JPH01108442A - Differential motion limiting device - Google Patents

Abstract

PURPOSE:To enhance the operability of differential motion and the limitation thereof by providing a pair of slidable gears meshed with a pinion gear and a pair of stationary gear integrally incorporated with a differential gear casing, and by providing rotatable twin planetary gears. CONSTITUTION:A pinion gear 13 is rotatably fitted on a pinion shaft 12 secured to a differential casing 5 into which power is inputted. A pair of slidable gears 20, 20' and a pair of stationary gears 21, 21' are arranged on both sides of the pinion gear 13. Carriers 20, 20' are integrally fitted on left and right axles 11, 11' through serration fitting or the like, and are provided thereon with twin planetary gears 24, 24'. Thus, it is possible to enhance the operability of differential motion and limitation of the latter.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a differential limiting device that is disposed between left and right wheels or front and rear wheels of a drive system of a vehicle such as an automobile and performs power transmission, differential operation, and differential locking. This relates to a differential limiting method.

[Conventional technology]

-a, a differential device is provided between the left and right or front and rear wheels of the drive system that transmits power in the vehicle to absorb the difference in rotation during turning. This differential device consists of a bevel gear and a planetary gear, and uses a differential operation based on the difference in road resistance, so there is a problem that even when driving straight, the differential operation is applied when the road resistance of one wheel decreases. Therefore, such a differential device is indispensable to have differential limiting means for regulating the rotational difference by braking mainly by friction, and this means complicates the structure. Further, even if the differential is limited, it is not possible to prevent some wheel slippage, and the traction force of the limited differential is always applied, which improves straight-line performance, but it lacks steering feel when turning. Because of this, in recent years, differential limiting devices have been proposed that use the function of the gear itself to freely operate the differential without being restricted when turning, and otherwise limit the differential regardless of road resistance, braking force, etc. be. Conventionally, regarding the above-mentioned gear type differential limiting device, there is a prior art, for example, disclosed in Japanese Utility Model Application Laid-Open No. 61-123250. Here, it is shown that a gear is constructed using a worm gear, a worm wheel, etc., and differential movement during turning is allowed, but other than this, differential movement is limited by locking due to the irreversibility of the gear train.

[Problems to be Solved by the Invention] By the way, since the above-mentioned prior art is based on a worm gear configuration, the structure is complicated and expensive. Furthermore, since the sliding resistance is large, there are problems such as poor transmission efficiency and large wear. The present invention has been made in view of the above problems, and an object of the present invention is to provide a differential limiting device that has a simplified structure using a gear configuration other than a worm, and that improves the operability of the differential and its limiting. shall be.

[Means to solve the problem]

In order to achieve the above object, the differential limiting device of the present invention has a meshing configuration of a pinion gear on the differential case side, a pair of sliding and fixed gears, and a pair of double planetary gears, so that the output elements are reversed by the same amount when turning. Rotation is allowed, but when the output elements rotate in the same direction when traveling straight, they are integrally locked while restricting idling or locking on one side. Therefore, in a configuration in which a pinion shaft is fixed to a differential case into which power is input, and a pinion gear is rotatably attached to the pinion shaft, a pair of sliding gears that are slidable on the differential case and mesh with the pinion gear, and a pair of sliding gears that are slidable on the differential case and mesh with the pinion gear, and It has a pair of fixed gears that are integrally coupled, and two sets of planetary gears are rotatably provided on a carrier integral with two output elements, and one planetary gear is connected to one sliding gear and the fixed gear, and the other planetary gear is connected to the sliding gear and the fixed gear. The planetary gear is meshed with the other sliding gear and the fixed gear to form a transmission structure, and the number of teeth of each gear is as follows. The pitch circle is configured to be set to allow only differential movement during turning.

[For production]

Based on the above configuration, when driving straight, power is input from the differential case, and under the condition that the two output elements rotate in the same direction, the relative rotation of each gear is regulated and locked in an irreversible state, so that the input element On the other hand, the two output elements are always integrally connected and power is transmitted to the two output elements regardless of road surface conditions and the like. Furthermore, when turning, each gear rotates relative to each other and becomes free under the condition that the two output elements rotate in opposite directions by the same amount, and differential operation is used so that the same amount of reverse rotation occurs regardless of road surface conditions. Thus, in the present invention, the meshing structure of gears other than the worm provides a simple structure and good transmission efficiency, and in particular, it becomes possible to smooth differential operation during turning.

【Example】

Embodiments of the present invention will be described below based on the drawings. In Figures 1 to 3, reference numeral 1 indicates a differential carrier of a differential limiting device, and inside this differential carrier 1, a large-diameter ring gear 4 changes direction to a drive pinion 3 of a drive shaft 2 that inputs power. The differential case 5 is integrally connected to the ring gear 4 by bolts 6. here,
Since the ring gear 4 is formed into a ring shape, the differential case 5 is formed by attaching a disc-shaped side plate 5b to a cylindrical case body 5a, and has shaft cylindrical parts 5c and 5d located at the center of the ends of the case body 5a and the side plates 5b. is bearing 8 of bearing case 7
It is pivoted on. Also, left and right wheels 10.10″ axle 1
1°11° passes through the shaft cylinder parts 5c and 5d and connects the differential case 5.
An oil seal 9 is fitted to each axle 11, 11" in the bearing case 7. A pinion shaft 12 is fixed to the center inside the differential case 5, and an oil seal 9 is fitted to each axle 11, 11" in the bearing case 7. The pinion gear 13 is rotatably mounted. Therefore, in the above configuration, a pair of sliding gears 20.20' and a fixed gear 21.21' are provided on the left and right sides of the pinion gear 13.
is provided. The sliding gear 20 has a gear part 20 on one side and inside.
The fixed gear 21 has a gear portion 21a inside and is integrally connected to the differential case 5 by a knock pin 22, and acts as a stopper for the sliding gear 20. It also serves as gear part 20b,
The number of teeth of 21a is different, and the sliding gear 20゛ on the right side,
The fixed gear 21° has a similar configuration. In addition, carriers 23.23 are installed on the left and right axles 11 and 11 degrees.
' are integrally fixed by serration fitting or the like, and two sets of planetary gears 24, 24' are provided on this carrier 23, 23'. The carrier 23 has notches 23 at three locations on the circumference.
a, and the planetary gear 2 is connected to this notch 23a by the shaft 25.
4 is rotatably mounted. The planetary gear 24 has two gear parts 24a and 24b with different numbers of teeth.
is meshed with the gear portion 21a of the fixed gear 21, and the gear portion 24b is meshed with the gear portion 20b of the sliding gear 20, so that they can rotate and revolve. The planetary gear 24° of the carrier 23° also has the same configuration, and the same parts are provided with dashes. Here, in the configuration of the gear train described above, in order to enable only differential movement during turning, the following relationship is established. That is,
When turning, the left and right axes increase or decrease by the same amount and rotate in opposite directions due to the difference between the left and right inner and outer wheels. Only under this condition is differential movement allowed; If it rotates at an increased speed due to a decrease in ground contact force, you can lock it. First, considering the case of straight traveling, the rotation of the differential case 5 causes the pinion gear 13 to revolve, and the fixed gear 21 to rotate integrally. Moreover, the sliding gear 20 rotates at the same speed as the fixed gear 21 by meshing with the pinion gear 13 through the gear portion 20a. Here, suppose the number of teeth of the fixed gear 21 is 21, the number of teeth of the gear portion 20b of the sliding gear 20 is 22,
The number of teeth of the gear parts 24a and 24b of the planetary gear 24 is Pl
, P2, and the relationship between the number of teeth is 21 /P1 = 72/P
2, the planetary gear 24 only rotates and does not transmit power. Therefore, 21 /P1≠Z2 /P2 (11/h < 72
/P2), the planetary gear 24 tends to rotate, producing a force that rotates the sliding gear 20 at different speeds as indicated by arrow A in FIG. 4(a). Also, each gear 2 on the right side
The same relationship exists at 0°, 21', and 24°, and since the rotation direction is the same, a force as shown by arrow B in FIG. 4 is generated on the sliding gear 20°. However, these sliding gears 20.2
Since the rotation directions of 0' are the same, their rotations are restricted by the pinion gear 13, and the planetary gears do not rotate and this gear train is locked. Also, due to the above gear ratio relationship, for example, when turning left,
A rotational force is generated in the left sliding gear 20 in the opposite direction as indicated by the arrow A° in FIG. 4(b). Since the rotational forces of the arrows A° and B are the same, the pinion gear 13 rotates on its own axis and enables the sliding gears 20 and 20'' to rotate, thereby establishing a differential.Furthermore, for example, the left wheel Considering the case where the right wheel floats or spins due to a decrease in road traction resistance and the right wheel stops, when the right carrier stops at 23 degrees, the planetary gear 24' only rotates and applies rotational force to the sliding gear 20 degrees. 4(a), the sliding gear 20 attempts to rotate as indicated by the arrow A'' in FIG. 4(a). On the other hand, on the left side, the constant rotation of the fixed and sliding gears 21 and 20 produces a rotating force on the sliding gear 20 as indicated by the arrow A in FIG. gear parts 24a, 24b
It also acts on the gear parts 21a and 20b of the fixed gear 21 and sliding gear 20 that mesh with the fixed gear 21 and the sliding gear 20. Here, the pitch circle diameter d1 of the fixed gear 21 and the sliding gear 20. ．． When the difference Δd in d2 is 1] small because of the relationship 1dl-621>Δd, the rotating force generated in the planetary gear 24 becomes very small. Therefore, the loose planet gear 24
receives only shearing force, and is canceled out by heavy friction on the tooth surfaces and bearings, and as a result, the star gear 24 on the right side
Only the rotation of ゛ no longer occurs, and eventually the left and right gear trains are locked and a limited differential is established. Next, the operation of the differential limiting device configured in this manner will be described. First, power from the engine is input to the differential case 5 through the drive pinion 3° ring gear 4, and the left and right fixed gears 21, 21' are rotated together. In addition, the pinion shaft 12
from the left and right sliding gears 20.2 via the pinion gear 13.
It will be in a state where it rotates around 0'. So, for example, when turning left, the right wheel is 10 degrees. The axle 11° and the carrier 23' increase their speed, causing the planetary gear 24' to rotate depending on the gear ratio, causing relative rotation in the sliding gear 20°, causing the pinion gear 13 to rotate in one direction. In addition, the carrier 23 on the left side decelerates, and the planetary gear 24 rotates while revolving due to the gear ratio, but the sliding gear 20
This causes a relative rotation in the opposite direction, and thus the carrier 23 and thereafter are differentially rotated by the same amount in the opposite direction, thereby smoothly turning. When driving straight on a dry road, the left and right fixed gears are 21° and 21°.
Due to the relationship between the planetary gear 24, 24' and the gear ratio, a rotational force in the same direction is generated in the sliding gear 20, 20', and the pinion gear 1
3 to lock it together. Therefore, the differential case 5 is directly connected to the left and right axles 11, 11°, and the left and right wheels are 10°10'.
power is transmitted to. Furthermore, if the wheels are about to spin due to a decrease in ground contact force, for example, the differential will be limited and locked due to the pitch circles of the meshing parts of the planetary gear 24 and the fixed and sliding gears 21 and 20. Power is transmitted to the right wheel that is in contact with the ground at 10 degrees. Note that the present invention is applicable not only to a differential device for opening left and right wheels, but also to a center differential device for a four-wheel drive vehicle.

【Effect of the invention】

As described above, according to the present invention, when turning, the left and right wheels can be rotated by the same amount and differential can be freely applied, and requests for differential from both wheels can be immediately responded to without being subject to restrictions such as friction. ! ! Improves rudder feeling. When driving straight, both wheels are directly coupled to drive the vehicle, improving straight-line performance and preventing one wheel from slipping or spinning.
Power can be reliably transmitted to the grounded wheels, and irregular turning of the vehicle due to one-wheel lock can be avoided. Since it consists of a gear mechanism other than a worm, there is no effect of sliding resistance, etc., resulting in high efficiency, and the structure can be simple and inexpensive. Since it is a combination of part of the bevel gear system and a planetary gear mechanism, it has good differential performance and fewer locking conditions.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the differential limiting device of the present invention, Fig. 2 is a sectional view taken along the line ■-■ of Fig. 1, Fig. 3 is a partially exploded perspective view, and Fig. 4(a). , (b) is a schematic diagram showing the operating state of rotational force. 5... Differential case, 11, 11°... Axle, 12.
...Pinion shaft, 20.20°...Sliding gear, 21.
21'...Fixed gear, 23°23°...Carrier,
24, 24°...Planetary gear patent applicant Fuji Heavy Industries Co., Ltd. agent Patent attorney Makoto Kobashi Ukiyo Patent attorney Susumu Murai 3rd dimension

Claims (2)

[Claims] (1) In a configuration in which a pinion shaft is fixed to a differential case into which power is input, and a pinion gear is rotatably attached to the pinion shaft, a pair of sliding gears that are slidable on the differential case and mesh with the pinion gear, and the differential case It has a pair of fixed gears that are integrally connected to the two output elements, and two sets of planetary gears are rotatably provided on carriers that are integral with the two output elements, and one planetary gear is connected to one sliding gear and the fixed gear, and the other is connected to the sliding gear and the fixed gear. A planetary gear is meshed with the other sliding gear and fixed gear to form a transmission configuration, and the number of teeth and pitch circle of each of the gears are set to allow only differential movement during turning. Motion limiting device. (2) If the number of teeth of the fixed gear and sliding gear is Z_1 and Z_2, and the number of teeth of the planetary gear is P_1 and P_2, the relationship between the number of teeth is Z
_1/P_1≠Z_2/P_2, and the difference in pitch circles between the fixed gear and the sliding gear is small.