KR100279976B1 - Differential limiter - Google Patents

Abstract

The present invention relates to a differential limiting device for distributing torque of left and right wheels in accordance with the rotation difference when a rotation difference occurs between the left and right wheels, in particular, two side gears each splined to the left and right drive shafts, and the side gears. And a two pinion gear coupled to each other, and a differential case surrounding the side gear and the pinion gear, wherein the left and right sides have a first ball guide groove formed on the outer circumferential surface of each drive shaft. Left and right coupling portions formed with an insertion portion, an outer side of the differential case and hollowed out so that the drive shaft penetrates, and a second ball guide groove having the same shape as the first ball guide groove on an inner circumferential surface thereof; The ball interposed therebetween when the first ball guide groove and the second ball guide groove are engaged. Is generated so that a simplified structure of the product by providing a differential limiting device is reduced in size and weight of the product, manufacturing costs are reduced and at the same time improves the mountability and assembly of the product.

Description

Differential limiter

The present invention relates to a differential device for easily turning a car, and particularly to a differential limiting device for distributing torque of left and right wheels according to the rotation speed difference when a rotation speed difference occurs between the left wheel and the right wheel. It is about.

In general, automobiles use clutches, transmissions, and differentials to properly transfer power generated from engines to wheels. A front wheel drive car directly connects an output from a transmission to a differential, and a rear wheel drive car outputs from a transmission. Is transmitted to the differential through the propulsion shaft.

The differential device is to allow the vehicle to smoothly change direction by generating a speed difference between the inner ring and the outer ring during turning of the vehicle, and to ensure the driving stability of the vehicle in uneven terrain.

However, in the above-described differential device, when a large difference occurs between the frictional force of the road surface where both driving wheels are in contact with each other, when the wheel with the less frictional force is idle and the wheel with the higher frictional force is stopped, the normal driving of the vehicle is difficult. Is generated.

For example, if one wheel falls into the bog, one wheel receives resistance from the road, and the missing wheel receives little resistance, so no power is transmitted to the wheel on the road side, and only the bogged wheel is idle by the differential. do. Therefore, the vehicle cannot be left in the quagmire by magnetic force, and further driving is impossible.

In such a case, if the operation of the differential device is stopped, it is possible to escape the bog, so adopt a differential limiting device for a vehicle that travels a lot of bad roads. By limiting the differential through the differential limiting device, it is possible to prevent a fish tail movement occurring during driving of the uneven road surface, or wheel idle during oscillation or curve.

As described above, there are various types of differential limiting devices for improving driving force of the vehicle, such as multi-plate clutch type, viscose coupling type, helical gear type, and electronically controlled type, but they are all expensive and increase in size compared to general differentials. There is a difficulty in that the mountability should be examined separately.

The prior art differential limiter comprises a first side gear 3 and a second side gear 5 splined to the drive shaft 1 as shown in FIG. 1, and each of the side gears 3, described above. 5 and a first pinion gear 7 and a second pinion gear 9 coupled to each other, a differential case 11 surrounding the side gears 3 and 5 and the pinion gears 7 and 9, and A ring gear 13 integrally formed with the differential case 11 and an insertion portion extending from the first side gear 3 into the differential case 11 and having a first ball guide groove 15 formed on an outer circumferential surface thereof; (17) and the second side gear (5) is formed to extend into the differential case (11) inside the hollow so that the insertion portion 17 can be embedded therein the first ball guide groove (15) on the inner peripheral surface Coupling part 21 having the second ball guide groove 19 formed in the same shape as the above, and the first ball guide groove 15 and the second When the guide groove 19 is engaged, the ball 23 interposed therebetween, and when the first ball guide groove 15 and the second ball guide groove 19 are engaged, the preload is applied to the ball 23. It is configured to include a preload member 25 installed on the inner end of the insertion portion 17.

In the above, the drive shaft 1 uses a constant velocity joint (Constant Velocity Joint: CVJ) as a shaft for transmitting power from the side gears (3, 5) to the driving wheels, which is a double gear. It consists of a double offset joint (DOJ), an intermediate shaft and a burfield joint (BJ).

Here, the double offset joint is slidably inserted into the splines of the side gears 3 and 5 and the burfield joint is fixedly inserted into the splines of the wheel hub.

The operation of the differential limiter configured as described above is as follows.

First, when the power of the engine is transmitted to the drive pinion 12 through the propulsion shaft, the rotational force of the drive pinion 12 is transmitted to the differential case 11 through the ring gear 13. When the differential case 11 rotates, the first pinion gear 7 and the second pinion gear 9 coupled to the differential case 11 by the pinion shaft revolve. When the pinion gears 7 and 9 are idle, the first side gear 3 and the second side gear 5 meshed with the pinion gears 7 and 9 are driven to the side gears 3 and 5. The splined drive shaft 1 is rotated. Therefore, the power of the engine is transmitted to the drive wheel through the drive shaft (1).

In the above, when the vehicle goes straight through the flat path, the rotational resistance of the left and right driving wheels is the same, so that the first side gear 3 and the second side gear 5 are in accordance with the revolution of the pinion gears 7 and 9 described above. At the same time, the insertion part 17 and the coupling part 21 are also rotated together, so that the whole system is rotated as one block.

On the other hand, when the vehicle is turning or one wheel is bogged down, since the rotational resistance received by the left and right driving wheels is different, a relative speed difference is generated between the first side gear 3 and the second side gear 5. There is also a difference in speed of rotation between the inserting portion 17 and the engaging portion 21.

When a rotation difference occurs between the insertion portion 17 and the coupling portion 21, the ball 23 is rolled along the first ball guide groove 15 and the second ball guide groove 19, the insertion portion 17 and the engaging portion 21 is brought into rolling contact by the ball 23. By the rolling contact of the ball 23 as described above, the speed difference between the first side gear 3 and the second side gear 5 is canceled so that the side gears 3 and 5 rotate at the same speed. do.

That is, torque is distributed between the first side gear 3 and the second side gear 5 by the rolling contact of the ball 23, and thus the rotation speeds of the side gears 3 and 5 are increased. Equalization realizes a differential limitation.

However, in the conventional differential limiter as described above, since the insertion part 17 and the coupling part 21 are extended to the first side gear 3 and the second side gear 5, respectively, the conventional differential limiting device is used. Compared with the size increase and the structure is complicated, the difficulty of the mountability due to the increase in size when considering the development of the product separately, and at the same time due to the increase in the number and weight of parts due to the complex structure, there is a problem that the assembly is lowered and the manufacturing cost is increased.

In addition, the conventional automatic limiting device directly recognizes the left and right wheels, so that the variable distribution of the torque is increased, thereby deteriorating the stability of the vehicle during rapid acceleration turning.

The present invention has been made to solve the above problems, it is provided between each of the left and right drive shaft and the differential case to generate a differential action by the rolling contact according to the relative rotation difference between the left and right drive shaft and the differential case. It is an object of the present invention to provide a differential limiting device which simplifies the structure of the product and reduces the size and weight of the product, thereby improving the mountability and assemblability of the product and at the same time reducing manufacturing costs.

1 is a block diagram showing a differential limiter according to the prior art,

Figure 2 is a block diagram showing a differential limiter according to the present invention.

<Explanation of symbols for main parts of drawing>

51: drive shaft 53: side gear

55: pinion gear 57: differential case

61, 61 ': 1st ball guide groove 63, 63': insertion part

65, 65 ': second ball guide groove 67, 67': coupling

69, 69 ': ball

Features of the differential limiter according to the invention for achieving the above object are two side gears splined to each drive shaft, two pinion gears coupled to the side gears, and the side gears and pinion gears. In the differential limiting device comprising a differential case surrounding the differential means, the differential means for generating a differential action by the rolling contact according to the relative rotation difference between the left and right drive shaft and the differential case between the left and right drive shaft and the differential case, respectively. Will be installed.

In addition, an additional feature of the present invention is that the differential means has left and right insertion portions formed with first ball guide grooves on the outer circumferential surface of each drive shaft, and extends outwardly of the differential case so that the drive shaft is penetrated. A left and right engaging portion having a hollow inside and having a second ball guide groove having the same shape as the first ball guide groove on an inner circumferential surface thereof, and interposed therebetween when the first ball guide groove and the second ball guide groove are engaged. It consists of balls.

The present invention configured as described above has the advantage of reducing the size and weight of the product by minimizing the structural change and at the same time the structure is simplified to improve the mountability and assembly of the product and reduce the manufacturing cost.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 2, the differential limiter according to the present invention has two side gears 53 splined to each drive shaft 51 and two pinion gears coupled to each other with the side gears 53. 55, a differential case 57 surrounding the side gear 53 and the pinion gear 55, a ring gear 59 integrally formed with the differential case 57, and the respective drive shafts ( The left and right insertion portions 63 and 63 'having the first ball guide grooves 61 and 61' formed on the outer circumferential surface of the 51 and the drive shaft 51 extend outwardly of the differential case 57. The left and right coupling portions 67 and 67 'having an inner hollow to penetrate the second ball guide grooves 65 and 65' having the same shape as the first ball guide grooves 61 and 61 '. When the first ball guide groove (61, 61 ') and the second ball guide groove (65, 65') is interposed therebetween It is configured to include a left and right view (69, 69).

In the above, the drive shaft 51 uses a constant velocity joint (Constant Velocity Joint: CVJ) as a shaft for transmitting power from the side gear 53 to the driving wheel, and the constant velocity joint is a double offset joint ( It consists of Double Offset Joint (DOJ), Intermediate Shaft and Burfield Joint (BJ).

Here, the double offset joint is slidably inserted into the spline of the side gear 53 and the burfield joint is fixedly inserted into the spline of the wheel hub.

The operation of the differential limiter configured as described above is as follows.

First, when the power of the engine is transmitted to the drive pinion 58 through the propulsion shaft, the rotational force of the drive pinion 58 is transmitted to the differential case 57 through the ring gear 59. When the differential case 57 rotates, the pinion gear 55 coupled to the differential case 57 by the pinion shaft rotates. When the pinion gear 55 is idle, the side gear 53 engaged with the pinion gear 55 is driven to rotate the drive shaft 51 splined with the side gear 53. Therefore, power of the engine is transmitted to the driving wheel through the drive shaft 51.

In the above case, when the vehicle goes straight through the flat road, the rotational resistance of the left and right driving wheels is the same, so that the side gear 53 is driven at the same rotational speed and the drive shaft 51 is driven at the same time as the pinion gear 55 is idle. ) And the differential case 57, that is, the inserts 63 and 63 'and the coupling parts 67 and 67' are also rotated together, so that the entire system is rotated in one block.

On the other hand, when the vehicle is turning or one wheel is in a bog, the rotational resistance received by the left and right driving wheels is different, so that the drive shafts 51 each of which is connected to the driving wheels are rotated at different speeds. When the drive shaft is rotated at different speeds, a speed difference generated between the insertion part 63 and the coupling part 67 on the left side and a speed generated between the insertion part 63 'and the coupling part 67' on the right side are generated. The size of the car will be different.

As described above, when a rotation difference is generated between the left and right insertion parts 63 and 63 'and the engaging parts 67 and 67', the first and second ball guide grooves 69 and 69 'have different speeds. Rolling along the 61 and 61 'and the second ball guide grooves 65 and 65', the insertion portions 63 and 63 'and the engaging portions 67 and 67' are brought into rolling contact, respectively.

Therefore, the speed difference between the left insert 63 and the right insert 63 'is canceled by the rolling contact of the balls 69 and 69', so that the left and right drive shafts 51 rotate at the same speed. As a result, since the rotational speeds of the left and right side gears 53 become the same, a differential restriction due to the relative speed difference between the differential case and the left and right drive shafts 51 is realized.

The differential limiting device according to the present invention constructed and operated as described above includes left and right insertion portions 63 and 63 'having first ball guide grooves 61 and 61' formed on the outer circumferential surface of each drive shaft 51. A second ball guide groove (not shown) is formed to extend outward of the differential case 57 and the inside thereof is hollow so that the drive shaft 51 penetrates, and has the same shape as the first ball guide grooves 61 and 61 'on its inner circumferential surface. The left and right coupling portions 67 and 67 'formed with the first and second ball guide grooves 61 and 61' and the second ball guide grooves 65 and 65 '. Minimizing the structural change by providing interposed balls 69 and 69 ', the size and weight of the product are reduced and the structure is simplified, thereby improving the mountability and assembly of the product and reducing manufacturing costs.

In addition, the differential limiting device of the present invention recognizes the difference in rotation between the differential case 57 and each drive shaft 51, so that the variable distribution of the torque is low, and thus the vehicle stability is improved during rapid acceleration turning.

In addition, the present invention has the advantage that the generation of noise is suppressed and durability is increased by extending the differential by using the rolling contact by the balls (69, 69 ') to extend the life of the product.

Claims (2)

A differential limiter comprising two side gears splined to left and right drive shafts, two pinion gears coupled to the side gears, and a differential case surrounding the side gears and pinion gears, Differential means between the left and right drive shaft and the differential case is provided with a differential means for generating a differential action by the rolling contact according to the relative rotation difference between the left and right drive shaft and the differential case, respectively. The method of claim 1, The differential means includes left and right insertion portions having a first ball guide groove formed on an outer circumferential surface of each drive shaft, and are formed to extend outwardly of the differential case and are hollowed out so that the drive shaft penetrates, and the first circumferential surface of the drive shaft is formed on the inner circumferential surface thereof. A left and right coupling portion having a second ball guide groove having the same shape as the ball guide groove, and a ball interposed therebetween when the first ball guide groove and the second ball guide groove are engaged. .

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