RU2436002C2 - Hydraulic-mechanical device for chain tension - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: hydraulic mechanical device for chain tension consists of case (1) in form of hollow cylinder, of movable cover with circular groove (3) and ball back valve (6), also, cover forms plunger pair with case, of plunger (7) with stop elements creating step mechanism for arrest of backward stroke. Oil feeding channel (5) is made in cover (2) whereon there is additionally made a groove connected with oil supplying channel (5). Throttle orifice (14) is made on cover (2) and is overlapped with case (1).

EFFECT: increased reliability of design, reduced labour input of manufacture due to absence of additional circular grooves on cover.

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Description

The invention relates to mechanical engineering, and in particular to devices for chain tension, and can find application in the camshaft drive of internal combustion engines.

For good engine performance throughout the run, it is desirable to maintain the chain tension as stable as possible. As a result of design searches, the necessary device was created - a chain tensioner.

A device for tensioning chains of machines and mechanisms having a hydraulic drive, protected by RF patent No. 2067232, class. F16H 7/08, publ. 1996.09.27.

The hydraulic tensioner includes a housing with an opening having a groove on the inner surface and a groove located in the housing opening and comprising a plunger pair with a plunger with two grooves on the outer surface, the thrust end of which is designed to interact with the chain. The mounting ring is located, in the inoperative state of the hydraulic tensioner, in the groove of the housing, and in the operating state of the hydraulic tensioner - in the first groove of the plunger. The thrust ring comprises a stepped step mechanism with body bores and a second plunger groove. The body is made in the form of a tube with a thread located at the end opposite the thrust end of the plunger. The hydraulic tensioner has a threaded cover in contact with the end of the threaded end of the housing for interaction with the thread of the housing. A hole is made in the lid, overlapped by a ball check valve, and a groove at the end for supplying oil through the lid opening into the cavity of the hydraulic tensioner. The end face of the housing in contact with the cover has at least one groove intended for connection through gaps in the thread of the internal cavity of the hydraulic tensioner with a lubrication system.

The disadvantages of the known device are the complexity of manufacturing and lack of reliability.

Known hydraulic tensioner for chain tensioning device, protected by RF patent No. 2154760, class. F16H 7/08, F16F 5/00, publ. 08/08/20. The hydraulic tensioner comprises a hollow cylindrical body, a cover with a non-return valve, a power spring, a plunger made in the form of a glass and making up a precision pair with the body. On the plunger there are a number of annular grooves of an asymmetric profile, and on the body there are radial holes with latches located in them, having a spherical surface in contact with the grooves on the plunger. The latches are pressed against the grooves on the plunger by means of an elastic ring. An additional extreme groove on the side of the open end of the plunger has a section of a rectangular profile.

The disadvantages of the known device are the complexity of manufacturing and lack of reliability.

Closest to the claimed technical essence and the achieved result, selected as a prototype, is a hydromechanical device for chain tension, protected by RF patent No. 2290554, class. F16H 7/08, publ. 2006.12.27.

The hydromechanical device for tensioning the chain includes a housing in the form of a hollow cylinder, a plunger coupled cover and a housing with an annular groove, an oil supply channel and a ball check valve, which forms a second plunger pair with a thrust element to form a mounting capsule and a step mechanism fixing backstop. An annular groove is additionally made on the outer surface of the cover on the plunger side, connected to the internal cavity by a throttle hole, and in the housing opposite the groove and the groove of the cover, an oil supply hole is made, part of the passage section of which, located opposite the groove, can overlap with the outer surface of the cover.

The disadvantages of the known device are the complexity of manufacturing and lack of reliability.

The problem solved by the invention is the improvement of the hydromechanical device for chain tension.

The technical result from the use of the invention is to increase the reliability of the structure and reduce the complexity of manufacturing due to the absence of additional annular grooves and grooves on the cover.

This result is achieved by the fact that in a hydromechanical device for tensioning a chain comprising a housing in the form of a hollow cylinder, a cover with a ring groove, an oil supply channel and a ball check valve that is movable and forms with the housing, spring-loaded and forms with the body a second plunger pair, the plunger with thrust elements for the formation of a stepping mechanism for fixing the reverse stroke, the throttle hole, the oil supply channel is made in the lid, on which an additional groove connected oil supplying passage, and a throttle hole is formed on the cap with the possibility of covering the housing.

Figure 1 shows a General view of the device, figure 2 is a section of the cover aa.

The hydromechanical device for chain tensioning comprises a housing 1 in the form of a hollow cylinder and a cap 2 movable and forming a plunger pair with housing 1. Cover 2 has an annular groove 3 with a spring ring 4, an oil supply duct 5 with a ball check valve 6 and forming a second plunger with housing 1 a pair of plunger 7 with a spring 8, a groove 9 and elastic ring elements 10, 11. The grooves 12 and the elastic ring element 11 form a step mechanism for fixing the reverse stroke. The oil supply channel 5 is made in the cover 2, on which a groove 13 is additionally made, connected to the oil supply channel 5. On the cover 2, a throttle hole 14 is made with the possibility of its overlapping by the housing 1. The housing 1 has a groove 15, which limits the axial movement of the cover 2 by means of a spring ring 4 located in the annular groove 3 of the cover 2.

Hydromechanical device chain tension works as follows.

Before mounting the device in the product, the plunger 7 is fixed in the housing 1 by means of an elastic ring element 10.

After installing the device in the product, the plunger 7 is released and the spring 8 through the plunger 7 pulls the chain. In this case, the elastic ring element 11 installed in the groove 9 occupies the position either in the groove 12 of the housing 1 or in the intermediate position between the grooves 12. After starting, for example, the gas distribution mechanism, dynamic loads from the camshaft drive begin to move the plunger 7, the elastic ring element 11, housing 1 to the cover 2. In this case, oil from the internal cavity is throttled through the throttle hole 14 into the lubrication system, providing smooth damping of dynamic loads. If the hydraulic resistance of the throttle hole 14 is not enough to ensure smooth damping, then there is an increase in its hydraulic resistance due to a decrease in the flow area of the throttle hole 14 by blocking the end face of the housing 1. Thus, the damping system automatically adjusts to shock-free operation. Oil losses are compensated from the engine lubrication system through the oil supply channel 5 and ball check valve 6. In the event of a weakening of the force of the spring 8 from the oil pressure of the lubrication system, the housing 1 rests on the plunger 7 through the locking mechanism and the device starts operating in the soft damping mode described above . The presence on the lid 2 of the groove 13 connected to the oil supply channel 5 ensures unhindered entry of oil from the lubrication system into the internal cavity. An annular groove 3 with a spring ring 4 is made on the cover 2 in contact with the housing 1, thereby restricting the movement of the housing 1 relative to the cover 2.

The hydromechanical device is made of steel.

Thus, in the proposed hydromechanical device for chain tension compared with the prototype increases the reliability of the design. The presence on the lid of the groove connected to the oil supply channel ensures unhindered entry of oil from the lubrication system into the internal cavity, which also increases the reliability of the device. In addition, there are no additional annular grooves and grooves on the lid. A decrease in the number of elements of mating parts made with high accuracy leads to an increase in the reliability of the device, a decrease in the complexity.

Claims (1)

A hydromechanical device for tensioning a chain, comprising a housing in the form of a hollow cylinder, a movable and forming a plunger pair cover with an annular groove, an oil supply channel and a ball check valve, spring-loaded and forming a second plunger pair with a housing, a plunger with thrust elements to form a stepping mechanism for fixing the reverse stroke, characterized in that the oil supply channel is made in the lid, which is additionally made a groove connected to the oil supply channel, and the throttle aperture The term formed on the lid, with its covering body.

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