JP2620429B2 - Differential device with differential limiting mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential with a differential limiting mechanism using a hydraulic power transmission coupling as a differential limiting mechanism.

[0002]

2. Description of the Related Art As a conventional differential with a differential limiting mechanism, for example, as shown in FIG. 7, there is a differential using a viscous joint as a differential limiting mechanism. In FIG. 7, reference numeral 1 denotes a differential device. The differential device 1 includes a differential case 3 connected to a propeller shaft via a ring gear 2, and a differential case 3.
And pinion gears 5 and 6 rotatably provided on a pinion shaft 4 fixed to the gears, and side gears 9 and 10 meshed with the pinion gears 5 and 6 and fixed to left and right axle shafts 7 and 8.

[0003] Reference numeral 11 denotes a viscous coupling for limiting the differential of the differential device 1. The viscous coupling 11 includes a plurality of outer plates 12 mounted on the inner periphery of the differential case 3 and a plurality of inner plates fixed on the axle shaft 8. 13. In this device, the differential limiting torque is transmitted according to the rotational speed difference between the axle shafts 7 and 8.

[0004]

However, in such a conventional differential with a differential limiting mechanism, since a viscous joint is used, the transmission torque is reduced as shown in FIG. 6A. Due to the torque characteristics that are high from the time of low differential and do not increase so much even if the differential becomes high, there was a problem that a tight corner braking phenomenon occurred, fuel efficiency was poor, and running performance on bad roads was also bad. .

The present invention has been made in view of such conventional problems, and uses a hydraulic power transmission coupling as a differential limiting mechanism to prevent the occurrence of a tight corner braking phenomenon. It is another object of the present invention to provide a differential device with a differential limiting mechanism capable of improving fuel efficiency and running performance.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a housing provided between three shafts rotatable relative to each other and connected to a first shaft, and having a radial inside of the housing. A plurality of shafts arranged and fixed, a plurality of pinion gears rotatably provided on the shaft, and a second or third shaft connected to the shaft, and rotatably housed in the housing; A differential device having a pair of side gears meshing with a pinion gear and transmitting torque to and from the first shaft while allowing differential rotation between the second and third shafts; A cam surface having two or more peaks on a side surface; connected to a second or third shaft and rotatably housed in the housing to face a plurality of plunger chambers to the cam surface. While forming in the axial direction, Rotor and the formation of the side gear to the other end face which does not form a flanger chamber; in each of the plurality of plungers chamber, while being accommodated freely reciprocate by receiving a pressing force of the return spring, first and second
Alternatively, a plunger driven by the cam surface during relative rotation between the first and third shafts; a suction / discharge hole that opens to an outer diameter portion of the rotor and communicates with a bottom of the plunger chamber; A plurality of suction ports, which are rotatably slidably in contact with the outer diameter portion, are positioned so as to be rotatable at a predetermined angle between the housing and the housing, and act as suction valves and discharge valves depending on a positional relationship with the suction and discharge holes. An orifice is provided between a cylindrical valve body having a port formed therein and a discharge port of the valve body and a low-pressure chamber in the housing, and a differential limiting torque according to a rotational speed difference between the second and third shafts. Is transmitted.

[0007]

In the present invention, a hydraulic power transmission joint for limiting the differential is provided between the differential case and one of the side gears. That is, a cam surface is formed on the inner surface of the differential case,
Of the rotor that stores the plunger movably in the axial direction,
Form a side gear on the opposite side without the plunger chamber.

Accordingly, when a differential rotation occurs between the rotor and the differential case, a torque characteristic in which the torque increases in a quadratic curve with respect to the differential rotation can be obtained. Therefore, at the time of low differential, the torque transmission can be reduced to prevent the occurrence of the tight corner braking phenomenon, and the fuel efficiency can be improved during normal running.

In addition, it is possible to enhance the running performance on a rough road where high differentials occur.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 are views showing one embodiment of the present invention.
First, the configuration will be described. In FIG. 1, reference numeral 21 denotes a differential case (housing) connected to a first shaft (for example, a propeller shaft), and a plurality of pinion shafts (shafts) 22 are radially fixed to the differential case 21. Have been.
A plurality of pinion gears 23 are rotatably provided on the pinion shaft 22, and differential rotation is performed by rotation of the pinion gears 23 (see FIG. 2).

Reference numeral 24 denotes a rotor connected to a second shaft (for example, a left axle shaft). The rotor 24 has a side gear 25 meshed with a pinion gear 23. Reference numeral 26 denotes a side gear connected to a third shaft (for example, a right axle shaft), and the side gear 26 meshes with the pinion gear 23. A cam surface 27 having two or more peaks is formed on one inner surface of the differential case 21.

A plurality of plunger chambers 28 are formed in the rotor 24 in the axial direction. A plurality of plungers 29 are slidably accommodated in the plunger chamber 28 via a return spring 30. . Further, a plurality of suction / discharge holes 31 are formed in the rotor 24 so as to open to the outer periphery so as to communicate with each plunger chamber 28 (see FIG. 3).

A rotary valve (valve element) 32 is provided on the outer periphery of the rotor 24, a suction port 33 is formed in the rotary valve 32 so as to open to the outer periphery, and a discharge port 34 is formed on the inner peripheral surface. An orifice 35 as a flow resistance generating means is formed in the discharge port 34 so as to communicate with the low pressure chamber (see FIG. 4). The rotary valve 32 has a notch 3 formed in the differential case 21.
A projection 37 for positioning engaging with 6 is formed at the end.

The rotary valve 32 constitutes a timing member for determining the opening / closing timing of the suction / discharge port 31, and the notch 36 and the projection 37 constitute a positioning mechanism for regulating the phase relationship between the differential case 21 and the rotary valve 32. . When the plunger 29 is in the suction stroke, there is a positional relationship between the suction port 33 of the rotary valve 32 and the suction / discharge hole 31 of the rotor 24, and the plunger passes through the orifice 35, the suction port 33, and the suction / discharge hole 31 of the rotor 24. Oil can be sucked into the chamber 28.

When the plunger 29 is in the discharge stroke, the relationship is opposite to that of the suction stroke, and the suction / discharge hole 31 of the rotor 24 communicates with the discharge port 34 of the rotary valve 32. Reference numeral 38 denotes an accumulator piston that rotates integrally with the rotor 24. The accumulator piston 38 absorbs expansion and contraction of the sealed oil. 39 is the side gear 2
Reference numeral 40 denotes an oil seal, reference numeral 40 denotes an oil seal, and reference numeral 41 denotes a bolt.

Next, the operation will be described. When there is no rotation difference between the left and right wheels, the driving force is transmitted from the pinion gear 23 via the differential case 21 to a pair of left and right side gears 25, 25.
26 is transmitted. When a rotation difference is generated between the left and right wheels, the differential is performed by the rotation of the pinion gear 23. In this embodiment, the differential limiting torque is transmitted by a hydraulic power transmission joint for limiting the differential.

That is, when a rotation difference occurs between the differential case 21 and the rotor 24, the plunger 29 in the discharge stroke is pushed in the axial direction by the cam surface 27 of the differential case 21. At this time, since the suction / discharge port 31 communicates with the discharge port 34, the plunger 29 is in the plunger chamber 2.
8 is pushed out from the suction / discharge hole 31 to the discharge port 34 of the rotary valve 32.

The oil pushed out to the discharge port 34 is
The gas is supplied to the suction port 33 through the orifice 35.
At this time, the oil pressure in the discharge port 34 and the plunger chamber 28 rises due to the resistance of the orifice 35, and a reaction force is generated in the plunger 29. By rotating the differential case 21 against the plunger reaction force, a torque is generated, and the torque is transmitted between the differential case 21 and the rotor 24.

Further, when the differential case 21 rotates, a suction stroke occurs, and the suction / discharge port 31 communicates with the suction port 33. And the plunger 29 is moved to the cam surface 2 of the differential case 21.
Return along 7. FIG. 5 shows the timing of such suction and discharge.

The differential limiting torque T thus obtained is
Is 2 with respect to the differential rotation speed ΔN, as shown in FIG.
It shows a characteristic that increases in a following curve. Therefore, since the torque T is small at the time of low differential, the occurrence of the tight corner braking phenomenon can be prevented, and the fuel efficiency can be improved during normal running.

Further, at the time of high differential, a large torque T can be output, so that the running performance on a rough road can be enhanced.

[0022]

As described above, according to the present invention, since the hydraulic power transmission coupling for limiting the differential is provided between the differential case and one of the side gears, it is possible to reduce the differential rotation to two.
Since the torque increases in a curve following the curve, the occurrence of the tight corner braking phenomenon can be prevented, and the fuel economy and running performance can be improved.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention.

FIG. 2 is a sectional view of a differential gear unit.

FIG. 3 is a sectional view of a rotor and a rotary valve.

FIG. 4 is a perspective view of a rotary valve.

FIG. 5 is an explanatory diagram of suction and discharge timings.

FIG. 6 is a graph showing torque characteristics.

FIG. 7 shows a conventional example.

[Explanation of symbols]

 21: differential case (housing) 22: pinion shaft (shaft) 23: pinion gear 24: rotor 25, 26: side gear 27: cam surface 28: plunger chamber 29: plunger 30: return spring 31: suction / discharge hole 32: rotary Valve (valve element) 33: suction port 34: discharge port 35: orifice 36: notch 37: projection 38: accumulator piston 39: cover lid 40: oil seal 41: bolt

Claims (1)

(57) [Claims] 1. A motor is provided between three shafts which can rotate relative to each other,
A housing connected to the first shaft; a plurality of shafts radially disposed and fixed in the housing; a plurality of pinion gears rotatably provided on the shaft; a second or third shaft And a pair of side gears rotatably housed in the housing and meshing with the pinion gear. The first and second side gears allow differential rotation between the second and third shafts. A differential for transmitting torque therebetween; a cam surface having two or more ridges formed on one inner surface of the housing; connected to a second or third shaft and rotated in the housing. A rotor which is freely stored and has a plurality of plunger chambers formed in the axial direction facing the cam surface, and the side gear formed on the other end face not forming the plunger chamber; Each A plunger that is housed so as to be reciprocally movable under the pressure of a return spring, and is driven by the cam surface during relative rotation between the first and second or first and third shafts; An inlet / outlet port that opens to the outer diameter portion and communicates with the bottom of the plunger chamber; rotatably slidably contacts the outer diameter portion of the rotor; and is positioned so as to be rotatable by a predetermined angle between the housing and the housing. A plurality of suction ports that act as suction and discharge valves depending on the positional relationship with the suction and discharge holes, a cylindrical valve body that forms a discharge port, and a discharge port of the valve body and a low-pressure chamber in the housing. A differential device with a differential limiting mechanism, comprising an orifice, for transmitting a differential limiting torque corresponding to a rotational speed difference between the second and third shafts.