JPH0510752U - Engine idler gear support device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an idler gear support device for an engine, which can suppress the swing of the idler gear during rotation and reduce vibration and noise. [Structure] Outer wall 32 of crankcase 31 of engine
An idler shaft supporting member is formed by projecting an idler shaft 34 to the idler shaft 34, and an idler gear 38 made of a helical gear is rotatably fitted to the idler shaft 34. This is because the pressure receiving surface 40 is provided on the outer peripheral side of the idler gear 38, and the crankcase 31 facing the pressure receiving surface 40 is provided with the outer peripheral thrust plate 41.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a diesel engine idler support device.

[0002]

[Prior Art]

 Gear drive, chain drive, and belt drive are used to drive the engine valve mechanism, but gear drive is used in diesel engines because the distance between the crankshaft and camshaft is short.

FIG. 3 shows a diesel engine, and 1 is a crankcase. An outer wall 2 of the crankcase 1 has an end portion of a crankshaft 3 projecting therefrom, and a crankshaft gear 4 is provided at this end portion. An idler shaft 5 protruding from the outer wall 2 is provided above the crankshaft gear 4, and an idler gear 6 is provided on the idler shaft 5.

The idler gear 6 meshes with the injection pump gear 7 and the camshaft gear 8, and the rotation of the crankshaft 3 is transmitted to the injection pump gear 7 and the camshaft gear 8 via the idler gear 6. The injection pump gear 7 meshes with the power steering pump gear 9, and the camshaft gear 8 meshes with the oil pump gear 10.

By the way, conventionally, the idler gear 6 is supported by a one-sided support system as shown in FIG. That is, a mounting flange 11 is integrally provided on the idler shaft 5, and the mounting flange 11 is fitted in the recess 12 of the crankcase 1.

The shaft portion of the idler shaft 5 is fitted to the shaft portion of the idler shaft 5 via a bush 13, and a through hole 14 is provided in the shaft center portion. A thrust plate 15 is joined to the shaft end surface of the idler shaft 6, and the thrust plate 15 is fixed together with the idler shaft 5 by a fixing bolt 16 which penetrates the through hole 14 and is screwed into the crankcase 1. ..

[0007]

[Problems to be solved by the device]

 However, the idler gear 6 is generally a helical gear. Therefore, the runout of the idler gear 6 with respect to the idler shaft 5 is large, one-side wear occurs on the sliding surface between the idler shaft 5 and the idler gear 6, and the large vibration causes noise.

On the other hand, as one of the measures for the injection system complying with the exhaust gas regulations, the high oil transfer rate of the injection pump is being promoted. Conventionally, a helical gear having a large meshing ratio has been adopted as a measure for noise, but as described above, the transmission force of the gear becomes large in order to drive a pump having a high oil transfer rate. As a result, the component of the transmission force of the helical gear in the axial direction becomes large, the surface deflection (tilt) of the gear becomes large, and vibration and stress increase.

Therefore, it is possible to reduce the swing of the idler gear 6 by reducing the end plays a and b, but there is a technical limit to reducing the end plays a and b, and there is a problem in management. is there.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an idler support device for an engine, which has a simple structure but can prevent idler shake and reduce vibration and noise. Is to provide.

[0011]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, this invention positions the shaft portion of an idler gear consisting of a helical gear in the thrust direction by a crankcase and an inner peripheral thrust plate, and provides a pressure receiving surface on the outer peripheral side portion of the idler gear. The outer peripheral thrust plate is provided on the crankcase facing the pressure receiving surface.

[0012]

[Action]

 Even if the idler gear sways, the pressure receiving surface provided on the outer peripheral side near the teeth of the idler gear contacts the outer peripheral side thrust plate, and the surface deflection force and the deflection range can be reduced.

[0013]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the outer wall 32 of the crankcase 31 is provided with a disc-shaped recess 33, and one end of an idler shaft 34 is fitted into the recess 33. There is. A through hole 35 is provided in the axial center of the idler shaft 34, and an inner peripheral thrust plate 36 is joined to the other end of the idler shaft 34.

The inner peripheral thrust plate 36 is fixed to the outer side wall 32 of the crankcase 31 together with the idler shaft 34 by a fixing bolt 37 inserted into the through hole 35.

Further, an idler gear 38 made of a helical gear is rotatably fitted to the idler shaft 34 via a bush 39. Therefore, the shaft portion 38 a of the idler gear 38 is in a state of being sandwiched between the crankcase 31 and the inner peripheral thrust plate 36.

On the outer peripheral side of the idler gear 38 close to the tooth portion 38 b, on the side facing the outer wall 32 of the crankcase 31, there is provided a pressure receiving surface 40 formed in an annular protrusion along the outer periphery of the idler gear 38. ing.

An outer peripheral thrust plate 41 is provided on the outer wall 32 of the crankcase 31 facing the pressure receiving surface 40. The outer peripheral thrust plate 41 has an annular shape, and split pins 42 whose both ends engage with the crankcase 31 and the outer peripheral thrust plate 41 are inserted and positioned at several positions in the circumferential direction.

Further, the outer peripheral thrust plate 41 is fixed to the crankcase 31 by a plurality of mounting screws 43 .... A slight gap is formed between the outer peripheral thrust plate 41 and the pressure receiving surface 40.

In the idler gear 38 thus fitted to the idler shaft 34, the shaft portion 38 a is supported by the inner peripheral thrust plate 36, and the outer peripheral portion is supported by the outer peripheral thrust plate 41. Then, the surface wobbling force and wobbling width of the idler gear 38 during rotation are suppressed to reduce vibration noise.

In the idler gear support device thus configured, the idler gear 38 is meshed with the crankshaft gear and the camshaft gear, and the rotation of the crankshaft gear can be transmitted to the camshaft gear and the like. The idler gear 38 has its shaft portion 38a supported by the inner peripheral thrust plate 36, and its outer peripheral portion supported by the outer peripheral thrust plate 41.

[0022]

[Effect of the device]

 As described above, according to the present invention, the shaft side of the idler gear is positioned in the thrust direction by the crankcase and the inner peripheral thrust plate, and the pressure receiving surface is provided on the outer peripheral side of the idler gear. Since the outer peripheral thrust plates are provided on the crankcase so as to face each other, both thrust plates can suppress the vibration of the idler gear during rotation, and have the effect of reducing vibration and noise.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of an idler gear support device showing an embodiment of the present invention.

FIG. 2 is a front view of an outer peripheral thrust plate of the embodiment.

FIG. 3 is a front view of a conventional diesel engine.

FIG. 4 is a vertical sectional side view of a conventional idler gear support device.

[Explanation of symbols]

31 ... Crankcase, 34 ... Idler shaft, 36
… Inner peripheral thrust plate, 38… Idler gya, 40
... Pressure receiving surface, 41 ... Outer peripheral side thrust plate.

Claims (1)

[Claims for utility model registration] [claim 1] An idler gear support device for an engine, wherein an idler shaft is projectingly provided on an outer wall of an engine crankcase, and an idler gear made of a helical gear is rotatably fitted to the idler shaft. The shaft portion of the idler gear is positioned in the thrust direction by the crankcase and the inner peripheral thrust plate, and a pressure receiving surface is provided on the outer peripheral side portion of the idler gear, and the outer peripheral thrust is provided on the crankcase facing the pressure receiving surface. An idler gear support device for an engine, which is provided with a plate.