GB2082682A

GB2082682A - An internal combustion engine having a vibration damping balancer arrangement

Info

Publication number: GB2082682A
Application number: GB8041553A
Authority: GB
Original assignee: Nissan Motor Iberica SA
Current assignee: Nissan Motor Iberica SA
Priority date: 1980-08-01
Filing date: 1980-12-31
Publication date: 1982-03-10
Also published as: ES493939A0; ES8105455A1; JPS5733249A

Abstract

A balancer arrangement for damping vibrations, comprises a pair of balancer shafts (1 and 2) which a driven by the engine crankshaft (5) through a gear train (3) positioned a the front or rear of the engine. <IMAGE>

Description

SPECIFICATION An internal combustion engine having a vibration damping balancer arrangement The present invention, as stated in this specification, consists in a system of operation for a balancing unit in internal-combustion engines.

The forces originating inside an internal combustion engine, direct consequence of the explosions of the fuel inside each one of the cylinders of the engine, systematically produce a series of vibrations that are transmitted to the chassis supporting said engine, causing stresses on the mechanical parts of the vehicle where it is installed, as well as conditions of instability.

In order to eliminate said forces, various systems have been created which in most cases begin by installing the engines by means of rubber bearings usually known as "silent block".

However, in spite of this technique, it has been necessary to provide the engines with other antivibration elements, the most efficient of which consist in incorporating inside the engine itself some balancing axes that originate opposing forces resulting from those produced inside the engine as a consequence of its operation, so that the vibration forces are neutralized.

The object of the present invention is to offer an operating system for an engine balancing-unit, in four-cylinder engines, by means of devices that make operate said balancing-unit in a novel way.

The solution provided by the present invention is based on the placement of an additional gear train to be mechanically associated to the engine crankshaft, which will constitute the operating means for two balancing axes, strategically placed in the opportune places, said gear train acting, besides, as operating means for other traditional elements of the engine, such as the fuel injection pump and the engine camshaft itself. These gear wheels can be straight- or helicoidal-toothed, and their thread will be such as to permit the operation of the balancing trains with the corresponding gear thereof in the crankshaft pinion.

Thanks to this system of gears, as stated above, the balancing axes will be operated, thus eliminating the vertical secondary forces or forces of inertia, as well as neutralizing, in the point of the design, the transverse overturning torques produced in the explosion phase of the engine.

Due to the different locations in vital elements of the four-stroke-cycle engines existing at present, the invention provides different way of operating, all of which are based on the abovementioned principles; that is to say, on the placement of a gear train. Said ways of operating only differ from one another in the location of this gear train with respect to the conventional elements of the engine such as the fuel injection pump and the camshaft.

According to all that was said above, the gear train can be located, inside the engine, according to the following variants: a) In the front part of the motor block; said gear train receiving motion from the crankshaft and transmitting it to one of the balancing axes, as well as to the fuel injection pump and the camshaft, which, according to this case will set in operation the second balancing train.

b) This case is particularly identical to the one above, except in that the gear train is located in the rear part of the motor block, which location is especially interesting to those engines that do not permit the arrangment as in case a). That is, the crankshaft will operate the gear train, which will then move one of the balancing axes, the injection pump and the camshaft, the latter setting in operation the second balancing axes.

c) According to this variant, the gear train is placed in the front part of the motor block, receiving the motion of the crankshaft and directly setting in motion one of the balancing axes and the camshaft of the engine. Similarity, the gear train sets in operation another gear which transmits the movement to the injection pump of the engine and the second balancing axis.

d) This variant is similar to c) above, except in that the whole operating system is located in the rear part of the motor block, the system of setting in operation the balancing axes being the same.

In order to give complementary details to the description below, as well as to ensure a better comprehension.of the characteristics of the invention, a set of drawings is attached to the present specification, to be considered corporate part of it, and in which the following is represented as illustration and in no way to be considered restrictive.

Figure 1 corresponds to a schematic diagram, in a front view of an engine provided with the operating system object of the invention according to variant a) above.

Figure 2 corresponds to a side view, partiaily sectioned, of a motor block provided with the operating system according to variant a), and where one of the balancing axes can be observed.

Figure 3 corresponds to a schematic upside view of an engine provided with the operating system of the invention, according to the version of variant b).

Figure 4 is a side view, partially in section, of an engine provided with the operating system given as solution in Figure 3, and where one of the balancing axes applied can be observed.

Figure 5 corresponds to a schematic upside view of a motor block provided with the variant in c) above.

Figure 6 corresponds to a schematic upside view of a motor block provided with an operating system built as in d) above.

In view of the above-mentioned figures, as can be observed, the system of operation of balancing unit in internal combustion engines, built according to the invention, consists in providing the engine with two balancing axes, references 1 and 2, that are operated directiy or indirectly by a gear train 3 that comprises one or various operating pinions, according to the variant selected, in function of the mechanical coupling of said gear train 2 with the different elements of an engine 4 of internal combustion.

In effect, Variant a) consists in placing in the engine 4 a gear train 3 that is operated mechanically from the engine crankshaft itself 5, said gear train being either straight- or helicoidal-toothed, and mounted in the front part of the engine 4. Due to the mechanical operation of the crankshaft 5, the gear train 3, in this variant a) directly moves the balancing train 1, the injection pump 6 and the camshaft 7, the latter (camshaft (7) moving the second balancing axis 2.

Variant b) adopts a configuration similar to that in variant a), except in that all these elements are placed in the rear part 8 of the engine 4, to be considered practically a mirror version of the one described above under variant a).

Variant c) presents a gear train conformed with the performance of two new axes comprising gears 9 and 10. Gear 9 receives the movement of the crankshaft 1 directly and transmits it to the balancing axis 2 and the camshaft 7. Moreover, gear 9 is used to set in operation gear 10, mounted with it in cascade, which constitutes the motive element for the fuel injection pump 6 and for the remaining balancing axis 1, which, as can be observed in comparison with the scheme of Figure 1 of the attached set of drawings, it adopts a lower location, the whole embodiment being mounted in the front part of the engine 4.

Finally, variant d), as schematically shown in Figure 6, corresponds to the same system of operation as in case of variant c), but all of it placed in the rear part 8 of the engine.

So, therefore, by means of any of the above variants, a system of operation for balancing axes is obtained, which by means of the application of a gear train, straight- or helicoidal-toothed, in the front or in the rear part of a four-cylinder engine preferably. Said gear train transmits the motion received from the crankshaft to a pair of balancing axes, thus achieving a perfect balancing of the vertical secondary forces, and the transverse overturning torques are neutralized, in the point of the design, said torques resulting from the combustion and the forces of inertia.

Claims

1. System of operation for balancing unit in internal combustion engines, specially applicable to engines provided with four cylinders, essentially characterized in that it consists of a gear train, straight- or helicoidal-toothed, mechanically associated to the engine crankshaft as well as to a pair of axes for balancing, in order to balance the vertical secondary forces, and to neutralize the transverse overturning torques originated by the combustion and the forces of inertia; said gear train to be placed in front part of the engine.

2. System of operation for balancing unit in internal combustion engines, according to claim 1 above, characterized in that the gear train is placed in the rear part of the engine.

3. System of operation for balancing unit in internal combustion engines, according to claims 1 and 2 above, characterized in that it comprises an idle gear inserted between the crankshaft and the gear train.

4. System of operation for balancing unit in internal combustion engines, according to claims 1 and 2 above, characterized in that it comprises two idle gears, one of which is associated to the crankshaft, to one of the balancing axes, and the remaining idle gear, which in its turn activates the second balancing axis.