Central valve for camshaft phaser

Abstract

A central valve for a camshaft phase shifter includes a hollow cylindrical housing, a hydraulic unit, a control piston, a retaining ring, and a washer. The hollow cylindrical housing includes a first radial opening and a recess. The hydraulic unit is disposed within the hollow cylindrical housing and includes a second radial opening and a passage. The control piston is axially movable within the hydraulic unit to regulate the flow of hydraulic medium through the first radial opening, the second radial opening, and the passage. The retaining ring is disposed in the recess to hold the hydraulic unit and the control piston within the hollow cylindrical housing. The washer is axially disposed within the hollow cylindrical housing between the hydraulic unit and the retaining ring.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. non-provisional application No. 16 / 997,466, filed August 19, 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to valves, and more specifically, to a central valve for a camshaft phase shifter. Background Technology

[0004] Valves for camshaft phase shifters are known. An example is shown and described in commonly assigned U.S. Patent No. 9,267,399 to Kohler et al., relating to a control valve for a camshaft adjuster, which is incorporated herein by reference as fully set forth herein. Summary of the Invention

[0005] The example implementation broadly includes a central valve for a camshaft phase shifter, comprising a hollow cylindrical housing, a hydraulic unit, a control piston, a retaining ring, and a washer. The hollow cylindrical housing includes a first radial opening and a recess. The hydraulic unit is disposed within the hollow cylindrical housing and includes a second radial opening and a passage. The control piston is axially movable within the hydraulic unit to regulate the flow of hydraulic medium through the first radial opening, the second radial opening, and the passage. The retaining ring is disposed in the recess to hold the hydraulic unit and the control piston within the hollow cylindrical housing. The washer is axially disposed within the hollow cylindrical housing between the hydraulic unit and the retaining ring.

[0006] In some example embodiments, the hydraulic unit includes a steel inner sleeve and a plastic overmolded outer shell. In one example embodiment, the plastic overmolded outer shell includes an axial groove forming a channel. In another example embodiment, the hollow cylindrical housing includes a notch, and the plastic overmolded outer shell includes a radial protrusion disposed in the notch for positioning the hydraulic unit within the hollow cylindrical housing.

[0007] In some example embodiments, the steel inner sleeve includes a first cylindrical end surface, and the plastic overmolded outer shell includes a second cylindrical end surface aligned with the first cylindrical end surface, and the first and second cylindrical end surfaces are flush with the first surface of the washer. In another example embodiment, the second surface of the washer, opposite to the first surface, is flush with the third surface of the retaining ring.

[0008] In some example embodiments, the first cylindrical end surface includes a first inner diameter, and the first surface includes a second inner diameter smaller than the first inner diameter. In some example embodiments, the control piston includes a body portion having a first outer diameter and a control portion having a second outer diameter, the second outer diameter being larger than the first outer diameter and larger than the second inner diameter. In example embodiments, the body portion and the control portion have the same control piston inner diameter.

[0009] In some example embodiments, the central valve has a check valve assembly. The plastic overmolded housing includes an axial cutout, and the check valve assembly includes an axial protrusion disposed in the axial cutout for rotationally positioning the check valve assembly relative to the hydraulic unit. In an example embodiment, the hydraulic unit is axially secured between the check valve assembly and a gasket within a hollow cylindrical housing.

[0010] In some example embodiments, the central valve has a pressure spring. The plastic-overmolded housing includes an end portion with radial walls, and the pressure spring is axially disposed between the radial walls and the control piston. In example embodiments, the end portion includes an axially extending portion that partially overlaps with the pressure spring in the axial direction. In example embodiments, the gasket is a heat-treated steel gasket.

[0011] In some example embodiments, the hollow cylindrical housing includes an inner cylindrical surface, and the gasket includes an outer cylindrical surface disposed adjacent to the inner cylindrical surface. In example embodiments, the hydraulic unit includes an outer cylindrical surface disposed adjacent to the inner cylindrical surface.

[0012] In an example embodiment, the hollow cylindrical housing includes a drive portion with a hexagonal periphery for receiving a tool used to mount a central valve into a camshaft bore. In an example embodiment, the hollow cylindrical housing includes a threaded portion for threading the central valve into the camshaft bore. In an example embodiment, the retaining ring includes a retaining ring outer diameter and a retaining ring inner diameter. The washer includes an outer diameter smaller than the retaining ring outer diameter and a larger than the retaining ring inner diameter, and an inner diameter smaller than the retaining ring inner diameter. Attached Figure Description

[0013] Figure 1 An exploded view of a central valve according to an example embodiment is shown.

[0014] Figure 2 The diagram shows Figure 1 Cross-sectional view of the central valve.

[0015] Figure 3 The diagram shows Figure 1 Detailed cross-sectional view of the central valve. Detailed Implementation

[0016] Various embodiments of this disclosure are described herein. It should be understood that similar reference numerals appearing in different views of the accompanying drawings identify the same or functionally similar structural elements. Furthermore, it should be understood that the disclosed embodiments are merely examples and other embodiments may take various alternative forms. The drawings are not necessarily to scale; some features may be enlarged or minimized to show details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to employ the various embodiments in various ways. As will be understood by those skilled in the art, various features illustrated and described with reference to any of the accompanying drawings may be combined with features illustrated in one or more other drawings to produce embodiments not explicitly illustrated or described. The combinations of illustrated features provide representative embodiments for typical applications. However, for a particular application or implementation, various combinations and modifications of features consistent with the teachings of this disclosure may be desired.

[0017] The terminology used herein is for descriptive purposes only and is not intended to limit the scope of this disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Although any method, apparatus, or material similar to or equivalent to those described herein may be used in the practice or testing of this disclosure, the following example methods, apparatus, and materials will now be described.

[0018] Reference Figures 1 to 3 Please describe it as follows. Figure 1 The diagram shows an exploded view of the central valve 100. Figure 2 The diagram shows Figure 1 Cross-sectional view of the central valve 100. Figure 3 The diagram shows Figure 1 Detailed cross-sectional view of the central valve 100.

[0019] A central valve 100 for a camshaft phase shifter (not shown) includes a hollow cylindrical housing 102, a hydraulic unit 104, a control piston 106, a retaining ring 108, and a washer 110. The housing 102 includes a radial opening 112 and a recess 114. The hydraulic unit is disposed within the hollow cylindrical housing and includes a radial opening 116 and a passage 118. As known from the prior art, the control piston 106 is axially movable within the hydraulic unit to regulate the flow of hydraulic medium through the radial openings 112 and 116 and the passage 118. The central valve 100 may include a magnet (not shown) located within the cylindrical housing for displacing the control piston. The retaining ring is disposed in the recess to hold the hydraulic unit and the control piston within the hollow cylindrical housing. The washer is axially disposed within the hollow cylindrical housing between the hydraulic unit and the retaining ring.

[0020] The hydraulic unit 104 includes a steel inner sleeve 120 and a plastic overmolded outer shell 122. The plastic overmolded outer shell includes an axial groove 124 forming a channel 118. The shell 102 includes a recess 126 and a radial protrusion 128 disposed in the recess for positioning the hydraulic unit within a hollow cylindrical shell.

[0021] Sleeve 120 includes a cylindrical end surface 130, and housing 122 includes a cylindrical end surface 132 aligned with surface 130. Surfaces 130 and 132 are flush with the face surface 134 of the washer. The face surface 136 of washer 110, opposite to face surface 134, is flush with the face surface 138 of retaining ring. Cylindrical end surface 130 includes an inner diameter 140, and face surface 134 includes an inner diameter 142 smaller than the inner diameter 140.

[0022] The control piston 106 includes a body portion 144 having an outer diameter 146 and a control portion 148 having an outer diameter 150 that is larger than the outer diameter 146 and larger than the inner diameter 142. The body portion 146 and the control portion 148 have the same control piston inner diameter 152.

[0023] The central valve 100 also includes a check valve assembly 154. The plastic overmolded housing includes an axial cutout 156, and the check valve assembly includes an axial protrusion 158 disposed in the axial cutout 156 for rotationally positioning the check valve assembly relative to the hydraulic unit. The hydraulic unit is axially secured between the check valve assembly and a gasket within a hollow cylindrical housing.

[0024] The central valve 100 also includes a pressure spring 160. The plastic-coated housing 122 includes an end portion 162 having a radial wall 164, and the pressure spring is axially disposed between the radial wall and the control piston. The end portion 162 also includes an axially extending portion 164 that partially overlaps with the pressure spring in the axial direction.

[0025] Washer 110 is a steel washer that has been hardened by heat treatment. Housing 102 includes an inner cylindrical surface 166, and washer 110 includes an outer cylindrical surface 168 disposed near the inner cylindrical surface. Hydraulic unit 104 includes an outer cylindrical surface 170 disposed near the inner cylindrical surface.

[0026] The hollow cylindrical housing 102 includes a drive portion 172 with a hexagonal periphery 174 for receiving a tool (not shown) for mounting a central valve into a camshaft bore (not shown), and a threaded portion 176 for threading the central valve into the camshaft bore. The retaining ring 108 includes a retaining ring outer diameter 178 and a retaining ring inner diameter 180. The washer 110 includes an outer diameter 182 smaller than the retaining ring outer diameter and larger than the retaining ring inner diameter, and an inner diameter 184 smaller than the retaining ring inner diameter.

[0027] While exemplary embodiments have been described above, it is not intended that these embodiments describe all possible forms covered by the claims. The language used in the application is descriptive rather than restrictive, and it should be understood that various changes may be made without departing from the spirit and scope of this disclosure. As previously described, features of various embodiments may be combined to form other embodiments that may not be explicitly described or illustrated in this disclosure. Although various embodiments may have been described as providing an advantage or superiority over other embodiments or prior art implementations in one or more desired characteristics, those skilled in the art will recognize that one or more features or characteristics may be compromised to achieve desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, cost, strength, durability, life cycle cost, merchantability, appearance, packaging, size, suitability, weight, manufacturability, ease of assembly, etc. Therefore, any embodiment described as being less desirable with respect to one or more characteristics than other embodiments or prior art implementations is not outside the scope of this disclosure and may be desirable for a particular application.

[0028] List of reference numerals

[0029] 100 Central Valve

[0030] 102 Hollow Cylindrical Shell

[0031] 104 Hydraulic Unit

[0032] 106 Control Piston

[0033] 108 retaining ring

[0034] 110 Washer

[0035] 112 Radial opening (first)

[0036] 114 Groove

[0037] 116 Radial opening (second)

[0038] Channel 118

[0039] 120 steel inner sleeve

[0040] 122 Plastic Overmolded Shell

[0041] 124 Axial Groove

[0042] 126 Notch

[0043] 128 Radial projection

[0044] 130 Cylindrical end surface (first)

[0045] 132 Cylindrical end surface (second)

[0046] 134-faceted surface (first)

[0047] 136-faceted surface (second)

[0048] 138-faceted surface (third)

[0049] 140 Inner Diameter (First)

[0050] 142 Inner Diameter (Second)

[0051] 144 Main Body (Control Piston)

[0052] 146 Outer Diameter (First)

[0053] 148 Control Section (Control Piston)

[0054] 150 outer diameter (second)

[0055] 152 Control the inner diameter of the piston

[0056] 154 Check Valve Assembly

[0057] 156 Axial cut

[0058] 158 Axial protrusion

[0059] 160 Compression Spring

[0060] 162 End portion

[0061] 163 Radial wall

[0062] 164 Axial extension portion

[0063] 166 Inner cylindrical surface of the shell

[0064] 168 Washer outer cylindrical surface

[0065] 170 Hydraulic unit outer cylindrical surface

[0066] 172 Drive Section

[0067] 174 Hexagonal perimeter

[0068] 176 Threaded section

[0069] 178 Maintain the outer diameter of the ring

[0070] 180 Keep the inner diameter of the ring

[0071] 182 Washer outer diameter

[0072] 184 Washer inner diameter

Claims

1. A central valve for a camshaft phase shifter, comprising: A hollow cylindrical shell, the hollow cylindrical shell including a first radial opening and a groove; A hydraulic unit, wherein the hydraulic unit is disposed in the hollow cylindrical shell and includes a second radial opening and a channel, the hydraulic unit including a steel inner sleeve and a plastic-coated outer shell; A control piston is provided, which is axially movable within the hydraulic unit to regulate the flow of hydraulic medium through the first radial opening, the second radial opening, and the channel. A retaining ring, disposed in the groove, is provided to retain the hydraulic unit and the control piston within the hollow cylindrical housing; as well as A washer, which is axially disposed in the hollow cylindrical housing between the hydraulic unit and the retaining ring; A check valve assembly, wherein: the plastic overmolded housing includes an axial cutout; and the check valve assembly includes an axial protrusion disposed in the axial cutout for rotationally positioning the check valve assembly relative to the hydraulic unit.

2. The central valve of claim 1, wherein, The plastic overmolded housing includes an axial groove forming the channel.

3. The central valve according to claim 1, wherein, The hollow cylindrical shell includes a notch, and the plastic overmolded outer shell includes a radial protrusion disposed in the notch for positioning the hydraulic unit in the hollow cylindrical shell.

4. The central valve according to claim 1, wherein: The steel inner sleeve includes a first cylindrical end surface; The plastic-coated outer shell includes a second cylindrical end surface aligned with the first cylindrical end surface; and The first cylindrical end surface and the second cylindrical end surface are flush with the first surface of the washer.

5. The central valve according to claim 4, wherein, The second surface of the washer, which is opposite to the first surface, is flush with the third surface of the retaining ring.

6. The central valve according to claim 4, wherein, The first cylindrical end surface includes a first inner diameter, and the first surface includes a second inner diameter smaller than the first inner diameter.

7. The central valve according to claim 6, wherein, The control piston includes: The body portion has a first outer diameter; and The control section has a second outer diameter that is larger than the first outer diameter and larger than the second inner diameter.

8. The central valve according to claim 7, wherein, The body portion and the control portion have the same inner diameter of the control piston.

9. The central valve according to claim 1, wherein, The hydraulic unit is axially fixed within the hollow cylindrical housing between the check valve assembly and the gasket.

10. The central valve according to claim 1, further comprising a pressure spring, wherein: The plastic overmolded shell includes an end portion having radial walls; and The pressure spring is axially positioned between the radial wall and the control piston.

11. The central valve according to claim 10, wherein, The end portion includes an axially extended portion that partially overlaps with the pressure spring in the axial direction.

12. The central valve according to claim 1, wherein, The gasket is a steel gasket that has been hardened by heat treatment.

13. The central valve according to claim 1, wherein: The hollow cylindrical shell includes an inner cylindrical surface; and The gasket includes an outer cylindrical surface disposed near the inner cylindrical surface of the housing.

14. The central valve according to claim 13, wherein, The hydraulic unit includes an outer cylindrical surface of the hydraulic unit disposed near the inner cylindrical surface of the housing.

15. The central valve according to claim 1, wherein, The hollow cylindrical housing includes a drive portion with a hexagonal periphery for receiving a tool for mounting the central valve into a camshaft bore.

16. The central valve according to claim 1, wherein, The hollow cylindrical housing includes a threaded portion for threading the central valve into the camshaft bore.

17. The central valve according to claim 1, wherein: The retaining ring includes: Maintain the outer diameter of the ring; and Maintain the inner diameter of the ring; and The washer includes: The outer diameter of the washer is smaller than the outer diameter of the retaining ring and larger than the inner diameter of the retaining ring; and The inner diameter of the washer is smaller than the inner diameter of the retaining ring.

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