TECHNICAL FIELD
[0001] The present invention relates to a valve timing control apparatus which controls
the timing of the opening and closing of intake and exhaust valves in an internal
combustion engine.
BACKGROUND ART
[0002] Conventional valve timing control apparatuses include those having a rotor linked
to a camshaft of an internal combustion engine; a housing member for supporting the
rotor in a relatively rotational manner; a front plate member joined to one axial
end of the housing member; a rear plate member joined to the other axial end of the
housing member and provided with a drive portion linked to the drive shaft of the
internal combustion engine; a hydraulic chamber partitioned by a vane and provided
between the rotor and a housing that comprises the housing member, the front plate
member, and the rear plate member; and a front cover that covers the front plate member
and the housing member forming the hydraulic chamber, and is joined to the rear plate
member via a seal member (for an example, see Patent Document 1).
[Patent Document 1] Japanese Laid-open Patent Application No. 2002-188414
[0003] WO 03/076771 A1 discloses a drive for valve operating control systems in motor vehicles, including
camshaft adjusters. This document forms the preamble of D1.
DISCLOSURE OF THE INVENTION
[PROBLEMS THAT THE INVENTION IS INTENDED TO SOLVE]
[0004] In conventional valve timing control apparatuses such as that described above, the
housing member and the front plate member are covered with a front cover in order
to prevent oil supplied to the hydraulic chamber from leaking out of the internal
combustion engine. Adopting this approach has been problematic in that the apparatus
is made larger in the axial direction, and the number of parts increases, driving
up costs. Another problem is that a larger apparatus limits the degree of freedom
in mounting the apparatus in the internal combustion engine.
[0005] In view of the foregoing, a technical object of the present invention is to prevent
oil from leaking out, to reduce axial dimensions, and to reduce the number of parts
and the cost in a valve timing control apparatus.
[Means for Solving the Problems]
[0006] The technical means employed by the present invention for solving the above-mentioned
problems relate to a valve timing control apparatus comprising a driven member linked
to a camshaft of an internal combustion engine; a drive member which is linked to
the drive shaft of the internal combustion engine and supports the driven member in
a relatively rotational manner; and a hydraulic chamber which is partitioned by a
vane and is disposed between the driven member and the drive member, wherein the drive
member comprises an outer rotor forming the hydraulic chamber together with the driven
member; a housing member including a front plate portion joined to one axial end of
the outer rotor and a tubular portion linked the front plate portion and positioned
on the outer radial side of the outer rotor; and a rear plate member joined to the
other axial end of the outer rotor and to the housing member.
[0007] According to these technical means, the periphery of the hydraulic chamber can be
enclosed by the tubular portion and the front plate portion of the housing member.
Therefore, oil in the hydraulic chamber can be prevented from leaking through the
housing member to the outside. Furthermore, the housing member can double as a covering
member for covering the periphery of the drive member, allowing the drive member to
be made more compact in the axial direction, and the number of parts and the cost
to be reduced. The outer rotor and the housing member can be separate members, whereby
the outer rotor and the housing member can be formed from different materials.
[0008] According to a further technical means used to solve the above-mentioned problems,
the housing member, the outer rotor, and the rear plate member are integrally fixed
together by a fastening member, a head portion of the fastening member is interlocked
with the rear plate member, a shaft portion thereof is passed through a hole in the
outer rotor, and the sealant-coated male threaded portion is threadably engaged with
a female threaded portion of the housing member.
[0009] According to these technical means, the sealant-coated male threaded portion of the
fastening member is threadably engaged with the female threaded portion of the housing
member, preventing the oil in the hydraulic chamber from leaking to the outside from
between the fastening member and the housing member. Therefore, oil leakage can be
prevented using a simple configuration.
[0010] According to a further technical means used to solve the above-mentioned problems,
the hole has a stepped tubular shape, with a large-diameter portion on the side of
the front plate portion and a small-diameter portion on the side of the rear plate
member.
[0011] According to these technical means, excess sealant squeezed out by the threadable
engagement of the fastening member and the housing member flows into the large-diameter
portion of the hole to form a seal, and can therefore be prevented from flowing toward
the hydraulic chamber.
[0012] According to a further technical means used to solve the above-mentioned problems,
a through hole for passing the fastening member is formed in the rear plate member,
and a seal member is provided for sealing the through hole.
[0013] According to these technical means, the oil in the hydraulic chamber can be prevented
from leaking out from between the fastening member and the rear plate member. Therefore,
oil leakage can be prevented using a simple configuration.
[0014] According to a further technical means used to solve the above-mentioned problems,
the through hole has a larger diameter than the small-diameter portion of the hole;
at least a portion of the head portion of the fastening member is inserted into the
through hole; and the seal member is placed within the through hole and is sandwiched
between the head portion of the fastening member and the other axial end of the outer
rotor.
[0015] According to these technical means, the seal between the fastening member and the
rear plate member can be adequately ensured using a simple structure in which the
seal member is merely sandwiched between the head portion of the fastening member
and the other axial end of the outer rotor.
[0016] A further technical means used to solve the above-mentioned problems has a seal member
disposed on the joint surface of the housing member and the rear plate member.
[0017] According to these technical means, the oil in the hydraulic chamber can be prevented
from leaking out from between the housing member and the rear plate member.
[0018] According to a further technical means used to solve the above-mentioned problems,
the outer rotor is composed of an iron-based metal, and the housing member is composed
of a light metal.
[0019] According to these technical means, the housing member and the entire apparatus can
be made more lightweight while the strength of the outer rotor is ensured.
[EFFECT OF THE INVENTION]
[0020] According to the present invention, the oil in the hydraulic chamber can be prevented
from leaking to the outside of the housing member. Furthermore, the drive member can
be made more compact in the axial direction, and the number of parts and the cost
can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021]
FIG. 1 is a longitudinal section of a valve timing control apparatus 1 showing an
embodiment of the present invention; and
FIG. 2 is a magnified view of the bolt region in which the housing member, the outer
rotor, and the rear plate member are fixed together.
BEST MODE FOR CARRYING OUT THE INVENTION
[0022] An embodiment of a valve timing control apparatus 1 according to the present invention
will be described below with reference to the accompanying drawings.
[0023] As shown in FIG. 1, the valve timing control apparatus primarily comprises a rotor
(driven member) 2 that is integrally assembled with and linked to the distal end of
a camshaft 1 of an internal combustion engine, and a drive member 30 that is linked
to the drive shaft (not shown) of the internal combustion engine and that supports
the rotor 2 in a relatively rotational manner within a specific range. A hydraulic
chamber 35 partitioned by a vane 6 is provided between the rotor 2 and the drive member
30.
[0024] The camshaft 1 has a cam (not shown) for opening and closing the intake or exhaust
valves (not shown) of the internal combustion engine. The camshaft 1 is rotatably
supported by a cylinder head 5 of the internal combustion engine.
[0025] The rotor 2 is integrally fixed by a bolt 23 to the axially forward end (left side
in FIG. 1) of the camshaft 1. The rotor 2 rotatably engages the internal peripheral
surface 31d of protrusions 31a on an outer rotor 31, which will be described below.
The rotor 2 includes the vanes 6 along its outer periphery, with each vane 6 extending
radially outward (vertical direction in FIG. 1) and partitioning the hydraulic chamber
35 formed between the rotor 2 and the drive member 30 into a spark-advance chamber
and a spark-retard chamber.
[0026] The drive member 30 has the outer rotor 31 forming the hydraulic chamber 35 together
with the rotor 2, a substantially bottomed tubular housing member 3 for housing the
outer rotor 31 in the internal peripheral part thereof, and a rear plate member 4
joined to the end face 3a on the side of the opening in the housing member 3. A seal
member 38 is disposed on the joint surface of the housing member 3 and the rear plate
member 4. The seal member 38 seals the joint surface of the housing member 3 and the
rear plate member 4, and is provided to prevent leakage of oil from the hydraulic
chamber 35 to the outside.
[0027] As shown in FIG. 2, the housing member 3, the outer rotor 31, and the rear plate
member 4 are integrally fixed together by a bolt (fastening member) 36. The head portion
36b of the bolt 36 engages the rear plate member 4, the shaft portion 36c passes through
a hole 31c in the outer rotor 31, and a male threaded portion 36a is threadably engaged
with a female threaded portion 32a of the housing member 3. The male threaded portion
36a of the bolt 36 is threadably engaged with the female threaded portion 32a of the
housing member 3 while coated with a sealant A. The sealant A is provided in order
to seal the fastened portions of the bolt 36 and the housing member 3, and to prevent
the oil in the hydraulic chamber 35 from leaking to the outside.
[0028] The outer rotor 31 and the housing member 3 are separate members integrally fixed
together by the bolt 36, allowing for the outer rotor 31 and the housing member 3
to be formed from different materials. In this case, the outer rotor 31 is preferably
composed of an iron-based metal, and the housing member 3 is preferably composed of
aluminum or another light metal. The required strength can thereby be obtained for
the outer rotor 2, and the housing member 3 and the entire apparatus can be made more
lightweight.
[0029] The radially inwardly extending protrusions 31a are formed spaced around the periphery
of the outer rotor 31. The hydraulic chamber 35 is formed in the space between adjoining
protrusions 31a. The rotor 2 is rotationally engaged with the internal peripheral
surface 31d of the protrusions 31a. The vanes 6, which partition the hydraulic chamber
35 into spark-advance and spark-retard chambers in a liquid-tight manner as mentioned
above, are in frictional contact with the internal peripheral surface 31b of the outer
rotor.
[0030] The housing member 3 is a substantially bottomed tubular member having a front plate
portion 32 that is joined to one axial end (left side in FIG. 1) of the outer rotor
31, and a tubular portion 33 that is integrally linked the front plate portion 32
and is disposed on the outer radial side of the outer rotor 31. The front plate portion
32 and the tubular portion 33 of the housing member 3 are thereby linked as a single
unit enclosing the periphery of the hydraulic chamber 35. Therefore, the sealing of
the hydraulic chamber 35 by the housing member 3 can be improved and the oil in the
hydraulic chamber 35 can be prevented from leaking to the outside of the housing member
3. Further, the housing member 3 can double as a covering member for covering the
periphery of the drive member 30, allowing the drive member 30 to be made more compact
in the axial direction, the apparatus to be made smaller, and the number of parts
and the cost to be reduced.
[0031] The front plate portion 32 comprises a tubular portion 32c that has a hole 32b for
fastening the bolt 23, and a discoid portion 32d for hermetically closing the front
side of the hydraulic chamber 35. The hole 32b provided in the central part of the
front plate portion 32 is blocked in a liquid-tight manner by fixing a cap 37 with
the aid of a seal washer 37a. The front plate portion 32 is positioned in contact
with the axial front-end surface (an end side) 31g of the outer rotor 31. The front
plate portion 32 blocks the front end face (left side in FIG. 1) of the hydraulic
chamber 35. In other words, the internal peripheral part of the discoid portion 32d
of the front plate portion 32 is in frictional contact with the front-end surface
2g of the rotor 2 and blocks the front side of the hydraulic chamber 35. Furthermore,
the discoid portion 32d is in frictional contact with the front-end surface 6g of
the vanes 6 and partitions the hydraulic chamber 35 into spark-advance and spark-retard
chambers in a liquid-tight manner.
[0032] A torsion spring 7 is positioned between a depression 32e formed on the internal
periphery of the tubular portion 32c of the front plate portion 32, and a circular
groove 31k formed on the front-end surface (an end side) 31g in the axial direction
of the rotor 2. The torsion spring 7 is attached to the front plate portion 32 on
one end and to the rotor 2 on the other end. The torsion spring 7 thereby urges the
rotor 2 to advance straight forward in relation to the drive member 30.
[0033] The housing member 3 and the rear plate member 4 are integrally fixed together by
the bolt 36. The bolt 36 passes through the hole 31c of the outer rotor 31, and the
male threaded portion 36a coated with sealant A threadably engages the female threaded
portion 32a formed on the front plate portion 32. The hole 31c is formed as a stepped
cylinder in which the level changes in the axially directed intermediate portion of
the hole, as shown in FIG. 2. In other words, the hole 31c has a small-diameter portion
31m, formed on the rear side (the side facing the rear plate member 4, the right side
in FIG. 2) of the outer rotor 31, and a large-diameter portion 31j, having a larger
diameter than the small-diameter portion 31m, on the front side (the side facing the
front plate portion 32, the left side in FIG. 2) of the outer rotor 31. Therefore,
excess sealant A squeezed out by the threadable engagement of the male threaded portion
36a of the bolt 36 coated with sealant A and the female threaded portion 32a of the
front plate portion 32 flows into space S formed by the internal periphery of the
large-diameter portion 31j and the external periphery of the bolt 36 to form a seal.
Accordingly, sealant A can therefore be prevented from flowing toward the hydraulic
chamber 35 and contaminating the oil therein. The large-diameter portion 31j may also
be formed on the side of the female threaded portion 32a that faces the outer rotor
31.
[0034] A seal member 39 is disposed between the head portion 36b of the bolt 36 and the
rear plate member 4, as shown in FIG. 2. The seal member 39 seals the hydraulic chamber
35 in a liquid-tight manner. A through hole 4c for passing the bolt 36 is formed in
the rear plate member 4, as shown in FIG. 1. The seal member 39 is configured to seal
the through hole 4c. In other words, the through hole 4c has a larger diameter than
the small-diameter portion 31m of the hole 31c, and at least part of the head portion
36b of the bolt 36 is inserted into the through hole 4c. In this case, the entire
head portion 36b of the bolt 36 is inserted so as to fit in the through hole 4c. The
seal member 39 is placed within the through hole 4c and is sandwiched between the
head portion 36b of the bolt 36 and the axial back-end surface (the surface on the
other axial end, the surface on the right side in FIG. 1) 31h of the outer rotor 31.
The seal member 39 thereby seals the space within the through hole 4c, which is enclosed
by the head portion 36b of the bolt 36, the axial back-end surface 31h of the outer
rotor 31, and the through hole 4c of the rear plate member 4. Therefore, the oil in
the hydraulic chamber 35 can be prevented from leaking out from between the bolt 36
and the rear plate member 4.
[0035] The rear plate member 4 has a larger diameter than the housing member 3, is joined
to the axial back-end surface 31h of the outer rotor 31, and blocks the rear side
(the right side in FIG. 1) of the hydraulic chamber 35. The internal peripheral part
of the rear plate member 4 is in frictional contact with the back-end surface 2h of
the rotor 2, blocking the rear side of the hydraulic chamber 35. A round tubular portion
4b protruding toward the camshaft 1 is formed in the central part of the rear plate
4. An oil seal 5a is disposed between the external periphery of the round tubular
portion 4b and the cylinder head 5, blocking the hydraulic chamber 35 in a liquid-tight
manner. The rear plate member 4 is supported while allowed to rotate relative to the
rotor 2 and the camshaft 1. Furthermore, a pulley 4a is formed integrally on the external
periphery that protrudes radially outward beyond the external peripheral surface 3b
of the housing [member] 3 of the rear plate member 4.
[0036] Following is a description of the operation of a valve timing control apparatus
configured as described above.
[0037] While oil is fed through supply lines connected to the spark-advance and spark-retard
chambers of the hydraulic chamber 35, a torque transmitted from the crankshaft of
the internal combustion engine to the pulley 4a is further transmitted from the drive
member 30 to the rotor 2 via the oil thus fed, whereby the pulley 4a and the camshaft
1 are made to rotate integrally together. As a result, the camshaft 1 of the internal
combustion engine is caused to rotate in sync with the crankshaft of the internal
combustion engine. In this case, the outer rotor 31, which forms the hydraulic chamber
35, is covered by the housing member 3, which has the front plate portion 32 and the
tubular portion 33 linked thereto. Furthermore, the housing member 3 is joined and
fixed to the rear plate member 4 via the seal member 38. Therefore, the oil fed to
the hydraulic chamber 35 is prevented from leaking to the outside.
[0038] The rate at which the oil is fed in this state is adjusted, and the oil pressure
generated in the spark-advance and spark-retard chambers of the hydraulic chamber
35 is also adjusted, whereupon the rotor 2 is caused to rotate relative to the drive
member 30, and the position of the camshaft 1 relative to the pulley 4a is varied.
The rotation timing of the camshaft 1 of the internal combustion engine relative to
the drives shaft is thus adjusted.
DESCRIPTION OF REFERENCE MARKS
[0039]
- 1
- Camshaft
- 2
- Rotor (driven member)
- 3
- Housing member
- 4
- Rear plate member
- 4c
- Through hole
- 6
- Vane
- 30
- Drive member
- 31
- Outer rotor
- 31c
- Hole
- 31j
- Large-diameter portion
- 31m
- Small-diameter portion
- 32
- Front plate portion
- 32a
- Female threaded portion
- 33
- Tubular portion
- 35
- Hydraulic chamber
- 36
- Bolt (fastening member)
- 36a
- Male threaded portion
- 36b
- Head portion
- 36c
- Shaft portion
- 38
- Seal member on joint surface of housing member and rear plate member
- 39
- Seal member for seal member
- A
- Sealant
1. A valve timing control apparatus comprising:
a driven member (2) linked to a camshaft (1) of an internal combustion engine;
a drive member (30) which is linked to a drive shaft of the internal combustion engine
and supports the driven member (2) in a relatively rotational manner; and
a hydraulic chamber (35) which is partitioned by a vane (6) and is disposed between
the driven member (2) and the drive member (30), wherein the drive member (30) comprises:
an outer rotor (31) forming the hydraulic chamber (35) together with the driven member
(2);
a housing member (3) including a front plate portion (32) joined to one axial end
of the outer rotor (31) and a tubular portion (33) linked the front plate portion
(32) and positioned on the outer radial side of the outer rotor (31); and
a rear plate member (4) joined to the other axial end of the outer rotor (31) and
to the housing member (3), and wherein the housing member (3), the outer rotor (31)
and the rear plate member (4) are integrally fixed together by a fastening member
(36); characterized in that a head portion (36b) of the fastening member (36) is interlocked with the rear plate
member (4), a shaft portion (36c) thereof is passed through a hole (31c) in the outer
rotor (31), a sealant-coated male threaded portion (36a) is threadably engaged with
a female threaded portion (32a) of the housing member (3), and in that the hole (31c) has a stepped tubular shape with a large-diameter portion (31j) on
the side facing the front plate portion (32), and a small-diameter portion (31m) on
the side facing the rear plate member (4).
2. The valve timing control apparatus according to claim 1, characterized in that a through hole (4c) for passing the fastening member (36) is formed in the rear plate
member (4), and a seal member (39) is provided for sealing the through hole (4c).
3. The valve timing control apparatus according to claim 2, characterized in that the through hole (4c) has a larger diameter than the small-diameter portion (31m)
the hole (31c);
at least a portion of the head portion (36b) of the fastening member (36) is inserted
into the through hole (4c); and
the seal member (39) is placed within the through hole (4c) and sandwiched between
the head portion (36b) of the fastening member (36) and the other axial end of the
outer rotor (31).
4. The valve timing control apparatus according to any of claims 1 through 3, characterized by a seal member (38) disposed on the joint surface of the housing member (3) and the
rear plate member (4).
5. The valve timing control apparatus according to any of claims 1 through 3, characterized in that the outer rotor (31) is composed of an iron-based metal, and the housing member (3)
is composed of a light metal.
1. Vorrichtung zur Zeitsteuerung eines Ventils, enthaltend:
ein angetriebenes Element (2), das mit einer Nockenwelle (1) eines Verbrennungsmotors
verbunden ist;
ein Antriebselement (30), das mit einer Antriebswelle des Verbrennungsmotors verbunden
ist und das angetriebene Element (2) in einem relativ drehbaren Verhältnis stützt;
und
eine Hydraulikkammer (35), die durch einen Schieber (6) unterteilt ist und zwischen
dem angetriebenen Element (2) und dem Antriebselement (30) angeordnet ist,
wobei das Antriebselement (30) enthält:
einen äußeren Rotor (31), der die Hydraulikkammer (35) zusammen mit dem angetriebenen
Element (2) bildet;
ein Gehäuseelement (3), das einen Frontplattenbereich (32) enthält, der mit einem
axialen Ende des äußeren Rotors (31) verbunden ist, und einen röhrenförmigen Bereich
(33), der mit dem Frontplattenbereich (32) verbunden ist und auf der äußeren radialen
Seite des äußeren Rotors (31) positioniert ist; und
ein hinteres Plattenelement (4), das mit dem anderen axialen Ende des äußeren Rotors
(31) und mit dem Gehäuseelement (3) verbunden ist; und
wobei das Gehäuseelement (3), der äußere Rotor (31) und das hintere Plattenelement
(4) integral aneinander durch ein Befestigungselement (36) befestigt sind;
dadurch gekennzeichnet, dass
ein Kopfbereich (36b) des Befestigungselements (36) mit dem hinteren Plattenelement
(4) verriegelt ist, ein Schaftbereich (36c) davon durch ein Loch (31c) in dem äußeren
Rotor (31) geführt ist, ein mit Dichtmittel beschichtetes Außengewinde (36a) in Gewindeeingriff
mit einem Innengewindebereich (32a) des Gehäuseelements (3) ist, und
dadurch, dass das Loch (31c) eine gestufte röhrenförmige Form mit einem Bereich (31j)
großen Durchmessers auf der Seite, die auf den Frontplattenbereich (32) gerichtet
ist, und einem Bereich (31m) kleinen Durchmessers auf der Seite, die auf das hintere
Plattenelement (4) gerichtet ist, hat.
2. Vorrichtung zur Zeitsteuerung eines Ventils nach Anspruch 1, dadurch gekennzeichnet, dass ein Durchgangsloch (4c) zum Durchführen des Befestigungselements (36) in dem hinteren
Plattenelement (4) geformt ist, und ein Dichtelement (39) zum Dichten des Durchgangslochs
(4c) vorgesehen ist.
3. Vorrichtung zur Zeitsteuerung eines Ventils nach Anspruch 2, dadurch gekennzeichnet, dass das Durchgangsloch (4c) einen größeren Durchmesser als der Bereich (31m) kleinen
Durchmessers des Lochs (31c) hat;
zumindest ein Bereich des Kopfbereichs (36b) des Befestigungselements (36) in das
Durchgangsloch (4c) eingeführt ist; und
das Dichtelement (39) innerhalb des Durchgangslochs (4c) platziert ist und zwischen
dem Kopfbereich (36b) des Befestigungselements (36) und dem anderen axialen Ende des
äußeren Rotors (31) platziert ist.
4. Vorrichtung zur Zeitsteuerung eines Ventils nach einem der Ansprüche 1 bis 3, gekennzeichnet durch ein Dichtelement (38), das auf der Fügefläche des Gehäuseelements (3) und des hinteren
Plattenelements (4) angeordnet ist.
5. Vorrichtung zur Zeitsteuerung eines Ventils nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass der äußere Rotor (31) aus einem Metall auf Eisenbasis zusammengesetzt ist, und das
Gehäuseelement (3) aus einem Leichtmetall gebildet ist.
1. Appareil de commande de synchronisation de soupape, comprenant :
un élément mené (2) lié à un arbre à came d'un moteur à combustion interne ;
un élément menant (30) qui est lié à un arbre d'entraînement du moteur à combustion
interne et supporte l'élément mené (2) en rotation relative, et
une chambre hydraulique (35) qui est divisée par une aube (6) et est disposée entre
l'élément mené (2) et l'élément menant (30) ;
dans lequel l'élément menant (30) comprend :
un rotor externe (31) formant la chambre hydraulique (35) conjointement avec l'élément
mené (2) ;
un élément de boîtier (3) comprenant une portion de plaque avant (32) assemblée à
une extrémité axiale du rotor externe (31) et une portion tubulaire (33) liée à la
portion de plaque avant (32) et positionnée sur le côté radial externe du rotor externe
(31) ; et
un élément de plaque arrière (4) assemblé à l'autre extrémité axiale du rotor externe
(31) et à l'élément de boîtier (3) et
dans lequel l'élément de boîtier (3), le rotor externe (31) et l'élément de plaque
arrière (4) sont fixés conjointement d'une seule pièce par un élément de fixation
(36) ;
caractérisé en ce qu'une portion de tête (36b) de - l'élément de fixation (36) est verrouillé sur l'élément
de plaque arrière (4), on fait passer une portion d'arbre (36c) de celui-ci à travers
un trou (31c) dans le rotor externe (31), une portion mâle filetée (36a) revêtue de
matériau étanche est engagé par vissage sur une portion femelle taraudée (32a) de
l'élément de boîtier (3), et
en ce que le trou (31c) a une forme tubulaire à gradins avec une portion de grand diamètre
(31j) sur le côté tourné vers la portion de plaque avant (32) et une portion de petit
diamètre (31m) sur le côté tourné vers l'élément de plaque arrière (4).
2. Appareil de commande de synchronisation de soupape selon la revendication 1, caractérisé en ce qu'un trou traversant (4c) pour faire passer l'élément de fixation (36) est ménagé dans
l'élément de plaque arrière (4) et un élément étanche (39) est mis en oeuvre pour
fermer hermétiquement le trou traversant (4c).
3. Appareil de commande de synchronisation de soupape selon la revendication 2, caractérisé en ce que le trou traversant (4c) a un diamètre supérieur à la portion de petit diamètre (31m)
du trou (31c) ;
au moins une portion de la portion de tête (36b) de l'élément de fixation (36) est
insérée dans le trou traversant (4c) ; et
l'élément étanche (39) est placé dans le trou traversant (4c) et pris en sandwich
entre la portion de tête (36b) de l'élément de fixation (36) et l'autre extrémité
axiale du rotor externe (31).
4. Appareil de commande de synchronisation de soupape selon l'une quelconque des revendications
1 à 3, caractérisé par un élément étanche (38) disposé sur la surface de joint de l'élément de boîtier (3)
et l'élément de plaque arrière (4).
5. Appareil de commande de synchronisation de soupape selon l'une quelconque des revendications
1 à 3, caractérisé en ce que le rotor externe (31) est composé d'un métal à base de fer et l'élément de boîtier
(3) est composé d'un métal léger.