KR102569737B1 - high pressure diesel fuel pump - Google Patents

Abstract

A pump housing 21, a location spigot 24 protruding from the front plate 23, and a drive shaft 22 protruding from the location spigot 24, wherein the drive shaft 22 ) is for assembly with the drive gear (31) of the engine, and the location spigot (24) is located in a bore (32) with respect to the front end of the engine block (30). The pump 20 includes an adapter 40 for positioning around the location spigot 24 between the front plate 23 and the engine block 30 . The adapter 40 includes a collar 43, an outer seal 45 for positioning between the collar 43 and the engine block 30, and between the collar 43 and the location spigot 24. and an inner seal 47 for positioning. The adapter 40 includes a spring means 49 located at the lower end 41 of the collar 43 between the collar 43 and the front plate 23 .

Description

high pressure diesel fuel pump

The present invention relates generally to the field of high pressure fuel pumps. More specifically, although not exclusively, the present invention relates to an engine location spigot adapter for a high pressure diesel fuel pump.

In high-pressure fuel pumps, the fuel pump is usually positioned against the front of the engine block. This is achieved through the position of the spigot (extending from the front plate) in the bore relative to the front of the engine block. The drive shaft passes through the spigot and, on the other side of the bore, the drive shaft attaches to a drive gear that rotates the drive shaft when actuated. The spigot is held in place due to the bore employing a snug fit.

Generally, the bore and location spigot of the pump has a spigot having a fixed diameter of relatively small dimensions, such as 50 mm to 68 mm diameter, and a bore of similar diameter to allow clearance. However, this small diameter does not permit assembly of the drive gear to the fuel pump prior to placing the spigot in the engine block.

It is advantageous to not allow pre-assembly of the drive gear to the fuel pump, since it allows the fuel pump to be removed from the engine block without requiring access to the rear of the engine block, as the engine often needs to be removed from the vehicle. Because.

One solution to the above problem is to make the diameter of the bore (and thus the spigot) larger than the drive gear, in order to allow the drive gear to pass through the bore and spigot so that there is a snug fit within the bore, e.g. It is to increase to 68mm or more. However, this increase in the diameter of the spigot on the pump introduces another problem, since the spigot often interferes with the screws securing the pump front plate to the pump housing.

To address this other problem, it is known to use an adapter between the location spigot on the pump and the bore in the engine block. The adapter keeps the spigot on the pump small, minimizing the problem of securing the pump front plate to the pump housing, while accepting a larger bore in the front of the engine block to drive gears to the fuel pump before being placed in the engine block. provides a diameter that allows assembly.

Various adapters have been developed for this reason. One conventional adapter shown in FIG. 1 includes a loose collar (4) that sits in a bore (2) of an engine block (1) around a spigot (3a) of a pump housing (3). The collar 4 has an outer peripheral o-ring seal 5 located in the groove 6 between the collar 4 and the engine block 1, and an inner o between the collar 4 and the spigot 3a. - Includes shallow annular design with ring seal (7). The inner seal (7) is trapped between the collar (4), the spigot (3a) and the front plate (3b) of the pump seated in a triangular channel (8) cut into the inner rear core of the collar (4). The seal 7 is held in part by a small circular segmental annular hollow 9 cut into the diagonal wall of the channel 8. When the inner seal (7) is compressed, it applies an axial load to the front plate (3b) and the collar (4) to minimize axial movement of the collar (4) within the bore (2). The depth of the collar (4) and the arrangement of the inner seal (7) must be made such that the front plate (3b) can rest against the engine block (1) to avoid distortion to the geometry of the pump (3). However, this may cause an axial gap when the inner seal 7 is compressed, resulting in galling corrosion and failure of the inner seal 7 .

Another problem with the adapter used in Fig. 1 relates to the location relative to the tell-tale drilling 10 and the interlocking tell-tale holes, whose functions are internal and It is to help detect failure of the outer drive shaft seal. In this case, the drilling 10 comes out on the rear of the front plate 3b of the pump housing 3 . However, in most other pump configurations, the inner seal 7 blocks the leakage path for the tell-tail hole, so the tell-tail function is compromised.

Thus, providing an engine location spigot adapter for high pressure diesel fuel pumps that can minimize axial movement within the engine block bores while allowing the pump to seat relative to the engine block, thereby reducing “tell-tail” drilling and hole Its purpose is not to affect the function of

Therefore, it is desirable to provide an improved construction for a high pressure diesel fuel pump that minimizes the effects of axial clearances leading to seal galling corrosion and failure. It is also desirable to provide an improved configuration for a high pressure diesel fuel pump to maintain the pump's tell-tail function.

In a first aspect of the present invention, a high-pressure diesel fuel pump includes a pump housing, a location spigot protruding from a front plate of the pump, and a drive shaft protruding from the location spigot, wherein the drive shaft is for assembly with the drive gear of the engine, the location spigot is located in a bore with respect to the front end of the engine block, and the pump is around the location spigot in the bore between the front plate and the engine block. an adapter for positioning on the collar, the adapter including a collar, an outer seal for positioning between the collar and the engine block, and an inner seal for positioning between the collar and the location spigot; A high-pressure diesel fuel pump is provided, characterized in that it further comprises a spring means located at the lower end of the collar between the collar and the front plate.

With this configuration using the spring means, the adapter can be seated firmly against the engine block to minimize or eliminate axial motion that can lead to seal wear, corrosion and failure. However, the use of a wave spring leaves the leakage path open and unaffected to maintain the pump's tell-tail function. The spigot can be kept small, minimizing the problem of securing the pump front plate to the pump housing, while allowing for a larger bore in the front of the engine block to allow assembly of the drive gear to the drive shaft prior to being placed in the engine block. there is.

Preferably, the spring means is configured to apply an axial load to the front plate upon compression. In this configuration, the spring means urges the adapter against the engine block, minimizing axial movement of the pump within the bore.

Preferably, the spring means is received substantially within the lower end of the collar. Preferably, said collar includes a recess for receiving said spring means.

Preferably, the collar comprises a shallow annular design comprising a centrally disposed axial bore.

Preferably, said recess comprises an annular groove in said collar. Preferably, the recess communicates with the bore of the collar. Most preferably, therefore, the recess is located at the lower inner corner of the collar which opens into the bore.

Preferably, the spring means comprises a wave spring. Preferably, the wave spring comprises a round wire profile. Preferably, the wave spring comprises a single-turn, eg one layer of wire.

The wave spring may be configured to provide a working load of approximately 50N to approximately 2000N. Preferably, the wave spring may be configured to provide an actuation force of approximately 700N to approximately 1000N, more preferably approximately 800N to approximately 900N.

The inner and outer seals may be positioned diametrically opposite each other on the collar, for example on the same diametrical plane. Preferably, the seals are disposed towards the upper end of the collar.

Preferably, the outer seal includes an o-ring of suitable sealing material. Preferably, the outer seal is located in a groove on the outer periphery of the collar.

Preferably, the inner seal includes an o-ring of suitable sealing material. Preferably, the inner seal is located in a groove in the location spigot. Alternatively, the inner seal may be located in a groove in the bore of the collar.

Preferably, the collar includes a main portion of a first outer diameter that includes an upper end portion of the collar. Preferably, the collar includes a secondary portion of a second larger outer diameter that includes the lower end of the collar. Preferably, the secondary is seated within a wider secondary bore as part of the lower end of the bore of the engine block, eg the engine block provides a recess.

Preferably, the first outer diameter of the collar is larger than the driving gear.

The adapter can convert an 80mm engine bore diameter to an approximate 50mm diameter. Thus, the adapter may have an inner diameter of approximately 50 mm and an outer diameter of approximately 80 mm.

In a second aspect of the invention, an adapter for a high-pressure diesel fuel pump, the adapter for positioning in a bore for a front end of an engine block around a location spigot protruding from a front plate of the pump, the adapter comprising a collar , an outer seal for positioning between the collar and the engine block, and an inner seal for positioning between the collar and the location spigot, wherein the adapter is positioned between the collar and the front plate at a lower end of the collar. An adapter is provided, characterized in that it further comprises spring means to be positioned.

It will be understood that the related preferred features described with respect to the first aspect of the invention apply to the second aspect of the invention.

In a third aspect of the present invention, a high pressure diesel fuel pump and drive gear assembly comprising a housing, a location spigot protruding from a front plate, and a drive shaft protruding from the location spigot, the drive shaft comprising: For assembly with the drive gear of the engine, the location spigot is positioned in a bore relative to the front end of the engine block, the assembly being around the location spigot in the bore between the front plate and the engine block. further comprising an adapter for positioning, the adapter comprising a collar, an outer seal for positioning between the collar and the engine block, and an inner seal for positioning between the collar and the location spigot, the adapter comprising: The high pressure diesel fuel pump and drive gear assembly is provided, characterized in that it further comprises a spring means positioned at a lower end of the collar between the collar and the front plate.

It will be appreciated that the related preferred features described with respect to the first and second aspects of the invention apply to the third aspect of the invention.

For a better understanding of the present invention and to show how exemplary embodiments may be practiced, reference is made to the accompanying drawings.
1 is a cross-sectional view of a prior art adapter and high pressure diesel fuel pump assembled in a bore of an engine block;
2 is a cross-sectional side view of a high-pressure diesel fuel pump assembled with a drive gear and seated in a bore of an engine block having an adapter according to one embodiment of the present invention;
Figure 3 is a perspective view of the adapter according to the present invention as shown in Figure 2;
Figure 4 is an exploded side cross-sectional view of a portion of Figure 2;
Figure 5 is a front perspective view of the adapter of Figure 3 installed on a high pressure diesel fuel pump;

2 to 5 show a preferred embodiment of the present invention, wherein the high pressure diesel fuel pump 20 comprises a pump housing 21, a location spigot 24 protruding from the front plate 23 of the pump 20, and a drive shaft 22 protruding from the location spigot 24, the drive shaft 22 is for assembly with the drive gear 31 of the engine, and the location spigot 24 is an engine block Located in a bore (32) for the front end of (30), the pump (20) is positioned within the bore (32) between the front plate (23) and the engine block (30) at the location spigot (24). ) an adapter (40) for positioning around the collar (43), an outer seal (45) for positioning between the collar (43) and the engine block (30), and and an inner seal (47) for positioning between the collar (43) and the location spigot (24), the adapter (40) between the collar (43) and the front plate (23) the collar ( It is characterized in that it further comprises a spring means 49 located at the lower end 41 of 43).

The adapter 40 includes a substantially annular collar 43 with a centrally disposed axial through bore 46 . Collar 43 includes aluminum to minimize mass and reduce load demand on spring means 49 .

The collar 43 includes a first lower end 41 and a second upper end 42 that sits proximate to the pump housing 21 . The collar 43 includes a main portion 43a of a first outer diameter enclosing an upper end portion 42 and a shallow secondary portion 43b of a second larger outer diameter encircling a lower end portion 41 . This gives the collar 43 a stepped outer profile between the lower portion 41 and the upper portion 42 .

The engine block 30 accommodates the stepped outer profile of the adapter by including a larger diameter secondary bore 32b concentric with the primary bore 32a to accommodate the outer diameter of the secondary 32b.

The main portion 43a of the collar 43 includes an outer circumferential groove 44 disposed proximate the top portion 42 to receive an outer seal 45 . Outer seal 45 includes an o-ring of suitable sealing material that is retained in groove 44 to provide a sealing interface between collar 43 and bore 32 of engine block 30 .

Within the main portion 43a of the collar 43, the bore 46 includes a substantially straight, non-profiled inner wall 46a.

In contrast, within the secondary portion 43b of the collar 43, the bore 46 includes a profiled inner wall 46b. Accordingly, the secondary portion 43b of the collar 43 includes an inner circumferential recess 48 disposed in the bore 46 and opening into the lower end 41 of the collar 43 . Recess 48 comprises a profile that is substantially square in cross section. When the recess 48 recombines the inner wall 46b of the bore 46, the recess 48 creates a short conical and decreasing gap 61 between the location spigot 24 and the inner wall 46b. and a short sharply tapered section 51 configured to provide.

Also, when the recess 48 recombines the lower end 41 of the collar 43, the recess 48 is formed between the lower end 41 of the adapter 40 and the front plate 23 for a short shallow cone and It includes a second short outwardly tapered section 52 configured to provide a wider mouth 62 .

The mouth 62, recess 48 and gap 61 come together to provide a flow path through the bore 46 between the front plate 23 and the collar 43 to the point where the inner seal 23 is positioned. It works.

The spring means 49 comprises a single-turn, round wire wave spring. The wave spring 49 is located in the recess 48 of the collar 43. Due to the shape of the recess 48, the mouth 62 and the gap 61, there is a flow path around the spring 49 in any compression of the spring 49.

During assembly, the inner seal 47 is first placed in the groove 25 provided by the location spigot 24 . The outer seal 45 is located within the groove 44 of the collar 43 and the wave spring 49 is located within the recess 48 of the collar 43.

The adapter 40 is then assembled onto the pump 20 by passing the lower end 41 over the drive shaft 22 and then over the location spigot 24 . The lower end 41 of the collar 43 is provided close to the front plate 23, but not adjacent to the front plate 23 with the wave spring 49 in an uncompressed ("free") form, so that the lower end 41 ) stays away from the front plate (23).

The collar 43 is machined to have a low clearance fit (10-85 microns diametrically) around the location spigot 24 of the pump 20. This helps reduce eccentricity errors that can be detrimental to the drivetrain of pump 20. The pressure provided by the outer seal 45 and the inner seal 47 is applied by the adapter 40 concentric within the engine block bore 32 and the location spigot 24 concentric within the bore 46 of the adapter 40. helps to maintain

The adapter is held in place on the front plate (23) due to friction between the inner seal (47) and the collar (43) and the groove (25).

As long as the adapter 40 is in a predetermined position on the pump 20, the drive shaft 22 can be assembled with the drive gear 31. The drive gear 31 can then pass through the bore 32 of the front end of the engine block 30 and then through the drive shaft 22 . The adapter 40 and the enclosed location spigot 24 are passed into the bore 32 until the secondary 43b of the collar 43 abuts the top wall of the secondary bore 32b.

Then, the pump 20-adapter 40 assembly is mounted on the engine block 30 by coupling and tightening bolts (not shown). This draws the front plate 23 of the pump 20 closer to the lower end 41 of the adapter 40 and compresses the wave spring 49 . Adapter 40 is then secured between engine block 30 and front plate 24 within engine block bores 32 so that it does not need to be bolted to pump 20 or engine block 30 itself.

Because the wave spring 49 is in compression form, the adapter collar 43 cannot vibrate, minimizing galling corrosion and failure of the seals 45 and 47.

Moreover, around the wave spring 49, the mouth 62 and the gap 61 as part of the recess 48 communicate with each other around the wave spring 49, maintaining a tell-to-tail leakage path.

The adapter 40 is space efficient and quick to install compared to conventional adapters because it does not require separate bolting to the pump 20 or engine block 30, and the collar 43 of the adapter has an inner seal ( 47) instead of being held on the location spigot 24 during pre-assembly. Additionally, the wave spring 49 can provide a higher axial load, reducing the risk of seal galling and failure. Finally, a tell-tail leakage path is maintained because the wave spring 49 does not provide a block at the lower end 41 of the adapter 40.

While several preferred embodiments have been shown and described, those skilled in the art will understand that various changes and modifications may be made without departing from the scope of the present invention as defined in the appended claims.

Claims (14)

In the high-pressure diesel fuel pump 20,
a pump housing (21), a location spigot (24) protruding from the front plate (23) of the pump (20), and a drive shaft (22) protruding from the location spigot (24); ,
The drive shaft (22) is for assembly with the drive gear (31) of the engine, the location spigot (24) is located in a bore (32) with respect to the front end of the engine block (30),
the pump further comprises an adapter (40) for positioning around the location spigot (24) in the bore (32) between the front plate (23) and the engine block (30);
The adapter 40 includes a collar 43, an outer seal 45 for positioning between the collar 43 and the engine block 30, and between the collar 43 and the location spigot 24. an inner seal (47) for positioning;
The adapter (40) further comprises a spring means (49) located at the lower end (41) of the collar (43) between the collar (43) and the front plate (23).
characterized in that,
High pressure diesel fuel pump.
According to claim 1,
wherein the spring means (49) is configured to apply an axial load to the front plate (23) and the collar (43) upon compression.
High pressure diesel fuel pump.
According to claim 1,
the spring means (49) is received substantially within the lower end (41) of the collar (43);
High pressure diesel fuel pump.
According to any one of claims 1 to 3,
The collar (43) comprises a recess (48) for receiving the spring means (49).
High pressure diesel fuel pump.
According to claim 4,
The collar (43) comprises a shallow annular design with a centrally disposed axial bore (46).
High pressure diesel fuel pump.
According to claim 5,
The recess (48) is disposed at the inner lower corner of the collar (43) that opens into the bore (46).
High pressure diesel fuel pump.
According to any one of claims 1 to 3,
The spring means (49) comprises a wave spring (49),
High pressure diesel fuel pump.
According to claim 7,
The wave spring (49) comprises a round wire profile with a single-turn,
High pressure diesel fuel pump.
According to claim 7,
The wave spring (49) is configured to provide an operating load of 700N to 1000N.
High pressure diesel fuel pump.
According to any one of claims 1 to 3,
the outer seal (45) is located in a groove (44) on the outer periphery of the collar (43);
High pressure diesel fuel pump.
According to claim 9,
The collar 43 has a main part 43a of a first outer diameter including the upper end 42 of the collar 43 and a second larger outer diameter including the lower end 41 of the collar 43. Including the secondary part 43b,
High pressure diesel fuel pump.
According to claim 11,
The secondary portion (43b) is seated in the wider secondary bore (32b) as a part of the lower end of the bore (32) of the engine block (30).
High pressure diesel fuel pump.
According to claim 11,
The first outer diameter of the collar 43 is larger than that of the drive gear 31,
High pressure diesel fuel pump.
In the adapter (40) for the high pressure diesel fuel pump (20),
the adapter (40) is for positioning in the bore (32) about the front end of the engine block (30) around the location spigot (24) protruding from the front plate (23) of the pump (20);
The adapter 40 includes a collar 43, an outer seal 45 for positioning between the collar 43 and the engine block 30, and between the collar 43 and the location spigot 24. an inner seal (47) for positioning;
The adapter (40) further comprises a spring means (49) located at the lower end (41) of the collar (43) between the collar (43) and the front plate (23).
characterized in that,
adapter.

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