JPH0473433A - Hydraulic type power transmission coupling - Google Patents

Abstract

PURPOSE:To prevent the generation of sealing disorder of a valve body and torque defect and suppress vibration even if an external force is applied on a coupling by separately forming a rotor and an input shaft, joining the rotor and the input shaft so as to be shiftable in the axial direction and axially supporting the input shaft on a cam housing. CONSTITUTION:A rotor 5 and an input shaft 6 are formed separately, and spline-connected so as to be shiftable in the axial direction and permit a certain degree of tilt, and the input shaft 6 is axially supported on a cam housing 4 through a bearing 21, and even if the external force Fg acts in the direction for pressing the rotor 5, all the external force Fg is received by the bearing 21. Accordingly, the external force Fg does not act on the rotor 5, and the relation Fc>Fv is not broken, and the generation of the sealing disorder on a valve surface as in the conventional can be prevented. Further, even in the case when the external force Fg acts in the direction for pulling the rotor 5, also the external force is received by the bearing 21 similarly, and the rotor 5 is prevented from being given with influence.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic power transmission joint used for distributing driving force in a vehicle.

[Prior Art] The present applicant has proposed the following hydraulic power transmission joint in Japanese Patent Application No. 02-40632.

That is, this hydraulic power transmission joint is provided between relatively rotatable input and output shafts, and includes a plunger pump driven by the difference in rotational speed between the two shafts, and a means for generating flow resistance in the discharge path of the pump. A power transmission joint in which transmission torque between the input and output shafts is controlled by the flow resistance, the cam housing being connected to the one shaft and forming a cam surface having two or more ridges on the inner surface; a rotor member connected to the other shaft, rotatably housed in the cam housing, and forming a plurality of plunger chambers, each of the plurality of plunger chambers being pressed by a return spring; a plurality of plungers that are housed in a reciprocating manner and are driven by the cam surface when the two shafts rotate relative to each other; a suction hole and a discharge hole that are formed in the rotor member and communicate with the plunger chamber; It is in rotatable and sliding contact with the rotor member, and is also positioned rotatably by a predetermined angle between it and the cam housing, and is connected to the suction hole and the discharge hole regardless of whether the relative rotation direction of the two shafts is forward or reverse rotation. a valve body forming a plurality of suction ports and discharge ports that function as suction valves and discharge valves depending on the positional relationship between the two; a high pressure chamber formed by communicating each of the discharge ports with a discharge passage through a communication passage; A flow resistance generating means is provided at the suction passage connecting the port and the low pressure chamber in the joint, and at the outlet section from the high pressure chamber to the low pressure chamber.

In this conventional example, the input shaft portion is integrally formed, and the structure is such that when an external force in the axial direction is applied to the input shaft, the external force also acts on the rotor via the shaft portion.

In addition, the structure is such that the bearing is pushed in the axial direction by a spring with a load greater than the spring force of the return spring acting on the rotor, and when the direction of relative rotation is switched, the rotor and the valve body that is in close contact with the end surface of the rotor are By moving the valve body in the axial direction, the valve body is lifted from the thrust receiver, and the cam and valve body are aligned in phase by allowing the valve body to rotate together with the valve body.

In addition, it fits into the valve body and the valve body that are in a state of being fitted with the shaft,
The shaft portion is rotatably supported by the cam housing via a bearing positioned so as to be axially movable and spaced apart from the cam housing.

[Problems to be Solved by the Invention] However, such conventional hydraulic power transmission joints have the following problems.

(1) In general, in axial plunger pumps with a valve body on the thrust surface of the rotor, the hydraulic reaction force in the plunger chamber that acts on the rotor causes the valve body to come into close contact with the rotor, resulting in oil leakage from the valve part. This is because high pressure also acts on the discharge port and seal land that open on the valve surface, which generates a force that pushes the rotor back against the thrust force and prevents the valve from coming into close contact.

If the hydraulic pressure acting on the valve surface is greater than the thrust force of the rotor, the valve portion will not be able to maintain close contact and the valve will lose its sealing function.

In the conventional case, the input shaft is formed integrally with the input shaft, and when an external force is applied to the input shaft in the axial direction, the external force is applied to the rotor via the shaft. When an external force is applied in a direction that pushes the rotor, the thrust force of the rotor is reduced, and there is a risk that the sill function of the valve part will be lost.

(2) Also, when an external force is applied in the direction of pulling the rotor, the thrust force of the rotor increases and becomes larger than the load of the spring set to push the bearing.
Since the valve body remained in contact with the thrust receiver, even if the direction of relative rotation changed, the phase of the valve body and the cam did not change, and there was a risk that torque would not be generated.

If an attempt was made to increase the load on the spring as a countermeasure to this problem, there was a problem in that the spring would become larger and would be difficult to store.

(3) In addition, the shaft can be rotated to the cam housing via a valve body that is fitted to the shaft and a bearing that is fitted to the valve disc and positioned with a clearance so that it can move in the axial direction with respect to the cam housing. Because the housing and shaft were supported by a large amount of play, there was a problem in that eccentricity during rotation generated an unbalanced load and increased vibration.

If an attempt was made to reduce the backlash as a countermeasure to this problem, the machining precision of each part would have to be increased, resulting in an increase in cost.

The present invention has been made in view of these problems, and even if an external force is applied to the joint, there will be no loss of torque due to poor sealing of the valve body or out of phase relationship between the valve body and the cam, and there will be no vibration. It is also aimed at providing a hydraulic power transmission coupling with less power.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a shaft that is provided between relatively rotatable input and output shafts, is connected to the one shaft, and has two or more peaks on the inner surface. a cam housing having a cam surface formed therein; a rotor connected to the other shaft and rotatably housed within the cam housing and having a plurality of plunger chambers formed in the axial direction; and the plurality of plungers. a plurality of plungers that are housed in each of the chambers so as to be reciprocally movable under the pressure of a return spring, and that are driven by the cam surface when the two shafts rotate relative to each other;
a suction and discharge hole formed in the rotor and communicating with the plunger chamber; and a suction and discharge hole that rotatably slides on the end surface of the rotor and is positioned in a predetermined relationship with the cam housing, and is positioned in a predetermined relationship with the suction and discharge hole. a valve body having a plurality of suction ports and a discharge port formed on its surface, which function as suction valves and discharge valves depending on the relationship; and means for generating flow resistance by the flow of discharged oil caused by driving of the plunger; In a hydraulic power transmission joint that transmits torque according to a rotational speed difference between It is pivoted on.

[Function] In the present invention, the rotor and the input shaft are separate bodies, the rotor and the input shaft are movably coupled in the axial direction, and the input shaft is pivotally supported on the cam housing, so that the external force acting on the joint is reduced. It is not transmitted to the rotor.

Therefore, even if an external force is applied to the joint, there is no risk of loss of torque due to poor sealing of the valve portion or out of phase relationship between the valve body and the cam.

Additionally, since there is little play between the input shaft and the cam housing, there is little unbalanced load due to eccentricity during rotation, and there is little vibration.

[Example] Embodiments of the present invention will be described below based on the drawings.

1 to 3 are diagrams showing one embodiment of the present invention.

First, to explain the configuration, in FIGS. 1 and 2, 1 is a cam with a cam surface 2 having two or more ridges on its inner surface, and the cam 1 is connected to an output shaft 3. 3
It rotates as one. Further, the cam 1 is fixed to a cam housing 4, and the cam housing 4 rotates integrally with the cam 1.

A rotor 5 is rotatably housed in the cam housing 4. The rotor 5 is coupled to the input shaft 6 and rotates together with the input shaft 6.

A plurality of plunger chambers 7 are formed in the rotor 5 in the axial direction, and a plurality of plungers 8 are formed in the plunger chamber 7.
is slidably housed via a return spring 9. Further, a plurality of suction and discharge holes 10 are formed in the rotor 5 so as to communicate with each plunger chamber 7.

11 is a rotary valve (valve body) having a suction port 12, a suction passage 13 and a discharge port 14 formed on its surface;
Each discharge port 14 of the rotary valve 11 is formed with an orifice 17 as a flow resistance generating means. Further, each discharge port 14 does not communicate with each other, and
Two or more plunger chambers 7 are not connected to one discharge port 14 at the same time. That is, if the number of cam ridges is N, the number of plunger chambers 7 is configured to be 2N-1 or less. In this embodiment, there are four cam ridges and seven plunger chambers 7.

Further, the interval between the suction port 12 and the discharge port 14 that are connected to each other is formed to be shorter than the diameter of the suction and discharge hole 10 of the rotor 5. Therefore, the entrapment phenomenon can be avoided even without providing an entrapment prevention notch.

Further, the rotary valve 11 has a positioning protrusion 19 that engages with a notch 18 formed on the inner circumference of the cam housing 4.

The rotary valve 11 constitutes a timing member that determines the opening/closing timing of the suction/discharge hole IO, and the notch 18 and the protrusion 19 constitute a positioning mechanism that regulates the phase relationship between the cam 1 and the rotary valve 11.

When the plunger 8 is in the suction stroke, the suction port 12 of the rotary pulp 11 and the suction/discharge hole 10 of the rotor 5 communicate with each other. Oil can be sucked into the jar chamber 7.

Further, when the plunger is in the discharge stroke, the relationship is opposite to the suction stroke, and the suction and discharge hole 10 of the rotor 5 is connected to the orifice 17 via the discharge port 14 of the rotary valve 10.
Leads to.

A thrust block 20 rotates integrally with the cam housing 4, and supports the input shaft 6 via a bearing 21. A needle bearing 22 is interposed between the thrust block 20 and the rotary valve 11, and the friction torque on the needle bearing 22 side is transmitted to the rotor 5.
It is set to be smaller than the friction torque between the rotary valve 11 and the rotary valve 11. Therefore, when the direction of differential rotation changes, the rotary valve 11 rotates together with the rotor 5, rotates until the positioning protrusion 19 of the rotary valve 11 hits the notch 18 of the cam housing 4, and then becomes integral with the cam housing 4. Rotate with. Thereby, the suction and discharge holes 10 are forcibly opened and closed at a predetermined timing even during forward rotation or reverse rotation. Note that 16 is a rolling wheel for a needle bearing.

23 is an accumulator piston that rotates integrally with the cam housing 4, and the accumulator piston 23 moves according to internal pressure. A return spring 25 is interposed between the accumulator piston 23 and the retainer 24.

In addition, 26 is an oil seal, 27 is a stop ring, 2
8 is a bolt, 29 is an oil hole, 30 is a bearing, 31 is a stop ring, and 32 is a removal prevention plate.

Here, the rotor 5 and the input shaft 6 are each constructed separately, and the rotor 5 and the input shaft 6 are spline-coupled.

That is, the output shaft 5 and the input shaft 6 are movable in the axial direction.
In addition, they are connected to allow some degree of inclination.

Further, the input shaft 6 is pivotally supported by the thrust block 20 and the cam housing 4 via a bearing 21.

Next, the effect will be explained.

When there is no difference in rotation between the cam 1 and the rotor 5, the plunger 8 does not operate and no torque is transmitted. Note that at this time, the plunger 8 is pressed against the cam surface 2 by the return spring 9.

Next, when a rotation difference occurs between the cam 1 and the rotor 5, the plunger 8, which is in the discharge stroke, is pushed in the axial direction by the cam surface 2 of the cam 1.

Therefore, the plunger 8 pushes the oil in the plunger chamber 7 from the suction and discharge hole 10 to the discharge port 14 of the rotary valve 11 .

The oil pushed out to the discharge port 14 flows through the orifice 17
It is supplied to the suction passage 13 through. At this time, the oil pressure in the discharge port 14 and the plunger chamber 7 increases due to the resistance of the orifice 17, and a reaction force is generated in the plunger 8. Torque is generated by rotating the cam 1 against this plunger reaction force, and the torque is transmitted between the cam 1 and the rotor 5.

Furthermore, when the cam 1 rotates, the suction stroke occurs, and the suction and discharge holes 10 communicate with the suction ports 12, so the oil in the suction passage 13 is sucked into the plunger chamber 7 through the suction ports 12 and the suction and discharge holes 10. The plunger 8 returns along the cam surface 2 of the cam 1.

Here, the effect when an external force is applied to the input shaft 6 will be explained in comparison with a conventional example.

FIG. 4 is an explanatory diagram of a conventional example when an external force is applied to the input shaft during torque transmission.

In FIG. 4, Fg is an external force applied to the input shaft 51,
Fv is the pressure (
F V = P X S V + y P X S S
), Fc is the pressure acting on the rotor 53 (Fc=PXSp
), Fr represents Fc-Fg, respectively. (However, P
is the discharge pressure, Sp is the total area of the plunger chamber 54 of the rotor 53, Sv is the total area of the discharge ports of the rotary valve 52, and Ss is the total area of the seal land portion of the rotary valve 52. ) When external force Fg acts in the direction of pushing the rotor 53, F r = F c - F g < F v, and the rotor 5
The thrust force of 3 is reduced, a seal failure occurs at the location indicated by A, and the sealing function of the valve part is lost.

In addition, as shown in Fig. 5, when switching between forward and reverse rotations, the rotor 5
When external force Fg acts in the direction of pulling 3, the rotor 53
The thrust load Fr, which is the sum of the loads Fa of each return spring 58 acting on ΣFa and the external force Fg, is the load Fb of the spring 56 set to push the bearing 55.
The rotary valve 5 becomes larger than the rotary valve 5, as shown by B.
2, the thrust receiver remains in contact with the part 57,
Even if the direction of relative rotation changes, the phases of the rotary valve 52 and the cam do not change, and no torque is generated.

Here, as shown in Fig. 6, when switching between forward and reverse directions, external force F
When g does not act, Fb>Fr, and a gap occurs as shown in C, and the rotary valve 52 and rotor 53
Since the friction of the bearing 55 becomes larger than the friction of the bearing 55, the rotary valve 52 rotates in the differential rotation direction of the rotor 53, thereby achieving a normal phase.

On the other hand, as shown in FIG. 3, in this embodiment, the rotor 5 and the input shaft 6 are separate bodies, are movable in the axial direction, and are spline-coupled to allow a certain degree of inclination. In addition, since the input shaft 6 is supported by the cam housing 4 via the bearing 21, an external force Fg is applied in the direction of pushing the rotor 5.
Even if the external force Fg is applied, all the external force Fg is received by the bearing 21. Therefore, since the external force Fg does not act on the rotor 5, the relationship Fc>Fv is not disrupted, and it is possible to prevent the occurrence of a seal failure on the valve surface as in the conventional case.

Furthermore, even if an external force Fg acts in a direction that pulls the rotor 5, all of it is similarly received by the bearing 21 and does not act on the rotor 5.

[Effects of the Invention] As described above, according to the present invention, the rotor and the input shaft are made separate, the rotor and the input shaft are coupled to be movable in the axial direction, and the input shaft is pivotally supported on the cam housing. Therefore, the external force acting on the joint is not transmitted to the rotor.

Therefore, even if an external force is applied to the joint, there is no risk of torque loss due to poor sealing of the valve portion or out of phase relationship between the valve body and the cam.

Additionally, since there is little play between the input shaft and the cam housing, there is little unbalanced load due to eccentricity during rotation, and there is little vibration.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
3 is an explanatory diagram of the action, and FIGS. 4 to 6 are explanatory diagrams of each conventional action. In the figure, 1: cam, 2: cam surface, 3: output shaft, 4: cam housing, 5: rotor, 6: input shaft, 7: plunger chamber, 8: plunger 9: return spring, 10: suction/discharge Hole, 11; Rotary valve, 12; Suction port, 13; Suction path, 14; Discharge port, 16; Rolling wheel for needle bearing, 17; Orifice, 18; Notch, 19; Projection, 20; Thrust block, 21; Bearing, 22; Needle bearing, 23; Accumulator piston, 24; Retainer, 25; Return spring, 26; Oil seal, 27; Stop ring, 28; Bolt, 29; Oil hole, 30; Bearing, 31; Stop ring, 32 ; Removal stop plate. Patent applicant: Fuji Iron Works Co., Ltd.

Claims (1)

[Scope of Claims] A cam housing provided between relatively rotatable input and output shafts, connected to the one shaft, and forming a cam surface having two or more ridges on the inner surface; a rotor that is connected and rotatably housed in the cam housing and has a plurality of plunger chambers formed in the axial direction; a plurality of plungers housed in the rotor and driven by the cam surface when the two shafts rotate relative to each other; a suction discharge hole formed in the rotor and communicating with the plunger chamber; and a rotatable plunger in an end surface of the rotor. a valve having a plurality of suction ports and discharge ports formed on its surface, which is in sliding contact with the cam housing, is positioned in a predetermined relationship with the cam housing, and functions as a suction valve and a discharge valve depending on the positional relationship with the suction and discharge hole; A hydraulic power transmission joint that includes a body and a means for generating flow resistance by the flow of discharged oil by driving of the plunger, and transmits torque according to a rotational speed difference between the two shafts, the rotor and the input shaft. A hydraulic power transmission joint characterized in that the rotor and the input shaft are connected to each other so as to be movable in the axial direction, and the input shaft is pivotally supported by the cam housing.