "off", so that the electromagnetic valve 72 is turned off and the fluid line 88 interrupts. Simultaneously the compressed air in the cylinder chamber 52b of the cylinder mechanism 52 is released to the environment via channels 88 and 89. At this point in time, the locking shaft 50 moves to the left in FIG. 4 in the direction of the axle shaft 46 and reverses due to the elastic restoring force of the return spring back to its original position.

According to the invention, the differential movement can therefore also be blocked in a planetary differential gear with double reduction, while by the locking device occupied space in the differential gear considerably is reduced and the differential lock can be easily controlled from the driver's seat.

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Claims (16)

π-Müller -STEiNMEiSTEn Nissan patent claims 1. Differential gear for vehicles with a drive pinion in connection with a drive source of the vehicle 'j stuff, a drive wheel in mesh with the drive pinion and in connection with a rotatably supported differential housing, at least one differential pinion that is fixed mounted on a shaft rotatably supported by the differential housing, two differential side gears, "■ 'which mesh with the differential pinion in the differential housing, and two separate and axially aligned axle shafts, each carrying a vehicle wheel and one of which is rigidly connected to one of the side ^{gears and rotates therewith, characterized by a r} > locking shaft (50) for the mechanical connection of the other axle shaft (46) and the other differential side gear (32) with the one axle shaft {44) and the one differential side gear (34), which locking shaft (50) axially from the other axle shaft (46) in Direction of one axle shaft (44) for mutual locking of the side gears (32,34) is displaceable, a device (67,53) for pretensioning the locking shaft (50) in the direction of the other axle shaft (4 6) and a device (64,66,68,70; 52,54,68,70) for displacement the locking shaft (50) in the direction of one axle 1 ") shaft (4 4) against the pre-tensioning force exerted by the driver of the Vehicle. 2. Differential gear according to claim 1, characterized in that the locking shaft (50) in wedge TO toothing engagement with the other axle shaft (46) and the other side wheel (32) is. 3. Differential gear according to claim 2, characterized in that the locking shaft (50) is a has axially inner end that is in spline engagement with at least one of the parts of the shaft (36) of the drive pinion (38, 40) or one of the differential side gears 70983Λ / 0321 ORIGINAL INSPECTED TER MEER-MÜLLER-STEINMEISTER Nissan (32) occurs during axial displacement by the displacement device in the direction of one axle shaft (44) and blocks the differential action of the two differential side gears (32, 34).
5 4. Differential gear according to one of the preceding Claims, characterized in that the displacement device (64, 66, 68, 70) is a displacement fork (64) for applying a mechanical displacement force in the axial direction to the locking shaft (50), a cylinder (68) for the axial displacement of the sliding fork (64) and a control device (72, 75) for controlling the mode of operation of the cylinder in accordance with an actuation signal from the driver. 5. Differential gear according to claim 4, characterized in that the control device has a Compressed air tank (71) for compressed air to actuate the cylinder (68), an air line (74) between the compressed air tank and the cylinder, an electromagnetic valve (72) for communication therebetween Compressed air tank and the cylinder via the air line (74) when switched on and a switch (75) for supplying electric power from a power source of the vehicle to the electromagnetic switch (72) Operation by the driver includes. 6. Differential gear according to claim 5, characterized in that the pretensioning device has a Return spring (67) in the form of a compression spring in the cylinder (68), which on the sliding fork (64) to Displacement of the locking shaft (50) in the direction of the other side wheel (32) when the electromagnetic one is switched off Switch (72) acts. 7. Differential gear according to claim 4, characterized in that the sliding fork (64) in 709834/0321 μ νν ^:! Ξ '> - νιύι_ι.Ηη-STEiN ¹ MEiSTeR Nissan * 7OÖI66 an annular groove (62) in a part of the circumference of the locking shaft (50) engages rotatably in the circumferential direction. 8. Differential gear according to claim 4, characterized by scanning means (76) for scanning the displacement of the lock shaft (50) from the other axle shaft (46) in the direction of one axle shaft (44) and a device (78) on the dashboard of the Vehicle to inform the driver about the shift. 9. Differential gear according to claim 8, characterized in that the scanning device has a Includes limit switch (76) which is activated by the cylinder (68,70) when the cylinder is actuated by the control device (72,75) is switchable, and that the display device is a control lamp. 10. Differential gear according to claim 3, characterized in that g e that the displacement device comprises a fluid-operated cylinder mechanism (52) for displacement the locking shaft (50) from the other axle shaft (■ 16) in the direction of one axle shaft (44) against the Biasing device (53) and a fluid system (88,72,71) 5 for introducing and releasing a pressure fluid into the and comprised of the cylinder. 11. Differential gear according to claim 10, characterized in that the fluid-operated cylinder the mechanism includes a portion of the other axle shaft (4-6) and the lock shaft which are in spline engagement stand. 12. Differential gear according to claim 11, characterized in that that the areas of the other axle shaft (46) and the locking shaft (50) have a cylinder wall (52a) of the cylinder drive mechanism, which have a fluid 709834/0321 MP> -; n-MÜLLER STEtNMEISTER Nissan channel (54) between the fluid system and the cylinder mechanism, and that a cylinder chamber (52b) with the Fluid channel is connected in the cylinder wall. 13. Differential gear according to claim 12, characterized in that the pressure fluid is compressed air. 14. Differential gear according to claim 13, characterized in that the fluid system is an electric magnetic valve (72) for the optional connection of the cylinder chamber (52b) of the cylinder mechanism (52) with a Compressed air source (71) and the environment comprises, which is actuated by an electrical signal which is transmitted by the driver is switched on. 15. Differential gear according to claim 14, characterized in that the fluid system continues a fixed fluid channel (94) in a channel ring surrounding the outer circumference of the cylinder wall (52a) in an airtight manner (92) which is rotatable with respect to the portions of the other axle shaft (46) and the locking shaft (50). 16. Differential gear according to claim 11, characterized in that the pretensioning device is a 5 compression spring (53) between the locking shaft (50) and the one axle shaft (44). 709834/0321