update notes on bearings, add past papers

uni/mmme/2044_design_manufacture_and_project/bearings.md

@@ -5,6 +5,7 @@ title: MMME2044 // Bearings
 tags: [ bearings ]
 uuid: 94cac3fd-c352-4fdd-833d-6129cb484b8a
 lecture_slides: [ ./lecture_slides/Lecture 7 - Bearings 1 – Plain Hydrodynamic Bearings 1.pdf ]
+anki_deck_tags: [ bearings ]
 ---
 
 > I don't think I ever finished these notes.
@@ -97,7 +98,6 @@ lecture_slides: [ ./lecture_slides/Lecture 7 - Bearings 1 – Plain Hydrodynamic
 </details>
 
 
-
 # fun graphs that may be useful for bearing selection
 
 ![](./images/bearings_1-035.jpg)
@@ -129,7 +129,7 @@ $$p = \frac{F_\text{radial}}{bD}$$
 
 $$V = \omega\frac D2$$
 
-![](./images/vimscrot-2022-11-15T17:48:21,486895199+00:00.png)
+![](./images/vimscrot-2023-04-28T18:17:05,184873693+01:00.png)
 
 
 ## Axial Sliding Bearing
@@ -138,7 +138,23 @@ $$p = \frac{4F_\text{axial}}{\pi(D^2-d^2)}$$
 
 $$V = \omega\frac{D+d}{4}$$
 
-![](./images/vimscrot-2022-11-15T17:48:34,860294942+00:00.png)
+![](./images/vimscrot-2023-04-28T18:17:16,580658677+01:00.png)
+
+## Plain Rubbing Bearings
+
+- does not rely on liquid lubricaton
+- usually made of polymers and moulded to final shape
+- dry lubricants like ptfe are added
+- reinforcements like glass fibres can be added
+- pressure is limited by strength
+- speed is limited by temperature
+
+## Oil Lubricated Porous Bearings
+
+- manufactured from sintered metal powders
+- porous & oil impregnated
+- more porous bearings are weaker but can run at higher speeds
+- lubricant needs to be replenished at regular intervals
 
 # Wear