JP2600591Y2 - Transmission mechanism for driving engine accessories - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission mechanism for driving an auxiliary machine for transmitting the driving force of an engine to an auxiliary machine such as an oil pump or a water pump.

[0002]

2. Description of the Related Art In engines for automobiles, motorcycles, boats, various industrial machines, etc., in addition to extracting output for driving original equipment such as vehicles and machines, auxiliary engines such as oil pumps and water pumps are used. It has been practiced to use a part of the engine output to drive equipment (auxiliary equipment). The transmission mechanism for driving such an accessory is for transmitting a rotational force from a crankshaft or a drive shaft rotationally driven by the crankshaft to an input shaft (an accessory shaft) of the accessory. Conventional transmission mechanisms of this type include:
A mechanism is used in which a rectangular projection formed at the tip of the drive shaft is engaged with a slit formed at the tip of the accessory shaft so as to transmit a rotational force. A document showing such a conventional example is, for example, Japanese Utility Model Publication No. 3-4746.

[0003]

However, in the above-described conventional accessory drive transmission mechanism, the tip of the accessory shaft is simply engaged with the end of the drive shaft so as to transmit the rotational force. When the overhang amount of the shaft increases, it becomes difficult to maintain the concentricity of the drive shaft and the accessory shaft with high accuracy, Shake tends to occur, and it is necessary to increase the shaft diameter in order to prevent the shake.

The present invention has been made in view of such technical problems, and an object of the present invention is to improve the accuracy of concentricity between a drive shaft and an auxiliary shaft at the time of assembling with a simple configuration, and to improve rotation. It is an object of the present invention to provide an auxiliary device driving transmission mechanism for an engine that can more smoothly and quietly drive auxiliary devices such as a pump by simultaneously preventing the movement of the shaft during power transmission.

[0005]

A transmission mechanism for driving an auxiliary machine of an engine according to the present invention supports a drive shaft, which is rotationally driven by a crankshaft, in a crankcase, and is rotatable about the same axis as the drive shaft. An auxiliary machine having an auxiliary machine shaft is fixed to a crankcase, and a slot formed of a vertical groove opened at an end surface is formed at a front end of the auxiliary machine shaft, and the auxiliary machine shaft is formed at a front end of the drive shaft. A center hole is formed for fitting and supporting the leading end formed with the slit, and a pin for locking the slit in a hole formed in a diameter direction in the center hole of the drive shaft is provided. The drive shaft is fitted without protruding from the outer peripheral surface, a circumferential groove is formed at the position of the diametric hole of the drive shaft, and the circumferential groove is used to prevent the pin from coming off. The circlip is attached, By providing a configuration in which the outer periphery of the distal end portion including the portion where the diametrical hole of the dynamic shaft is formed is rotatably supported by a bearing hole formed in the crankcase as a journal portion having a circular cross section, The purpose is achieved.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of a transmission mechanism for driving an auxiliary machine of an engine to which the present invention is applied. In FIG. 1, a crankshaft 2 is rotatably supported inside a crankcase 1 of an engine. The illustrated engine shows a case of a two-cylinder engine, in which crank pins 4 are fixed at two locations in the axial direction of the crankshaft 2 via crank webs 3 and 3, respectively. Connecting rods (not shown) are connected to each of the crank pins 4, and the other ends of these connecting rods are connected to pistons (not shown) in the corresponding cylinders (cylinders).

[0007] The crankshaft 2 has two side walls 5, 6 of the crankcase 1 and two central walls 7A, 7A.
B is supported by bearings provided at a total of four locations. The illustrated crankshaft 2 is provided with an output gear 8 for extracting engine output, a cam gear 9 for driving a cam for operating intake and exhaust valves, and the like.

A drive shaft 11 that is driven to rotate by a crankshaft 2 is mounted in the crankcase 1. The drive shaft 11 is rotatably supported at two places, that is, the side wall 5 of the crankcase 1 and one center wall 7B. The auxiliary drive gear 1 is provided on the crankshaft 2.
2 are integrally formed, a drive shaft gear 13 is formed on the drive shaft 11, and these gears 12 and 13 are always meshed. Note that the drive shaft 11 of the present embodiment is
Is also a balancer of the crankshaft 2 and is constituted by a rotating member having a member eccentric mass (weight) 14 which opposes the moment of inertia of the crankshaft 2.

At a predetermined position of the crankcase 1, an auxiliary device 15 such as an oil pump or a water pump, which is driven in synchronization with the rotation of the crankshaft 2, is mounted. The auxiliary machine 15 is provided with an input shaft (auxiliary machine shaft) 16. The auxiliary shaft 16 is connected to the drive shaft 11.
Are connected to each other so as to be able to transmit a rotational force at the same axis, and are assembled so as to drive the auxiliary device 15 by the rotational force of the drive shaft 11. In this embodiment, the auxiliary device 15
Is positioned and fixed to the side surface 6 of the crankcase 1, and an input shaft (auxiliary shaft) 16 of the auxiliary machine 15 extends through the side surface 6 into the crankcase 1.

FIG. 2 is an exploded perspective view of a connecting portion between the drive shaft 11 and the accessory shaft 16 before assembling, and FIG. 3 shows an assembled state of a connecting portion between the drive shaft 11 and the accessory shaft 16. It is a longitudinal cross-sectional view. In FIG. 1 to FIG. 3, a slot 17 formed of a vertical groove having a constant width and opened at an end face is formed at a tip end portion 26 of the auxiliary shaft 16, and a center hole ( A concentric hole 18 is formed, and the accessory shaft 16 having the slit 17 is provided.
Is inserted through the center hole 18.
That is, the overhanging tip portion 26 of the accessory shaft 16 is supported not by the free end but by the center hole 18 of the drive shaft 11.

In FIG. 1 to FIG. 3, a pin 19 is fixed to the center hole 18 of the drive shaft 11 so as to be engaged with a slot 17 of the accessory shaft 16 fitted thereto. In the illustrated example, the pin 19 is fitted into a diametric hole 20 formed in the drive shaft 11 without protruding from the outer peripheral surface of the drive shaft 11. Is formed with a circumferential groove 21, and a circlip 22 for retaining the pin 19 is mounted in the circumferential groove 21. When the pin 19 is fixed to the diametric hole 20 by press fitting or the like, the circumferential groove 21 and the circlip 22 may be omitted.

The outer periphery of the tip of the drive shaft 11 (including the portion where the diametric hole 20 is formed) is a journal 23 having a circular cross section. And the drive shaft 11
The journal part 2 is, as shown in FIGS.
In a portion 3, the crankcase 1 is rotatably supported by a bearing hole 24 formed in one central wall 7 </ b> B of the crankcase 1. That is, the drive shaft 11 is rotatably supported at two positions, the side surface portion 5 and the center wall portion 7B of the crankcase 1.

According to the embodiment described above, the drive shaft 11 rotatably driven by the crankshaft 2 is rotatably supported in the crankcase 1 and has the auxiliary shaft 16 rotatable about the same axis as the drive shaft. Auxiliary machine 15 to crankcase 1
The auxiliary shaft 16 is formed with a slit 17 formed of a vertical groove open to the end face at the distal end portion 26 of the auxiliary shaft 16, and the slit 17 of the auxiliary shaft is formed at the distal end portion of the drive shaft 11. A pin 19 is formed to form a center hole 18 that fits and supports the distal end portion 26 through which it is inserted, and a pin 19 that engages with the slot in a hole 20 formed in the center hole 18 of the drive shaft 11 in a diametrical direction. The diametrical hole 2 of the drive shaft is fitted without protruding from the outer peripheral surface of the drive shaft.
0, a circumferential groove 21 is formed, a circlip 22 for retaining the pin 19 is mounted in the circumferential groove 21, and the diametric hole 20 of the drive shaft 11 is formed. The outer periphery of the distal end portion including the portion where is formed is rotatably supported by a bearing hole 24 formed in the crankcase as a journal portion 23 having a circular cross section. By simultaneously improving the accuracy of the concentricity between the drive shaft 11 and the auxiliary shaft 16 and preventing the shaft from shifting when transmitting the rotational force, the auxiliary device 15 such as a pump can be driven more smoothly and quietly. A transmission mechanism for driving an auxiliary machine of an engine is provided.

In the above embodiment, the auxiliary shaft 16
Although the case where the balancer itself driven by the crankshaft 2 is used as the drive shaft 11 is shown as the drive shaft, any shaft member that can rotationally drive the accessory shaft 16 may be used as the drive shaft. Arbitrary members such as various shaft members driven to rotate by a shaft can be used. As the auxiliary device 15, any device (auxiliary device) such as an oil pump, a water pump, a generator (generator) and the like, which is a relatively light-load device driven by an engine (auxiliary device), is selected. can do.

[0015]

As is apparent from the above description, according to the transmission mechanism for driving an accessory of an engine of the present invention, a drive shaft that is rotationally driven by a crankshaft is supported in a crankcase, and the drive shaft is connected to the drive shaft. An auxiliary machine having an auxiliary machine shaft rotatable about the same axis is fixed to a crankcase, and a slit formed of a vertical groove opened at an end face is formed at a front end of the auxiliary machine shaft, and a front end of the drive shaft is formed. A center hole for fitting and supporting the leading end of the accessory shaft where the slot is formed, and forming the center hole in a diametrically formed portion of the center hole of the drive shaft. The drive shaft is fitted with a pin that does not project from the outer peripheral surface of the drive shaft, a circumferential groove is formed at the position of the diametric hole of the drive shaft, and the circumferential groove is formed in the circumferential groove. A support for retaining the pin A configuration in which a clip is mounted, and the outer periphery of a tip portion including a portion in which the diametrical hole of the drive shaft is formed is rotatably supported by a bearing hole formed in the crankcase as a journal having a circular cross section. With a simple configuration, the drive of auxiliary equipment such as pumps can be achieved by simultaneously improving the accuracy of the concentricity of the drive shaft and auxiliary equipment shaft during assembly and preventing shaft runout during transmission of rotational force. Provided is a transmission mechanism for driving an auxiliary machine of an engine, which can be performed more smoothly and quietly.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a transmission mechanism for driving an accessory of an engine to which the present invention is applied.

FIG. 2 is an exploded perspective view of a connection portion between a drive shaft and an accessory shaft in FIG. 1 before assembling.

FIG. 3 is a longitudinal sectional view showing an assembled state of a connecting portion between a drive shaft and an accessory shaft in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crankcase 2 Crankshaft 5 Side part (crankcase) 6 Side part (crankcase) 7B Central wall part (crankcase) 8 Output gear 11 Drive shaft 12 Auxiliary drive gear 13 Drive shaft gear 14 Eccentric mass part 15 Supplement Machine 16 Auxiliary shaft 17 Slot 18 Central hole 19 Pin 20 Diameter hole 21 Circular groove 22 Circlip 23 Journal part (drive shaft) 24 Bearing hole (Central wall part) 26 Tip (Auxiliary shaft)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16D 1/02 F02M 37/06 F02M 39/02

Claims (1)

(57) [Scope of request for utility model registration] A drive shaft rotatably driven by a crankshaft is supported in a crankcase, and an auxiliary machine having an auxiliary machine shaft rotatable about the same axis as the drive shaft is fixed to the crankcase. A slot formed of a vertical groove opened at the end face is formed at the tip of the machine shaft, and the tip of the accessory shaft, at which the slot is formed, is inserted and supported at the tip of the drive shaft. A pin formed in a center hole of the drive shaft and diametrically formed in the center hole portion of the drive shaft, the pin being engaged with the slit without being projected from an outer peripheral surface of the drive shaft; A circumferential groove is formed at the position of the diametric hole of the shaft, and a circlip for retaining the pin is mounted in the circumferential groove, and the diametric hole of the drive shaft is provided. Tip including the portion with Journal section with circular cross section
Accessory drive power transmission mechanism of an engine, characterized in that the pivotally supported more <br/> rotate in the bearing hole formed in the crankcase as.